湿地高等植物初级生产力对全球变化响应的研究进展

在全球环境变化的背景下,影响湿地高等植物初级生产力的生态因子也在发生着不同程度的变化,大气中CO2浓度升高、气温升高和降水格局变化等已经严重地影响了高等植物的生理生态过程,改变了湿地高等植物的初级生产力。CO2在大气中不断增加,并通过植物光合作用及其他生理代谢作用,在一定程度上影响了湿地高等植物的生长状况和物质积累;气候变暖改变了一些地区的降水格局,从而影响了这些地区湿地的水文情势,使湿地水位波动的频率和幅度不断增加,直接影响了湿地高等植物的初级生产力;温度升高严重影响了湿地土壤中氮的矿化速率以及矿质氮的转化过程,直接影响土壤的供氮能力,进而影响湿地高等植物的初级生产力。回顾了湿地高等植物初级生产力对全球变化响应的研究进程,指出近期湿地高等植物初级生产力对全球变化响应研究的重点方向和领域。

Response of Primary Productivity of Higher plants in Wetlands to Global Change: A Research Review

With the global change process accelerated,the environmental factors that affect on primary productivity of higher plants in wetlands have been changed to various degrees.The increase of CO2 concentration and air temperature,and the changes of precipitation pattern have already affected the higher plants ecophysiological processes in wetlands.As a result,the primary productivity of higher plants has changed.A review on the research development of response of primary productivity of higher plants in wetlands to global change was made.The increase of CO2 concentration has enhanc ed the net photosynthetic rate of higher plants in wetlands,and thus,net biomass increase.However,there is a significant difference in the increment of the biomass and their distribution among higher plant species in wetlands.Global warming has affected hydrological situation of wetlands by changing precipitation patterns,increased the frequency and extent of the water-table level fluctuation in wetlands.The direct impact on the wetlands is the alteration of primary productivity of higher plants.However,the biomass and their allocation respond to water table level fluctuations variously among higher plant species in wetland.The increase of air temperature has impacted gravely on nitrogen mineralization rate,mineral nitrogen conversion process and the nitrogen availability in the soil;as a result,the primary productivity of higher plants in wetlands is influenced.Currently,the research on the response of the primary productivity of higher plants in wetlands to global change has focused primarily on the response of the primary productivity of higher plants to key factors of global change.For example,the mechanism of primary productivity responds to CO2 concentration,temperature and hydrological condition changes.Whereas,the relationship between the primary productivity of higher plants and global change is not totally clear.The simulation study on the primary productivity of higher plants in wetlands relative to global change,the response of the primary productivity of higher plants to global change in different scales and the effect of multi-factor interaction on the primary productivity of higher plants should be paid more attention to in the future research.