【作者】 王立新；

【导师】 杨劼；

【作者基本信息】 内蒙古大学 ， 生态学， 2012， 博士

【摘要】 河流河滨带是陆地与河流水体系统之间的界面或生态群落交错区,是河流景观的重要组成部分。河流河滨带具有重要的生态系统功能和价值,而河滨带中湿地植物及其群落在维系这些功能和价值方面扮演着重要的角色,且湿地植物群落的空间分布格局影响着湿地生态系统的功能表达。通过河流河滨带研究可将当前生态学研究中的热点领域——河流景观生态学与湿地生态学有机结合起来。本论文选择内蒙古草原区典型内陆河——乌拉盖河和锡林河河滨带为主要研究对象,确定了野外实验区和实验样地,通过植物群落调查、土壤及河流上覆水理化性质测定、河滨带微地形分析以及河滨带植被制图,研究了不同尺度下河流河滨带湿地植被空间分布格局及其生态系统功能与过程,进而结合河滨带生境空间异质性、湿地植物物种适应及种间竞争,阐释了不同尺度下河滨带植被空间分布格局形成及维持机理。此外,基于围封保育与放牧退化河滨带的对比研究,分析了人为干扰对河流河滨带湿地的影响。最后,通过河流河滨带湿地生态系统功能与过程模型的构建将河滨带植被空间分布格局与其生态系统功能和过程整合在一起。通过上述研究,本论文取得如下主要结论：1.在河流流域大尺度下,河流河滨带湿地植被沿河长方向呈现乔木沼泽→→灌木沼泽→→草本湿草甸→→草本沼泽→→草本盐化草甸的“溯源成带性”分布格局。流域海拔、温度(年均温和日照时数)和水分(年降水量)共同决定了该分布格局的形成与维持。2.在河流河段中小尺度下,河流河滨带湿地植物群落沿河宽方向呈现水生植物群落→→岸边先锋植物群聚→→以湿中生植物为主的湿草甸植物群落→→以耐轻度盐碱化植物为主的盐化草甸群落的“岸带成带性”分布格局。河滨带微地形起伏、土壤理化特征的空间异质性、湿地植物物种适应与种间竞争共同决定了该分布格局的形成与维持。3.放牧影响了河流河滨带湿地植物群落的岸带成带性,主要表现为植物群落优势种发生变化,旱生植物成分增加,地上、地下生物量明显降低,土壤紧实度增加,土壤有机碳、全氮和全磷等养分含量降低。4.利用系统动力学软件(STELLA)构建了河流河滨带生态系统功能与过程模型,通过模型模拟研究,河滨带低河漫滩植物群落的地上与地下生物量显著高于高河漫滩植物群落及河漫滩塔头植物群落；河滨带微地形差异是导致土壤有机碳积累的重要影响因素,河滨带低河漫滩群落对湿地有机碳的贡献最大；通过模型预测分析,河滨带植物群落地上生物量、土壤呼吸作用和有机质分解作用存在差异,但其光合能力基本保持恒定。本文基于湿地生态学和河流景观生态学原理,从河滨带生境异质性出发,将不同尺度下湿地植被空间分布格局与生态系统功能及过程联系在一起,从而拓宽和丰富了河流景观生态学的研究领域和研究内容。论文成果可为我国北方草原区湿地合理开发利用、保护与管理湿地自然资源提供理论依据,为受损湿地生态系统的恢复、重建与健康(或生态完整性)评价提供理论参考。对此问题的研究亦涵盖了物种多样性和物种组成等内容,对湿地生物多样性保护与管理具有一定的指导意义。更多还原

【Abstract】 Riparian zone is the interface or ecological ecotone between river system and adjacent terrace terrestrial ecosystems, which is an important part of the riverscape. Riparian zone possesses an important functions and values of ecosystem. While wetland plants and their communities on riparian zone play essential roles in maintaining these functions and values, and also the spatial distribution pattern of wetland plant communities affects the expression of ecosystem functions. The focus on riparian zone will associate Riverscape Ecology which is one of hot area of current ecological research with Wetland Ecology.Selected the riparian zones of the typical inland rivers-Wulagai River and the Xilin River in the grasslands of Inner Mongolia as the main object of study, this paper determined the field experimental area and the experimental plots firstly, and then by the survey of wetland plant biodiversity and plant communities, the measure of the physical and chemical characterizations of soil and river water column, the analysis of micro-topography of riparian zones, and the mapping of riparian vegetations, the formation and maintenance mechanism for the spatial distribution pattern of riparian vegetations at different scales was illustrated, with combining the spatial habitat heterogeneity with biological adaptation and inter-specific competition of wetland species in riparian zones. In addition, based on a comparative study between the enclosed conservation plots and grazing degradation plots, this paper analyzed the degradation characterization of wetland on riparian zone by the human disturbances. Finally, based on modeling the ecosystem function and process of riparian vegetation on riparian zone, the spatial distribution pattern of vegetation was combined with its ecosystem functions and processes. The main conclusions are as followed:1. On the watershed scale, the wetland vegetation on riparian zone along the longitudinal direction presents wooded swamp, shrub swamp, wet meadow, herbaceous swamp and herbaceous saline meadow, from the river source to the end of river, which is forming the spatial distribution pattern named riparian sourceward banded zonation. The Elevation, Temperature (annual mean temperature, insolation duration) and moisture (annual precipitation) are the main environmental factors affecting the formation and maintenance of this pattern. 2. On the river reaches scale, along the wetland vegetation on riparian zone along the lateral direction presents aquatic plant communities, shoreline pioneer plant clusters, wet meadow communities and saline meadow communities, from river water column to terrace, which is forming the spatial distribution pattern named riparian shoreward banded zonation. The Microtopography, spatial heterogeneity of physical and chemical characteristics of soil, the biological adaptation and inter-specific competition of wetland plants determine this pattern together.3. Grazing affects the riparian shoreward banded zonation of wetland plant communities, which is expressed on the change of dominant species in the wetland communities, the gradually transition of the hygrophyte to the xerophytic, significantly reduction of the aboveground and belowground biomass, the reduction of content of soil organic carbon, total nitrogen and total phosphorus, and the increase of soil compaction.4. Based on system dynamics software (STELLA), the model of ecosystem function and process on riparian zone was built. The model simulation showed that the aboveground and below-ground biomass of plant communities on lower riparian zone was significantly higher than that of the higher floodplain and "Tatou" wetland on riparian zone. The micro-topography of riparian zone is the important factor affecting the accumulation of soil organic carbon. The wetland plant communities on lower riparian zone have the greatest contribution to organic carbon. There are differences of the aboveground biomass, soil respiration, and the decomposition of organic matter of plant community on riparian zone, while the photosynthetic capacity remains constant through the forecast of this model.Based on the principles of wetland ecology and riverscape ecology, from the habitat heterogeneity of riparian zone, the spatial distribution patterns of wetland vegetation at different scales was associated with ecosystem functions and processes in order to broaden and enrich the research content and field of riverscape ecology. The results of this thesis can provide a theoretical basis for the rational development, protection and management of wetland in the grassland region of Northern China. This thesis also provides the theoretical reference for rehabilitation, reconstruction and wetland ecosystem health (or ecological integrity) assessment of the degraded wetland ecosystems. This issue also covers the study of species diversity and species composition in the wetland communities, so it also plays an important role in the guidance on wetland biodiversity conservation and management.更多还原