Windows 2000使公司可以将不同的商业单元集成到一个统一的结构中，这个结构就是活动目录森林，这在Windows NT4．0中是不可能的。许多在NT4．0域中不能共存的商业单元现在可以在活动目录的组织单元(OUs)或域中和平共处。但是正如一些...Windows 2000使公司可以将不同的商业单元集成到一个统一的结构中，这个结构就是活动目录森林，这在Windows NT4．0中是不可能的。许多在NT4．0域中不能共存的商业单元现在可以在活动目录的组织单元(OUs)或域中和平共处。但是正如一些使用单森林结构的人所说，也存在一些商业单元不能共处的场合。有时商业需求或政治原因要求您实现分离的森林。在许多情况下，分离森林中的用户仍然需要访问中心森林中的资源。因此，你需要在中心森林和其他森林之间建立信任关系。Windows2003在不同森林域之间建立信任关系的方法与NT4．0一致。但是Windows Server 2003新的森林信任功能使其变得更简单。展开更多
The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen’s test. In both the upper...The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen’s test. In both the upper reaches (Xiaohekou) and the lower reaches (Xiaohuangguayuan), the sediment fluxes showed a significant increase from 1970 to 2001, despite the fact that the water discharge did not change significantly during the period and numerous reservoir constructions which contribute to the trap of sediment. This can be attributed to the intensification of human activities, especially the activities related to land surface disturbances such as deforestation and afforestation, expansion of agriculture land, and road constructions. This increase is more significant in the lower reaches of the river observed at the place of Xiaohuangguayuan due to the dry-hot climate. The profound increase in sediment flux has significant implications for effective management of the sedimentation problems of the on-going Three Gorges Reservoir.展开更多
The aim of this research is to identify the most suitable land for forestry, afforestation and rangeland management in Hamadan province. This research has been accomplished using Makhdoum＇s model. In this research 30...The aim of this research is to identify the most suitable land for forestry, afforestation and rangeland management in Hamadan province. This research has been accomplished using Makhdoum＇s model. In this research 30 digital data layers are used. The Geographic Information System （GIS） has been used as main tool and overlay method has been used to implement the mentioned model. The results of this research revealed that the extent of favorite areas for fifth grade forestry, favorite areas for fourth grade afforestation, and favorite areas for third grade and fourth grade range management in the studied area. Based on the results of this research, the studied area has limited potentials for forestry and afforestation activities. The obtained results of evaluation also showed that the rangelands of Hamadan province are extremely poor. Since the rangelands have a substantial role in preservation of soil and water, therefore it is necessary to take appropriate measures for better exploitation of rangelands.展开更多
The study of tree mortality and recruitment contributes to the understanding of forest dynamics and, at the same time, supplies a baseline to evaluate the impact of human activities. The study site is a moist semi-dec...The study of tree mortality and recruitment contributes to the understanding of forest dynamics and, at the same time, supplies a baseline to evaluate the impact of human activities. The study site is a moist semi-deciduous forest located in the Caparo Forest Reserve, Venezuela. Tree data were obtained from permanent plots established in unlogged and logged stands. Successive measurements were taken during a 15 yr period. Tree species mortality and recruitment was analyzed for individuals with diameter at breast height （d）〉-- 10 cm. The species were classified according to their shade tolerance （low or intolerant, intermediate and high or tolerant） and the maximum height （hmax） （small〈15 m, medium： 15-30 m and large 〉30 m）. Palms were considered as a separate group. In the unlogged stands 307 and 274 trees ha-1 were found at the beginning and final time of the monitoring period, respectively. These trees were classified into 55 and 48 species, respectively. Among them predominate species from the shade intermediate tolerant and large size group and palms. Similarly, in the logged forest 155 and 207 trees ha^-1 were found, whereas 59 and 60 tree species were recorded. Only four species were found with 〉10 individuals had, the majority of these species belong to the functional group of shade intolerant medium size species, which may be partly explained by forest recovering after selective logging. In the unlogged stands the mean annual rate of tree mortality is 2.61% and the highest values corresponded to shade intermediate tolerant and intolerant small size species. Tree density was not significantly correlated to tree mortality in both forest conditions （logged and unlogged）. The recruitment rate in the unlogged forest was 1.33%, with the lowest values obtained for the same groups with highest mortality; whereas in the logged stands reached 2.58%, with the highest value for the shade tolerant small size species, followed by shade intermediate tolerant large size species. A significant difference was found between forest conditions for tree recruitment rates （H=0.0649）. In contrast, the correlation between tree mortality and recruitment was higher for logged （r=0.5988） than unlogged stands （r=0.4904） but not significant.展开更多
