Distribution Patterns And Its Response To Environmental Factors Of Plant Communities In Taihang Mountains

The distribution pattern of biodiversity and its formation mechanism have always been the hotspots in ecological research.Exploring the geographical distribution pattern of species diversity and its response to environmental factors are of great significance for the conservation and sustainable use of species diversity.Taking Taihang Mountains as the research area,based on a systematic field survey,the species composition and ecological characteristics of the community were analyzed,and the species diversity pattern of the community and its relationship with environmental factors were analyzed in combination with species diversity,phylogenetic diversity,and functional diversity.The main results were as follows:(1)The species composition of the plant communities in Taihang Mountains is rich.Based on 309 field investigations,a total of 668 species of seed plants belonging to 337 genera and 88 families were found,among which 11 species of gymnosperms belonging to 7 genera of 3 families,657 species of angiosperms belonging to 330 genera of 85 families.The flora of the Taihang Mountains has an ancient origin,and has significant temperate properties and tropical origins.Among them,the distribution types of family are mainly pan-tropical(24 families,27.3%)and northern temperate(19 families,21.6%),and the types of genus are dominated by northern temperate(124 families,36.8%)components.(2)The diversity level of the plant communities in Taihang Mountains is relatively high as a whole.The species richness index and diversity index are as follows: herbaceous plants> shrub plants> arbor plants,and the evenness index as arbor plants> shrub plants> herbs.The distribution pattern of species diversity shows that as the altitude increases,the species richness index,diversity index,and evenness index all show a significant upward trend,with a clear vertical pattern.For plants of different life forms,the species richness index and diversity index of herbaceous plants and arbor plants showed a significant upward trend with increasing altitude,but the indices of shrub plants did not change significantly.As the latitude increases,the species richness index shows a trend of decreasing first and then increasing,while the diversity index and evenness index have no significant changes.Among the different life-type plants,only the indices of herbaceous plants show a significant upward trend.Overall,the latitude pattern is not obvious.From the perspective of latitude,the pattern is not obvious.(3)Correlation analysis shows that factors such as altitude,annual average temperature,and seasonal temperature have significant effects on species richness.For different life form plants,factors such as altitude,annual average temperature,and aspect have significant effects on the richness of herbs;factors such as annual average temperature,annual precipitation,and aspect have significant effects on the richness of shrubs;factors such as altitude,annual average temperature and seasonal temperature have significant effects on the tree richness.The results of further variance decomposition showed that the total explanation rate of environmental factors to community species diversity was 50.3%,and the separate explanation rates of climatic and topographic factors were 31.3% and 8.1%,indicating that climatic factors are the main factors affecting community species richness.From the perspective of different life-form plants,the total explanation rates of environmental factors for herbaceous plants,shrub plants,and arbor plants are 61.6%,32.9%,and 40.6%,respectively.Among them,the climatic factors have the highest explanation rates for the richness of each life-form plant.They are 35.3%,14.1%,and 17.6%,respectively,indicating that climatic factors are the main factors affecting the richness of various life-form plants in the community.(4)The phylogenetic diversity distribution pattern of the plant communities in the Taihang Mountains shows that as the altitude increasesthe phylogenetic diversity index and the mean phylogenetic distance show asignificant upward trend,with a clear vertical pattern;there is no significanchange in the latitude gradient.The community net relatedness indexindicates that the community species in low altitude areas show thecharacteristics of lineage aggregation under the effect of habitat filtrationand the community species in high altitude areas show the characteristics olineage divergence under the effect of competition.Correlation analysis andvariance decomposition results show that factors such as altitude,annuaaverage temperature,and isothermal temperature have significant effects onphylogenetic diversity.The overall explanation rate of environmental factorson the diversity of community phylogenetic is 34.1%,and the interpretationof climatic and topographic factors were 18.8% and 8.2%,respectivelyindicating that climatic factors are the main factors affecting the phylogeneticdiversity of the community.(5)The distribution pattern of the functional diversity of the plant communities in the Taihang Mountains shows that as the altitude increases,the functional richness index shows a significant upward trend,with a clear vertical pattern;with the increase of latitude,neither the functional richness index nor the functional evenness index showed a significant change trend,and the functional divergence index showed a gradually increasing trend,latitude pattern is generally not obvious.Correlation analysis and variance decomposition results show that factors such as annual average temperature,wettest monthly precipitation,and altitude have significant effects on functional diversity.The overall explanation rate of environmental factors on the functional diversity of communities is 53.5%,and the explanation of climatic and topographic factors were 35.2% and 8.7%,respectively,indicating that climate factors are the main factors affecting the functional diversity of the community.(6)In general,the distribution of plant communities in different dimensions in the Taihang Mountains has obvious vertical patterns,and the latitude pattern is not obvious.Comparing the results of the three different dimensions of plant communities in the Taihang Mountains,it was found that there was a correlation between species diversity,phylogenetic diversity,and functional diversity patterns.The species richness index and the phylogenetic diversity index have a very significant positive correlation,which indicates that in the historical evolution of community species,their ecological traits are conservative in the process of adapting to environmental changes and have phylogenetic characteristics.The species richness index and functional richness index have a very significant positive correlation,indicating that the increase in species in the community will increase the characteristic value of the functional traits of the species,which will increase the functional space range occupied by the functional traits of the species to a certain extent,and promote the utilization of effective resources in the community.The purpose of this thesis is to clarify the species composition and community structure of the plant communities in Taihang Mountains,to reveal the geographic pattern of biodiversity in different dimensions and its response to environmental factors,so as to provide a theoretical reference for the protection of wild plant resources in Taihang Mountains.