Study On The Species Diversity Of Plant Community In Manghe Nature Reserve In Shanxi

Manghe National Nature Reserve is located in the eastern section of the Zhongtiao Mountains.Geographical location 112°22'E-112°31'E,35°12'N-35°17'N,area 5573 hm~2.Based on the field survey data,the vegetation ecology and quantitative ecology related methods were used to categorize and sort the communities with different elevation gradients from species composition and flora,community species diversity,pedigree structure and pedigree diversity,and quantity.Studies on inter-specific associations and other aspects were conducted.The results showed that:(1)The composition of the endophyte in the Manghe Nature Reserve is relatively abundant,with 179 seed plants recorded,belonging to 145 genera and 76 families.Among them,there are 1 family,1 genera and 1 species of ferns,and 2 families and 2genera of gymnosperms.The angiosperms occupy a particularly important position in the plant components of this area,with angiosperms belonging to 73 families,96 genera,176species,monocotyledons,65 families,46 genera and 84 species,and dicotyledons,38families,50 genera,and 92 species.There are 11 types of distribution areas in this community.There are few types,which indicates that the geographical distribution of the plant communities in Luanhe Nature Reserve is narrow and the flora composition is simple.The flora is characterized by the north temperate zone and predominance in the world.The temperate nature of the community is obvious,the north temperate zone distribution is the basic attribute,and the second is the tropical zone,which is consistent with the typical warm temperate climate characteristics in the south of Jinan where the sampling area is located.(2)In this study,the taxonomy was adopted.According to the classification principle and system of“Chinese Vegetation”,68 plant plots in Manghe Nature Reserve were divided into 6 cluster types,and 68 plots were calculated using Phylocom software.The value of the pedigree diversity index(PD)was analyzed using the regression analysis method to analyze the relationship between the species pool(richness index S)and the pedigree diversity index(PD)of each plot,indicating the small size of the plot.The domain community structure is divergent.Regression analysis found that there was a very significant positive correlation between the S index value and the PD index value of each sample in the tree layer,and there was a highly significant positive correlation between the NRI of the tree layer species and the elevation gradient.The species richness index(S)and the pedigree diversity index(PD)of each species in the shrub layer were significantly positively correlated.The NRI of the shrub species showed a significant positive correlation with the elevation gradient.There was a significant positive correlation between the species richness index(S)and the pedigree diversity index(PD)in each herb layer,and there was a very significant positive correlation between the NRI index of herbaceous layer species and the elevation gradient.(3)When two species use the same resource or share a certain resource(light,nutrients,space,etc.),niche overlap occurs.In general,niches with larger niche breadth have similar niches and niche overlaps.This study found that in the T.chine nsis community,the niche similarity between Taxus chinensis var.Mairei and other broad niche populations with wider niche was also greater,but the niche overlap value between Taxus chinensis var.Mairei and other populations in the community.However,they are all very small,including hornbeams with wide niche and Vitex.According to Gause's theory of competitive exclusion,if the niches of two species overlap,then there must be competition between the two species,and the greater their niche overlap value,the more fierce the competition.It can be inferred that:Taxus chinensis var.Mairei and other species in the community share or share a certain resource,showing a shared tendency,and lack of inter-species competitiveness.This may also be one of the reasons why southern yew has become an endangered species.(4)Due to the difference of solar radiation intensity and sunshine hours on different slopes,there are great differences in hydrothermal conditions and physicochemical properties of different slopes.The species richness index of the two southern slopes is the largest,and the southern slope is the smallest.It may be related to the difference in the thermal factors caused by different light orientations due to different light intensities.The northern and southern slopes have relatively short illumination time relative to other slopes,and the moisture and nutrients in the soil are not easy to evaporate.Their habitat conditions are suitable for different conditions.Types of plants grow.By c omparing the values of the diversity indexes of different slopes,the index values of the tree layer and the herb layer in the southwest slope are the largest.It can be seen that comparing the species diversity indices of different slope orientations,we know that the types of habitats on the southwest slope are more complex and diverse,and species are more abundant.Different grades of mountainous terrain,because of the different solar radiation angles,the solar radiation obtained by it is also different,and the temperature,soil temperature and other ecological factors are also changing.The trends of the indices in different slopes are generally consistent.In the 30°-40°and 20°-30°slopes,the index values of the species diversity at different levels in the communities and communities at other slopes are larger,that is,the slope of 20°-30°is conducive to the improvement of the diversity of the communities and the soils with different gradients.Different soil-retaining and fertilizer-holding abilities are related.The smaller the slope is,the less moisture and nutrients in the soil are lost.The accumulation of organic matter is also more,which is beneficial to the common growth of different types and types of plants.(5)Based on the 2×2 contingency table tast,Spearan's rank correlation coefficient test and Pearson's correlation coefficient test,this study performed a correlation analysis of dominant species at different altitudes,and compared and analyzed different result.After comparison,it was found that the test results of the three methods were consistent and different.The qualitative data that can be used for the?2 test will lose part of the information during the conversion process and can only make qualitative judgments.On the contrary,the Spearman rank correlation coeffiicient and the Pearson correlation coefficient tast are quantitative test methods.The significant rate of the correlation test between the 48 dominant species was 11.64%and 18.38%respectively.The Spearman rank correlation coefficient test significantly higher than the Pearson correlation coefficient test.This is because the Pearson correlation coefficient test is a parameter test and has certain limitations.The sample is required to follow a normal distribution,while the Spearman rank correlation coefficient test is a non-parametric test and there is no restriction on the species distribution.Through the comparison of the three tests,it has been found that there are certain positive and negative associations between the dominant species.Positive association is due to the fact that species live in the same or similar climatic and environmental conditions,long-term subject to a certain factor leading to the formation of similar adaptation methods,and negative correlation is that the community species are mutually exclusive and incompatible.The?2 test results showed that the ratio of positive and negative related species pairs was 1.26.The significant positive correlation was greater than the significant negative correlation.Negative correlation was dominant among the species pairs,but some species pairs were still positively correlated,indicating the plants in the study area.At the stage of competition and growth,the use of resources is strained and it is in the development stage of the survival of the fittest.It is relatively unstable.The ratio of Spearman rank correlation coefficient and Pearson's correlation coefficient is 1.16 and 1.19,respectively,indicating that the dominant species still have relatively different ecological adaptability and mutual niche.Combining the three test results shows that the community is in the process of dynamic development.With the continuation of the time,the community structure and species composition will be more perfect until the stable coexistence of various dominant species.