乐安河-鄱阳湖段典型环境胁迫下河岸带植物的生态适应性与响应机制定量研究

In the project, we will select the riparian zone of Lean River from its upstream to its entrance in Poyang Lake as the study area, which had the typical environmental stresses problems such as the prominent heavy metals pollution problems, the disordered sand mining activities and the frequent water level fluctuations. We will use the field investigation methods, the laboratory methods, the greenhouse ecological simulation control methods and other methods in the project, and will select the dominant plants and their communities of the riparian zone as the research objects. We will investigate some typical environmental stressed districts of the riparian zone in Lean River and Poyang Lake such as the upstream typical districts with the serious heavy metals pollution problems, the midstream districts with the disordered sand mining activities problems, and the downstream zone of the frequent water level fluctuations. The project will aim to study the ecological adaptability to the typical environmental stresses of the plant populations and their communities, and will also evaluate their biological diversity. We will use the dominant plants of the riparian zone along Lean River of the different environmental stressed districts as the cultivation experimental materials of the greenhouse ecological simulation control experiment, in order to explore the response strategy and adaptation mechanisms by using the growth indexes, the morphological indexes , the chlorophyll fluorescence and other photosynthetic physiological indexes and various enzyme activity indexes, and other various aspects of the different dominant plants individuals which will be cultivated under the different environmental stresses such as the water stress conditions, heavy metals pollution stress conditions, the grazing defoliation interference stress and other three kinds of environmental stress conditions. We also want to select some more better tolerant species under the different environmental stresses (such as some submergence tolerance and water resistant species, heavy metals pollution resistant species, grazing resistant species). We will also combine the field investigation results of the plant communities ecological adaptability and populations adaptation mechanisms of Lean River and Poyang Lake in order to evaluate the response mechanisms of the dominant plants to environmental stresses in the riparian zone of Lean River and Poyang Lake scientifically and quantitatively.

项目选择重金属污染问题突出，无序采砂活动过度、水位波动频繁的乐安河-鄱阳湖段的河岸带作为研究区，采用野外调查、室内实验以及温室生态模拟控制等方法，以河岸带优势植物及其群落为研究对象，对乐安河上游重金属污染区、中游高密度采砂区、下游入鄱阳湖段水位频繁波动区等典型胁迫区进行调查，研究植物种群和群落对不同环境胁迫的生态适应性，评价其生物多样性。利用乐安河野外采集的优势植物作为栽培实验材料，通过温室控制生态模拟水淹胁迫、重金属污染胁迫、采食去叶干扰胁迫等不同环境胁迫条件，探究乐安河河岸带不同优势植物类群在典型环境胁迫下，其个体生长指标、形态指标、叶绿素荧光等光合生理指标及其各种酶活性指标等表现出的响应机制，筛选出不同环境胁迫条件下耐受能力更强(耐水淹、耐重金属污染、耐采食)的河岸带植物，结合乐安河野外植物种群与群落的生态适应性，科学定量地评价乐安河-鄱阳湖段河岸带植物及其群落对典型环境胁迫的响应。

项目以乐安河-鄱阳湖段河岸带为研究区，通过野外调查、室内监测以及室内模拟控制实验，在不同水期对乐安河典型胁迫区域进行了调查，以河岸带各季节优势植物为研究对象，评价其生物多样性，研究植物种群和群落对不同环境胁迫的生态适应性。利用野外采集的优势植物作为栽培实验材料，模拟水淹胁迫、重金属污染胁迫及采食去叶胁迫等实验，探讨了不同胁迫条件下各植物个体的生长指标、形态指标、生理指标等表现出的响应特征，筛选出了不同环境胁迫条件下耐受能力更强(耐水淹、耐重金属污染、耐采食)的河岸带植物，结合乐安河野外植物种群与群落的生态适应性，科学定量地评价了乐安河-鄱阳湖段河岸带植物及其群落对典型环境胁迫的响应。研究结果表明：.（1）乐安不同季节河河岸带优势植物呈季节性更替：春季平水期以苔草为优势种，伴以狗牙根、喜旱莲子草等；夏季丰水期以羊蹄、牛鞭草、狗牙根为优势种，伴以蓼子草和天胡荽等种群。秋季苔草、喜旱莲子草、丁香蓼、牛鞭草、狗牙根为优势种，伴以蓼子草和天胡荽等种群。冬季蓼子草成为优势种，伴有苔草、牛鞭草和狗牙根等。.（2）在不同季节分别采集到河岸带植物狗牙根、牛鞭草、喜旱莲子草、蓼子草、风花菜和羊蹄等优势种，分别采用室内盆栽进行水淹控制实验。结果表明不同强度水淹胁迫对河岸带不同植物的生长均有不同程度的抑制，植物表现出显著的抗逆响应，各项光合生理指标产生显著变化，各物种的不同酶活指标及其形态学指标均表现出显著变化，表现出显著的响应特征。.（3）以此同时，采用盆栽模拟不同强度重金属污染Cd、Pb等对河岸带不同季节优势植物羊蹄、丁香蓼的室内控制实验，通过不同周期观测对比不同重金属Cd、Pb胁迫下各优势植物的生理生化效应及其植株不同部位对重金属的吸收特性，结果也表明不同优势植物的各种生长、形态学及生理、生化等指标均表现出显著变化，均表现出显著的响应特征。.（4）另一方面，采用室内盆栽模拟不同强度采食胁迫对河岸带优势植物羊蹄、虉草等进行控制实验，通过不同周期观测对比不同采食强度对各植物的生长指标、形态学指标、光合色素、叶绿素荧光、光合参数、保护酶活性等生理指标,结果均表明不同优势植物的各种形态学指标及生理生化等指标均表现出显著变化。