(3)During the process of some rain, SO 4 2- ,NO 3 -,NH 4 +,Al 3+ ,Na + appeared negative leaching in the pine forests and evergreen broad leaved forest, this phenomenon illustrates that the forests can absorb these ions (especially NO 3 - and Al 3+ ) under the condition of acid rain.
The average percentage contents of N,P,K,Ca and Mg in the litters for the3stands was1.08,0.07,0.37,1.37and0.21respectively. In general,the average fig ure in sharp tooth oak stand was much higher than in Armand pine and Chinese pine stands,but there was no evident difference between that in Armand pine and Chinese pine stands.
According to 6 553 korean pines (18—30 year old) collected from 68 sampling sites, we expound the following points:1. The growth and development of a great majority of stands is normal in Yichun forest region, average furcaticn percentage is 20%, half of them is serious, therefore, it is possible that the high-stem korean pine stands will be raised in this region.
The authors suggested to maintain the density of CMense pine stands by using " the reserved stemnumber standard for thinning Chinese pine stand" , They also laid down a standard for reasonable pruning.
For example, Shannon-Wiener index and abundance index is higher and Simpson's dominance index is the lowest in succession layer of medium-size gap (100-250 m2) in the broad-leaved Korean pine forest of Changbai Mountains.
Here, we suggest a method for adjusting boundary effect in the analysis of spatial patterns at different stages of development of the broad-leaved Korean pine forest.
Based on the sampling data, a correct approach to the boundary effect on aggregation index was put forward to the spatial pattern analysis of the broad-leaved Korean pine forest in its different stages of development.
The spatial pattern of the broad-leaved Korean pine forest changing from clumped to random distribution is influenced by biological characteristic, the adaptive strategy of tree species and the natural disturbance in its entire development.
With these equations, the aboveground biomass of Masson pine forest, slash pine forest and Chinese fir forest were estimated, in addition to the allocation of aboveground biomass.
Regeneration of tree species associated with canopy gaps in broad-leaved Korean pine forests was investigated.
Although the habitat composition of the core area varied greatly for individuals, a large part of the habitats used were composed of confier and broadleaf mixed forests, masson pine forests, fir forests, and shrubs.
Population dynamics of Dremomys pernyi and Callosciurus erythraeus in protective and non-protective pine forests at different ag
allosciurus erythraeus were important for pine forests to scatter pine seeds.
Human activities in the nonprotective pine forests decreased the vegetation heterogeneity at the bottom layer of pine forests, postponed the occurrence of D.