中国地理科学 ›› 2015, Vol. 25 ›› Issue (6): 739-756.doi: 10.1007/s11769-015-0774-x

• 论文 • 上一篇    下一篇

Effects of Water-table Depth and Soil Moisture on Plant Biomass, Diversity, and Distribution at a Seasonally Flooded Wetland of Poyang Lake, China

XU Xiuli1,2, ZHANG Qi1,3, TAN Zhiqiang1,2, LI Yunliang1, WANG Xiaolong1   

  1. 1. Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330000, China
  • 收稿日期:2014-08-26 修回日期:2014-12-29 出版日期:2015-06-27 发布日期:2015-11-05
  • 通讯作者: ZHANG Qi. E-mail: qzhang@niglas.ac.cn E-mail:qzhang@niglas.ac.cn
  • 基金资助:

    Under the auspices of National Natural Science Foundation of China (No. 41371062), Collaborative Innovation Center for Major Ecological Security Issues of Jiangxi Province and Monitoring Implementation (No. JXS-EW-00), National Basic Research Program of China (No. 2012CB417003), Science Foundation of Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (No. NIGLAS2012135001)

Effects of Water-table Depth and Soil Moisture on Plant Biomass, Diversity, and Distribution at a Seasonally Flooded Wetland of Poyang Lake, China

XU Xiuli1,2, ZHANG Qi1,3, TAN Zhiqiang1,2, LI Yunliang1, WANG Xiaolong1   

  1. 1. Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330000, China
  • Received:2014-08-26 Revised:2014-12-29 Online:2015-06-27 Published:2015-11-05
  • Contact: ZHANG Qi. E-mail: qzhang@niglas.ac.cn E-mail:qzhang@niglas.ac.cn
  • Supported by:

    Under the auspices of National Natural Science Foundation of China (No. 41371062), Collaborative Innovation Center for Major Ecological Security Issues of Jiangxi Province and Monitoring Implementation (No. JXS-EW-00), National Basic Research Program of China (No. 2012CB417003), Science Foundation of Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (No. NIGLAS2012135001)

摘要:

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distribution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cinerascens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical correspondence analysis (CCA), spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community (ranging from -0.5 m above ground to +10.3 m below ground), intermediate in P. australis community (-2.6 m to +7.8 m) and shallowest in C. cinerascens community (-4.5 m to +6.1 m). Soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above-and belowground biomass are positively correlated with moisture. Above-and belowground biomass present Gaussian models along the gradient of average water-table depth in growing season, while species diversity indices show bimodal patterns. The optimal average water-table depths for above-and belowground biomass are 0.8 m and 0.5 m, respectively, and are 2.2 m and 2.4 m for species richness and Shannon-Wiener indices, respectively. Outcomes of this work improved the understandings of the relationship between hydrology and vegetation.

关键词: water-table depth, soil moisture, species diversity, biomass, Gaussian model, Poyang Lake wetland

Abstract:

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distribution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cinerascens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical correspondence analysis (CCA), spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community (ranging from -0.5 m above ground to +10.3 m below ground), intermediate in P. australis community (-2.6 m to +7.8 m) and shallowest in C. cinerascens community (-4.5 m to +6.1 m). Soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above-and belowground biomass are positively correlated with moisture. Above-and belowground biomass present Gaussian models along the gradient of average water-table depth in growing season, while species diversity indices show bimodal patterns. The optimal average water-table depths for above-and belowground biomass are 0.8 m and 0.5 m, respectively, and are 2.2 m and 2.4 m for species richness and Shannon-Wiener indices, respectively. Outcomes of this work improved the understandings of the relationship between hydrology and vegetation.

Key words: water-table depth, soil moisture, species diversity, biomass, Gaussian model, Poyang Lake wetland