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Volume 37,Issue 19
  • Land cover changes in the Xiong'an New Area and a prediction of ecological response to forthcoming regional planning
  • Authors:XU Hanqiu, SHI Tingting, WANG Meiya and LIN Zhongli
  • Abstract:The Xiong'an New Area is a recently established state-level new area in Baoding, Hebei province, China. Green construction and development are the most important issues to be considered and must be given priority by area planners during forthcoming construction of the new area. Green ecological planning cannot be implemented without a clear understanding of an area's ecological status and an accurate prediction of an area's ecological status responding to forthcoming regional planning. Therefore, using Landsat images of 2004 and 2015, feature inversion and extraction techniques, and the remote sensing-based ecological index (RSEI), this study investigated changes in three main land cover types (impervious surface, vegetation, and water) in the Xiong'an New Area over the last 11 years from 2004 to 2015 and predicted the ecological and thermal effects responding to the upcoming regional construction on the new area. The results show that the areas of impervious surface, vegetation, and water covers have changed over the 11-year study period, but the change intensity was less than 5%. In addition, the ecological status was stable during the study period as the RSEI increased only slightly from 0.629 in 2004 to 0.639 in 2015. Therefore, the overall development intensity was relatively low, and the area's current ecological quality is good. Quantitative analysis indicates that the area of impervious surface has the strongest influence on both ecological quality and land surface temperature among the three main land cover types of the area. The area's ecological responses to upcoming regional planning were predicted using regression relationship models of RSEI and land surface temperature with the three main land cover types. The prediction, based on the known goal of population and area development, revealed that the increase of population to 2.5 million with a 25% of impervious surface cover in the new area would have noteworthy effects on regional ecological conditions, potentially decreasing the area's RSEI by 10 % and increasing land surface temperature by 1.1 ℃. Alternatively, if the proportion of impervious surface could be controlled within 20%, the area's RSEI would increase by 3.6%, and land surface temperature would decrease by 0.3 ℃.
  • DownLoad:Land cover changes in the Xiong'an New Area and a prediction of ecological response to forthcoming regional planning.PDF
  • Gross ecosystem product accounting for the Garzê Tibetan Autonomous Prefecture
  • Authors:Pema Dolkar, XIAO Yi, OUYANG Zhiyun and WANG Liyan
  • Abstract:Garzê Tibetan Autonomous Prefecture (hereafter Garzê) is located along the upper reaches of the Yangtze River, a unique geographical location that contributes to the prefecture's complex and diverse landscapes and rich biodiversity. Garzê possesses hydropower resources, which comprises thousands of rivers and can be divided into three parts: Jinsha River, Yalong River, and Dadu River. Owing to its important ecological location, Garzê has many ecosystem functions, such as water retention, soil retention, flood mitigation, the protection of biological diversity. Although the ecological condition of Garzê is excellent, the prefecture's economy has lagged behind that of the rest of the country, and many of the important ecosystem products and services that it provides have not been fully recognized or adequately quantified. Therefore, assessing Garzê's ecosystem services is both essential and urgent and will contribute to the sustainable development of the prefecture's society and economy. In this study, Garzê's ecosystem services were divided into three categories (ecosystem provisioning, regulating, and cultural services), and Garzê's gross ecosystem product (GEP) was evaluated using the market value, replacement cost, and travel cost methods, among others, in order to assess the direct contribution of Garzê's ecosystem to beneficiaries. Our results indicated that the GEP of Garzê was 754.559 billion Yuan in 2010 and that the per capita GEP was 711,800 Yuan, which is about 61 times the prefecture's gross domestic product (GDP) and per capita GDP of the same year. Among the ecosystem services, the total value of ecosystem-regulating services was the largest, at 684.228 billion Yuan and accounting for 90.68% of the prefecture's GEP. The total value of ecosystem provisioning services and cultural services was 63.264 billion Yuan and 7.067 billion Yuan, respectively, accounting for 8.38 and 0.94% of the prefecture's GEP. In terms of types of services, water retention, climate regulation, and carbon sequestration-oxygen release were the core services, with a total value of 84.38% of the prefecture's GEP, thus confirming Garzê's high plant cover and function as a significant water retention area of the upper reaches of the Yangtze River. In terms of types of ecosystems, the values of the ecosystems were ranked as follows: Grassland > Forest > Shrub > Wetland > Farmland > Bare land > Glaciers and snowfield > Town; and the total value of the Grassland, Forest, Shrub, and Wetland was 98.87% of the prefecture's GEP. This indicated that these four ecosystems are the main source of ecological products and services; contribute vast economic value to human society and, therefore, to the process of resource development and management; and deserve relatively more attention than other ecosystem types. Our study suggests that Garzê's ecosystem services are highly valuable and that protecting the prefecture's ecosystem will also protect human welfare. The findings of the study can be applied to administrative policymaking and environmental protection, and it will provide a scientific basis for the management, protection, and compensation of the region's ecosystems.
  • DownLoad:Gross ecosystem product accounting for the Garzê Tibetan Autonomous Prefecture.PDF
  • Ecological land use planning for Beijing City based on the minimum cumulative resistance model
  • Authors:ZHANG Jiping, QIAO Qing, LIU Chunlan, WANG Haihua and PEI Sha
  • Abstract:Ecological land planning places emphasis on protecting the structure and function of regional ecological systems and reinforcing the eco-environmental support capacity of social-economic development. Allowing for the comprehensive consideration of ecological security demands, air-quality improvement requirements, and livable city needs, we firstly identified pivotal ecological land based on an integrated evaluation of the ecological importance of Beijing City. Ecological importance was evaluated using an analysis of ecological quality and function. The key areas, with great importance to the improvement of the atmospheric and residential environments, were identified. Ecological quality was based on vegetation coverage and biomass using 3S technology. The ecological functions of water conservation, soil conservation, and biodiversity maintenance were evaluated using the integrated water storage capacity calculation, the universal soil loss equation, and InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) model, respectively. Forest resource inventory data were used to identify key areas with great importance to the improvement of atmospheric environmental quality. Distribution maps of forest parks, nature reserves, water source conservation areas, and scenic spots were used to identify key areas of great importance to the improvement of residential environments. Pivotal ecological land was finally identified by spatial overlay analysis using the ArcGIS 10.1 software platform. Secondly, we considered the pivotal ecological land as the "source," and built upon the resistance surface according to land use type, distance to roads, and distance to settlements to run the minimum cumulative resistance model and simulate the spatial expansion of ecological land. From this, we established three planning scenarios for ecological land. Thirdly, ecological protection effectiveness under different planning scenarios was evaluated by analyzing landscape patterns, protection levels for ecological functions, and conflicts with actual construction areas. Landscape patterns were analyzed by calculating landscape indexes using Fragstats 4.2 software. The protection level of ecological functions was determined by weight calculations. Conflicts with actual construction areas were based on spatial analysis statistics. Finally, we chose the best planning scenario, and determined the minimum scale and optimized spatial pattern for ecological land. The results showed that 1) the area of pivotal ecological land in Beijing City covered 9879 km2, accounting for 60.20% of the total area of the city; 2) the area of minimum ecological land was 12417 km2, accounting for 75.67% of the total area of the city; 3) the area of minimum ecological land in plain terrain was 2944 km2, accounting for 46.45% of total plain terrain area, and was mainly located in the surrounding transition areas of the construction areas; and 4) the area of the minimum ecological land in mountainous areas was 9473 km2, accounting for 94.05% of total mountainous area. The minimum ecological land area in this study was larger than that in other similar studies. Our study took not only the demand of ecological security into consideration but also the major environmental problems and urban construction target areas of Beijing City. The key areas with great importance to the improvement of atmospheric and residential environmental conditions were analyzed together and given ecological importance. Therefore, the minimum scale and optimized spatial pattern of ecological land in this study was more practical and corresponded with the development demands of the city.
  • DownLoad:Ecological land use planning for Beijing City based on the minimum cumulative resistance model.PDF
  • Urban expansion and its ecological environmental effects in Bangkok, Thailand
  • Authors:HAN Ruidan, ZHANG Li, ZHENG Yi, WANG Heng and ZHANG Jing
  • Abstract:On the basis of Landsat images acquired in 1990, 2000, 2010, and 2015 and MODIS NDVI datasets acquired from 2010 to 2015, we analyzed urban expansion in Bangkok, including the spatio-temporal characteristics of built-up land, ecological-environmental effects (including vegetation greenness and land surface temperature), and the main driving factors of urban expansion. The results showed that (1) the built-up land areas in Bangkok has expanded continuously since 1990, showing a rapid-slow-rapid change trajectory. Urban expansion occurred mainly in the northeast direction and within the range of 14-20 km from the city center. The expansion patterns followed infilling pattern and edge-expansion pattern. (2) Urbanization affected vegetation greenness and heat island. Vegetation greenness declined overall, and a significantly decreased area was in the range of 10-20 km from the city center, which was in accordance with the main urban expansion area. Similarly, the spatial distribution of the heat island was coincident with urban expansion. The heat island increased overall, although local variations were less obvious. (3) Geographical conditions, social economy, and city layout were the main driving factors in urban expansion.