The dynamics and performance of soil biota during forest rotation were studied in monoculture beech stands forming a chronosequence of four different age-classes(30,62,111,153 yr).Biomass was monitored in major groups...The dynamics and performance of soil biota during forest rotation were studied in monoculture beech stands forming a chronosequence of four different age-classes(30,62,111,153 yr).Biomass was monitored in major groups of microflora,microfauna,mesofauna,and macrofauna.Resource availability(litter layer,soil organic mater),biomass of the two dominant decomposer groups(microflora,earthworms)as well as the biomass of mesofauna and microfauna were found to remain quite stable during forest succession.Nevertheless,the marked increase of the biomasses of primary decomposers(fungi,saprophagous macroinvertebrates)in the 62-year-old stand,followed by an increase of the biomasses of macropredators in the 111-year-old stand,indicate substantial changes of several components of edaphic communities during forest development.However,constant values of soil respiration suggest that the overall performance of the soil food web does not change during beech forest succession.Thus,the decomposer system of lowland managed beech forests on calcareous soils seems to be very stable over time.We suggest that earthworm activity might have masked impacts of forest development on other soil biota and led to an astounding stability of decomposer assemblages during beech forest rotation.展开更多
Over the years, protected areas have largely been associated with tourism activities where the global meets the local. Indeed, it is widely acknowledged that ＂parks are for people and forever＂. This implies that con...Over the years, protected areas have largely been associated with tourism activities where the global meets the local. Indeed, it is widely acknowledged that ＂parks are for people and forever＂. This implies that conservation areas must serve different and divergent interest groups for posterity. Moreover, amidst the proposal to manage natural resources at a local level, it should be appreciated that the local people have continuously been alienated. This paper discusses the conservation areas of Kakamega Forest and Saiwa Swamp in Western Kenya. Through questionnaire interviews with the local communities and natural area managers, it investigates the link among the local communities, protected areas, and tourism as envisaged in the Ecotourism Kenya motto. It concludes that sometimes tourism can be so close to the local people yet so far. Thus, for this linkage to occur, tourists should be fascinated by the cultural aspect （if provided by the local people） and that the local people should seize the opportunity to benefit from such visits.展开更多
文摘Windows 2000使公司可以将不同的商业单元集成到一个统一的结构中，这个结构就是活动目录森林，这在Windows NT4．0中是不可能的。许多在NT4．0域中不能共存的商业单元现在可以在活动目录的组织单元(OUs)或域中和平共处。但是正如一些使用单森林结构的人所说，也存在一些商业单元不能共处的场合。有时商业需求或政治原因要求您实现分离的森林。在许多情况下，分离森林中的用户仍然需要访问中心森林中的资源。因此，你需要在中心森林和其他森林之间建立信任关系。Windows2003在不同森林域之间建立信任关系的方法与NT4．0一致。但是Windows Server 2003新的森林信任功能使其变得更简单。
基金National BasicResearch Program of China(also called 973program)(project No.2003CB415105-6)National University of Singapore(NUS grantnumber R-109-000-034-112).
文摘The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen’s test. In both the upper reaches (Xiaohekou) and the lower reaches (Xiaohuangguayuan), the sediment fluxes showed a significant increase from 1970 to 2001, despite the fact that the water discharge did not change significantly during the period and numerous reservoir constructions which contribute to the trap of sediment. This can be attributed to the intensification of human activities, especially the activities related to land surface disturbances such as deforestation and afforestation, expansion of agriculture land, and road constructions. This increase is more significant in the lower reaches of the river observed at the place of Xiaohuangguayuan due to the dry-hot climate. The profound increase in sediment flux has significant implications for effective management of the sedimentation problems of the on-going Three Gorges Reservoir.
