氮沉降、增温和降水变化对草地碳固存的影响研究进展

Research progress on effects of nitrogen deposition,warming and precipitation pattern changes on grassland carbon sequestration

草地作为一种自然资源,是陆地生态系统重要组成部分,对人类生产、生活和生态环境改善具有重要意义。近年来,人们不断重视外界环境因素对草地碳固存的影响过程和机制,形成许多关于气候、环境因素对草地碳固存影响的研究成果。氮沉降、增温和降水变化通过草地净初级生产力影响草地碳吸收,通过生态系统呼吸影响草地碳释放。氮沉降显著改变植物物种组成,提高草地生产力,增加草地碳固持能力。适宜的增温有利于促进草地总碳积累,过度增温则会与其他非生物因子(如降水)相互作用导致干旱胁迫,抑制植物生长,减少碳固存。与温度相比,降水变化对植物碳固存影响更为显著。在一定范围内,降水量增加有助于提高植物固碳能力,降水量减少则减少草地碳固存。

As a natural resource,grassland is an important part of terrestrial ecosystem,and is of great significance to human production,life and ecological environment improvement.In recent years,people have paid attention to the influence process and mechanism of external environmental factors on grassland carbon sequestration,and many research results have been formed on the impact of climate and environmental factors on grassland carbon sequestration.Nitrogen deposition,warming,and precipitation pattern changes affect grassland carbon uptake by affecting grassland net primary productivity,and affect grassland carbon release by affecting ecosystem respiration.Nitrogen deposition significantly changes plant species composition,improves grassland productivity,and increases grassland carbon sequestration.Appropriate warming is conducive to promoting the accumulation of the total carbon in grassland,while excessive warming will interact with other abiotic factors(such as precipitation)to cause drought stress,inhibit plant growth and reduce carbon sequestration.Precipitation pattern changes are more significant to the effects of plant carbon sequestration thantemperature. In a certain range, the increase in precipitation helps to improve the carbon sequestrationcapacity of plants, while the decrease in precipitation will reduce the sequestration of plant carbon.