  • DownLoad:Urban expansion and its ecological environmental effects in Bangkok, Thailand.PDF
  • Spatial differences in per capita ecological footprint and per capita ecological carrying capacity in Chengdu
  • Authors:PAN Hongyi, ZHU Wanqiu, CUI Lvye, FENG Maoqiu and ZHU Fang
  • Abstract:By comparing the natural resources consumed by human activities and the ecological carrying capacity of natural ecosystems, the ecological footprint method was employed to quantitatively estimate the status of regional sustainable development. Through the calculation of the ecological footprint and ecological carrying capacity, regional resource and energy consumption could be transformed into a certain amount of land for production of resources. If demand, based on the ecological footprint, was greater than the ecosystem carrying capacity the region could provide, it was deemed an ecological deficit area. In these areas, the pressure on land resource production was great and the ecosystems were less stable. Conversely, if demand, based on the ecological footprint, was less than the ecological carrying capacity of the region, it was an ecological surplus area. These areas exhibited reasonable regional land use, with sustainable use of land resources. In this study, the ecological footprint model was used to investigate ecological footprints, ecological carrying capacity, and ecological surplus and deficit, and ArcGIS was used to conduct spatial analyses to determine the relationship among these areas in Chengdu from 2009 to 2014. Using spatial evolution law analysis, the results showed the following: (1) overall, the spatial pattern of the per capita ecological footprints was relatively stable, and the change was not severe. There was strong variation among regions with high- and low-level areas. The per capita ecological footprint decreased annually, from 2.759 hm2/cap to 1.937 hm2/cap. Because agricultural products are numerous in Chengdu, the per capita ecological footprint was the most affected by the ecological footprint caused by cultivated land. The basic distribution pattern characteristics were low in the middle region, high in the southwest, and medium in the two side areas. For example, low-level per capita ecological footprints were found in the five urban districts. High-levels per capita ecological footprints were found in Pujiang, Dayi, and Qionglai. Medium per capita ecological footprints were distributed in the two side areas, including Dujiangyan, Jintang, and Pengzhou, among others. These areas reflected the average level of ecological footprints in Chengdu, which was approximately 3.53 hm2/cap. (2) The per capita ecological carrying capacity of Chengdu was relatively stable and presented a downward trend, from 0.2314 hm2/cap to 0.2215 hm2/cap, from 2009 to 2014. Having the most stringent farmland protection system, the per capita ecological carrying capacity was relatively stable. Low-level per capita ecological carrying capacity areas were the five urban districts, among others. The high-level per capita ecological carrying capacity areas were Pujiang, Dayi, and Qionglai. The spatial distribution characteristics of the per capita ecological footprint and per capita ecological carrying capacity were positively correlated. (3) The per capita ecological surplus and deficit of this area exhibited improving trends with time. But in fact, the developing trend in ecological deficits was becoming increasingly serious, which was opposite to that of the ecological carrying capacity distribution. The per capita ecological surplus and deficit distribution was dispersed in the five urban districts. During the study period, the rest areas were deficit and the most serious areas were concentrated in Pujiang which located in the southwest and the maximum was -9.3189 hm2/cap. It was suggested that effective regulation of ecological footprints and complementary mechanisms were needed in the future.
  • DownLoad:Spatial differences in per capita ecological footprint and per capita ecological carrying capacity in Chengdu.PDF
  • Land use spatial-temporal evolution analysis using a self-organizing map in Beijing, 2005-2013
  • Authors:QI Jianchao, LIU Huiping and YI Yaoguo
  • Abstract:Multiple time series land using spatial-temporal evolution analysis is an important research area. In this study, we investigated the spatial-temporal integrated expression of multiple time series land use change. A self-organizing map (SOM) neural network was used to explore regional land use change modes and to analyze what has driven these changes. Remote sensing data for five land use classification data periods (2005, 2007, 2009, 2011, and 2013) for Beijing were used to train the network, and the outputs identified the aggregation modes for building land, farmland, forest land, grassland, and gardens by using the clustering, dimension-reducing, and visual functions of the SOM. Then we conducted second-step clustering to produce the neuron and build the land use change trajectories that are needed to analyze the spatial-temporal features of Beijing suburban land use changes during the five monitoring periods. The results revealed that there were two land use changes in the Beijing suburbs between 2005 and 2013. One was the development of buildings on farmland located on the plains and the other was the development of forest land in mountainous areas. Furthermore, development in each district had its own time sequences. This meant that we eventually obtained six land use change trajectories in total.
  • DownLoad:Land use spatial-temporal evolution analysis using a self-organizing map in Beijing, 2005-2013.PDF
  • Spatial-temporal pattern of land ecological security at a township scale in the bortala mongolian autonomous prefecture
  • Authors:YU Haiyang, ZHANG Fei, CAO Lei, WANG Juan and YANG Shengtian
  • Abstract:Regional land ecosystem is facing deterioration from the rapid growth of urbanization. In order to promote sustainable development of the land ecosystem, it is necessary that we evaluate regional land ecological security. Many researchers have studied and evaluated for regional land ecological security; however, most of the evaluation was based on watershed and county scale, and few researches focused on the township scale. In this study, Bortala Mongolian Autonomous Prefecture (i.e. Bortala) in Xinjiang Uygur Automous region was taken as study area, and Remote Sensing (RS), Geographical Information System (GIS), and Global Position System (GPS) technologies were adopted to analyze temporal and spatial perspectives of land ecological security in Bortala. On the basis of the natural geographic features and socio-economic situation of Bortala, we constructed the pressure-state-response (P-S-R) land ecological security evaluation model (township scale) in Bortala. Based on the two period's data of statistic yearbook and remote sensing in 2011 and 2014, we first constructed the index system, using 25 indices reflecting regional P-S-R. The entropy weight and analytic hierarchy process methods were used to determine the indices weight of Bortala P-S-R model. Finally, the land ecological security index of Bortala was calculated with the data obtained from the P-S-R model by GIS Grid. The results show that: (1) The land ecological security index had deteriorated from 2011 to 2014 in Bortala. Between 2011 and 2014, 2555.33 km2 of level III (grade of security) transferred to level IV, which deteriorated areas mainly concentrated in Wenquan County; 1356.53 km2 of level V transferred to level IV, which improved areas concentrated in the Mangding town and Tuotuo town of Jinghe County. (2) The land ecological security index of most towns was at level III in Bortala, which respected the ecological structure of these towns were not stable. (3) The spatial difference of land ecological security index was obvious in Bortala, the worst places were located in the eastern desert, and the best places were concentrated in the central oasis and lake. The evaluation results and major environment problems may help the local government finding inappropriate and inadequate for Bortala development. Bortala Prefecture is a drought-prone and ecologically vulnerable region in the Northwest region. Temporary land use regulation cannot guarantee long-term regional ecological balance and security. In this study, we recommend increased attention on regional ecological protection and sustainable development for villages and towns.
  • DownLoad:Spatial-temporal pattern of land ecological security at a township scale in the bortala mongolian autonomous prefecture.PDF
  • Characteristic mineralization of soil organic carbon in different successional series of broadleaved Korean pine forests in the temperate zone in China
  • Authors:ZHANG Ling, ZHANG Donglai and MAO Zijun
  • Abstract:The soil carbon cycle and global climate change are closely related to the mineralization of carbon in terrestrial ecosystems. To accurately assess the characteristics of carbon mineralization and variation in the mineralization of carbon in different succession series (mesosere series, hydrosere series, and xerosere series) in the broadleaved Korean pine forests of the Xiaoxing'an Mountains in the temperate zone of China, we measured the mineralization of carbon and the mineralization rate based on the chronosequence method. The results showed that the carbon mineralization rate and the extent of carbon mineralization in the three successional series exhibited consistent cross-sectional variation, and gradually decreased with depth. The extent of carbon mineralization in the different successional series was different. The virgin forest accumulated soil organic carbon and mineralization in the mesosere was the greatest among the three series, followed the xerosere and hydrosere series. The carbon mineralization rate of the three successional series varied with time and exhibited a consistent trend (decreasing quickly during the first stage and gradually stabilizing). The six kinds of community-type carbon mineralization in the three successional series were significantly different. The carbon mineralization rate of the three successional series in broadleaved Korean pine forests was original forest > Betula platyphylla-Pinus koraiensis forest > Picea koraiensis-Pinus koraiensis forest > Betula costata-Pinus koraiensis forest > Quercus-mongolica-Pinus koraiensis forest > Betula davurica-Pinus koraiensis forest. Mesosere series carbon mineralization fit a nonlinear exponential better. Carbon mineralization of soil organic carbon was significantly positively correlated with soil total nitrogen and litter-fall amount in different successional series in the broadleafed Korean pine forests, and negatively correlated with soil moisture, soil bulk density, and soil pH. In short, successional histories, soil texture, and nutrient status resulted in differences in soil organic carbon mineralization of the different succession series in the broadleaved Korean pine forests.
  • DownLoad:Characteristic mineralization of soil organic carbon in different successional series of broadleaved Korean pine forests in the temperate zone in China.PDF
  • Carbon emission characteristics, carbon library components, and enzyme activity under long-term fertilization conditions of black soil
  • Authors:HE Mei, WANG Ligang, ZHU Ping, QI Ruimin and WANG Yingchun
  • Abstract:As black soil is the important soil resources on bearing food security and ecological security in China, the carbon emission characteristics and carbon library components of it has always been a hotspot in research of ecology. Fertilization is the important factors influencing the black soil organic carbon input as well as its output, and the effect under fertilization need long time scales of inquiry. Our experiments were carried out in National Fertility Monitoring Net in Gongzhuling City began in 1990, we intended to clarify the soil carbon emissions and its mechanism under long-term different fertilization. Six of the fertilization treatments were chosen including: no fertilizer (CK), only chemical fertilizer application (NPK), combining chemical and low levels of organic manure (NPKM1), 1.5 times the amount of inorganic and organic fertilizer of NPKM1 (1.5 (NPKM1)), combing chemical and high amounts of organic manure (NPKM2), and inorganic fertilizer straw (NPKS),to analyze the changes in soil carbon dioxide emissions(CO2-C) and the soil carbon library included dissolved organic carbon (DOC), microbial biomass carbon (MBC), particulate organic carbon (POC), readily oxidized organic carbon (ROC), soil enzyme activity beta glycosidase enzymes (BG), β-xylosidase (BXYL), cellulose (CBH), and acetyl beta glucosamine enzyme (NAG). The results showed that compared with CK, all kinds of fertilizer processing can significantly increase the chernozem soil carbon emissions (P < 0.05), and among these processing types, NPK carbon emissions is about 2633.33 kg/hm2, significantly higher than the CK treatment by 37.36%. NPKM1, 1.5 (NPKM1), NPKM2 significantly increased soil carbon emissions by 71.81%-88.51%, and the effect was best; NPKS significantly increased soil carbon emissions by 56.32%, and three kinds of long-term organic and inorganic fertilization treatments had no significant difference. Relative to CK, NPKM1, 1.5 (NPKM1) and NPKM2 increased the DOC content by 16.07%-56.34%, enhanced MBC content by 128.84%-185.77%, improved POC content by 128.84%-497.45%, and increased ROC content by 841.03%-1145.94% content significantly (P < 0.05), respectively, the effect of 1.5 (NPKM1) was the best. At the same time, organic and inorganic fertilization treatments can increase NAG, BG, BXYL, and CBH activity by 313.22%-452.65%, 313.22%-250.74%, 159.08%-273.32%, and 72.21%-273.32%, and the effect of 1.5 (NPKM1) is also the best here. Soil carbon emissions were significantly correlated with soil activity and soil enzyme activity (P < 0.001), shows that fertilization could change the composition content of soil carbon library and soil microbial activity, which resulted in the difference in the soil carbon emissions.
