增温和增/减水及氮沉降对中国草地植物多样性影响的研究进展

Effects of climate change and N deposition on plant diversity in grassland in China

摘要:

植物是生态系统的第一营养级，植物多样性在生物多样性中占主要地位。回顾了国内外学者近年来关于我国草地生态系统的研究，综述了气候变化和氮沉降增加对草地植物多样性的影响。温度增加没有显著改变高寒草甸和温性草地的物种丰富度，但降低了高寒草原和荒漠草原的物种丰富度，但是增温的影响与增温方式、增温年限有关。增水增加了物种丰富度，减水则相反。氮添加显著降低草地植物物种丰富度。增温和水分耦合以及氮添加和水分耦合对物种多样性的作用是可加的，总效应可能取决于相对效应大小：降水增加减缓了温度增加对物种丰富度的降低效应，降水增加和氮添加耦合作用降低了物种丰富度。未来需要加强长期监测温度增加对草地植物多样性的影响、更加关注物种组成的动态变化、加强降水格局变化的模拟试验和多因子耦合试验对草地植物多样性的影响的研究。

Abstract:

Plants make up the first trophic level in ecosystems. Plant diversity plays a leading role in biodiversity and reflects bio - community characteristics. Changes in plant diversity not only influence diversity conservation but also induces changes in ecosystem functions. Here，the paper reviews the effects of climate change and nitrogen depo- sition on plant diversity in grassland in China. Warming did not significantly change species richness in alpine mead- ows and temperate grasslands but reduced species richness in alpine steppe and desert grasslands. However，the influ- ences of warming on plant diversity varied with heating methods and experiment duration. Increased water precipita- tion yielded an increase in species richness，but decreasing in precipitation reduced species richness. Nitrogen addition significantly reduced grassland species richness. The interactions between warming and precipitation were additive and their coupling effects were determined by their relative effect. Increased precipitation would alleviate the decrease in plant species richness through warming. Interactive effects of multi-factors，such as interaction of warming，precipi- tation pattern and nitrogen deposition，on plant composition and diversity need to be addressed further in the future.