本文選題：生態(tài)化學計量學　切入點：土壤養(yǎng)分含量　出處：《內(nèi)蒙古大學》2017年碩士論文

【摘要】：生態(tài)化學計量學通過分析植物與土壤的C、N、P等元素及其比值特征,揭示生態(tài)系統(tǒng)過程及其對環(huán)境的響應。本文以內(nèi)蒙古錫林河流域羊草草原為研究對象,通過野外調(diào)查與測試分析,利用生態(tài)化學計量學理論與方法,在群落、功能群和物種三個水平上探討不同退化階段羊草草原植物生態(tài)化學計量學特征,分析其對土壤養(yǎng)分環(huán)境的響應,闡明植物—土壤養(yǎng)分關系,明晰植物生長的限制因子。主要結論如下:1.利用所觀測的69個樣地資料,將羊草草原劃分為4個不同的退化階段:Ⅰ羊草+雜類草群落(22個樣地)、Ⅱ羊草+針茅群落(18個樣地)、Ⅲ羊草+糙隱子草群落(21個樣地)和Ⅳ羊草+冷蒿群落(8個樣地)。2.研究區(qū)域羊草草原土壤養(yǎng)分含量匱乏,土壤肥力處于較低水平。退化導致土壤養(yǎng)分含量逐漸減少,全氮、全磷與速效氮顯著降低。3.在群落、功能群以及物種水平,植物氮、磷含量與土壤速效氮、速效磷均多呈極顯著正相關,植物C:N比值、C:P比值分別與土壤速效氮、速效磷呈極顯著負相關。退化造成的土壤養(yǎng)分含量減少,導致植物養(yǎng)分含量與生態(tài)化學計量特征發(fā)生了改變。4.在群落、功能群和物種水平,除一、二年生草本植物外,其他植物的C:N比值隨著草地退化加劇而減小,植物可能是通過提高生長速率的途徑應對變化的環(huán)境。5.群落、功能群和物種水平,除一、二年生草本植物的N:P比值隨著退化程度的加劇而降低外,其他植物的N:P比值均有所升高,表明植物的生長可能由受到N元素限制轉為受到P元素的限制。本項研究進一步明確了草地退化過程中植物生態(tài)化學計量動態(tài)特征,及其與土壤養(yǎng)分環(huán)境的關系,豐富了人們對草地生態(tài)系統(tǒng)生態(tài)化學計量學的認知,對于促進退化草地生態(tài)系統(tǒng)的恢復與保護具有參考價值。
[Abstract]:Eco-chemometrics reveals the ecosystem processes and their responses to the environment by analyzing plant and soil elements such as C ~ (+) N ~ (+) P and their ratios.This paper takes Leymus chinensis grassland in Xilin River Basin of Inner Mongolia as the research object, through field investigation and test analysis, using ecochemometrics theory and method, in community,The ecochemometrics characteristics of Leymus chinensis grassland in different degradation stages were discussed at the three levels of functional group and species. The responses to soil nutrient environment were analyzed. The relationship between plant and soil nutrients was clarified and the limiting factors of plant growth were clarified.The main conclusions are as follows: 1.Using the 69 sample plots observed,The steppe of Leymus chinensis was divided into four different stages: 鈪，

本文編號：1717112