  • DownLoad:Carbon emission characteristics, carbon library components, and enzyme activity under long-term fertilization conditions of black soil.PDF
  • Analysis of spatio-temporal patterns of carbon emission from energy consumption by rural residents in China
  • Authors:WAN Wenyu, ZHAO Xueyan, WANG Weijun and XUE Bing
  • Abstract:With the development of economy and improvement in the living standard of people, life energy consumption has been increasing with each passing year. The life energy consumption of residents is expected to become a new growth point for carbon emissions. Using GiNi index, a method for spatial autocorrelation analysis, the characteristics, regional disparity, and spatio-temporal pattern of carbon emissions from life energy consumption were analyzed on regional and provincial levels from 2001 to 2013, in China. We used the STIRPAT model to simulate the impact of factors such as population, affluence level, age structure of population, and the proportion of use of electric energy, on carbon emissions. We observed that for the life of rural residents, the direct and indirect energy carbon emissions increased by 7.65% and 9.16%, respectively. The GiNi index analysis indicated that the difference in carbon emissions was shrinking among the three zones of eastern, central, and western regions. The distribution of rural residents' life energy per capita carbon emissions in provincial China was not completely random. The areas with low levels of direct carbon emissions were mainly distributed in the eastern and western regions, whereas areas with the high levels of direct carbon emissions were relatively stable, and were mainly distributed in Sichuan, Hebei, and Anhui. Population, affluence level, and age structure of population were the main driving factors for the carbon emissions from the life energy consumption of residents, and the change in the rate of carbon emissions from residents' life energy caused by them exceeded that of themselves. Moreover, the rural residents' life energy carbon emissions were higher in the north than that in the south. However, the areas with low levels of indirect carbon emissions were relatively stable with respect to their carbon emissions. Within the range of calculated data, the results of the present analysis support the Environmental Kuznets Curve hypothesis, and the economic development has been the important factor for prompting the turning point of the Environmental Kuznets Curve hypothesis.
  • DownLoad:Analysis of spatio-temporal patterns of carbon emission from energy consumption by rural residents in China.PDF
  • Correlation analysis of variation of extreme temperature events and El Niño Southern Oscillation(ENSO) in Yangtze River Delta region during 1960-2014
  • Authors:JIA Yanqing, ZHANG Bo, ZHANG Yaozong, TANG Min, MA Bin and WANG Guoqiang
  • Abstract:Based on daily temperature (maximum, minimum, and average) data of 65 stations, spatial and temporal changes of extreme temperature events and the El Niño Southern Oscillation (ENSO) influence on the extreme temperature threshold over Yangtze River Delta were analyzed for the period 1960-2014. The results showed that in the last 55 years, the extreme temperature indices, i.e. summer days (SU), tropical nights (TR), warm days (TX90), warm nights (TN90), warm spell duration days (WSDI), and growing season length (GSL) have all increased significantly, and TN90 showed an increasing rate of 8.55d per decade. The extremal indices (TXn, TNn, TXx, and TNx) had increasing trends in the Yangtze River Delta region, and TNn showed an increasing rate of 0.53℃ per decade. The ice days (ID), frost days (FD), cold days (TX10), cold nights (TN10), and cold spell duration days (CSDI) have decreased significantly by 0.40 d, 4.03 d, 2.56 d, 6.06 d and 0.33 d per decade, respectively, and TN10 showed a decreasing rate of 6.06 d per decade. DTR has decreased by 0.11℃ per decade. For the spatial distribution of SU, TXn and TNx, all meteorological stations showed increasing trends during 1960-2014. TR, TX90, TN90, TNn, TXx, WSDI, and GSL showed increasing trends at 97%, 85%, 98%, 95%, 78%, 92%, and 94% of meteorological stations, respectively. ID, FD, TX10, and TN10 showed decreasing trends for all stations. For CSDI and DTR, 87% and 77% stations showed decreasing trend. Most extreme temperature indices show good correlation with latitude, longitude, and altitude. After the detected abrupt climate changes, extreme warm indices increased, and extreme cold indices decreased significantly. Overall, the effect of El Nifio on extreme temperature indices was greater than the effect of La Nina.
  • DownLoad:Correlation analysis of variation of extreme temperature events and El Niño Southern Oscillation(ENSO) in Yangtze River Delta region during 1960-2014.PDF
  • The existence value of Qinghai-Tibetan Plateau: a case study on Maqu grassland
  • Authors:CAO Jianjun, YANG Shurong, ZHOU Junju, ZHANG Lili, HU Ziying and ZHANG Qiang
  • Abstract:Existence value as a non-use value means that people feel lost when something disappeared. Exploring the existence value of grassland is a powerful tool for strengthening our awareness of environmental protection and for developing strategies for resource use. Contingent valuation method (CVM), a survey-based method, can reveal consumer preferences for public goods and services and infer respondents' willingness to pay (WTP) to improve environmental quality. After several decades of development, it has emerged as the principal means for measuring the existence value. Although it is questioned by its validity and reliability in decision-making processes, it has become a dominant technique for the valuation of non-market environmental costs and benefits since the 1990s. WTP technique of CVM was used to explore systematically the existence value of Maqu grassland, which is located on the eastern of Qinghai-Tibetan Plateau. The results showed that the average WTP of each household was 339 Yuan/a, and the total WTP was 0.03×108 Yuan/a in 2005. WTP was positively related to the income. From 2005 to 2016, the income of local resident increased by about 20%, with the average WTP being 407 Yuan/a in 2016 and the total WTP being 0.033×108 Yuan/a. Compared with other studies, the existence value of Maqu grassland was smaller due to the limited population base. However, if we considered the role of Maqu grassland in maintaining the global biodiversity and its importance for water conservation of the Yellow River, this existence value would increase largely, which reached up to 636×108 Yuan/a in 2005 and to 763×108 Yuan/a in 2016. From 2005 to 2016, the existence value of Maqu grassland increased about 20% which is equalled to an increase of the income. These results suggest that the existence value of Maqu grassland is significant, and we should consider it in cost-benefit analysis. Furthermore, the existence value changes with time and is needed to evaluate continuously in order to make the right decisions.
  • DownLoad:The existence value of Qinghai-Tibetan Plateau: a case study on Maqu grassland.PDF
  • Evaluating the ecosystem services of Gaotianyan Nature Reserve in Lianhua County, Jiangxi Province
  • Authors:MIAO Jianqun, SUN Song, WANG Zhiqiang and HUANG Guoqin
  • Abstract:Gaotianyan Nature Reserve, a provincial natural conservation area, located in Lianhua County, Jiangxi Province, provides many ecosystem services for the local people. Economic valuation of the main ecosystem services of Gaotianyan Nature Reserve can help us to better understand the direct contribution of the Natural Reservation system to Lianhua County, and ensures that the government comprehensively considers the importance of protecting the Nature Reserve ecosystem when planning a strategy for economic development. In the present study, we established a system of evaluation indexes for the ecosystem service function of Gaotianyan Nature Reserve, according to its ecological and social economic characteristics. We then evaluated the eco-economic values provided by the ecosystem of Gaotianyan Nature Reserve in 2014, using factors such as replacement cost, market value, shadow engineering, cost of afforestation, reference results, and travel expenses. The following results were obtained. Firstly, the total economic value of the ecosystem services provided by Gaotianyan Nature Reserve was estimated to be 7.16 × 108 Yuan in 2014, and the values of soil conservation and carbon fixation and oxygen released were 4.39 × 108 Yuan and 1.16 × 108 Yuan, which accounted for 60.89% and 16.11% of the total value, respectively. Secondly, primary production was a major direct economic source; however, the value of the primary production in Gaotianyan Nature Reserve only accounted for 10.75% of the total value of the ecosystem services. This means that using only the value of primary production to measure the value of total ecosystem services would seriously underestimate the ecosystem service value of Gaotianyan Nature Reserve. Finally, the economic values of nine ecosystem service indexes were sorted as soil conservation, carbon fixation and oxygen release, primary production, biodiversity protection, environmental purification, climate regulation, tourism and recreation, flood control and water storage, and social security, according to the value of the evaluation. In conclusion, the direct economic data revealed that Gaotianyan Nature Reserve makes a considerable contribution to our society. It not only helps to improve the consciousness of the administrators and the people involved in protecting the traditional agricultural culture but also provides data support for the government to formulate a compensation standard for Gaotianyan Nature Reserve.
  • DownLoad:Evaluating the ecosystem services of Gaotianyan Nature Reserve in Lianhua County, Jiangxi Province.PDF
  • Research of the coupling relationship between the vulnerable ecological environment and poverty in Gansu Province
  • Authors:NIU Yaqiong and WANG Shenglin
  • Abstract:Maintaining the coordinated correlation between the ecological environment and economic development is one of the important strategies in the initial stages of national poverty alleviation and development. Taking Gansu Province as a study area, we designed a dual system development multi-index comprehensive evaluation system based on the theory of system coupling coordination degree. Between 2000 and 2014, we measured and analyzed the scores of vulnerable ecological environment and poverty and the coupling degree and spatio-temporal variability in the study area. The vulnerable ecological environment and poor coupling degree of Gansu showed a general rising trend, but exhibited three stages that were affected by factors such as policy adjustment. From the point of view of spatio-temporal variability, the coupling degree of vulnerable ecological environment and poverty increased from the southeast to the northwest, whereas spatial distribution was unbalanced. Given that the vulnerable ecological environment coexists with poverty, the strategic significance of protecting the environment of poor areas should be given full consideration.
