By the methods of sampling soil profiles which A,B,and C represent humus horizons,illuvial horizons,and parent materials horizons respectively,relationships between the activities of soil enzymes (which include catala...By the methods of sampling soil profiles which A,B,and C represent humus horizons,illuvial horizons,and parent materials horizons respectively,relationships between the activities of soil enzymes (which include catalase,invertase,protease,and acid phosphatase) and plant species diversity in three secondary successional plant communitites of forest ecosystem in Mt.Jinyun were studied in this paper.Results showed that different degree′s correlations existed between soil enzymic activities and plant species diversity indice (PSDI) which included Shannon-Wiener H′ index and Hill′s species diversity indice family \%N A\%,moreover,the degree of correlation depended on the horizon of soils,the type of enzymes,and the life form of plants (i.e.,tree,or shrub or grass).The degree of correlation between PSDI and soilenzymic activities decreased by the orders of A→B→C.The most significant correlation with PSDI was the activity of soil catalase,and in turn,was the activity of soil invertase,On the whole,the correlation between soil enzymic activities and tree layer′s PSDI was the most evident.Tree layer′s PSDI were positively and significantly (P<0.05) or very significantly (P<0.01) correlated with the activities of catalase and invertase of A and B horizons,and of protease and acid phosphatase of A horizons.Grass layer′s PSDI were also positively and significantly (P<0.05) correlated with the activities of catalase and invertase of A horizons.Shrub layer′s PSDI were not significantly correlated with soil enzymic activities.展开更多
Seed sizes of 74 woody species, including 40 trees and 34 shrubs, of middle subtropical evergreen broad-leaved forest in Mt. Jinyun were investigated and the likely mechanism of seed size variation was analysized. The...Seed sizes of 74 woody species, including 40 trees and 34 shrubs, of middle subtropical evergreen broad-leaved forest in Mt. Jinyun were investigated and the likely mechanism of seed size variation was analysized. The results showed that: 1) There was considerable variance in the seed length and great variance in the seed weight among the 74 species. The maximum seed length was 100 times greater than the minimum. The lengths of most seeds were in a range of 0.1～1 cm, accounted for 71.62% of the total species. The maximum seed weight was 10 000 times greater than the minimum. A 39.41% of species had their 1 000 seed weights in a range of 10～100 g. 2) The results of statistic analysis indicated the seed sizes were influenced by their habitats. The longest seeds were born in canopy layer, the middle in forest edge & understorey and the shortest in dankness habitat. Additionally, the seed sizes were also influenced by growth forms of species. The seed sizes gradually decreased with the growth forms sequence of large tree, middle tree, small tree, large shrub and small shrub. Moreover, the phylogenetic backgrounds of species had little influences on the seed sizes. Little correlations were found between seed sizes and their orders, families, taxonimical groups with the different weight ratio of endosperm and different fruit types.展开更多
文摘By the methods of sampling soil profiles which A,B,and C represent humus horizons,illuvial horizons,and parent materials horizons respectively,relationships between the activities of soil enzymes (which include catalase,invertase,protease,and acid phosphatase) and plant species diversity in three secondary successional plant communitites of forest ecosystem in Mt.Jinyun were studied in this paper.Results showed that different degree′s correlations existed between soil enzymic activities and plant species diversity indice (PSDI) which included Shannon-Wiener H′ index and Hill′s species diversity indice family \%N A\%,moreover,the degree of correlation depended on the horizon of soils,the type of enzymes,and the life form of plants (i.e.,tree,or shrub or grass).The degree of correlation between PSDI and soilenzymic activities decreased by the orders of A→B→C.The most significant correlation with PSDI was the activity of soil catalase,and in turn,was the activity of soil invertase,On the whole,the correlation between soil enzymic activities and tree layer′s PSDI was the most evident.Tree layer′s PSDI were positively and significantly (P<0.05) or very significantly (P<0.01) correlated with the activities of catalase and invertase of A and B horizons,and of protease and acid phosphatase of A horizons.Grass layer′s PSDI were also positively and significantly (P<0.05) correlated with the activities of catalase and invertase of A horizons.Shrub layer′s PSDI were not significantly correlated with soil enzymic activities.
基金International Foundation for Science"The spatial variability of soil water movement properties with macropores in forestland in Jinyun Mountain region in China(W/3430-1)"国家自然科学基金"长江三峡花岗岩地区林木根系与优先路径形成机制(30571478)"
文摘Seed sizes of 74 woody species, including 40 trees and 34 shrubs, of middle subtropical evergreen broad-leaved forest in Mt. Jinyun were investigated and the likely mechanism of seed size variation was analysized. The results showed that: 1) There was considerable variance in the seed length and great variance in the seed weight among the 74 species. The maximum seed length was 100 times greater than the minimum. The lengths of most seeds were in a range of 0.1～1 cm, accounted for 71.62% of the total species. The maximum seed weight was 10 000 times greater than the minimum. A 39.41% of species had their 1 000 seed weights in a range of 10～100 g. 2) The results of statistic analysis indicated the seed sizes were influenced by their habitats. The longest seeds were born in canopy layer, the middle in forest edge & understorey and the shortest in dankness habitat. Additionally, the seed sizes were also influenced by growth forms of species. The seed sizes gradually decreased with the growth forms sequence of large tree, middle tree, small tree, large shrub and small shrub. Moreover, the phylogenetic backgrounds of species had little influences on the seed sizes. Little correlations were found between seed sizes and their orders, families, taxonimical groups with the different weight ratio of endosperm and different fruit types.
