不同类型森林植被群落多样性与土壤养分的关联分析

Correlation Analysis of Vegetation Community Diversity and Soil Nutrients in Different Forest Types

为了探究不同植被类型群落分布多样性与土壤养分之间的关系,本研究将琅琊山不同林木作为研究对象,所选择林木不仅包括天然次生林和针叶林,还包括阔叶林及人工林,为了进一步降低实验误差,本研究从2013年开始进行为期五年的持续性实验,通过实验对比得知:(1)无论是次生林和针叶林,还是阔叶林及人工林,虽然其群落分布特点存在较大的差异,但是其整体的群落变化态势较为一致,无论是丰度、匀度指数方面,还是Wiener多样性指数方面,最高的属于次生林,而最低的则是针叶林;在Wiener多样性方面,不同林木类型之间的差异尤为突出,且通过了0.05显著检验。在Simpson指数方面,最高的则是针叶林,其次是人工林,而次生林最低,这与其他多样性指数恰好相反;(2)在Cody指数方面,最高的是次生林,其次是阔叶林,而针叶林最低,前两者之间的差异并不突出,且未通过显著检验,但与后两者的差异较为突出,且通过了0.05显著检验。对于Sorenson指数来讲,最高的是针叶林,其次是人工林,而次生林最低,不同林木类型之间的差异并不突出,未通过显著检验;(3)在土壤方面,无论是有机碳、磷等养分,还是微生物量,随着深度增加,其下降态势尤为突出,且这种减小幅度较为突出的是在20 cm内的表层土壤,而在80~100 cm的土层则幅度微小,对于同一土层而言,次生林含量最高,其次是阔叶林,而针叶林最低;(4)通过交互因子分析得知,林木多样性分布不仅受土壤深度制约,还受到林型差异的影响,且达到了0.05显著水平,尤其是林型和深度的交互作用更为突出;(5)通过开展冗余分析得知,土壤养分状况直接制约着林木群落分布多样性,成为关键性的作用因子。

Different types of forest vegetation communities(natural secondary forest,broad-leaved forest,artificial forest and coniferous forest)were selected from langya mountain forest park in anhui province to study the relationship between diversity and soil nutrients for 5 consecutive years(2013-2017).Results show that:(1)of natural secondary forest and plantation,coniferous and broad-leaved forest,the species diversity variation law of each index showed a consistent Margalef abundance index,Mclntosh species evenness index and Shannon Wiener diversity index were as follows:the natural secondary forest>broad-leaved forest plantation>coniferous forest,the natural secondary forest and broad-leaved forest Mclntosh evenness index and Margalef abundance index difference was not significant(P>0.05),significantly higher than both plantation and coniferous forest(P<0.05);The shannon-wiener diversity index of different forest types was significantly different(P<0.05).Simpson dominance index shows that natural secondary forest<broad-leaved forest<artificial forest<coniferous forest;In general,the natural secondary forest and broad-leaved forest are more complex,and the plant diversity index is higher than that of other habitat communities.(2)the Cody index was as follows:natural secondary forest>broad-leaved forest>artificial forest>coniferous forest,among which there was no significant difference in Cody index between natural secondary forest and broad-leaved forest(P>0.05),which was significantly higher than artificial forest and coniferous forest(P<0.05).The Sorenson index was successively shown as natural secondary forest<broadleaf forest<artificial forest<coniferous forest,and there was no significant difference in Sorenson index among different forest types(P>0.05).(3)different forest types of soil nutrients(organic carbon,total nitrogen,total phosphorus and total potassium content),microbial biomass carbon,nitrogen,phosphorus and microbial biomass carbon turnover rate and turnover period decreasing trend with the increase of soil depth,among them,20-40 cm soil layer under sharply reduce the trend,80-100 cm difference is not obvious,the basic trend of equal;The same soil layer is roughly manifested as:natural secondary forest>broad-leaved forest>artificial forest>coniferous forest.(4)two-factor interaction analysis showed that soil depth and forest type had a significant impact on forest community diversity(P<0.05),in which soil depth had no significant impact on and diversity index(P>0.05),and forest type and diversity index had a significant impact on and diversity index(P<0.05).Soil depth and forest type had significant effects on soil nutrients(P<0.05),in which soil depth had no significant effect on soil nutrients(P>0.05),and forest type and forest type×depth had significant effects on soil nutrients(P<0.05).(5)the results of redundancy analysis showed that soil nutrients were significantly correlated with the diversity of vegetation communities and were an important factor affecting the diversity of vegetation communities.