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Wang W.,Northeast Forestry University | Wang W.,Mudanjiang Forest Ecosystem Research Station | Wang W.,Heilongjiang Forestry Engineering and Environment Institute | Chi D.,Northeast Forestry University | And 5 more authors.
Journal of Food, Agriculture and Environment | Year: 2014

This study aimed to investigate the effects of forest woody plant diversity (FWPD) on resisting plant diseases (PD) and insect pests (IP) for verifying forest biodiversity-stability hypothesis. White birch, larch, Mongolian Scots pine and aspen in Amuer Forestry of Da Xing'an Mountains in northern China during 2008-2011 were analysed. Sampled fields were surveyed for PD and IP. The results showed that PD and IP were concentrated on gentle slope of Rhododendron birch forest, hillside Rhododendron larch forest and hillside larch forest. When infection index of disease (IID) of infected field (IIDIF) and canopy density (CD) were fitted, the equation y = -139.32×2+116.36×+4.6231 with correlation coefficient (R2) (0.7998) was obtained. When Simpson IIDIF and IID were fitted, the equation y = 0.0022×2-0.1422×+2.7906 with R2 (0.7267) was obtained. When sample's infection rate of insect pests (IRIP) and Simpson index were fitted, equation y = 0.0007×2-0.1174×+5.6639 with R2 (0.8096) was obtained. These analysis revealed that DI was not increased with increasing CD, but decreased when CD reached certain density. When CD was 0.4176, IID began to fall, while IID and IRIP were decreased with increasing Simpson DI. These results indicate that FWPD differs with different types of forest species compositions. When FWPD is higher, its ability to resist damages of PD and IP is higher. Source

Tian S.-Y.,Heilongjiang Forestry Engineering and Environment Institute | Liu Y.-K.,Heilongjiang Forestry Engineering and Environment Institute | Wo X.-T.,Heilongjiang Forestry Engineering and Environment Institute | Li Y.-H.,Heilongjiang Forestry Engineering and Environment Institute | Chen Y.,Heilongjiang Forestry Engineering and Environment Institute
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2014

To understand the characteristics of soil organic carbon and its correlations with soil properties in the three original Pinus koraiensis forest types in XiaoXing'an Mountains of northeastern China, Picea sp.-Abies sp.-Pinus koraiensis forests, Tilia sp.-Pinus koraiensis forests and Quercus mongolica-Pinus koraiensis forests along elevation gradient were selected for this study, and soil samples were analyzed for soil total organic carbon (TOC), easily-oxidized carbon (EOC), microbial biomass carbon (MBC) and basic properties. Results showed that the contents of soil TOC, EOC and MBC in the three forest types decreased with increase of soil depth. Exception of the depth of 10-20 cm, the soil TOC and EOC concentration ranged in order as follows: Quercus mongolica-Pinus koraiensis forests > Tilia sp.-Pinus koraiensis forests > Picea sp.-Abies sp.-Pinus koraiensis forests, it had the same trend as elevation gradient. Soil MBC varied in different soil depths for the three forest types. Soil EOC, MBC and TOC were all significantly related to total N and C/N, and were negatively significantly related to soil bulk density. We concluded that the combined effects of forest type, elevation, and soil environment contributed to the differences in the soil organic carbon found across the three original P. koraiensis forest types. Source

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