土地利用方式对湖泊洲滩湿地植物生物量的影响——以西洞庭湖国家级自然保护区为例

【目的】为了解土地利用方式对西洞庭湖洲滩湿地生态系统服务功能的影响,探索土壤含水率和物种丰富度在湿地恢复过程中所起的作用,进而为今后西洞庭湖湿地恢复工程提供指导。【方法】于2015年冬季通过收割法和生物量模型对杨树种植区域、退林还湿区域、天然洲滩这3个区域间的土壤含水率、物种丰富度和植物地上生物量差异及土壤含水率和物种丰富度与地上生物量相关性进行了初步探究。【结果】1)不同土地利用方式下洲滩土壤含水率与物种丰富度差异显著;天然洲滩土壤含水率最高,退林还湿区最低,杨树种植区和退林还湿区物种丰富度高于天然洲滩。2)不同土地利用方式下洲滩植被地上生物量差异显著;杨树林种植区的植物地上生物量高于天然洲滩,而退林还湿区与天然洲滩无差异;草本植物地上生物量呈现出天然洲滩区最高、杨树林种植区最低的规律。3)不同土地利用方式下土壤含水率与草本植物地上生物量呈正相关,物种丰富度与草本植物地上生物量呈负相关。【结论】利用和恢复工程对洲滩湿地土壤含水率和物种丰富度存在影响;土地利用方式对洲滩湿地生态系统功能存在影响;土壤含水率和物种丰富度对于修复退化湿地及生态系统功能具有重要意义。后续退林还湿工程开展可考虑人为增加土壤含水率以及移植苔草等优势物种等人工辅助措施,以促进退林还湿区域向天然洲滩湿地的演替。

Effects of land-use categories on wetland plant biomass in floodplain: Taking west Dongting lake national nature reserve as an example

【Objective】In order to understand the impact of land use patterns on the service function of wetland ecosystem at the natural shoal of west Dongting lake,and explore the role of soil moisture content and species richness in the wetland restoration process,so as to provide guidance for the wetland restoration project of west Dongting lake in the future.【Method】In the winter of 2015,through harvesting method and biomass model,we conducted preliminary researchon soil moisture content,species richness,aboveground biomass difference,and their relevance,among three regions:poplar planting area,reclaimed wet area from forest,and the natural shoal.【Result】The results showed that:1)there were significant differences in soil moisture content and species richness under different land use patterns in floodplain;The natural shoal showed the highest moisture content,and that of the reclaimed wetland was the lowest.As for species richness,the poplar planting area and the reclaimed wetland were higher than that of the natural shoal;2)there were significant difference in aboveground biomass of plants under different land use patterns in floodplain;The aboveground biomass of plants in poplar plantation area is higher than that at the natural shoal,while there is no difference between the reclaimed wet area and the natural shoal;The aboveground biomass of herbaceous plants was highest at the natural shoal area and the lowest in the poplar plantation area;3)soil moisture content was positively correlated with aboveground biomass of herbaceous plants,and species richness was negatively correlated with aboveground biomass of herbaceous plants under different land use patterns.【Conclusion】The results showed that the utilization and restoration project had an effect on the soil moisture content and species richness of floodplain.The land use pattern has an effect on the ecosystem function of floodplain.Soil water content and species richness are of great significance for the restoration of degraded wetlands and ecosystem functions.In order to continuously promote the reclamation of wet area and change it into natural shoal wetland,artificial assistant measures can be considered in the following projects,including manually increase soil moisture content or transplant dominant species such as Carex chinensis.