Responses of Gross Primary Production to Changes of Temperature and Precipitation in Different Forests Dominated by Different Mycorrhizal Strategies
Symbiotic associations between plant roots and mycorrhizal fungi are almost ubiquitous in forest ecosystems.Mycorrhizal fungi play a crucial role in the regulation of terrestrial gross primary production (GPP),coupled with climatic changes in temperature and precipitation altering the carbon cycle.This study aimed to explore how temperature and precipitation influence GPP in global forest ecosystems that are classified by the mycorrhizal association of the dominant plants.New databases were created to investigate GPP and mean annual temperature (MAT),mean annual precipitation (MAP) and leaf area index (LAI) of forests dominated by different mycorrhizal strategies based on an existing global forest database.The responses of forest GPP to changes of MAT,MAP,and LAI changed with the differences of mycorrhizal strategies.Of all forests dominated by five different mycorrhizal types including arbuscular mycorrhiza (AM),AM+ectomycorrhiza (ECM,ECM,ECM+ectendomycorrhiza (EEM) and ECM+EEM+ nonmycorrhiza (NM),GPP increased with the enhancement of MAT.The highest GPP was observed in AM dominated forest with the value of 1 994.05 g·m2·a-1.The GPP in AM dominated forest was most sensitive to temperature change with the explained rate of 88.27%.The responses of GPP were contrary to MAP change in different forests donated by five mycorrhizal strategies.The relationship between GPP and MAP in ECM+EEM dominated forest was contrary to others with negative relationship.As far as the effect of LAI was concerned,GPP enhanced with increase of LAI in all mycorrhizal dominated forest,though the pattern between them were varied in different mycorrhizal dominated forests.The relationship between LAI and GPP is bestly simulated in AM+EEM dominated forest with r2=0.423.This investigation highlights mycorrhizas important influence on GPP and responses of forest to global climatic changes.
mycorrhizal strategiesforestgross primary productontemperatureprecipitationleaf area index