Correlation Analysis On The Spatial Distribution Of Seedlings In A Pinus Tabuliformis-Quercus Wutaishanica Mixed Forestand Topographic Factors In Lingkong Mountain

As Pinus tabulaeformis forest 4 hm2 long-term monitoring samples for platform in Lingkong mountain of Shanxi,continuous sampling method was used to monitor each wood,all tree seedlings in samples were investigated in June 2014,June 2015 and October 2015,the species composition and quantitative dynamics of tree species were analyzed in detail,studying on two edificators of samples-the spatial distribution pattern of Pinus tabulaeformis and Quercus wutaishanica population seedlings and the relationship between the distribution of death individual and environmental factors,the results are as follows:In June 2014,a total of 16 species of tree seedlings were investigated,they belong to 10 families and 11 genera.The investigation of June 2015 and October 2015 than 2014 one more species-Populus davidiana;a total of 42364 seedlings were recorded in the three survey,the most individual tree species were Quercus wutaishanica,accounted for 49.57% of the total survey seedlings number,respectively accounted for 49.98%,49.46% and 49.33% of the total individual seedlings number in the same year,then Pinus tabulaeformis,respectively accounted for 17.42%,15.79% and 13.65% of the total individual seedlings number in the same year.Pinus tabulaeformis and Quercus wutaishanica were edificators of the samples.Pinus tabulaeformis,Quercus wutaishanica,Pyrus betulifolia,Acer ginnala,Crataegus kansuensis,Crataegus pinnatifida and Fraxinus chinensis were main tree species in the samples,the total number of seedlings of the seven tree species accounted for about 98.59% of the total number of seedlings.In June 2014 and October 2015,the spatial distribution patterns of Pinus tabulaeformis and Quercus wutaishanica seedlings respectively present was consistent,and two population spatial distribution pattern were similar.In <5 m scale present aggregation distribution,random distribution in other scales.Pinus tabulaeformis was concentrated distribution in the southeast corner and north-central area in the sample area,and Quercus wutaishanica was centrally located in northeast,west and central area of the sample area.Pinus tabulaeformis and Quercus wutaishanica seedlings death individual distribution were affected by the part of the terrain factors.Quercus wutaishanica seedlings death individual distribution was related to slope(P = 0.039)and the slope position(P = 0.014),but Quercus wutaishanica seedlings mortality was no significant difference under different slope,the mortality was significantly different at different slope positions(P < 0.01),and the highest mortality was found in the middle slope position of Quercus wutaishanica seedlings;Individual death distribute of Pinus tabulaeformis seedlings showed significant correlation(P=0.01)with slope distribution,and significant difference under different slope,in gentle slope mortality was the largest.The result has an important meaning for further studying on the correlation between Pinus tabulaeformis seedlings regeneration and topographic factors.In respect of the spatial distribution of individual seedling death in two populations,between the two previous investigation,dead seedling of Quercus wutaishanica population was more in the sample area midwest and sample area southwest and northeast corner,but among the second and the third surveys,the seedlings died in the northeast corner of the plot was more;between the two previous investigation,dead seedling of Pinus tabuliformis population was more in the sample area mideast and sample area northeast corner,but among the second and the third surveys,death seedlings only appeared in the eastern of the sample.From the above results,the space distribution pattern of Pinus tabulaeformis and Quercus wutaishanica seedlings were mainly randomly distributed,aggregation distribution is only presented in a smaller scale.The slope had an effect on the distribution of the dead individuals in two populations,but under different slope,only Pinus tabulaeformis seedlings death individual distribution exist significant difference;Quercus wutaishanica seedlings death individual distribution was influenced by slope positions,and the highest mortality was found in the middle slope position,Pinus tabulaeformis seedlings death individual distribution was not affected by slope position.