Knowledge about cumulative effects of forest management alternatives on forest landscape is required to make forest management decision. In this paper,a spatially explicit landscape model,LANDIS,was applied to simulat...Knowledge about cumulative effects of forest management alternatives on forest landscape is required to make forest management decision. In this paper,a spatially explicit landscape model,LANDIS,was applied to simulate forest landscape changes in 200 years under four management alternatives (no cutting,clearcutting,selective cutting I and II) in Youhao Forestry Bureau located in Small Khingan Mountains. APACK was used to calculate distribution area of the representative species and species age cohort for six species. The results showed:1) timber harvest decreased area percentage of representative conifer species,Pinus koraiensis,Picea koraiensis and Picea jezoensis,Larix gmelinii to some extent compared to no cutting. The most influencing cutting mode for the area percentage of Tilia amurensis and Quercus mongolica was selective cutting II,followed by selective cutting I and clearcutting. To the contrast,the change of area percentage of Betula phatyphylla was contrary to the management alternatives; 2) As to species age cohort composition,timber harvest significantly changed age structure,that is,it decreased over-matured age cohort of representative species,and increased seedling and middle-age cohort (B. phatyphylla was not included,because its area percentage of over-mature age cohort was the highest under clearcutting than other three scenarios).展开更多
在美国首都华盛顿的国家广场的博物馆群中,有一座气势恢宏的国家自然博物馆(National Museum of Natural History)。作为史密森研究院(Smithsonian Institution)的一员,该馆及其附属设施的总面积近12.3万平方米,自然类标本和文化类藏品...在美国首都华盛顿的国家广场的博物馆群中,有一座气势恢宏的国家自然博物馆(National Museum of Natural History)。作为史密森研究院(Smithsonian Institution)的一员,该馆及其附属设施的总面积近12.3万平方米,自然类标本和文化类藏品的总量超过1.45亿件,是全球藏品数量最多的自然博物馆。展开更多
文摘Knowledge about cumulative effects of forest management alternatives on forest landscape is required to make forest management decision. In this paper,a spatially explicit landscape model,LANDIS,was applied to simulate forest landscape changes in 200 years under four management alternatives (no cutting,clearcutting,selective cutting I and II) in Youhao Forestry Bureau located in Small Khingan Mountains. APACK was used to calculate distribution area of the representative species and species age cohort for six species. The results showed:1) timber harvest decreased area percentage of representative conifer species,Pinus koraiensis,Picea koraiensis and Picea jezoensis,Larix gmelinii to some extent compared to no cutting. The most influencing cutting mode for the area percentage of Tilia amurensis and Quercus mongolica was selective cutting II,followed by selective cutting I and clearcutting. To the contrast,the change of area percentage of Betula phatyphylla was contrary to the management alternatives; 2) As to species age cohort composition,timber harvest significantly changed age structure,that is,it decreased over-matured age cohort of representative species,and increased seedling and middle-age cohort (B. phatyphylla was not included,because its area percentage of over-mature age cohort was the highest under clearcutting than other three scenarios).
文摘在美国首都华盛顿的国家广场的博物馆群中,有一座气势恢宏的国家自然博物馆(National Museum of Natural History)。作为史密森研究院(Smithsonian Institution)的一员,该馆及其附属设施的总面积近12.3万平方米,自然类标本和文化类藏品的总量超过1.45亿件,是全球藏品数量最多的自然博物馆。
