The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, ...The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, total P and C: N ratio of the soil inP. sylvestris var.mongolica stands were significantly higher in comparison with those inP. tabulaeformis andP. densiflora stands. ForP. sylvestris var.mongolica, the foliar P concentration appeared to decrease with age, and the foliar N and K concentrations did not show a consistent change with age. As for the different tree species of the similar age, the foliar N and P concentrations were significantly different (p<0.05), being withP. sylvestris var.mongolica>P. densiflora>P. tabulaeformis. The foliar N: P ratio ofP. densiflora significantly was higher thanP. sylvestris var.mongolica andP. tabulaeformis, while the foliar K was no obvious difference between the three tree species. There were significant correlation (p<0.05) between soil total N and P, soil organic matter and total P, foliar N and P, but it did not show significant correlations between soil and foliar nutrient concentrations, which might attribute to the excessive litter raking, overgrazing and low soil moisture in this area. Based on the foliar N: P ratio, we introduced a combination threshold index of N: P ratio with their absolute foliar nutrient concentrations to determine the possible limiting nutrient. According to the critical N: P ratio and their absolute foliar N, P concentrations, theP. sylvestris var.mongolica stands showed a decreased N limitation degree with age, theP. densiflora stands showed unlimited by N and P in the whole, and theP. tabulaeformis stands showed co-limited by N and P. No significant difference in soil nutrient concentrations of the surface soils was found between 45, 29, 20-yr-oldPinus sylvestris var.mongolica plantation stands. Keywords coniferous trees - foliar nutrient concentration - limiting nutrients - N - P ratio - Zhanggutai sandy land CLC number S718.55 Document code A Article ID 1007-662X(2004)01-0011-08 Foundation item: This research was supported by Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences.Biography: CHEN Guang-sheng (1978-), male, master candidate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. ChinaResponsible editor: Song Funan展开更多
The expansion of fast-growing tree plantations is a worldwide process,with consequences on soil fertility and soil carbon storage.Disparate results were found on the effects of afforestation with Eucalyptus on soil ca...The expansion of fast-growing tree plantations is a worldwide process,with consequences on soil fertility and soil carbon storage.Disparate results were found on the effects of afforestation with Eucalyptus on soil carbon and other nutrient contents.These discrepancies are usually caused by differences in climate,land use history,soil texture as well as by management related factors such as plantation age,number of rotations,method of establishment(plantation or coppice),harvest residue management and soil preparation.We studied the effect of plantation age,number of rotations,and method of establishment on soils and plant nutrient concentrations in Eucalyptus grandis plantations in NE Argentina on different textured soils.We also determined if yields changed with nutrient variations in soils,and compared soils under plantations to soils under grasslands they replaced.Thirty-one E.grandis stands of different ages,number of rotations and method of establishment were evaluated as well as eight grassland sites.Levels of carbon,nitrogen,phosphorus,potassium,calcium and magnesium were determined for soils and plants.Soil carbon and nitrogen decreased over the number of rotations and were more pronounced in soils with 50-60%sand than soils with>75%sand.Coppice stands showed higher soil carbon and nitrogen levels than plantations,suggesting a negative effect of site preparation before planting on soil nutrient conservation,especially in fine-textured soils.Foliar nutrient concentrations did not follow the trends observed for soil nutrients nor did they reflect nutrient limitations.There was no evidence of decreased yields over successive rotations.Soil carbon and nitrogen contents decrease when grasslands are replaced by E.grandis plantations,and therefore a yield limitation may occur in a medium to long-term frame,especially in stands re-established for short-rotation management.Harvest residue management and site preparation must be specifically designed for improving soil nutrient management.展开更多
基金Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences.
文摘The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, total P and C: N ratio of the soil inP. sylvestris var.mongolica stands were significantly higher in comparison with those inP. tabulaeformis andP. densiflora stands. ForP. sylvestris var.mongolica, the foliar P concentration appeared to decrease with age, and the foliar N and K concentrations did not show a consistent change with age. As for the different tree species of the similar age, the foliar N and P concentrations were significantly different (p<0.05), being withP. sylvestris var.mongolica>P. densiflora>P. tabulaeformis. The foliar N: P ratio ofP. densiflora significantly was higher thanP. sylvestris var.mongolica andP. tabulaeformis, while the foliar K was no obvious difference between the three tree species. There were significant correlation (p<0.05) between soil total N and P, soil organic matter and total P, foliar N and P, but it did not show significant correlations between soil and foliar nutrient concentrations, which might attribute to the excessive litter raking, overgrazing and low soil moisture in this area. Based on the foliar N: P ratio, we introduced a combination threshold index of N: P ratio with their absolute foliar nutrient concentrations to determine the possible limiting nutrient. According to the critical N: P ratio and their absolute foliar N, P concentrations, theP. sylvestris var.mongolica stands showed a decreased N limitation degree with age, theP. densiflora stands showed unlimited by N and P in the whole, and theP. tabulaeformis stands showed co-limited by N and P. No significant difference in soil nutrient concentrations of the surface soils was found between 45, 29, 20-yr-oldPinus sylvestris var.mongolica plantation stands. Keywords coniferous trees - foliar nutrient concentration - limiting nutrients - N - P ratio - Zhanggutai sandy land CLC number S718.55 Document code A Article ID 1007-662X(2004)01-0011-08 Foundation item: This research was supported by Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences.Biography: CHEN Guang-sheng (1978-), male, master candidate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. ChinaResponsible editor: Song Funan
文摘The expansion of fast-growing tree plantations is a worldwide process,with consequences on soil fertility and soil carbon storage.Disparate results were found on the effects of afforestation with Eucalyptus on soil carbon and other nutrient contents.These discrepancies are usually caused by differences in climate,land use history,soil texture as well as by management related factors such as plantation age,number of rotations,method of establishment(plantation or coppice),harvest residue management and soil preparation.We studied the effect of plantation age,number of rotations,and method of establishment on soils and plant nutrient concentrations in Eucalyptus grandis plantations in NE Argentina on different textured soils.We also determined if yields changed with nutrient variations in soils,and compared soils under plantations to soils under grasslands they replaced.Thirty-one E.grandis stands of different ages,number of rotations and method of establishment were evaluated as well as eight grassland sites.Levels of carbon,nitrogen,phosphorus,potassium,calcium and magnesium were determined for soils and plants.Soil carbon and nitrogen decreased over the number of rotations and were more pronounced in soils with 50-60%sand than soils with>75%sand.Coppice stands showed higher soil carbon and nitrogen levels than plantations,suggesting a negative effect of site preparation before planting on soil nutrient conservation,especially in fine-textured soils.Foliar nutrient concentrations did not follow the trends observed for soil nutrients nor did they reflect nutrient limitations.There was no evidence of decreased yields over successive rotations.Soil carbon and nitrogen contents decrease when grasslands are replaced by E.grandis plantations,and therefore a yield limitation may occur in a medium to long-term frame,especially in stands re-established for short-rotation management.Harvest residue management and site preparation must be specifically designed for improving soil nutrient management.