  • DownLoad:Research of the coupling relationship between the vulnerable ecological environment and poverty in Gansu Province.PDF
  • Effects of different altitudes on the nutrient and amino acid contents of bamboo (Fargesia denudata), staple food of the giant panda, in Minshan, Sichuan, China
  • Authors:WANG Danlin, GUO Qingxue, WANG Xiaorong, LIANG Chunping and ZHANG Yuanbin
  • Abstract:Nutritional components of plant species (e.g., contents of crude protein, crude fat, and amino acids), as well as the contents of fiber that influence animals' food digestibility, collectively determine animal food preferences. Animals would prefer to feed on leaves or stems with higher contents of crude protein, crude fat, and amino acids and a lower content of fiber. Many studies have demonstrated that nutritional components or fiber contents are differently impacted by various environmental factors. It is possible that differences in the nutrient or fiber content of vegetation under different conditions would potentially affect animal distribution through food choice. Dwarf-bamboo species dominate the underground layer of subalpine forests. However, the distribution or growth of these bamboo species is predicted to be markedly affected by global warming. As the main food source for the panda, changes in temperature may influence their preference for bamboo by altering bamboo nutrition. Although the temperature difference along vertical altitudinal gradients is obvious, there have been few studies focusing on the effects of different temperatures on bamboo due to altitudinal gradients, which could potentially influence panda food preference and distribution. We designed an in situ experiment to examine the effects of different altitudes on the contents of nutrients, such as crude protein and amino acids, and parameters related to animal food digestibility, such as fiber content, of dwarf bamboo (Fargesia denudate) in Wanglang Nature Reserve in the northwest Sichuan Province, China. Samples (leaf, shoot, and culm) of F. denudata were selected from three altitudes (2600 m, 2850 m, and 3100 m) to study differences that may be attributable to differences in altitude. The results indicated that the nutrient compositions and amino acid contents of different parts of F. denudata showed different change patterns among the different altitudes. Our main results were as follows. (1) At the same altitude, nutrients of different F. denudata tissues (leaf, shoot, and culm) were significantly different from each other. For instance, the crude protein and crude fat contents of the leaf were the highest, whereas those of the stem were the lowest. In the shoot, these parameters were in the middle range. (2) Most interestingly, the amount of crude protein and total amino acids were markedly influenced by the altitudinal gradient, being significantly higher at 3100 m than at 2600 m. For example, the contents of crude protein and total amino acids of bamboo shoots were highest at 3100 m. However, crude fat and crude fiber showed no significant differences among the different altitudes. (3) In addition to the threonine, glycine, and cysteine in shoots, serine and methionine in culms, and cysteine in leaves, contents of the other amino acids were significantly affected by the altitudinal gradient. For example, the histidine content in shoots increased with increasing altitude. Altitude had significant effects on the ratios of crude protein/crude fat and crude protein/crude fiber; however, no significant effects were observed on the ratios of cellulose/crude fiber and crude fat/crude fiber. Our results demonstrate that at higher altitude, F. denudata accumulates higher contents of crude protein and total amino acids. Warmer climates would probably affect the distribution of F. denudata and characters related to panda food preference, such as crude protein content, which may, to a certain extent, determine panda movement or migration to higher altitudes to feed on relatively nutritious food.
  • DownLoad:Effects of different altitudes on the nutrient and amino acid contents of bamboo (Fargesia denudata), staple food of the giant panda, in Minshan, Sichuan, China.PDF
  • Assessment and spatial variation of biodiversity in the Bailong River Watershed of the Gansu Province
  • Authors:XIE Yuchu, GONG Jie, Qi Shanshan, HU Baoqing and WANG Kelin
  • Abstract:The loss of biodiversity has become one of the major global environmental problems, with strengthening of biodiversity conservation and protection urgently required. The first step in solving this problem is the identification and understanding of the spatial variation of biodiversity on a regional scale, with the formulation and implementation of biodiversity protection schemes imperative. This has become the focus of biodiversity assessments over both large and medium scales. The Bailong River Watershed of the Gansu Province (BRWGP), one of the most abundant biodiversity regions in China, is located in the transitional ecotone along the Tibet Plateau, Loess Plateau, and Qinba Mountains. The BRWGP was selected in the present study to analyze the spatial heterogeneity of biodiversity. Inclusion of three assessment indicators (habitat quality, vegetation net primary productivity, and landscape state index) enabled the construction of a comprehensive index system of biodiversity spatial patterns and application of spatial differentiation analysis under the landscape geography perspective. Our goal was to revise the biodiversity evaluation module of the InVEST model and demonstrate biodiversity spatial patterns on a grid cell. The results indicated that biodiversity was high and had obvious spatial pattern variations in the BRWGP. The land area containing higher biodiversity accounted for 39.8% of the total watershed area, which was mainly distributed in the national nature reserve and forest. The relatively poor biodiversity areas were mainly distributed in the valleys of the BRWGP between Zhouqu-Wudu-Wenxian, the valley of Minjiang in Tanchang County, alpine mountain snow regions, and bare rock zones.
  • DownLoad:Assessment and spatial variation of biodiversity in the Bailong River Watershed of the Gansu Province.PDF
  • Decomposition and transformation of input straw in several typical paddy and upland soils in subtropical China
  • Authors:WANG Yuzhu, ZHOU Ping, WANG Juan, MA Bei, LIU Yihan and WU Jinshui
  • Abstract:Decomposition and transformation of input straw in four types of paddy soils were investigated under incubation at 25℃ and 45% water holding capacity (WHC) for 180 d. The soils were derived from different parent materials (weathered granite, quaternary red clay, weathered shale, and river alluvial) in subtropical China, and the adjacent upland soils were selected as a control. During the 180 d period, the mineralization ratios of input straw in the selected paddy soils (18%-21%) were lower than those in the corresponding upland soils (21%-28%). The priming effects of straw amendment on native soil organic carbon mineralization were also lower in the paddy (5%-37%) than in the corresponding upland soils (23%-65%). The decomposed products of input straw were mainly distributed in particulate organic carbon (POC, 9%-21%) and Fe/Al-bound organic carbon (Fe/Al-OC, 12%-24%), followed by humus carbon (HMC) (11%-15%), whereas only a small part was distributed as microbial biomass carbon (MBC, 2%-7%) and dissolved organic carbon (DOC, 0.1%-0.7%). In paddy soils, the conversion ratios of input straw in POC, Fe/Al-OC, and MBC (15%-21%, 17%-24%, and 6%-7%) were higher than those in upland soils (9%-17%, 13%-18%, and 2%-4%). In addition, the 2,000-250 μm coarse water-stable aggregates in paddy soils tended to receive more decomposed products of input straw than those in upland soils (10%-13% vs. 6%-7%), whereas no significant difference was observed between paddy and upland soils in other small sizes of aggregates. The results indicated that the mineralization of input straw may be lower in paddy than in upland soils derived from different parent materials, possibly owing to stronger physical protection in soil coarse aggregates, chemical protection by binding with Fe/Al oxyhydrates, and larger transformation to stable fractions of input straw during its decomposition in paddy soils. This fate of input straw decomposition may contribute to a higher organic carbon accumulation in paddy than in upland soils.
  • DownLoad:Decomposition and transformation of input straw in several typical paddy and upland soils in subtropical China.PDF
  • The 13C-CO2 pulsing labeling method: distribution of rice photosynthetic carbon in plant-soil systems during different rice growth stages
  • Authors:DENG Yangwu, TANG Chun, YUAN Hongchao, NING Zhao, ZOU Guanfa, WANG Jiurong, GE Tida and WU Jinshui
  • Abstract:Photosynthesis by terrestrial vegetation is the driving force for carbon (C) cycling between the Earth and the atmosphere. Information on the input and distribution of photosynthesized C in plant-soil systems is essential for understanding their nutrient and C dynamics. Stable isotope and labeling technology is one of the most effective methods to trace the C cycle processes in terrestrial ecosystems. In the present study, the 13C-CO2 pulsing labeling method in combination with indoor incubation and the element analyzer-stable isotope analysis (Flash HT-IRMS) system were utilized to analyze the δ13C values of rice plants and soil. The distribution of photosynthetic C in different sections of the rice was compared and the photosynthetic C that was transferred to the soil C pool quantified. The results showed that the dry matter of the rice increased with growth stages, but the root-shoot ratio declined from approximately 0.4 at its highest during the tillering stage to approximately 0.2 at its lowest during the heading stage. The δ13C values of the rice shoot and root were between -25.52‰ - -28.33‰, which demonstrated an obvious fractionation pattern among different sections of the rice plant, and followed an order of stem (grain) > leaf > root. This fractionation pattern indicated that the distribution of photosynthetic C changes with progress of the rice growth stages. During early growth stages, the proportion of photosynthetic C distribution in the root and soil was high, implying a high C sink ability of the root-soil system; however, it decreased along with the growth stages of the rice, even though the total photosynthetic C accumulation in the root-soil system increased. As the results showed, during the tillering stage, nearly 30% of photosynthetic C was distributed to the underground parts of the plant for root formation and approximately 10% of this portion entered the soil organic C pool via root exudates. During the maturity stages, however, more photosynthetic C was distributed to the grain and the portion allocated to the soil decreased with growth of the rice. The present study provides scientific basis for better understanding the C cycle processes in paddy ecosystems. However, further study on the distribution of rice assimilated C in plant and soil systems, and the quantitative relationships of several C transformation steps such as input, transformation, protection, and stabilization in different ecosystems is required. The component and structure of new C input into the soil by rhizosphere deposition in C assimilation and its relationship with oxidation and mineralized stability should also be elucidated in the future.
  • DownLoad:The 13C-CO2 pulsing labeling method: distribution of rice photosynthetic carbon in plant-soil systems during different rice growth stages.PDF
  • Tolerance and accumulation characteristics of Viburnum odoratissinum to cadmium in contaminated soil
  • Authors:ZENG Peng, CAO Xia, GUO Zhaohui, XIAO Xiyuan, LIU Yanan and XIN Liqing
  • Abstract:A pot experiment was conducted to study the tolerance and accumulation characteristics of Viburnum odoratissinum growing in cadmium (Cd)-contaminated soil. The results showed that V. odoratissinum had a strong tolerance to Cd in contaminated soil. The biomass of V. odoratissinum was slightly changed by the soil Cd content within 56 days cultivation. With extended cultivation time (105-203 d), the growth of V. odoratissinum was obviously inhibited by the soil Cd content. After 154 days of cultivation, when the content of Cd in soil was 24.6 mg/kg, the contents of chlorophyll a, chlorophyll b, carotenoid and malondialdehyde (MDA) in fresh leaves of V. odoratissinum were slightly different from that of the control. After 203 days of cultivation, the carotenoid and MDA contents in fresh leaves increased slightly, whereas the chlorophyll a and chlorophyll b contents was obviously inhibited. Especially, the leaf growth of V. odoratissinum was inhibited significantly (P < 0.05) when the Cd content in soil was 24.6 mg/kg. Moreover, the accumulation and transferring factors of V. odoratissinum for Cd in the soil were more than 1 after 203 days of cultivation. The results suggested that V. odoratissinum is helpful for Cd-contaminated soil ecoremediation.
