Species-area Relationships And Interspecific Correlations In Mixed Broadleaf-conifer Forest In Jiaohe, Jilin Province, China

The Species Area Relationship (SAR) is one of the most fundamental patterns in ecology. Recent analyses have often demonstrated substantial uncertainty in selecting the best SAR model for a given data set, how the way they were constructed influences resulting SAR still remains elusive. By using the nested sample design and random sample design, this paper studied the relationships between species and area of42hm2board-leaved Korean Pine mixed forest plot in Jiao He. The species with diameter at breast height (DBH)>1cm were all tagged, recorded height, diameter at breast height and crown diameter. We propose three SARs models, including power function, logarithmic function and logistic function to compare SARs constructed from nested design and random design. In this study, we use Akaike’s Information Criterion (AIC) to compare the quality fit of each SAR model given the data. The results appeared that the way of constructing SARs influences the outcome. The random design showed significantly better goodness of fit of SARs model than the nested design. Among the three SARs model, Power function and Logistic function model from the random design are clearly appropriate model, suggesting that was the reasonable description of the species area relationship in Jiao He forest plot. However, due to the species distribution patterns and spatial scale varies greatly, further work is needed to consider the species abundance and distribution patterns on different spatial scales. Abstract We sampled100plots with20m×20m in the coniferous and board-leaved mixed forest communities of Jiao He, selected18dominant species according to importance values and studied interspecific associations and correlations by using variance ratio (VR) analysis of the overall association and χ2-test, Pearson correlation coefficient test, Spearman rank correlation coefficient test., Ochiai index, Dice index, Jaccard index, AC value.Based on2×2contingency tables of species presence/absence data and the VR analysis,18 dominant species overall association was positive correlation, but most species had insignificant positive. The result of χ2-test showed that88species-pairs were positively correlated,65species-pairs had negative correlations. The Spearman rank correlation coefficient test was more positive correlation species-pairs than the Pearson correlation coefficient test. P. koraiensis in the community was positively associated with A. mono and C. cordata, negatively associated with the7tree species including A. mandshuricum. The positive association coefficients was large (OI=0.85).According to the semi-matrix figure correlation coefficients and the dominants’ecological and biological characteristic, the18dominant species divided into3ecological species groups. It is found species association caused by the species adaptability to different habitats. Similar/same ecological habitats led to niche overlap between species, which appeared positive association; oppositely, different environment requirement resulted in niche differentiation between species, and then negatively associated.