| This study was aimed at investigating the species diversity and the altitude distribution of soil factors in the HuoShan Mountaln Qiliyu. And the author selected several plants and their corresponding environment at950-2200m altitude and the total number of selected community samples were118.Quadrat method and R-language was adopted for data analysis in this study. And the main analytic elements were as follow: species composition, plant flora, diversity change with the altitude, correlation analysis on the diversity index, the classification and clustering of the species diversity and their corresponding environmental interpretation. The results show that:1. the author analyzed the species diversity of the community as a whole, the tree layer, the shrub layer and the herb layer respectively for the every sample of118in Qiliyu. And these four diversity indexes were thoroughly analyzed; species richness (3), species diversity (H), evenness index (J) and ecological dominance (A). The results show that:the species diversities of S, H, γ are herb1ayer>tree layer>shrub layer. However, the species diversity of J is tree layer>shrub layer>herb layer. The exponential curve fitting of S, H and λ of the community the tree layer and the shrublayer show a bimodal pattern, and the two peak values are allbetween1400m and1990m. The first peak value of the communityand the shrub layer is greater than the second one, especially theshrub layer. However, the second peak value of the tree layer isgreater than the first one, and one of the low peak is at the altitudeof1650m and it shows a declining trend. On the other hand, theexponential curve fitting of S,H and λ shows a fluctuations in thepattern of wave equation. And the two peak values are at thealtitude of1400m and1990m respectively. At the same time, thetwo low peak values are at the altitude of1170m and1650mrespectively and then it becomes steady. The index J shows thesame sign of change in volatility with shrub layer but it tends to be alinear and it show a rising state. The tree layer shows a “～” pattern,with on peak value and a low peak value, which are at the altitude of1650m and1900m respectively. Still, herb layer shows a singlepeak pattern, and the peak value is at the altitude of1400m.2. From the estimated nuclear density curve, we can see that S、H、λ and J density curve of tree layer are highly overlapped withthose of the shrub layer, which infers that the changes of tree layerand shrub layer are dependent on each other. However, comparedwith the herb layer, the species distribution of the tree layer and theshrub layer is relatively narrow. The density curves of thecommunity and the herb layer are highly overlapped, which declarethe four species indexes are greatly influenced by the S index ofherb layer. Analysis on the four indexes show that there is apositive correlation among S、H、λ indexes(P<0.05) while there is a negative correlation among J and S、 H、 λ(P<0.05). Afterexploratory factor analysis, the two factors can be extracted--species kinds and species amounts. The adequacy index of thefour species diversity indexes is82%. And it shows a bimodalpattern：the first peak value is at the altitude of1440m, and thesecond one1990m. In addition, the first one is greater than thesecond one. Also, there is a low peak value at the altitude of1650m. As a result, it shows a negative correlation-0.57betweenthe factor scores and the altitude(P<0.05).3. The118samples are classified into9associations by k-meanclustering, and the results show a highly correlation with altitude.Combined with the dominant species of tree layer of differentaltitude, the Qiliyu forest is divided into6vertical vegetation zones.The index of9kinds of association along altitude gradient showthat the species diversities value at low altitude and high altitudeare high and that the index at medium altitude shows a bimodalpattern, which is exactly the same with the species diversity ofdifferent altitudinal gradient. The peak value is in the associationII and association VII, both of which are in a state of steady anddominance. In addition, the low peak value is in the association V,and the intraspecific competition and the interspecific competitionof its association are both very strong.4. After the correlation analysis between species diversity and13environmental factors, we can draw the conclusion that S、H、λindexes are negatively correlated with altitude, aspect, litterthickness and canopy density. On the contrary, it is positivelycorrelated with PH. Furthermore, λ is negatively correlated with complete-k and the altitude of lower branch. The soil pHysical andchemical factors which are correlated with altitude gradient in Qiliy.Among these, only complete-k has positive correlation with altitude,the rest show a negative correlation with altitude. And the degreeof correlation are as follow: available P>hydrolytic-N>complete-N>PH. What’s more, complete-N is positively correlated with availableK, as well as PH and complete-P while complete-K is negativelycorrelated with complete-N, hydrolytic-N and available-P.5. Based on Monte Carlo Permutation Test, eight environmentalfactors are selected: altitude, slope, aspect, complete-K. PH, litterthickness and canopy density. And the DNA query results ofspecies diversity show that the adequacy index of eightenvironmental factors on the species diversity is45.03%. And onthe first axis from left to right, S、H、λ species diversity indexes aredeclined gradually, and the corresponding environment aretransited from Shady-Slopes and half Shady-Slopes to Sunny-Slopes,which highlights the canopy density and PH gradient. On thesecond axis, they are highly correlated with the altitude of lowerbranch. Species diversity of changed significantly with differentaltitude gradient in Qiliyu. However, these changes are influencedby slope, aspect, altitude of lower branch, litter thickness, PH,complete-K and canopy density. Biological factors andenvironmental factors can account for45.03%of the speciesdiversity pattern. Among them, biological factors can account for5.23%while environmental factors31.36%. The joint part of thetwo factors take up8.44%altogether. A good environmentalinterpretation reflects the rationality of data sample and the selection of the environmental factors. The environmental factorsare much more important than the biological factors, whichsuggests that the environmental factors play an indispensable rolein the species diversity pattern in Qiliyu. But as for the rest54.97%that can not be interpreted, it may be attributed to the otherenvironmental factors we didn’t select, such as the extent ofdeforestation, the developmental history of the community and soon. |
PDF Full Text Request