  • DownLoad:Tolerance and accumulation characteristics of Viburnum odoratissinum to cadmium in contaminated soil.PDF
  • Effect of different soil properties on plow-layer soil quality of sloping farmland in purple hilly areas
  • Authors:DING Wenbin, JIANG Guangyi, SHI Dongmei, LIU Yijun, JIANG Ping, CHANG Songguo and LIU Zhipeng
  • Abstract:As the most easily eroded land-use type, severe soil degradation of the plow layer (as a shallow soil layer), deterioration of soil properties, and gravel process, could restrict the sustainable utilization of slope farmland, which also directly threatens local food security and ecological security. Plow-layer soil quality is highly sensitive to both natural factors and artificial farming tillage. Taking the plow-layer soil quality of three slope farmlands in the southern purple hilly area (Hechuan-Chongqing, Xingguo-jiangxi, and Chuxiong-Yunnan) as examples, this study mainly analyzed the differences in soil physical properties, soil reservoir characteristics, and soil nutrient characteristics of slope farmlands, and their vertical distribution characteristics, from the perspective of soil properties, so did the forming causes at the same time. The results indicated the following. (1) The soil organic matter of the plow-layer in the three locations in decreasing order was as follows: Chuxiong-Yunnan (28.80 g/kg) > Xingguo-jiangxi (9.03 g/kg) > Hechuan-Chongqing (8.80 g/kg). With the exception of total soil potassium content, other contents such as total soil nutrients and available soil nutrients, could be arranged in the following order: Chuxiong-Yunnan > Hechuan-Chongqing > Xingguo-jiangxi. The vertical characteristics of available soil nutrients in the plow-layer of slope farmland showed the same distribution, being mainly concentrated in the 0-20-cm soil layer. However, there were no significant differences between the 20-40-cm soil layer and the 40-60-cm soil layer. (2) The soil physical properties of the plow-layer of slope farmlands among the three purple hilly locations showed significant differences. The soil physical quality of the plow-layer in Hechuan-Chongqing was the worst, with the characteristic of soil sand content > 60%, maximum soil bulk density of 1.43 g/cm3, minimum soil total porosity of 45.97%, and capillary porosity of 34.36%. From the viewpoint of the plow-layer vertical characteristics of slope farmland, the soil physical properties of the tillage layer (0-20 cm) were better than those of the subsoil (20-40 cm) and bottom layer (40-60 cm). (3) The initial soil infiltration rate of the plow-layer in the Xingguo-jiangxi slope farmland was the largest (0.32 mm/min), and the initial soil infiltration rate in Hechuan-Chongqing plow-layer was the lowest (0.19 mm/min). The soil infiltration rate and the average soil infiltration rate both showed the same order of Chuxiong-Yunnan > Xingguo-jiangxi > Hechuan-Chongqing. The soil maximum effective capacity of the plow-layer in Chuxiong-Yunnan slope farmland was the best (873.311 t/hm2), which indicated that such plow-layers of slope farmland have better resistance to seasonal drought. Plow-layer vertical characteristics, such as the total storage capacity, dead storage capacity, active storage capacity, flood detention storage capacity, and maximum effective capacity, all showed the same order: tillage layer (0-20 cm) > subsoil layer (20-40 cm) > bottom layer (40-60 cm). (4) The soil shear strength and the soil penetration resistance of the plow-layer among the three slope farmland locations showed the same regular changes. The soil shear strengths of the plow-layer were Hechuan-Chongqing (15.39 kg/cm2) > Chuxiong-Yunnan (14.74 kg/cm2) > Xingguo-jiangxi (10.66 kg/cm2), whereas the soil penetration resistances of the plow-layer were Hechuan-Chongqing (424.83 kPa) > Chuxiong-Yunnan (252.50 kPa) > Xingguo-jiangxi (188.87 kPa), which indicated that the plow-layer soil of slope farmland in the Hechuan-Chongqing purple hilly area has better resistance to shear stress and greater resistance to farming tillage. These results could provide a theoretical basis and supporting data not only for soil quality diagnosis but also for rational plow-layer evaluation for slope farmlands in different purple hilly areas.
  • DownLoad:Effect of different soil properties on plow-layer soil quality of sloping farmland in purple hilly areas.PDF
  • Analysis of vegetation variation and stress factors in the Pearl River Basin from 2004 to 2013
  • Authors:WANG Xinghan, CONG Peitong, LIU Chaoqun, KANG Qing, FU Qinghua, ZHAO Min, WANG Xiaogang and LIU Xiaolin
  • Abstract:In recent years, extreme weather events have happened frequently in the south of China, especially with the frequent occurrence of droughts. Vegetation is an important environmental factor, which is a comprehensive reflection of human activities and the natural environment. In this study, we selected the Pearl River Basin as a study area, using MODIS Enhanced Vegetation Index data, and analyzed the vegetation changes resulting from human activity and natural environment. Where human activities are present, our analysis mainly used DMSP data from the United States military meteorological satellite to analyze light data changes from 2004 to 2013. Natural environments were analyzed mainly by meteorological stations; the main parameters analyzed included mean daily temperature and precipitation. The results show that in the Pearl River Basin, the yearly average Enhanced Vegetation Index was between 0.33 to 0.38 during 2004 to 2013, the order of Enhanced Vegetation Index was as follows: evergreen broad-leaved forest > mixed forest > woody savannas > evergreen coniferous forest > grassland. In addition, during this period, the level of urbanization increased by approximately 71%, and the changes in urban development trends were opposite to those of Enhanced Vegetation Index. Thus, the results of this study showed that human activity is the major stress factor causing vegetation changes in the Pearl River Basin and that the natural environment is not dominant.
  • DownLoad:Analysis of vegetation variation and stress factors in the Pearl River Basin from 2004 to 2013.PDF
  • The shelter belt effect: beetles in the litter-layer of Tamarix nebkha in the north rim of Taklamakan
  • Authors:WANG Jing, LÜ Zhaozhi, YIN Chuanhua, LI Jinhui and WU Wenyue
  • Abstract:Tamarix nebkhas (nebkhas) has been widely planted to stabilize sand movement and develop soils along desert margins. The influence of this man made localized landscape on insect diversity is not well known. Some groups of beetles are well adapted to life in the arid and thermally stressing environments found in desert regions. In 2005 and 2006, we investigated the species diversity and abundance of beetles in the litter-layer in areas planted with T. nebkhas and bare patches between these in the northern edge of Taklamakan desert, the biggest sand dune area in China, and second in the world in terms of sand dune movement. Six nebkhas areas and contiguous bare patches were monitored from June to August in both years by pitfall traps. Beetle in each trap were collected at half-month intervals, and kept in alcohol for later identification. A mark-recapture method was employed to estimate the density of beetles and the probability of movement between nebkhas. The community of litter-layer beetles in the T. nebkhas was higher and stabilized than in bare patches. In 2005 and 2006 the total number of beetles collected in the T. nebkhas, 360 and 209 in each year, was greater than in bare patches,209 and 158. Some 21 species of litter-layer beetles were observed in the T. nebkhas and 10 species in bare patches in 2005, with 16 species and 12 species trapped in each patch type in 2006. Species richness, Shanon-Weiner index and Evenness 21 species of litter-layer beetles were observed in the T. nebkhas and 10 species in bare patches in 2005, with 16 species and 12 species trapped in each patch type in 2006. Species richness, Shanon-Weiner index and Evenness index were higher at the T. nebkhas areas than in bare patches, and Simpson Index was greatest in bare patches in 2005.Based on mark-recapture the density of Penthicicus koltzei Reitter was higher in T. nebkhas areas (13/m2) compared to bare patches (6/m2). Areas planted with T. nebkha act as a refuge for conserving P. koltzei and other beetles in desert areas. Movement of beetles was very localized. Only one beetle was recorded as moving from on nebkhas to another, a distance of 30 m. This implied that beetle in nebkhas might be independent, and refuges are highly localised. There was high seasonal variability in the litter-layer beetles species abundance and biodiversity in the two types of patchy: the beetle density in both areas peaked in the June, 2005 and July, 2007. This may be attributed to the abundance of food for beetle in different season and the effect of microhabitat, particularly moisture effects in harsh desert areas. The nebkhas alongside deserts offer a refuge, sustaining the diversity of beetle. Expanding the creation of the distinctive landscape composed of nebhkhas and its biodiversity, provides a buffer between desert and agriculture reclamation should be a priority.
  • DownLoad:The shelter belt effect: beetles in the litter-layer of Tamarix nebkha in the north rim of Taklamakan.PDF
  • Effects of climate change on the distribution of main vegetation types in Northeast China
  • Authors:LIU Dan and YU Chenglong
  • Abstract:A suitable distribution of zonal vegetation types could provide a reference for the restoration and reconstruction of regional vegetation and protection of biodiversity. Between 1961 and 2013, we used mutation point detection and the thermal index to study the impacts of climate change on the distribution of the main vegetation types in Northeast China. The land cover data for 2000 and 2013 from NASA LPDAAC (The Land Processes Distributed Active Archive Center) EOS were used to verify the simulated distribution regions. The results showed that the temperature mutation point for Daxing'an Mountains was in 1982, and the mutation points for the other regions were in 1988. The annual precipitation at each eco-geographical region showed no obvious mutation. After 1982, the main vegetation types, which were suitable for growth,showed no obvious changes;however, their distribution regions had been changed. The areas of suitable distribution regions for alpine tundra, subalpine forest, cold-temperate coniferous forest, and temperate mixed forest decreased continuously;however, the areas for warm-temperate deciduous broad-leaved forest and temperate grassland increased. The geographic centers for the suitable distribution of each vegetation type had moved to different degrees before and after the temperature mutation points. Among them, the center of the subalpine forest had moved towards the northeast, and the distance was the longest (135.44km). On the basis of the comparative analysis,we concluded that climate change possibly had an impact on the distribution of vegetation types in Northeast China.
