Chemical and biochemical analysis methods were used to monitor the vedations of nitrogen nutrient among the dominance trees species in secondary succession process of the mixed broad - leaved/Korean pine forest on Cha...Chemical and biochemical analysis methods were used to monitor the vedations of nitrogen nutrient among the dominance trees species in secondary succession process of the mixed broad - leaved/Korean pine forest on Changbai Mountains, Northeast China. Amounts of total nitrogen, anunonium and NRA in soils of virgin broad-leaved/Korean pine forest which is in climax were higher than those of secondary birch forests those are in succession Stage. The amount of nitrate was in the other hand. In climax, dominance trees species are tolerant mesophytic trees such as Pinus Koraiensis, Tilia amurensis, Acer mono and also Fraxinus mandshurica, they are all ammonium + nitrate adapted species, but they show a preference for the anunonium rather than those of the pioneer trees species in secondary birch forest, such as Populus davidiava and Betula platyphylla. Because they have more ammonium in their leaves and roots, especially Pinus koraiensis. Populus davidvana and Betula plaaphlla are intolerant trees, amounts of nitrate and total nitrogen is higher in their leaves and roots and also NRA in their leaves, so they preference for the nitrate rather than the others.In secondary birch forest, the regeneration trees species adapt their nitroggn nutrient to the variation of nitrogen nutrient situation in soil, finally they could survival well and the secondary birch forest would succession to climax. In climax, dominance trees species adapt their Nitrogen nutrient to the situation in soil and there are not strong competition in nitrogen nutrient among them, so they can coexist well and keep the climax as stable vegetation.展开更多
Impacts on growth of young trees of Pinus Koraiensis of 6 environmental factors of intensityof sunlight, direct sunlight, thickness of soil humus, neighboring trees, upper canopy species, herbs andshrubs were investig...Impacts on growth of young trees of Pinus Koraiensis of 6 environmental factors of intensityof sunlight, direct sunlight, thickness of soil humus, neighboring trees, upper canopy species, herbs andshrubs were investigated on young tree of Pinus Koraiensis and 4 neighboring trees which are consideredthe structural unit of the microenvironment. Results indicated that the 6 environmental factors underinvestigation had effects, to various extents, on growth of the young trees. Based on the findings, suitablegrowing conditions for regenerated young tree of Pinus Koraiensis under forest were identified andcorresponding silvicultural measures were proposed for operational practice.展开更多
Soil animal communities of Pinus koraiensis broad_leaved mixed forest were studied.The purpose was to discuss the dynamic characteristic of soil animals and relationship with environmental factors.The ecosystem geogra...Soil animal communities of Pinus koraiensis broad_leaved mixed forest were studied.The purpose was to discuss the dynamic characteristic of soil animals and relationship with environmental factors.The ecosystem geography distribution law of soil animals, soil animals’role and function in ecological system were revealed.In June,August,October each year,three plots were selected. In each plot, four layers were sampled(litter layer,0～10 cm,10～20 cm & 20～30 cm),adding up to 72 soil sample.The area for large_sized soil animals was 50 cm×50 cm,and the area for middle_small_sized soil animals was 10 cm × 10 cm.Separated soil animals through adopting hand_picking method and Tullgren method respectively.Sampled the soil animals in two continuing years.Shannon_Wiener index was adopted to analyze the diversity of soil animals.Monad liner regression was used to search the relationship between soil animals and environmental factors.The dominant groups were Oribatida, Isotomidae.There were relatively great changes in groups and individual numbers of dominant groups and rare groups when the reason changed.The individual numbers of dominant groups and the groups of rare groups changed.The number of individual and group was the most in August.Obviously it correlated with climatic factors in middle temperate zone.The evenness was low and dominance was high. The diversity index was not most.Among the annual fluctuating there was a increasing trend. The evenness was low and dominance was high.The diversity index was low.It conformed with the law of reason change.The correlation between soil animals and atmospheric temperature,rainfall,ground temperature and sunlight showed the correlation with rainfall and soil temperature was the most significant.展开更多
文摘Chemical and biochemical analysis methods were used to monitor the vedations of nitrogen nutrient among the dominance trees species in secondary succession process of the mixed broad - leaved/Korean pine forest on Changbai Mountains, Northeast China. Amounts of total nitrogen, anunonium and NRA in soils of virgin broad-leaved/Korean pine forest which is in climax were higher than those of secondary birch forests those are in succession Stage. The amount of nitrate was in the other hand. In climax, dominance trees species are tolerant mesophytic trees such as Pinus Koraiensis, Tilia amurensis, Acer mono and also Fraxinus mandshurica, they are all ammonium + nitrate adapted species, but they show a preference for the anunonium rather than those of the pioneer trees species in secondary birch forest, such as Populus davidiava and Betula platyphylla. Because they have more ammonium in their leaves and roots, especially Pinus koraiensis. Populus davidvana and Betula plaaphlla are intolerant trees, amounts of nitrate and total nitrogen is higher in their leaves and roots and also NRA in their leaves, so they preference for the nitrate rather than the others.In secondary birch forest, the regeneration trees species adapt their nitroggn nutrient to the variation of nitrogen nutrient situation in soil, finally they could survival well and the secondary birch forest would succession to climax. In climax, dominance trees species adapt their Nitrogen nutrient to the situation in soil and there are not strong competition in nitrogen nutrient among them, so they can coexist well and keep the climax as stable vegetation.
文摘Impacts on growth of young trees of Pinus Koraiensis of 6 environmental factors of intensityof sunlight, direct sunlight, thickness of soil humus, neighboring trees, upper canopy species, herbs andshrubs were investigated on young tree of Pinus Koraiensis and 4 neighboring trees which are consideredthe structural unit of the microenvironment. Results indicated that the 6 environmental factors underinvestigation had effects, to various extents, on growth of the young trees. Based on the findings, suitablegrowing conditions for regenerated young tree of Pinus Koraiensis under forest were identified andcorresponding silvicultural measures were proposed for operational practice.
文摘Soil animal communities of Pinus koraiensis broad_leaved mixed forest were studied.The purpose was to discuss the dynamic characteristic of soil animals and relationship with environmental factors.The ecosystem geography distribution law of soil animals, soil animals’role and function in ecological system were revealed.In June,August,October each year,three plots were selected. In each plot, four layers were sampled(litter layer,0～10 cm,10～20 cm & 20～30 cm),adding up to 72 soil sample.The area for large_sized soil animals was 50 cm×50 cm,and the area for middle_small_sized soil animals was 10 cm × 10 cm.Separated soil animals through adopting hand_picking method and Tullgren method respectively.Sampled the soil animals in two continuing years.Shannon_Wiener index was adopted to analyze the diversity of soil animals.Monad liner regression was used to search the relationship between soil animals and environmental factors.The dominant groups were Oribatida, Isotomidae.There were relatively great changes in groups and individual numbers of dominant groups and rare groups when the reason changed.The individual numbers of dominant groups and the groups of rare groups changed.The number of individual and group was the most in August.Obviously it correlated with climatic factors in middle temperate zone.The evenness was low and dominance was high. The diversity index was not most.Among the annual fluctuating there was a increasing trend. The evenness was low and dominance was high.The diversity index was low.It conformed with the law of reason change.The correlation between soil animals and atmospheric temperature,rainfall,ground temperature and sunlight showed the correlation with rainfall and soil temperature was the most significant.
