Effects Of Forest Fire Disturbance On Functional Diversity Of Birds In Typical Forest Ecosystem

Moderate/high-severity fire is highly likely to induce changes in forest structure and functioning and even a forest succession,which further exert an enormous threat to bird composition and diversity.Daxing’anling is a fire-prone region,however,little is known about how forest fires influence bird diversity,particularly its functional diversity.At the same time,it’s not enough that the research on the response pattern of bird functional traits and functional diversity to forest fire disturbance in global forest ecosystem.Based on this,this study discussed the effects of forest fire on the functional traits and diversity of birds from three spatial scales:Heilongjiang Nanwenghe National Nature Reserve,boreal forest region of Daxing’an region and global forest ecosystem.Firstly,we used point counts and sample lines approach to survey composition and distribution of forest birds and quantified changes in bird functional traits and diversity post several fire events at both forest interiors and edges in the Heilongjiang Nanwenghe National Nature Reserve.Secondly,a systematic literature review was conducted to investigate the relationship between forest stand and bird functional diversity in the Daxing’anling region.Thirdly,systematically reveal the effects of several forest fire events on the functional traits and diversity of birds on a global scale through meta-analysis.The main results are as follows:(1)Difference in bird community composition was small in the forest interiors(Jaccard index>0.5),under different fire histories,and the functional richness and evenness of birds increased with the increase of recovery time post-fire.At the forest edges,the composition of birds was greatly under different recovery time post-fire(Jaccard index<0.5),and bird functional richness was greatest at the forest edges in the early stage post-fire disturbance.with the increased time post-fire,the proportion of resident birds increased,but the proportion of summer migratory birds decreased at the forest edges.(2)In the boreal forest of Daxing’an region,bird species richness was greatly higher in larch dominant forests than that in Pinus sylvestris var.mongolica forests,but the functional richness is the opposite(P<0.05).Bird functional richness was significantly higher in the coniferous and broad-leaved mixed forest than that in larch dominant forests in the Daxing’anling.(3)In the global forest ecosystem,forest fire increases the number of birds foraging on the ground and nesting in bushes,which has an adverse effect on birds foraging in the forest canopy and understory.High-severity forest fire has a significant effects on functional richness and functional divergence,and the recovery time post-fire has a positive correlation with functional richness and functional evenness(P<0.05).The bird functional evenness of coniferous and broad-leaved mixed forest is the highest,and coniferous forest has higher functional evenness and functional divergence than broad-leaved forest under the same conditions(P<0.05).Through the above research,we found that the disturbance of forest fire had a significant effects on some functional traits and diversity indexes of birds,in which the intensity of forest fire and the recovery time after fire determined the functional diversity of birds,and forest types also played a role in it.The purpose of this study is to grasp the response patterns of birds to different forest fire disturbance events,and to provide a reference basis for post-fire forest resources management and bird diversity conservation.