  • DownLoad:Effects of climate change on the distribution of main vegetation types in Northeast China.PDF
  • Biomass allocation and biomass allometric models of six early-summer herbs under the canopy of broad-leaved Korean pine forest during different growth periods in Jiaohe, Jilin Province
  • Authors:SUN Yue, HE Huaijiang, LI Liang, SONG Caimin, WANG Fengjie and XIA Fucai
  • Abstract:As the one kind of dominant component under broad-leaves Korean pine forest stands, the early-summer herbs have an important influence on herb layer species diversity and biomass in the whole growth periods. Studying on the biomass allocation structure and biomass allometric model in different growth stages will further help to understand the survival strategy and carbon storage of these species. Cardamine leucantha, Paris verticillata, Smilacina japonica, Meehania fargesii, Anisodus acutangulus and Sanicula rubriflora were selected for phenological observation and periodical sampling from the beginning of April to the end of August. Biomass allocation characteristics and the relationships between above-ground biomass (AGB) and below-ground biomass (BGB) in different growth stages for the six early-summer herbs were analyzed. With height classes as the independent variable, the single-species and mix-species allometric models were established with five model forms (linear regression of one-variable, quadratic model, exponential model, power model, and logarithmic model). Then the optimization models were chosen and validated. The result shows that the florescence generally began in late April and ended in mid June, and the fruit period began in late May and ended in mid August for the six herbs. The duration of flower and fruit period was different in different species. The plant height, biomass and root shoot ratio (R/S) were significant various with plant growth in the whole growth periods, but the changing tendency was different. The allocation proportion of components in different species was different and the proportion of biomass allocation for reproduction was usually less than 5%. The relationships between above- and below-ground biomass were both allometric relationship (the P-value less than 0.0001 and the allometric exponent a≠1). The power model was the most frequently chosen as the optimization model base on the R2 (coefficient of determination) and SEE (standard error of estimate), followed by quadratic model and exponential model. The higher R2 value and lower SEE value of all optimization models indicate that the model was the better usability. And the models about AGB and TB were better than BGB, the single-species models were better than the mix-species ones. The RS, EE and RMA value of all optimization models were less than 30% excepting the model of mix-species model about BGB (RMA=30.679%) and the P-value were more than 80% by data verification. We conclude that these optimization models were able to calculate biomass of early-summer herbs under canopy of broad-leaves Korean pine in this region.
  • DownLoad:Biomass allocation and biomass allometric models of six early-summer herbs under the canopy of broad-leaved Korean pine forest during different growth periods in Jiaohe, Jilin Province.PDF
  • Determination of dominant tree species and effects of tree distribution on the habitat of Rhinopithecus roxellana using Remote Sensing imagery in Shennongjia
  • Authors:LIN Liqun, WANG Zhengxiang, LEI Yun, LI Tingting, WANG jun and YANG Jingyuan
  • Abstract:Because of the difficulty in obtaining large-scale distribution data on tree species in Rhinopithecus roxellana habitat in Shennongjia, we attempted to use multi-source and multi-temporal remote sensing data combined with expert knowledge to identify species at different levels. Firstly, after analyzing the discrimination of sample trees, we used winter Landsat8/OLI image data to extract evergreen and deciduous forest, respectively. Secondly, we used summer Worldview-2 high resolution image data to for the recognition of tree species, which included the evergreen species (Abies fargesii, Pinus armandii, Picea wilsonii, Quercus spinosa) and deciduous tree species (Betula albo- sinensis, Larix kaempferi, Fagus engleriana, Toxicodendron vernicifluum, Quercus aliena, Populus wilsonii), respectively. Thirdly, combining the vegetation quadrats and expert knowledge on elevation, we corrected the classification results based on the second step. Finally, making use of GIS spatial analysis, we analyzed the terrain and geographical distribution on the dominant species. The experiment revealed that accuracy was higher in evergreen forests, such as Abies fargesii, Pinus armandii, Quercus spinosa, and Pinus armandii affected by pests, whereas relatively higher in deciduous forest, such as Betula albo-sinensis and Toxicodendron vernicifluum. Some species, such as Populus wilsonii and Quercus aliena, showed poor accuracy. In general, evergreen species had higher accuracy than deciduous trees. By combining plant geography, remote sensing, and GIS, we integrated the multi-source, multi-temporal remote sensing data, phenological characteristics of the tree species, and expert knowledge to propose a method for identifying tree species. This method (1) provides an effective way to identify dominant tree species in complex mountainous environments, and it has the versatility for a variety of geographical environments; (2) makes full use of the integration of species phenological features and characteristics of remote sensing data to reduce data costs; (3) uses ground sampling and expert knowledge, ensuring the classification results are correct, which can avoid excessive reliance on spectral characteristics, and reduce the possibility of misclassification. This method will provide more accurate data for the protection and restoration of the habitat of Rhinopithecus roxellana in Shennongjia.
  • DownLoad:Determination of dominant tree species and effects of tree distribution on the habitat of Rhinopithecus roxellana using Remote Sensing imagery in Shennongjia.PDF
  • Effects of genotypic diversity of neighboring species on the growth of Artemisia frigida plants
  • Authors:LIU Lei, XIN Xiaojing, WANG Yukun, QU Yaobing, YANG Xue, LI Geping, ZHAO Nianxi and GAO Yubao
  • Abstract:Anthropogenic activities are dramatically altering patterns of biodiversity around the globe, triggering extensive research on the consequences of changes in biodiversity of ecosystem and community processes. Multiple investigations on the ecological effects of both plant genetics and species diversity have shown, for example, that more diverse systems are generally more productive, and support more abundant and more diverse animal communities. In recent years, some research have shown showed that the outcome of plant-plant interactions varies with the diversity of dominant neighbor genotypes. Plant diversity, either genotypic or species diversity, could mediate plant-plant interactions in communities via at least two mechanisms. First, increased relative competition intensity between neighboring plants and target species typically leads to higher productivity of neighboring plants. Alternatively, increased trait variation of neighboring plants rather than increased competition in different communities may explain the change in plant-plant interactions. In the present study, we hypothesized that genotypic diversity of the neighboring plants may affect the growth of the target species by changing the coefficient of trait variation of the community. In this study, we conducted a factorial microcosm experiment with three combinations of genotypes (1, 3, 6 genotypes = G1, G3, G6) of two neighboring plants (Leymus chinensis and Koeleria cristata), and one genotype of the target species, Artemisia frigida. Furthermore, we investigated the growth performance (aboveground biomass, belowground biomass, total biomass, and plant height) and relative competition intensity (RCI) of A. frigida when surrounded by different levels of genetic diversity for L. chinensis or K. cristata. We analyzed six traits (aboveground biomass, belowground biomass, total biomass, plant height, root length, and specific leaf area [SLA]) of L. chinensis or K. cristata at different levels of genotypic diversity using principal component analysis (PCA). In addition, the correlations between the four traits of A. frigida and six traits of L. chinensis or K. cristata were calculated by means of Kendall rank correlation coefficient analysis. The results revealed the following: (1) The performance of A. frigida was dependent on neighboring plants. Higherg genotypic diversity of L. chinensis significantly decreased aboveground biomass, total biomass and plant height of A. frigida, and A. frigida grew the least when the genotype number of L. chinensis was six. For G6 of L. chinensis, the RCI of aboveground, belowground and total A. frigida was significantly greater than that for the G1 treatment (P < 0.05). However, for K. cristata, genotypic diversity did not exhibit significant effects on the performance or RCI of A. frigida. (2) The trait variation of neighboring plants was also dependent on the species and their genotypic diversity. When the neighboring plant was L. chinensis, genotypic diversity significantly affected trait variation, and trait variation increased with an increasing number of genotypes, whereas no significant differences were detected when the neighboring plant was K. cristata. (3) The results of the Kendall correlation coefficient analysis revealed significant negative correlations between total biomass and SLA of L. chinensis and aboveground biomass and total biomass of A. frigida. These results provided experimental data on the effects of genotypic diversity of neighboring plants on the target species, and we outlined how more traits or relative competition intensity mediating plant-plant interactions could be identified. Future studies may use population genetic survey of genotype distribution in fields and methods from trait-based ecology to better quantify the impact of intraspecific genetic variation on plant-plant interactions, so as to facilitate and enhance ecological restoration in the typical steppe of northern China in the context of global change.
  • DownLoad:Effects of genotypic diversity of neighboring species on the growth of Artemisia frigida plants.PDF
  • Ecological characteristics of vegetation and their responses to permafrost degradation in the north slope of Great Khingan Mountain valley of northeast China
  • Authors:GUO Jinting, HAN Fenglin, HU Yuanman, NIE Zhiwen, REN Baihui and BU Rencang
  • Abstract:Permafrost, which is defined as ground that remains below 0℃ for at least two consecutive years, is an important component of the cryosphere and is vulnerable to climate warming. Global warming has accelerated permafrost degradation, as evidenced by a thickening of permafrost thaw depths, increasing ground surface temperature, and the change from continuous permafrost to island permafrost. Vegetation is a vital component of the permafrost ecosystem and is sensitive to permafrost degradation. The degradation of permafrost leads to changes in the characteristics of permafrost plant communities, such as species composition and diversity and vegetation cover and biomass. The impacts of permafrost on vegetation have become a key topic in the field of climate change research. However, previous studies of permafrost have mostly focused on the distribution of permafrost, whereas there has been little quantitative research on the mechanistic connection between permafrost and environmental factors and the impacts of permafrost degradation on the ecological characteristics of vegetation. Thus, understanding the response of vegetation ecological characteristics to permafrost degradation is vital. In the present study, we investigated plant ecological characteristics and their responses to changes in the permafrost thaw depths on the north slope of the Great Khingan Mountain valley of northeast China. The results showed that there were 85 plant species belonging to 29 families and 55 genera in 30 plots. Angiosperms were dominant, accounting for 97.6% of the total species, whereas there was only one species each of fern and gymnosperm, accounting for 1.2% of the total species. In terms of four life forms, there were 51, 12, 19, and 3 species of hemicryptophytes, phanerophytes, geophytes, and chamaephytes, respectively, accounting for 60%, 14.1%, 22.4%, and 3%, of total species. Of four hydro-ecotypes, there were 50 species of mesophytes, accounting for 58.8% of the total species, whereas hygrophytes, helophytes, and xerophils accounted for 30.2%, 8.2%, and 2.4% of species, respectively. Families, genera, and species of plants reached a maximum at approximately 50-150 cm of the permafrost active layer thickness (ALT). Plant taxa were next most abundant at an ALT > 150 cm, whereas an ALT ≤ 50 was associated with the fewest families, genera, and species of plants. Species of hemicryptophytes showed a significant increasing trend with increasing permafrost melting depth, whereas the numbers of phanerophyte species decreased. Changes in the numbers of geophytes and chamaephytes with a change in permafrost melting depth were not significant. Species of helophytes decreased significantly with an increase in permafrost melting depth, whereas mesophytes showed an increasing trend. Hygrophyte and xerophil species did not change significantly with a change in permafrost melting depth. Collectively, our study results suggest that the study area has a short summer and a long cold winter, and that the conditions conducive to the growth of plants have tended to moderate. This research provides a theoretical basis for predicting trends in the variation of vegetation ecological characteristics against a background of permafrost degradation. The findings are also important for the development and implementation of agriculture and forestry in the permafrost zone. In addition, our observations potentially provide an effective guide for forest management and biodiversity conservation efforts in permafrost areas.
