伊犁河流域水文生态学研究-以水生植物为例

Hydroecology is defined as the linking of knowledge from hydrological, hydraulic, geomorphological and biological/ecological sciences to predict the response of freshwater biota and ecosystems to variation of abiotic factors over a range of spatial and temporal scales, focusing on the links between hydrological processes and ecological processes. The subject is paid more attention from the field of ecology and hydrology, but related researches were seldom reported. The project intends to carry out in Ili River Basin in Xinjiang Province, mainly through integrated field investigation, long-term location study and common garden experiments. Ili River Basin is one piece of "wet island" in Arid Zone in Xinjiang Province and one of the five major key areas of terrestrial biodiversity. However, aquatic plants are rarely concerned in this area. In this study, we selected aquatic plants as our target species and explored the interaction between hydrological elements and aquatic plants, which could be helpful to understand the mechanisms for species diversity, distribution and phenotypic plasticity, and also deepen our understanding of the impact on the hydrological elements of aquatic plants. We measured the functional traits of aquatic plants, including morphological, anatomical and physiological characteristics of leaf and root, and explored the relationships between the functional traits and hydrological elements. First, we collected specimens of all aquatic plants species in Ili River Basin. At the same time, we collected samples of aquatic plants, water and sediment in this area, to measure the functional traits of plants and nutrient content of water and sediment. Second, we investigated the hydrological elements of Ili River Basin, including depth, flow velocity, water quality, the runoff sediment concentration, flood period, etc. Finally, we analyzed the relationships between hydrological elements and the functional traits in different scales which were individual level, community level and flora level. We examined the key factors of hydrological elements affecting aquatic plants distribution and the phenotypic plasticity of aquatic plants. Such analysis could enhance our knowledge to understand the mechanisms of aquatic plants phenotypic plasticity, biodiversity and distribution patterns. Additionally, this study could provide basic data and reference information for conservation of aquatic plants, water resources sustainable management and ecological evaluation of hydraulic project construction in Ili River Basin, and also provide a case study of relationships between aquatic plant communities and river morphology or floodplain.

水文生态学作为研究水生生物和水文要素等非生物环境因素相关关系的学科，在生态学和水文学领域越来越受到重视，但在国内相关的研究却十分缺乏。本项目拟在新疆伊犁河流域开展，以水生植物为研究对象，主要通过系统的野外调查、定位研究和同质园实验，针对全球气候变化和人类活动等因素所带来的河流水文要素的变化，阐明水文要素对水生植物的影响，结合相应的水文数据和气候数据，探讨水生植物的表型可塑性和生态适应策略，揭示河流水文要素中影响水生植物分布的关键因子，解析水生植物对河流水文要素的反馈调节机制。本项目的实施有助于加强对河流水生植物表型可塑性、生物多样性和分布格局的理解，可以为伊犁河流域的水生植物保护、水资源的可持续管理和水利工程建设的生态环境评价提供基础资料和参考依据，并为水生植物群落与河流形态或洪泛区关系的研究提供案例。

水文生态学作为研究水生生物和水文要素等非生物环境因素相关关系的学科，在生态学和水文学领域越来越受到重视，但在国内相关的研究却十分缺乏。本项目在新疆伊犁河流域开展，以水生植物为研究对象，通过系统的野外调查、定位研究和同质园实验，针对全球气候变化和人类活动等因素所带来的河流水文要素的变化，阐明水文要素对水生植物的影响，结合相应的水文数据和气候数据，探讨水生植物的表型可塑性和生态适应策略。研究结果表明：（1）伊犁河流域水生植物26科46属85种，其中，挺水植物64种，浮叶植物2种，漂浮植物1种，沉水植物18种；（2）轮藻的碳氮含量最低，而δ13C比值最高；单子叶植物和双子叶植物的氮含量显著最高，藓类δ13C比值最低；（3）挺水植物和浮叶植物的C含量显著高于漂浮植物和沉水植物，浮叶植物的氮含量显著高于挺水植物、漂浮植物和沉水植物；（4）水生植物δ13C比值随着海拔和经度的升高而降低，随着纬度的升高而升高，而N含量随着经度的升高而升高，C/N比值随着经度的升高而降低；（5）水生植物C/N和δ13C比值随着年均温（AMT）和生长季均温（GST）的升高而升高，δ13C比值随着年降雨量（AMP）和生长季降雨量（GSP）的升高而降低， C/N随着生长季降雨量（GSP）的升高而降低；（6）静水水体中蓼叶眼子菜的叶长、叶宽、叶面积和比叶面积相对于流水水体更大。本项目的实施有助于加强对河流水生植物表型可塑性、生物多样性和分布格局的理解，可以为伊犁河流域的水生植物保护、水资源的可持续管理和水利工程建设的生态环境评价提供基础资料和参考依据。