| The forest landscape pattern change, species diversity, soil heterogeneity, the relationship between landscape pattern and environmental elements and their scale effects were studied in this paper. The main conclusions were as follows:(1) The analyzing of forest landscape pattern trait demonstrated that both evergreen broadleaf forest and evergreen conifer-broadleaf mixed wood were the superior landscape types and both of them accounted for 75% of the total area. Except for evergreen mixed wood, the area of the other forest landscape types was increasing, the highest amplitude of which is bamboo forest and its amplitude was 32.94 hm2, and the followed one was evergreen broadleaf forest, the increasing area of which was 32.22 hm2, and the last one was deciduous broad- leaf forest. Considering the 3 aspects of indexes of fragmentation division degree and patch density revealed that the sphagnum moss had the highest index values 0.511, 5.835, 0.163 respectively while they all showed a decreasing trend. Evergreen broadleaf forest had the highest indexes of patch shape index, related circumscribing circle, fractal dimension, which were 1.916, 0.706, 1.084 respectively and also showed a decreasing trend. However, patch shape index and fractal dimension of deciduous broad leaved forest and sphagnum moss were closing to 1, and related circumscribing circle index values were about 0.4. All the forest landscape types were changed gently. The landscape diversity and evenness of the overall landscape types increased while the dominance decreased, however, the amplitude of variation of the 3 indexes were little.(2) The analyzing of species diversity of landscape pattern showed that certain degree of similarity exist in the distribution of families and genus of different forest landscape types. Besides, the tropical and subtropics families and genus accounted for comparatively large percent. bamboo and evergreen conifer-broadleaf mixed wood were abundant in the families and genus compare with Rhododendron simiarum forest and Shrub-meadow were relatively less. The sequence of the species evenness was consistent with diversity, which was shrub layer> herb layer>arbor layer,but the richness was shrub layer> arbor layer>herb layer. The species diversity in decreasing orders are Evergreen broadleaf forest > Deciduous broad leaved forest > Evergreen coniferous forest > Mixed broadleaf-conifer forest > Rhododendron simiarum forest > Bamboo grove > Shrub-meadow.(3) Rearch on the soil heterogeneity and inner change of different landscape types showed that except for Shrub-meadow and Sphagnum bog, the forest landscape had good aeration, permeability and soil nutrient content. The Sphagnum bog had highly storage, hydrology regulation capacity water and high soil nutrient content but inferior to other forest types in aeration and permeability. The difference in the soil deep of Evergreen broadleaf forest, Bamboo grove, Shrub-meadow and Sphagnum moss achieved the level of significance in terms of N, Sphagnum moss, Deciduous broad leaved forest and Shrub-meadow reached the level of highly significant or significant difference in term of P, except for Sphagnum moss and Rhododendron simiarum forest in the significant different, others were non-significant. Besides, Evergreen broadleaf forest, Mixed broadleaf-conifer forest, Evergreen coniferous forest and Bamboo grove were preponderantly landscape types in area. The relationship between the species diversity indexes and soil physical and chemical properties was not significant in arbor. The species richness, Brillouin index, Shannon-Wiener index and Soil bulk density correlation coefficient respectively were -0.84,-0.77,-0.75 in bush,but which of the effective holding capacity, the total water storage capacity and the permeability were 0.72～0.93,and the correlation coefficient were 0.83(H′-P2),0.81(H′-P3).The species diversity and the total water storage capacity are closely related in herb layer,the correlation coefficient was 0.86～0.91,but which of the others were not significant.(4)The study on relationship between forest landscape pattern and environmental elements revealed that non-uniform distribution of landscape types in term of elevation, slope and aspect. The distribution range of Bamboo grove was widest, expect for over 1400m, Evergreen broadleaf forest and Mixed broadleaf-conifer forest mainly existed in model elevation, other special landscape types were concentrating distribution, for example, Deciduous broad leaved forest only been found about 1000m, Rhododendron simiarum forest were almost distributed over 1200m, the distribution of Sphagnum moss were form 1000 to 14000m, and Shrub-meadow existed above 800m. Evergreen coniferous forest, Evergreen broadleaf forest and Mixed broadleaf-conifer forest mainly distributed from 5-35°, Rhododendron simiarum forest was suitable for high slope, comparing with Deciduous broad leaved forest, Shrub-meadow and Sphagnum moss in low slope. Evergreen broadleaf forest, Evergreen coniferous forest, Mixed broadleaf-conifer forest and Rhododendron simiarum forest mainly distributed on semi-cloudy and cloudy slope, comparing with scare in other slopes. Exceed half of Deciduous broad leaved forest delivered in semi-cloudy, and Bamboo grove distributed equality, however, Shrub-meadow and Sphagnum moss delivered extremely non-uniform, such as Shrub-meadow on the sunny and semi-sunny slope, but Sphagnum moss cloudy and semi-cloudy slope.(5) Analyzing on the relationship between environmental elements and landscape pattern contributed to the revelation of the changing mechanism of landscape pattern. The results showed that the total Eigen value increased with the downscaling which were 3.137, 3.349, 3.484, 4.660 and 4.848 respectively. However, both the Cumulative percentage variance of species-environment relation and species-environment correlation coefficients first increased and then decreased with reaching the maximum value at scale3 (97.4%) and scale2 respectively. The landscape presented latitude variation (the correlation coefficients between latitude and first axis was -0.354～-0.604) and vertical distribution regularity (the correlation coefficients between )which was more obvious. The latitudinal distribution regularity was as follows: Bamboo grove→Deciduous broad leaved forest→Mixed broadleaf-conifer forest→farmland→Evergreen broadleaf forest→Evergreen coniferous forest→Rhododendron simiarum forest→Shrub-meadow→Sphagnum moss. Bamboo grove and farmland distributed at the low elevation comparing with Sphagnum moss, Shrub-meadow and Rhododendron simiarum forest at the high elevation. The relationship between landscape and environment had scale effect, but the results were basically identical with a little change.(Fig.16,Tab.24)... |
PDF Full Text Request