  • DownLoad:Ecological characteristics of vegetation and their responses to permafrost degradation in the north slope of Great Khingan Mountain valley of northeast China.PDF
  • The annual variation of effects under different grassland utilization types on typical steppe species interactions in Inner Mongolia
  • Authors:GAO Shaobo, LIU Lei, WANG Yukun, LI Jingpeng, ZHAO Nianxi and GAO Yubao
  • Abstract:Grazing and mowing were the most common utilization types in the Inner Mongolia steppe, and they had been proved to play different roles on the plant-plant interactions and community succession. In the present study, There was a 3-years of continuous monitoring experiment on the typical steppe community. We compared the two different indices of community small scale patterns with 2 algorithms by the Ecosim 7.72 software. The results were shown as follows: (1) For 3 consecutive years, the plant species interactions in community-level under grazing were competitive,especially in 2014, the results didn't support the stress gradient hypothesis. (2) In 2013 and 2015, the species interactions of community under mowing were competitive, but in 2014, on account of the drought and elevated air temperature, they were facilitative. (3) Different grassland utilization types had distinct effects on plant species interactions, and the effect were also regulated by monthly precipitation and monthly average air temperature in growing season. The present results provided the improvement of stress gradient hypothesis and the theoretical foundation in rational utilization of grassland and the recovery of degraded grassland.
  • DownLoad:The annual variation of effects under different grassland utilization types on typical steppe species interactions in Inner Mongolia.PDF
  • Root pattern of Stipa plants in semiarid grassland after long-term grazing exclusion
  • Authors:SU Jishuai, ZHAO Jie, JING Guanghua, WEI Lin, LIU Jian, CHENG Jimin and ZHANG Jin'e
  • Abstract:We selected five grassland sites with different grazing exclusion times (0, 5, 9, 22, and 30 years) on Yunwu Mountain as the study sites, where the roots of Stipa plants in the 0-30 cm soil layer and soil of the 0-20 cm soil layer were collected. Roots were washed and identified to the species level based on attached aboveground parts and root color, texture, and branching. Root samples of the same species were scanned using an Epson Scanner to obtain images for analysis of root morphological traits using WinRhizoPro software. Root length, surface area, and volume were analyzed at 0.1 mm intervals in root diameter, the measurements of which could be used for calculations of specific root length (SRL), specific root surface area (SRS), and root tissue density (RTD). Soil samples were analyzed to determine soil moisture, soil bulk density, soil pH, soil organic carbon, total soil nitrogen, total soil phosphorous, available soil nitrogen, available soil phosphorus, microbial biomass carbon, and microbial biomass nitrogen. One-way analysis of variance was conducted to determine the effect of grazing exclusion time on Stipa root traits, and to determine differences in the roots of different Stipa species. Redundancy analysis was conducted to determine soil variables that best explain the variations in Stipa root traits. The main results were as follows. (1) The root biomass, root length density, root surface area, and root volume of Stipa plants showed a slight decrease at the beginning of grazing exclusion, but thereafter gradually increased and showed significant increases in grassland with grazing exclusion for 30 years. (2) All of the root trait indexes showed similar species compositional changes with grazing exclusion time. Specifically, the proportion of Stipa bungeana was the highest in grazed grassland, then gradually declined with grazing exclusion time, and disappeared after 30 years' grazing exclusion; the proportion of Stipa grandis initially increased, peaked in grasslands after 20 years' grazing exclusion, and then sharply decreased to the initial status; and Stipa przewalskyi appeared only in grassland with 30 years' grazing exclusion and became the dominant Stipa species. (3) Compared with the roots of S. grandis, the roots of S. bungeana and S. przewalskyi were thinner and had higher SRL and SRS, mainly resulting from a larger proportion of root traits in the 0-0.6 mm root diameter class. Besides, root tissue density of S. bungeana was higher than that of S. grandis and S. przewalskyi.(4) Long-term grazing exclusion significantly increased soil water content, total soil nitrogen, total soil phosphorus, soil nitrate nitrogen, and available soil phosphorus, and showed limited impacts on soil bulk density, soil pH, soil ammonium nitrogen, soil microbial biomass carbon, and soil microbial biomass nitrogen. With significantly increased total soil nitrogen, long-term grazing exclusion significantly decreased the ratio of soil carbon to nitrogen and significantly increased the ratio of soil nitrogen to phosphorus. (5) Redundancy analysis showed positive correlations among root biomass, root length density, root surface area, and root volume, and total soil nitrogen and ammonium nitrogen were significant factors explaining variations in the root traits of Stipa plants after grazing exclusion. Furthermore, root traits were positively affected by soil water content and available soil phosphorus, and were negatively affected by soil pH. In conclusion, inherent differences in the root traits of three Stipa species and changes in soil properties collectively drove the root trait patterns of Stipa plants in semiarid grassland after long-term grazing exclusion in this area.
  • DownLoad:Root pattern of Stipa plants in semiarid grassland after long-term grazing exclusion.PDF
  • Effect of heat shock on seed germination of three Pinaceae species in Great Hing'an Mountains
  • Authors:GU Huiyan, JIANG Keyan, ZHANG Yunhui, WANG Shunzhong and CHEN Xiangwei
  • Abstract:This study examines the effect of heat shock on the seed germination of Larix gmelinii, Pinus sylvestris var. mongolica and Picea koraiensis from a fire-prone forest in the Great Hing'an Mountains. Seeds of the three species were exposed to a range of temperatures (80,100,120, and 150℃) for different exposure times (1, 3, 5 and 10 min). The results show that the germination rate of Larix gmelinii seeds decreased significantly (P < 0.05) relative to the control when seeds were subjected to 100℃ for 10min, 120℃ for 5min and 10min, and 150℃ for 5min. With the exception of exposures at 80℃ for 1, 3 and 5 min; 120℃ for 1min; and 150℃ for 1min, the germination velocity index of Larix gmelinii seeds showed a significant(P < 0.05) decrease for all other heat shock treatments. For sylvestris var. mongolica, the germination rate subsequent to all heat shock treatments above 80℃ decreased significantly (P < 0.05)relative to the control. Even to the point where no germination occurred at all. At the same time, the germination velocity index for every heat shock treatment higher than 80℃ decreased significantly at 1min exposure. For Picea koraiensis, the germination rate increased significantly (P < 0.05) relative to the control when subjected to heat shock treatments of 80℃ for 5min and 100℃ for 1min. Moreover, the germination velocity index increased significantly(P < 0.05)for heat shock treatments of 80℃ for 1, 3, and 5min and 100℃ for 1min. On an overall basis, Larix gmelinii seeds was able to maintain standard germination rate after a transitory high intensity heat shock of 150℃; however, it cannot tolerate a longer heat shock, the influence of transitory high intensity heat on the germination rate was more significant than that on the germination velocity index. Pinus sylvestris var. mongolica seeds were quite sensitive to a heat shock above 80℃: the germination rate sharply decreased with a 100℃ heat shock and almost no seeds germinated above 100℃. Picea koraiensis seeds are capable of tolerating an instantaneous (1min) high intense heat shock (150℃), and a light heat shock over short time periods(1min, 3min, 5min)for 80℃ (100℃ for 1min included) stimulated seed germination of Picea koraiensis.
  • DownLoad:Effect of heat shock on seed germination of three Pinaceae species in Great Hing'an Mountains.PDF
  • Variations in PM2.5 concentration and leaf adsorption capacity of Pinus tabulaeformis forests at different altitudes on Beijing Xishan Mountains
  • Authors:LU Shaowei, LI Shaoning, CHEN Bo, LIU Hailong, ZHAO Dongbo and CHEN Pengfei
  • Abstract:PM2.5 concentration and leaf PM2.5 adsorption capacity of Pinus tabulaeformis artificial forests at different altitudes on Beijing Xishan Mountains were analyzed, surface micro-morphological characteristics of Pinus tabulaeformis at different altitudes were observed using electron microscopy, and differences in leaf PM2.5 adsorption were then interpreted. The results revealed the following: PM2.5 concentration decreased as the altitude increased; diurnal variations in PM2.5 concentration displayed a typical bimodal curve for the Pinus tabulaeformis forests at different altitudes; the highest peaks were observed at 7:00 and 19:00, while minimum concentrations were detected at 13:00-15:00; PM2.5 concentration was the highest in the winter month of February and the lowest in August; annual mean PM2.5 concentration at varying forest altitudes was 84 m ((102.28 ± 18.44) μg/m3) > 110 m ((94.18 ± 18.34) μg/m3) > 160 m ((81.53 ± 19.23) μg/m3) > 230 m ((75.39 ± 15.71) μg/m3); PM2.5 adsorption amount per unit leaf area decreased as the altitude increased (PM2.5 adsorption amount per unit leaf area reduced by 23.25% as the altitude increased by 50 m); PM2.5 adsorption amount per hectare decreased by 26.43%, with the Pinus tabulaeformis forests at different altitudes exhibiting annual mean values of 84 m ((8.61 ± 1.08) kg/hm2) > 110 m ((7.30 ± 0.94) kg/hm2) > 160 m ((6.35 ± 0.99) kg/hm2) > 230 m ((4.34 ± 1.14) kg/hm2); leaf surface texture was rough at the lower altitudes, with a high number of particles inside and around the stomata (a function more conducive to PM2.5 adsorption with respect to leaf morphology); and leaf surface texture at the high altitudes exhibited opposite features. Air quality at the high altitudes was superior to that at the low altitudes, and plant adsorption particles were higher at the low altitudes than at the high altitudes. The results can provide data support for urban afforestation and purification of the atmosphere using forests.
