气候遗留效应和河流缓冲作用对北方河岸森林植被生长的影响研究

Objective:The boreal riparian forest is one of the important areas in the ecosystem process and is sensitive to climate change.Temperature,precipitation,and snow cover have a significant impact on the vegetation growth of the boreal riparian forest.The effect of climate on vegetation productivity/growth can be long-lasting,and this extended impact is commonly referred to as"climate legacy"or"climate memory".However,little is known that the impact of concurrent and antecedent climate,particularly snow cover duration,on vegetation growth in a boreal riparian forest.Additionally,large uncertainty exists regarding whether distance to a river(as a proxy of groundwater availability)further modifies these climatic legacy effects on vegetation growth. Methods:To fill this knowledge gap,we quantified the responses of different vegetation types(shrub,deciduous coniferous and broadleaf forests)to concurrent and antecedent climate variables(temperature,precipitation,snow cover duration)in a boreal riparian forest,and further determined the magnitude and duration of climate legacies in relation to distance to a river,using MODIS derived NDVI time series with gridded climate data from 2001 to 2020.Results:Results showed that higher temperature and precipitation and longer snow cover duration increased vegetation growth.The climate memory varies among different vegetation types.Distance to a river modified the concurrent and antecedent temperature and snow cover duration legacy effects on vegetation growth. Conclusions:Our research highlights the importance of snow cover duration on vegetation growth and that closeness to a river can buffer adverse climate impacts by shortening the strength and duration of climate legacies in a boreal riparian forest.We suggest that future studies on investigating the response of boreal forests and similar ecosystems to climate change should consider the positive and long-lasting effect of snow cover.