[Effects of fire intensity on leaf functional traits and functional diversity of Larix gmelinii community].

Fire is an important ecological factor in boreal coniferous forest, which directly affects plant taxonomic and functional diversity and consequently forest succession. We analyzed the changes of soil nutrient contents, leaf functional traits, taxonomic and functional diversity of a Larix gmelinii community under different fire intensity levels (low, medium, heavy). The forest stand had been naturally recovered for 12 years in Yakeshi area. The results showed that fire significantly reduced soil total nitrogen content, but did not affect soil total phosphorus content. Low and medium fire intensities could maintain higher species diversity and functional diversity of the community. Medium fire disturbance significantly increased species diversity of the community, with maximum species richness index, Shannon index, Simpson index and Pielou evenness index. Fire disturbance reduced functional richness and functional divergence of the community, which were the largest in medium and low fire intensity respectively (except unburned). Functional evenness and Rao qua-dratic entropy index increased after forest fire disturbance, and the largest was in the low intensity burned area. With the increases of fire intensity, leaf dry matter content, leaf tissue density and leaf total phosphorus content showed a significantly increased trend, while specific leaf area, leaf water content, leaf total nitrogen content and leaf N:P showed the trend unburned ＞ medium fire ＞ low fire ＞ heavy fire, leaf thickness increased first and then decreased. Fire intensity had significant effects on leaf functional traits and functional diversity of forest community. Moderate fire distur-bance could promote forest restoration.