  • DownLoad:Variations in PM2.5 concentration and leaf adsorption capacity of Pinus tabulaeformis forests at different altitudes on Beijing Xishan Mountains.PDF
  • Relationship between recruitment of Microcystis dormant in sediment and annual dynamics of bacterial flora in Lake Chongtian
  • Authors:ZOU Wansheng, WANG Zhi, LIU Liangguo, WANG Wenbin and SHI Yingpu
  • Abstract:Recruitment of Microcystis dormant from the upper sediment is a critical stage in its life history and plays an important role in forming blooms. However, little is known about the benthic bacteria associated with recruitment of Microcystis cells in sediment. To investigate the relationship between the recruitment of dormant Microcystis and bacterial flora in the upper sediment, we detected and comparatively analyzed the density of bacteria and the abundance of Microcystis dormant in the upper sediment in Lake ChongTian, situated to the west of Lake DongTong, where Microcystis blooms have formed frequently in recent years. At the same time, bacterial density,the abundance of Microcystis cells, and some of the physical and chemical properties of the overlying water column were measured. Results show that total bacterial density in both the upper sediment and the overlying water column gradually increased from January to May, remained stable from June to September, and decreased gradually from October to December. However, the total bacteria density in sediment was significantly higher than that in the overlying water column in each month. From April to June, total bacterial density significantly increased (P < 0.05) and the density of dormant Microcystis significantly decreased (P < 0.05) in the upper sediment, which indicated that the recruitment of dormant Microcystis began in April. In the same period, the concentration of dissolved oxygen (DO) and the TN/TP ratio decreased significantly in the overlying water column. In May, the total bacterial density in sediment was 7.32×105 colony-forming units (cfu)/mL, significantly higher than that in April; moreover, the proportion of dominant flora increased remarkably(up to 61%). The density of Microcystis cells in the overlying water column increased significantly to 180×106 cells/mL in June, and Microcystis aeruginosa was dominant the Microcystis species.The density of dormant Microcystisin the upper sediment reduced to its minimum value,3.71×106cells/mL, at this time. In July, the total bacterial density in the upper sediment was not significantly different from that in May and June, and the proportion of dominant flora decreased to 40%-42%, which was the average value in other months. Meanwhile, the density of Microcystis cells in the overlying water column decreased significantly, and the density of dormant Microcystis increased significantly in the upper sediment (P < 0.05). In August, the total bacterial density in the upper sediment was 8.89×105cfu/mL,which was the highest value for all months, and the proportion of dominant flora increased significantly (up to 57%). Consequently, in September, the density of dormant Microcystis in the upper sediment again decreased significantly; in contrast, the density of Microcystis cells in the overlying water column increased significantly (P < 0.05). This study also revealed that the dominant Microcystis species in Lake ChongTianwere M.aeruginosa, M.flos-aqua, and M.wesenbergii, though the relative proportions of these species differed in different months. The dominant bacterial flora in the sediment and overlying water column were Exiguobacterium, Pseudomonas,and Bacillus,all of which can promote, to some extent, the recruitment of dormant M.aeruginosa, M.flos-aqua,and M.wesenbergii from the upper sediment. These results have important implications in that dominant bacterial flora in the upper sediment may exert important effects on the recruitment of dormant Microcystis species from the upper sediment.
  • DownLoad:Relationship between recruitment of Microcystis dormant in sediment and annual dynamics of bacterial flora in Lake Chongtian.PDF
  • Analyzing the nitrate reductase gene (nirK) community in the peat soil of the Zoige Wetland of the Tibetan Plateau
  • Authors:WANG Yingyan, LU Sheng'e, CHEN Xiaomin, LI Yuefei and GU Yunfu
  • Abstract:The Zoige Wetland, which is located in the northeast of the Tibetan Plateau, is a typical low latitude permanent permafrost wetland, with high altitude intensive ultraviolet radiation and high soil organic matter content. The nitrous oxide fluxes in this area are critical to global warming. The main objective of this study was to elucidate the diversity and structure of the nitrate reductase (nirK) gene denitrifier community, and to further explore the microbial mediated mechanism of N2O release in this climatically extreme area. Based on the soil physicochemical properties and denitrifying activity (PDA) analysis, restriction fragment length polymorphism (RFLP), clone library and sequencing were further used to analyze the diversity and structure of the nirK gene in the denitrifier community. The results showed that the highest activity of PDA was detected in the Axi soil, while the lowest activity was in the Fenqu soil. The PDA was significantly and positively correlated with soil organic carbon, total nitrogen and nirK gene richness (P < 0.05). The highest and lowest Shannon-Wiener diversity indices were detected in Axi and Fenqu soils, respectively. Based on the RFLP patterns, 15 different nirK gene clones were selected for sequencing and further phylogenetic analysis. The phylogenetic analysis showed that the majority of the nirK-denitrifiers in the peat soil of the Zoige Wetland belonged to Proteobacteria, and the dominant species in the Axi soil were Alphaproteobacteria, whereas Betaproteobacteria species dominated in the Maixi soil. The dominant nirK denitrifiers remained unidentified in the Fenqu soil. Redundancy analysis (RDA) was used to explore the possible relationship between the nirK denitrifiers community and soil physicochemical parameters, and the results showed that soil available potassium and available phosphorus were the two most important factors in shaping nirK denitrifier communities. In conclusion, the current study revealed obvious denitrifying activities in the Zoige Plateau Wetland. The nirK gene denitrifying community, which plays an important role in mediating the denitrifying process, was relatively diverse and positively influenced by soil available potassium and available phosphorus.
  • DownLoad:Analyzing the nitrate reductase gene (nirK) community in the peat soil of the Zoige Wetland of the Tibetan Plateau.PDF
  • Effects of cadmium on the distribution and accumulation of benzo[a]pyrene in subcellular fractions of Eisenia fetida
  • Authors:ZHOU Lina, ZHOU Jing, LI Huixin, HU Feng and XU Li
  • Abstract:This experiment explored the mechanism underlying benzo[a]pyrene (BaP) distribution in different subcellular fractions of the earthworm Eisenia fetida (Fraction C: associated with the cytosol; Fractions D: associated with granules; and Fraction E: associated with tissue fragments and cell membranes) under conditions of contamination with both BaP and cadmium ions (Cd2+) at different concentrations. The results showed that Cd2+ inhibited the accumulation of BaP in the earthworm, and that BaP was accumulated to the greatest extent in Fraction E, followed by Fraction C and Fraction D. With the addition of Cd2+, BaP concentrations in the three fractions initially decreased, but subsequently increased with the increasing concentration of Cd2+, whereas protein content and acetylcholinesterase (AChE) activity showed the opposite trend. In contrast, glutathione s-transferase (GST) activity initially decreased and then subsequently increased with increasing Cd2+ concentration in Fraction C and E, whereas the activity gradually increased in Fraction D. Correlation analysis indicated that protein content showed a significant negative correlation with BaP concentration in Fraction C and E; AChE activity showed a significant negative correlation with BaP concentration in Fraction C; and GST activity showed a non-significant correlation with BaP concentration. Collectively, the results indicate that BaP mainly accumulated in Fraction E, and that the accumulation of BaP in Fraction C and E was correlated with the content of protein and activity of AChE, which was influenced by Cd2+. Furthermore, BaP concentration initially decreased, but subsequently increased, with the increasing concentration of Cd2+.
  • DownLoad:Effects of cadmium on the distribution and accumulation of benzo[a]pyrene in subcellular fractions of Eisenia fetida.PDF
  • A review of point pattern analysis in ecology and its application in China
  • Authors:MA Zhibo, XIAO Wenfa, HUANG Qinglin and ZHUANG Chongyang
  • Abstract:Point pattern analysis, i.e., spatial point pattern analysis (SPPA) is a tool used in ecological pattern research and has recently become increasingly popular in ecology. To better understand SPPA research and its application in China, in this review we examined articles regarding SPPA published from 1996 to 2015 in China, which was based on a summary of the research progress, using steps and key points of SPPA. It was found that most articles focused on application research. Although there were extensive study objects, including forests, shrubs, grasslands, and landscapes, trees in forest communities were the main focus in all these application studies. Fundamental studies were found to be underdeveloped, such as studies regarding summary statistics and null models or point process models in SPPA, and the development of specific software packages for SPPA. Two important problems were found in SPPA applications: Firstly, although there are many alternatives, researchers preferred single summary statistics and only selected the K-function or its transformations; and secondly, although selecting null models as null hypotheses was a key step in SPPA, more than half of the research examined did not specify explicit null models. Therefore, it is recommended that different types of summary statistics are used to capture detailed spatial pattern structures, and the ecological questions or hypotheses should be clearly stated and correctly translated into statistical language, i.e., the null model and tests. Vertical layers and different generations should also be considered when studying systems with complex spatial structures, such as in tropical rainforests and subtropical evergreen broad-leaved forests. To enhance basic SPPA applications, these aspects discussed should be strengthened.
  • DownLoad:A review of point pattern analysis in ecology and its application in China.PDF
  • Advances in photo-physiological responses of leaves to environmental factors based on the FvCB model
  • Authors:TANG Xinglin, CAO Yonghui, GU Lianhong and ZHOU Benzhi
  • Abstract:Biochemical models of leaf photosynthesis are invaluable tools for exploring the photo-physiological responses to environmental factors and identify potential targets to improve the efficiency of CO2 fixation. The FvCB model can be used to fit CO2 response curves developed under different environmental conditions and predict underlying photosynthetic biochemistry. However, to do this successfully it is important to improve chloroplast electron transport modeling, and gain a better understanding of internal CO2 diffusion limitations and elucidate the mechanisms of stomatal (gs) and mesophyll (gm) conductance responses to environmental factors. The FvCB model and its application in determining the photo-physiological responses to environmental factors, such as light, CO2, water, temperature, and N nutrition have been reviewed in this paper. To improve the veracity of the parameter estimations and reveal the mechanism of photo-physiological responses to environmental factors, the following studies should be emphasized in the future: 1) the relationship between the carboxylation rate of Rubisco and chloroplast electron transport rate; 2) the CO2 diffusion limitations in mesophyll cells and its effect on parameter estimations; and 3) the regulation of gs and gm responses to different environmental conditions.
  • DownLoad:Advances in photo-physiological responses of leaves to environmental factors based on the FvCB model.PDF

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