【作者】 曾朝旭；

【导师】 李洪建；

【作者基本信息】 山西大学 ， 生态学， 2011， 硕士

【摘要】 近年来,农田生态系统碳库作为陆地生态系统碳库重要的组成部分而越来越受到人们的关注。农田生态系统的碳循环受人类活动的直接影响,碳源与汇的交替性出现是农田生态系统碳循环的明显特征。作物通过光合作用固定能量和积累有机物,伴随着碳和水两个主要无机物的循环。水分利用效率是一个重要的农艺学指标,是对生态系统碳和水两个循环间的关系进行联接的纽带。通常对生态系统尺度上的碳水通量观测的方法有涡度相关法和箱式法,本研究用透明箱式法对太原盆地冬小麦生态系统从起身期至成熟期6个生育期内的碳通量和水通量及其环境因子进行了观测,旨在对二者之间的关系进行一个初步探讨。主要观测和研究结果如下：1)碳通量的变化有明显的日变化、季节变化。光合有效辐射(PAR)和温度(T)是生态系统CO2净交换(NEE)的主要影响因子,NEE与二者间存在显著的二元线性关系,并且与冠层温度(Tc)的关系最显著,R2达到了0.739。2)观测期内冬小麦农田生态系统的碳源汇强弱关系是：起身期>拔节期>抽穗期>孕穗期>成熟期>灌浆期3)光合有效辐射(PAR)和温度(T)也与蒸散(ET)存在显示著的线性关系。ET与碳通量间有明显的线性关系。由此可以看出,小麦农田生态系统碳水通量间由PAR和T联系的。4)对水分利用效率(WUE)进行了NEE和GEP两个水平上的计算,分别可以作为小麦自身需水和生态系统需水的参考。更多还原

【Abstract】 Field ecosystem carbon pool as the major component of the terrestrial carbon pool was paid more and more attention over the recent years. Field ecosystem carbon cycle was disturbed directly by mankind’s activities. A distinct characteristic of field ecosystem carbon cycle was carbon sink and source alternating occured. Through photosynthesis crops could fixate the energy and accumulate the organisms with two cycles of carbon and water. Water use efficiency is an important agronomical norm and linking to both carbon and water cycles. Eddy covariance method and chamber method are two mainstream methods to observate the carbon and water fluxes. In order to find the initial relationships between carbon and water fluxes, we used chamber method to measure fluxes at six different growing stages from erecting to ripening in a winter wheat crop ecosystem in Taiyuan basin and the related environmental factors also were observed at the same time. We found that1) There are apparently daily variation and seasonal variation to carbon fluxes. Both photosynthesis active radiation (PAR) and temperature (T) are the major factors to net ecosystem exchange (NEE) and there is a significant linear relation between NEE and PAR and T. The most significant relation is between NEE and PAR and canopy temperature (Tc) with a R2 of 0.739.2) During the observation stages, we found the carbon source and sink relations’rank is that:erecting> jointing> heading> booting ripening> grain filling.3) There is also a significant linear relations between photosynthesis active radiation (PAR) and temperature (T) and evaportranspiration (ET). Between ET and carbon fluxes have an apparent linear relation. As a result, PAR and T linking to both of the carbon and water fluxes.4) The water use efficiency (WUE) was calculated by two levels of NEE and GEP and they would be the references for water demand in a winter wheat field.更多还原