Dynamics of fixed NH in NH-treated soils incubated with glucose at 37±2℃ during the course ofincubation and factors affecting it were studied. Results showed that content of fixed NH in soil reached aminimun on ...Dynamics of fixed NH in NH-treated soils incubated with glucose at 37±2℃ during the course ofincubation and factors affecting it were studied. Results showed that content of fixed NH in soil reached aminimun on day 7 after incubation and then increased gradually regardless of the amount of glucose addedand the kind of soil tested. However, the amount of fixed NH released from the soil at the given time variedwith both the amount of glucose added and the kind of soil examined. In cases glucose was added at a rateof 10.0g C/kg soil, the amount of fixed NH retained in soil after 7 days of incubation was almost identicalto that found by Neubauer test. Addition of K￣+ depressed the release of fixed NH significantly. Based onthe results obtained a method for determining the content of available fixed NH in soils was proposed andthe amount of N as available fixed NH in two soils measured by this method on an area profile-depth basiswas presented.展开更多
This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of car...This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of carbon sequestration in five typical forest types have been studied by calculating the biomass from the timber accumulation data and converting to the money value. The results show that: in the duration of 100 years, at a discount rate of 5%, and 197 RMB yuan/t as the price of the carbon sequestration, the present value (PV) of the carbon sequestration in different forests are: 6900-9300 yuan/ha in Chinese pine forest,6100-8200 yuan/ha in oak forest, 4500-6100 yuan/ha in other broadleaf forests, 2300-3200 yuan/ha in shrubs and 1300-1800 yuan/ha in cypress forest. The annual mean economic benefit of carbon sequestration is 770-1040 yuan/ha. The pine forest has the highest carbon sequestration benefit, followed by oak forest, other broadleaf forest, shrubs, and cypress forest. If the land is suitable for all forests, pine forest and oak forest should be planted in order to sequestrate more carbon.展开更多
文摘Dynamics of fixed NH in NH-treated soils incubated with glucose at 37±2℃ during the course ofincubation and factors affecting it were studied. Results showed that content of fixed NH in soil reached aminimun on day 7 after incubation and then increased gradually regardless of the amount of glucose addedand the kind of soil tested. However, the amount of fixed NH released from the soil at the given time variedwith both the amount of glucose added and the kind of soil examined. In cases glucose was added at a rateof 10.0g C/kg soil, the amount of fixed NH retained in soil after 7 days of incubation was almost identicalto that found by Neubauer test. Addition of K￣+ depressed the release of fixed NH significantly. Based onthe results obtained a method for determining the content of available fixed NH in soils was proposed andthe amount of N as available fixed NH in two soils measured by this method on an area profile-depth basiswas presented.
文摘This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of carbon sequestration in five typical forest types have been studied by calculating the biomass from the timber accumulation data and converting to the money value. The results show that: in the duration of 100 years, at a discount rate of 5%, and 197 RMB yuan/t as the price of the carbon sequestration, the present value (PV) of the carbon sequestration in different forests are: 6900-9300 yuan/ha in Chinese pine forest,6100-8200 yuan/ha in oak forest, 4500-6100 yuan/ha in other broadleaf forests, 2300-3200 yuan/ha in shrubs and 1300-1800 yuan/ha in cypress forest. The annual mean economic benefit of carbon sequestration is 770-1040 yuan/ha. The pine forest has the highest carbon sequestration benefit, followed by oak forest, other broadleaf forest, shrubs, and cypress forest. If the land is suitable for all forests, pine forest and oak forest should be planted in order to sequestrate more carbon.
