气候变暖对陆地生态系统的影响

人类活动引起的温室效应导致全球气候变暖,气候变暖对全球生态环境的影响越来越受到人们的关注.作为人类赖以生存的环境主体,陆地生态系统对气候变暖将做出何种响应,更是人们关注的重点.植物物候的变化可以直观地反映某些气候变化,尤其是气候变暖.气候变暖影响植物的生长节律,进而引起植物与环境关系的改变及生态系统物质循环(如水和碳的循环)的改变.不同种类植物对气候变化的差异响应,会使植物间和动植物间的竞争与依赖关系发生深刻的变化,如北半球中高纬度地区植被生长季延长、植物提早开花、昆虫提早出现、鸟类提早产蛋以及冰川退缩、永冻土带融化、江河湖泊结冰推迟而融化提早等.本文主要从陆地生态系统的分布和演替两方面着眼,以植物和动物作为考察对象,系统论述了森林、草原、荒漠、湿地及农田等陆地生态系统在气候变暖背景下产生的变化,并从微观和宏观尺度上提出陆地生态系统变化的生态学机制,最后在技术和政策层面给出若干对策.

Effect of climate change and global warming on terrestrial ecosystems

Human-induced greenhouse effects can lead to climate change, global warming, and adverse impacts on the larger global ecological environment;a phenomenon that has aroused significant interests from scientific community. Terrestrial ecosystems, the main body of the environment on which human life rests for existence, response to global climate change is the principal focus of scientific research. Changes in plant phenology directly manifest changing climate, especially climate warming. Changes in plant growth rhythm may alter plant-environment relationship ,hence mass cycle of the ecosystem, such as water and carbon. Individual plant species respond to climatic changes differently ,which may cause great changes in competition and dependence among different species and plant-animal interactions. In the midto high-latitude areas of the northern hemisphere, flowering date of most plants tends to be earlier. Some insects also now break their cocoons much earlier. The timing of bird migration and breeding is sensitive to changes in temperature, and global warming would be expected to lead to earlier onsets of these activities in the spring. These changes in plant and animal phenology may lead to a decoupling of species interaction. It also trends towards earlier icebreak and snow-meh in the spring, consistent with enhanced warming observed at higher latitudes. All the phenological changes are very much link with increasing surface temperatures ; an obvious respond to globe warming. In this paper, the effect of climate warming on terrestrial ecosystems was systematically reviewed using plants and animals as breaking point, including changes in geographical distributions and succession of forest ecosystem, steppe ecosystem, desert ecosystem, wetland ecosystem, farmland ecosystem. It expatiates the mechanism of terrestrial ecosystem change from both microcosmic and macroscopic viewpoint. Lastly, some policy and technology measures are advanced.