Two methods in evaluating soil fertility in semi-natural larch-spruce-fir (Larix olgensis-picea jezoensis-abies nephrolepis) plantations in northeast China

The objective of this study is to compare two methods in evaluating soil quality, and to find the change regulation of soil quality with varied stand density. The result will provide a theoretical basis for local forest management. Study area was Jingouling forest farm, Jilin Province, northeast China. A total of 10 temporary circular sample plots with different stand density ranging from 488 trees/hm2 to 930 trees/hm2 were set up in semi-natural larch-spruce-fir plantations. Principal component analysis and particle size distribution were used to evaluate soil quality under different stand densities. Although the result did not show a change pattern following stand densities, soil quality showed the same tendency using these two methods. Soil particle structure is more sensitive to soil moisture and it is much easier using particle size distribution (PSD). Therefore, we could use PSD to evaluate soil quality in similar stands in the future research. The objective of this study is to compare two methods in evaluating soil quality, and to find the change regulation of soil quality with varied stand density. The result will provide a theoretical basis for local forest management. Study area was Jingouling forest farm, Jilin Province, northeast China. A total of 10 temporary circular sample plots with different stand density ranging from 488 trees/hm2 to 930 trees/hm2 were set up in semi-natural larch-spruce-fir plantations. Principal component analysis and particle size distribution were used to evaluate soil quality under different stand densities. Although the result did not show a change pattern following stand densities, soil quality showed the same tendency using these two methods. Soil particle structure is more sensitive to soil moisture and it is much easier using particle size distribution (PSD). Therefore, we could use PSD to evaluate soil quality in similar stands in the future research. (author)