This study is being carried out in the cross-border area of </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-fam...This study is being carried out in the cross-border area of </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the tri-national Dja-Odzala-Minkébé (TRIDOM), subject of a cooperation agreement between Cameroon, Congo a</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">nd Gabon in 2005. The purpose of this study is to analyze the dynamics of changes in land use in the context of cross-border cooperation. Geographic information systems and remote sensing were used to produce the various land use maps. For this purpose, the MERIS satellite images for the periods 1992, 2005 and 2018 were used. The exploration of the different images and the field visits made it possible to identify the following six land use classes: dense forests, degraded/deforested forests, savannas, swamp forests, buildings and bare soils, water surfaces. It emerges that the TRIDOM landscape is mainly occupied by dense forests which represent 97.02%, 96.72% and 96.52% respectively in 1992, 2005 and 2018. Then, degraded/deforested forests and savannas which would correspond to cultivation areas and fallow land only represent respectively 1.06% and 0.68% of the landscape in 1992. This proportion in 2005 is respectively 1.22% and 0.77%, whereas in 2018, it is respectively 1.36% and 0.81% of the massif. The landscape of TRIDOM has not experienced any significant land use change during the period after the signing of the cooperation agreement. Historical rates of deforestation are low during the period under study. They are estimated at 0.042% and 0.030% respectively for the period 1992-2005 and the period 2005-2018. These low rates of deforestation seem to be due to the measures taken to secure and sustainably manage the massif taken by the three countries, the low population density in this area and the still difficult level of accessibility of a large part of the massif.展开更多
The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected ...The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected combination of treatments depends on the conditions of the forest, and the objectives of the forest landowners. A two-step procedure is commonly used to derive the plan. First, treatment alternatives are generated for the stands using an automated simulation tool. Second,the optimal combination of the simulated treatment schedules is found by using mathematical programming or various heuristics. Simulation of treatment schedules requires models for stand dynamics and volume for all important tree species and stand types present in the forest.A forest planning system was described for Northeast China. The necessary models for stand dynamics and tree volume were presented for the main tree species of the region. The developed models were integrated into the simulation tool of the planning system. The simulation and the optimization tools of the planning system were described. The optimization tool was used with heuristic methods, making it possible to easily solve also spatial forest planning problems, for instance aggregate cuttings.Finally, the use of the system is illustrated with a case study, in which nonspatial and spatial management plans are developed for the Mengjiagang Forest District.展开更多
Dear Editor,Lake Baikal and its neighboring territories are an intermediate zone for the'steppe'and'arctic-like'rabies virus lineages in Russia.After the elimination of dog-mediated rabies during the e...Dear Editor,Lake Baikal and its neighboring territories are an intermediate zone for the'steppe'and'arctic-like'rabies virus lineages in Russia.After the elimination of dog-mediated rabies during the early 1980s,this area remained rabies-free for over 25–30 years.A sudden reappearance of rabies occurred in this zone in the Republic of Buryatia in 2011–2012.A marginal part of the Mongolian steppe penetrates the Siberian taiga forests in this area,and human and animal rabies have been repeatedly recorded in the Republic of Buryatia from the end of展开更多
文摘This study is being carried out in the cross-border area of </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the tri-national Dja-Odzala-Minkébé (TRIDOM), subject of a cooperation agreement between Cameroon, Congo a</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">nd Gabon in 2005. The purpose of this study is to analyze the dynamics of changes in land use in the context of cross-border cooperation. Geographic information systems and remote sensing were used to produce the various land use maps. For this purpose, the MERIS satellite images for the periods 1992, 2005 and 2018 were used. The exploration of the different images and the field visits made it possible to identify the following six land use classes: dense forests, degraded/deforested forests, savannas, swamp forests, buildings and bare soils, water surfaces. It emerges that the TRIDOM landscape is mainly occupied by dense forests which represent 97.02%, 96.72% and 96.52% respectively in 1992, 2005 and 2018. Then, degraded/deforested forests and savannas which would correspond to cultivation areas and fallow land only represent respectively 1.06% and 0.68% of the landscape in 1992. This proportion in 2005 is respectively 1.22% and 0.77%, whereas in 2018, it is respectively 1.36% and 0.81% of the massif. The landscape of TRIDOM has not experienced any significant land use change during the period after the signing of the cooperation agreement. Historical rates of deforestation are low during the period under study. They are estimated at 0.042% and 0.030% respectively for the period 1992-2005 and the period 2005-2018. These low rates of deforestation seem to be due to the measures taken to secure and sustainably manage the massif taken by the three countries, the low population density in this area and the still difficult level of accessibility of a large part of the massif.
基金financially supported by the Ministry of Science and Technology of the People’s Republic of China(2015BAD09B01)the Fundamental Research Funds for the Central Universities of the People’s Republic of China(2572014BA09)
文摘The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected combination of treatments depends on the conditions of the forest, and the objectives of the forest landowners. A two-step procedure is commonly used to derive the plan. First, treatment alternatives are generated for the stands using an automated simulation tool. Second,the optimal combination of the simulated treatment schedules is found by using mathematical programming or various heuristics. Simulation of treatment schedules requires models for stand dynamics and volume for all important tree species and stand types present in the forest.A forest planning system was described for Northeast China. The necessary models for stand dynamics and tree volume were presented for the main tree species of the region. The developed models were integrated into the simulation tool of the planning system. The simulation and the optimization tools of the planning system were described. The optimization tool was used with heuristic methods, making it possible to easily solve also spatial forest planning problems, for instance aggregate cuttings.Finally, the use of the system is illustrated with a case study, in which nonspatial and spatial management plans are developed for the Mengjiagang Forest District.
基金supported by the Federal Service for Surveillance in the Sphere of Consumers’ Rights Protection and Human Welfare (Rospotrebnadzor)All animal experiments were performed in accordance with Regulations for Proper Conduct of Animal Experiments (confirmed by order of the Ministry of Health USSR N 755 12-8-1977)
文摘Dear Editor,Lake Baikal and its neighboring territories are an intermediate zone for the'steppe'and'arctic-like'rabies virus lineages in Russia.After the elimination of dog-mediated rabies during the early 1980s,this area remained rabies-free for over 25–30 years.A sudden reappearance of rabies occurred in this zone in the Republic of Buryatia in 2011–2012.A marginal part of the Mongolian steppe penetrates the Siberian taiga forests in this area,and human and animal rabies have been repeatedly recorded in the Republic of Buryatia from the end of
