The Ecology of Nitrogen Fixation

温带生态系统中植物的生长受到氮素有效性的限制。的确，现代农业的成功主要归功于氮肥的发明。然而，使用氮肥需要密集的能源投入，并可能导致环境富营养化。氮也可以通过固氮微生物提供给生态系统。植物与固氮菌的共生作用使植物摆脱了土壤氮素有效性的限制。新的固氮共生体的开发可以使我们摆脱对氮肥的依赖。然而，这一植物育种者长期追求的目标尚未实现。了解现有固氮菌的生态，不仅可以帮助我们了解它们在自然系统中的作用，还可以指导我们开发新的固氮系统和应用。

Plant growth in temperate ecosystems is limited by nitrogen availability. Indeed, the success of modern agriculture is due primarily to the invention of nitrogen fertilizers. However, the use of nitrogen fertilizer requires intensive energy inputs and can result in eutrophication of the environment. Nitrogen can also be supplied to ecosystems by nitrogen fixing microbes. The symbiotic interaction between plants and nitrogen fixing bacteria frees plants from the limitations of soil nitrogen availability. The development of new nitrogen fixing symbioses could free us from our reliance on nitrogen fertilizer. However, this long sought goal of plant breeders has yet to be realized. Understanding the ecology of existing nitrogen fixing organisms may help us not only to understand their roles in natural systems, but also guide us in developing new nitrogen fixing systems and applications for them.