| The distribution characteristics of communities and their environmental interpretations have always been the core content of community ecology.Exploring the dominant forces affecting distribution characteristics during community development is of great significance for community restoration and construction.In recent years,the area of planted forests has been increasing.However,plantation forests cannot compare with natural forests in terms of ecological restoration goals,biodiversity conservation,and ecosystem versatility.It is helpful for us to understand the basic principles of natural forest biodiversity maintenance,reveal its inherent scientific mechanism,and make it exert greater ecological,economic and social benefits.The current research mostly focuses on single organ,single functional group and their interpretation of single environmental variables.There are few reports exploring the distribution characteristics and environmental explanations of species diversity and functional traits in different functional groups and different organs during the growth and development of natural communities of single dominant species.This paper took Quercus wutaishanica as the research object,which is the main vegetation type in the warm temperate zone.Community investigation was carried out on different functional groups(tree layer,shrub layer,herb layer)of typical Quercus wutaishanica forest during the development process in the Lingkong Mountain forest area of Taiyue Mountain,Shanxi Province.The leaves,twigs,fine roots and seeds of species were collected and measured their morphological and chemical functional traits.At the same time,environmental factors such as light,soil,and terrain were also measured in the community.By analyzing the species diversity of different functional groups,the functional traits characteristics of different organs and their environmental interpretations in this region,combined with the distribution pattern of species and functional traits,the main forces affecting the distribution characteristics of Quercus wutaishanica were determined,and the ecological processes in the development of Quercus wutaishanica were elucidated finally.It was expected to provide a certain theoretical basis for the protection of biodiversity in this region and the restoration and reconstruction of natural secondary forests.The main results of the study were as follows:(1)The trees in this fixed plot were mainly Quercus wutaishanica,accounting for 83% of the total number of trees,which was a natural secondary pure forest of Quercus wutaishanica.The diameter at breast height of Quercus wutaishanica in the fixed plot was mostly distributed in the range of 6-22 cm,and the height of the tree was mostly distributed in the range of 4-12 m.The height structure and diameter class structure were close to normal distribution.The species distribution pattern of the community at different research scales is different.Under the research scale of 20m×20m,the distribution of species was obvious,and the species diversity of adjacent plots was significantly different,which was consistent with the community appearance in the region.Among them,the species diversity of the tree layer showed opposite distribution characteristics with the species diversity of the shrub layer.The species diversity of the herb layer was significantly higher than that of the tree layer and the shrub layer,and the community species diversity was mainly affected by the herb layer.The explanation rates of environmental factors to the species diversity of tree layer,shrub layer and herb layer were 35.3%,33.1% and 37.9% respectively.The distribution of species diversity in tree layer was mainly affected by site conditions and light,while the distribution of the species diversity in shrub layer was mainly affected by the light above the canopy;the distribution of the species diversity in the herb layerwas mainly affected by the light above the canopy and soil p H;the distribution of community species diversity was mainly affected by soil factors.Based on the distribution of species point patterns,it could be seen that the spatial distribution of species on the scale of 0-19 m is clustered,the spatial distribution of species on the scale of 19-27 m is random,and the spatial distribution of species above 27 m is uniform.(2)The distribution of morphological functional traits in the fixed plot was patchy and fragmented,and there was no obvious distribution pattern.Morphological and functional traits were generally correlated,especially among leaf functional traits,which conformed to the law of leaf economic spectrum.The stoichiometric characteristics of different organs and functional groups showed different patterns.The contents of total N,total P and total K in leaves were significantly higher than those in other organs,and the contents of total N,total P and total K in herbs were significantly higher than those in other functional groups.At the species level,environmental factors explained 4.1% and 7.0% of the variation in leaf and stem functional traits of Quercus wutaishanica,respectively.Soil and light were the main factors affecting leaf functional traits at the species level,and terrain and light were the main factors affecting the stem functional traits at the species level.At the community level,environmental factors explained 82.4% and 99.9% of the variation in leaf and twig functional traits,respectively.Environmental factors had a greater impact on community functional traits.The explanation rates of environmental factors on the variation of chemical functional traits in the tree layer,shrub layer and herb layer were 38.0%,31.2% and 11.3%,respectively.Among them,topography had a relatively greater impact on the chemical functional traits in the tree layer;Soil had a relatively greater impact on the chemical functional traits in the shrub layer and herb layer.There was no obvious regularity in the distribution pattern of leaves and twigs functional traits,and most of the SES values of functional traits in leaves and twigs were negative,which showed the divergence of functional traits.(3)Plant functional attributes were not significantly different at the community level among different developmental stages,but were significantly different at the species level.At the species level,topographic factors and soil factors were the main factors affecting the functional properties among different developmental stages,and topographic factors and light factors also indirectly affected the functional properties by affecting soil factors.At the community level,the physical and chemical properties of soil and light were the main factors affecting community functional attributes among different developmental stages,and topographic factors indirectly affected the community functional attributes by acting on soil factors.To sum up,by comparing the interpretation rate by environmental factors to species diversity and species distribution pattern with the interpretation rate by environmental factors to functional attributes and functional trait distribution pattern,it could be concluded that the Quercus wutaishanica community in this fixed plot was mainly affected by biological competition.Because the functional attributes of different functional groups in this region were not the same,the similarity of functional traits was low,and the functional overlap between traits was small,so there was a positive correlation between species diversity and plant functional traits,which made the same distribution pattern of functional traits and functional traits.Except that,the differences in functional traits at the species level were mainly affected by individual differences and genetic factors,while the insignificant differences in functional traits at the community level were mainly because community functional diversity offset the differences between individuals.During the development of Quercus wutaishanica,environmental factors and competitive forces jointly affected the spatial distribution in the community.The difference in functional diversity,the distribution pattern of functional traits and the interpretation rate of functional attributes by environmental factors indicated that environmental factors were the main forces affecting functional attributes during Quercus wutaishanica forest development at the community and species levels.In this paper,the distribution characteristics of Quercus wutaishanica forest and its environmental interpretation were explored from the perspective of species diversity and functional traits,and the main influencing factors and forces affecting the distribution characteristics of Quercus wutaishanica forest were preliminarily elucidated,which hoped to improve the community diversity and lay a theoretical foundation for natural community stability. |
PDF Full Text Request