| 摘要: |
| 湿地植物演替对土壤微生物量具有显著影响，但不同土壤理化环境下的植物演替对湿地土壤微生物量的影响有何差异还不清楚。以鄱阳湖土壤理化性质不同的四个碟形子湖（包括相对肥沃的东湖和白沙湖以及相对贫瘠的蚌湖和大湖池）为研究对象，运用空间代替时间的方法，在泥滩带、湿生植被带（苔草）和挺水植被带（南荻或芦苇）采集0-10 cm表层土壤，分析不同土壤理化性质条件下植物群落演替对土壤微生物量的影响。采用土壤微生物量碳（MBC）和微生物熵（qMB）指示土壤微生物量。蚌湖、大湖池、东湖和白沙湖洲滩湿地表层土壤MBC的平均值分别为1077.27、888.29、942.45和1162.46 mg/kg，土壤qMB的平均值分别为6.07%、6.17%、3.60%和3.79%。在泥滩-苔草-南荻植物演替洲滩，土壤MBC先增加后减少；但是在泥滩-苔草-芦苇植物演替洲滩，土壤MBC持续增加。植物演替没有显著改变土壤qMB。尽管植物的生长会增加所有洲滩湿地的土壤MBC，但增加的幅度在相对贫瘠的蚌湖和大湖池明显强于相对肥沃的东湖和白沙湖。蚌湖和大湖池的土壤qMB也显著高于东湖和白沙湖。在植被演替梯度上，洲滩湿地土壤MBC和qMB普遍受到土壤碳氮磷含量和pH的影响，但是不同洲滩湿地影响微生物量的关键元素并不相同。这些结果证明植物演替对湿地土壤微生物量的影响不仅与植物物种有关，还受土壤理化环境的影响。本研究将为认识湿地土壤微生物量的变化机制和科学管理长江中下游湖泊湿地提供依据。 |
| 关键词: 植物演替 土壤微生物 微生物量碳 微生物熵 鄱阳湖 |
| DOI： |
| 分类号: |
| 基金项目: |
|
| The effects of vegetation succession on soil microbial biomass at the lakeshore wetlands of Poyang Lake, China |
|
Wen Xiuting,Zheng Bofu,Chen Chenchen,Gong Leiqiang,Zhan Huiying,Zhu Zhirui,Shen Ruichang
|
|
Nanchang University
|
| Abstract: |
| Vegetation succession could significantly affect soil microbial biomass, yet how soil physicochemical variables impact the relationships between vegetation succession and soil microbial biomass have not been settled. The current study investigated the effects of vegetation succession on soil microbial biomass at various soil environments based on the “space-for-time” assumption at the lakeshore wetlands of Poyang Lake, China. We collected soil samples at 0-10 cm depth increment at mudflat belts, hygrophilous vegetation belts, and emergent vegetation belts on four typical lakeshore wetlands (including Banghu and Dahuchi which had barren soils and Donghu and Baishahu which had fertile soils). Soil microbial biomass carbon (MBC) and microbial quotients (qMB) were used to indicate soil microbial biomass. Lakeshore wetlands at Banghu, Dahuchi, Donghu and Baishahu had average soil MBC of 1077.27, 888.29, 942.45 and 1162.46 mg/kg, respectively, and mean soil qMB of 6.07%, 6.17%, 3.60% and 3.79%, respectively. Along the mudflat - C. cinerascens – M. lutarioriparius succession, soil MBC firstly increased and then decreased. However, along the mudflat - C. cinerascens – P. australis succession, soil MBC continually increased. Vegetation succession did not significantly influence soil qMB. Although plant growth promoted soil MBC at all lakeshore wetlands, the increments at two relatively infertile lakeshore wetlands (Banghu and Dahuchi) were much higher than those at two relatively fertile lakeshore wetlands (Donghu and Baishahu). Soil qMB at Banghu and Dahuchi were significantly higher than those at Donghu and Baishahu. Soil MBC and qMB were determined by soil pH and soil carbon, nitrogen or phosphorus contents, but the key elements were varied among the four lakeshore wetlands. The results proved that the effects of vegetation succession on wetland soil microbial biomass not only depended on plant species, but also had close relationships with soil physicochemical variables. Our study was helpful for understanding the change mechanism of soil microbial biomass in wetland ecosystem, and could be used to improve the management in the floodplain lakes in the middle and lower reaches of the Yangtze River. |
| Key words: Vegetation succession Soil microorganism Microbial biomass carbon Microbial quotients Poyang Lake |
