Temporal And Spatial Correlation Between Forest Loss And Forest Fire In The Humid Ecological Region Of Southern China

Forest fire is one of the important causes of forest loss.The influence of forest fire on forest includes the change and loss of forest ecosystem structure and function,and the change and loss of forest ecosystem will have far-reaching influence on climate,environment,economy and so on.However,with the extension of growing season,forest fire frequency and burning area have increased greatly,which will pose great challenges to human beings and the environment.Exploring the temporal and spatial correlation characteristics between forest loss and forest fire is helpful to understand the restoration of vegetation after burning and to provide scientific reference for the formulation of forest fire management and vegetation restoration management strategy after burning in China.The results show that:（1）Between 2003 and 2015,A total of 69314.8 km²,of forest resources were lost in the humid ecological areas of southern China An average annual loss of 5331.9 km²of forests.During the study period（2003-2015）,Forest loss showed a significant increase（R²=0.72;p<0.01）.For four ecological regions,Forest losses also showed a fluctuating upward trend.Among them,The fastest rise is in the Yungui Plateau,The slowest rise is in Sichuan and Chongqing ecological areas.Forest loss trends in each ecological region,The forest loss in the middle and lower reaches of the Yangtze River,the ecological region of the Yungui Plateau and the ecological region of South China increased significantly,Consistent with the entire ecological region（p<0.01）,However,the ecological area of Sichuan and Chongqing showed no significant increase（p=0.07）.（2）Between 2003 and 2015,the forest burning area in the humid ecological region of southern China was 8104.9 km²,with an average annual forest burning area of 623.5km^2.;and The forest burning area showed a downward trend and fluctuated greatly during the whole study period,but the total burning area changed not significantly every year（R²=0.18,p=0.15）.In the period of 2003-2015,the forest burning area is the smallest in Sichuan and Chongqing ecological area,while the forest burning area in South China ecological area is the largest.Judging from the trend of burning area,the burning area of each ecological area is different every year and fluctuates greatly.The forest burning area of the middle and lower reaches of the Yangtze River,Yungui Plateau and South China ecological area shows a downward trend,which is consistent with the ecological area（p>0.05）,while the Sichuan-Chongqing ecological area distinguishes the ecological area from the other three ecological areas,showing an upward trend（p>0.05）.（3）During the study period 2003-2015,The correlation between forest loss and forest burning area of all 3582 grid cells in the whole ecological region is analyzed,found a positive correlation between forest loss and forest fire in 26.2%of grid cells（r≥0.003）.Among them,1.9%grid showed significant positive correlation（r≥0.55,p<0.05）.Forest loss in only 15 grid cells showed a significant negative correlation（r≤-0.55,p<0.05）.Because in the humid ecological region of southern China,Hot and humid,The forests are mainly subtropical evergreen broad-leaved,And relatively densely populated,The road traffic network is developed.Although the frequency of fire is high,But forest fires are small,Low intensity,And it’s easy to find out,Even the death rate of trees is low.The correlation between forest loss and forest burning area is low.（4）The results show that when the vegetation type is coniferous forest,the correlation between forest loss and fire is the highest,and the difference is significant with broad-leaved forest and mixed forest.In the study area,the combustible load of coniferous forest area is higher,which makes the forest and canopy more flammable,while the mountain slope is larger,the terrain is more complex,and many mountain vegetation types are mainly coniferous forest.These factors contribute to the spread of fire.The results are expected to provide scientific reference for forest fire management and vegetation restoration management strategy in humid ecological areas in southern China.