文摘The aim of this research is to identify the most suitable land for forestry, afforestation and rangeland management in Hamadan province. This research has been accomplished using Makhdoum＇s model. In this research 30 digital data layers are used. The Geographic Information System （GIS） has been used as main tool and overlay method has been used to implement the mentioned model. The results of this research revealed that the extent of favorite areas for fifth grade forestry, favorite areas for fourth grade afforestation, and favorite areas for third grade and fourth grade range management in the studied area. Based on the results of this research, the studied area has limited potentials for forestry and afforestation activities. The obtained results of evaluation also showed that the rangelands of Hamadan province are extremely poor. Since the rangelands have a substantial role in preservation of soil and water, therefore it is necessary to take appropriate measures for better exploitation of rangelands.
文摘The study of tree mortality and recruitment contributes to the understanding of forest dynamics and, at the same time, supplies a baseline to evaluate the impact of human activities. The study site is a moist semi-deciduous forest located in the Caparo Forest Reserve, Venezuela. Tree data were obtained from permanent plots established in unlogged and logged stands. Successive measurements were taken during a 15 yr period. Tree species mortality and recruitment was analyzed for individuals with diameter at breast height （d）〉-- 10 cm. The species were classified according to their shade tolerance （low or intolerant, intermediate and high or tolerant） and the maximum height （hmax） （small〈15 m, medium： 15-30 m and large 〉30 m）. Palms were considered as a separate group. In the unlogged stands 307 and 274 trees ha-1 were found at the beginning and final time of the monitoring period, respectively. These trees were classified into 55 and 48 species, respectively. Among them predominate species from the shade intermediate tolerant and large size group and palms. Similarly, in the logged forest 155 and 207 trees ha^-1 were found, whereas 59 and 60 tree species were recorded. Only four species were found with 〉10 individuals had, the majority of these species belong to the functional group of shade intolerant medium size species, which may be partly explained by forest recovering after selective logging. In the unlogged stands the mean annual rate of tree mortality is 2.61% and the highest values corresponded to shade intermediate tolerant and intolerant small size species. Tree density was not significantly correlated to tree mortality in both forest conditions （logged and unlogged）. The recruitment rate in the unlogged forest was 1.33%, with the lowest values obtained for the same groups with highest mortality; whereas in the logged stands reached 2.58%, with the highest value for the shade tolerant small size species, followed by shade intermediate tolerant large size species. A significant difference was found between forest conditions for tree recruitment rates （H=0.0649）. In contrast, the correlation between tree mortality and recruitment was higher for logged （r=0.5988） than unlogged stands （r=0.4904） but not significant.
基金funded by the EU in the context of the FORCAST project
文摘The dynamics and performance of soil biota during forest rotation were studied in monoculture beech stands forming a chronosequence of four different age-classes(30,62,111,153 yr).Biomass was monitored in major groups of microflora,microfauna,mesofauna,and macrofauna.Resource availability(litter layer,soil organic mater),biomass of the two dominant decomposer groups(microflora,earthworms)as well as the biomass of mesofauna and microfauna were found to remain quite stable during forest succession.Nevertheless,the marked increase of the biomasses of primary decomposers(fungi,saprophagous macroinvertebrates)in the 62-year-old stand,followed by an increase of the biomasses of macropredators in the 111-year-old stand,indicate substantial changes of several components of edaphic communities during forest development.However,constant values of soil respiration suggest that the overall performance of the soil food web does not change during beech forest succession.Thus,the decomposer system of lowland managed beech forests on calcareous soils seems to be very stable over time.We suggest that earthworm activity might have masked impacts of forest development on other soil biota and led to an astounding stability of decomposer assemblages during beech forest rotation.
文摘Over the years, protected areas have largely been associated with tourism activities where the global meets the local. Indeed, it is widely acknowledged that ＂parks are for people and forever＂. This implies that conservation areas must serve different and divergent interest groups for posterity. Moreover, amidst the proposal to manage natural resources at a local level, it should be appreciated that the local people have continuously been alienated. This paper discusses the conservation areas of Kakamega Forest and Saiwa Swamp in Western Kenya. Through questionnaire interviews with the local communities and natural area managers, it investigates the link among the local communities, protected areas, and tourism as envisaged in the Ecotourism Kenya motto. It concludes that sometimes tourism can be so close to the local people yet so far. Thus, for this linkage to occur, tourists should be fascinated by the cultural aspect （if provided by the local people） and that the local people should seize the opportunity to benefit from such visits.
