Effect of road density on abundance of white-footed mice     

Trina Rytwinski  Lenore Fahrig 《Landscape Ecology》2007,22(10):1501-1512

While several studies have demonstrated that roads can act as barriers to small mammal movement, the relationship between road density and small mammal abundance has not yet been investigated. In southeastern Ontario, Peromyscus leucopus (white-footed mice) suffer high over-winter mortality rates, resulting in small springtime populations and frequent local extinctions. Peromyscus leucopus movement is known to be inhibited by roads, which should result in lower rates of immigration into and recolonization of habitats in landscapes with high road density. We tested two predictions: (1) Forest sites situated in landscapes with high road densities have a higher chance of P. leucopus being absent during the early spring than forest sites situated in landscapes with low road densities and (2) P. leucopus populations during the summer are smaller in forest sites situated in landscapes with high road densities than in landscapes with low road densities. We sampled P. leucopus in focal patches within nineteen landscapes (7 rural, low-road-density landscapes; 7 rural, high-road-density landscapes; 5 urban landscapes). There was no significant relationship between road density and the presence/absence of P. leucopus during the early spring. We found a significant positive effect of road density on P. leucopus relative abundance during the summer, even when we excluded the urban landscapes and based the analysis on only the 14 rural landscapes. Our results suggest that any negative effect of roads on P. leucopus populations, created by their inhibition to moving across roads, is far outweighed by some positive effect of roads on P. leucopus abundance. We suggest that the two most likely explanations are that roads are positively correlated with an important as-yet-undetermined component of habitat quality, or that roads positively affect P. leucopus by negatively affecting their predators.  相似文献   

论天然林保护工程中森林工程学科的发展     

朱永林 《森林工程》1999,15(3):12-13

本文论述了天然林保护工程中森林工程学科的任务。学科发展追求的目的,从学术研究角度探讨了众林工程学科将要遇到的新机遇和新课题。  相似文献   

河南引栽栀子自然类型的研究     

孙军  朱秀谦 《河南林业科技》1999,19(2):13-14

本文首次报道了河南引种栽培栀子的研究结果。主要介绍了栀子的５个自然类型，即：（１）栀子，（２）大花栀子，（３）小果栀子，（４）红果栀子，（５）兰紫果栀子。  相似文献   

Variability in feeding ecology of a South American cichlid: a reason for successful invasion in mediterranean‐type rivers?     

F. Ribeiro  R. L. Orjuela  M. F. Magalhães  M. J. Collares-Pereira 《Ecology of Freshwater Fish》2007,16(4):559-569

Abstract –  Ecological attributes behind the success of the South American cichlid Australoheros facetus in mediterranean-type rivers remain unclear. This study addresses this issue, by analysing its abundance and feeding patterns in the lower Guadiana drainage (Portugal), during the dry season of 2003. Despite slight spatial variations in abundance and individual size, A. facetus seemed well established in the Guadiana, Vascão and Ardila rivers. No seasonal or size-related changes in feeding intensity were found, but the diet changed across rivers, over time and throughout ontogeny. Feeding seemed highly generalist, with fish apparently reacting to both spatial and temporal changes in food supply and tending to use the most abundant and easily accessible food items. Overall prey breadth was broad relative to that of other native and non-native species. It is suggested that a generalist feeding strategy may play a significant role in the establishment of non-native fish in mediterranean-type rivers.  相似文献   

尖扎县天保工程建设探讨     

马启明  梁沛轩 《青海农林科技》2007,(3):77-78

阐述了尖扎县的天保工程建设情况,总结分析了本区林业发展过程中的经验和问题,提出了今后尖扎县更好发展天保工程建设的对策。  相似文献   

Strategies on natural forest protection of collective forest area in minority nationality community in China     

Luo Ming-can  Qin Jia-li  Liu Si-hui  Jiang Xing-long 《林业研究》2000,11(2):132-134

In the recent 20 years, it is a trend that forest will be distributed to villagers to manage in the world. Also in China, “forestry three determinations” has been carried out since 1980, and many new forestry devolutions have been put forward to and come into being. To face the fact of overusing up natural forest to result in the deterioration of ecology environment, the strategy of natural forest protection project (NFPP) is raised after the heavy flood in 1998. Now, it is paid close attention to systematically study to carry out the strategies of NFPP in collective forest area, especially in the community of minority nationalities. Based on the case of forest resource management in Datu Miao Village, the experience of its forest management in the past is analyzed and the strategies of NFPP in collective forest area are put forward. Foundation item: This project is a part of research project “forest devolution management of IFAD/CIFOR” Biography: L{upuo} Ming-can (1961-), maie, associate professor, vice director of post-graduate school of Southwest Forestry College, Kunming 650224, P.R. China. Responsible editor: Song Funan  相似文献   

雷公山姊妹岩大果马蹄荷群落初步研究   总被引：1，自引：0，他引：1  

伍铭凯杨汉远  吴智涛 《贵州林业科技》2007,35(1):15-19

大果马蹄荷群落是雷公山森林生态系统中的一个类型，通过调查，对大果马蹄荷群落结构、群落特征、天然更新进行初步研究。  相似文献   

贵州省天柱县天然林资源保护工程封山育林调查分析     

秦冬月  胡跃芝 《贵州林业科技》2007,35(1):48-50

本文通过对天柱县1999、2000年度天保工程封山育林情况的调查分析：基于本地区丰富的水热、物种资源条件和独特的自然地理，封山育林作为保护和恢复森林资源的主要工程措施效果显著，值得推广。项目建设应选择栎类、马尾松、杂阔等先锋乔木为主要组成树种的疏林地和灌木林地作为封育对象。在天然林资源保护工程建设中，森林三大效益能否达到和谐统一，有待进一步研究。  相似文献   

沙兰杨短轮伐期定向培育中小径材的研究     

朱灵益  王朝智 《林业科学》1990,26(6):550-555

短轮伐期的研究工作,首先由美国杨格于1944年提出,1970年美国、加拿大开始杨树短轮伐期试验,70年代中后期又有许多国家开展这项工作。我国于1978年在河北省邯郸地区漳河林场开始探索该项工作,从80年代开始各省(区)建立速生丰产林基地,1989年全国营造速生丰产林33万ha。我们于1978年在漳河林场进行了沙兰杨短、中短两种轮伐期试验。一、试验区自然概况河北省漳河林场位于北纬36°19′,东经114°24′,属暖温带大陆性半湿润季风气候区,  相似文献   

Switch of tropical Amazon forest to pasture affects taxonomic composition but not species abundance and diversity of arbuscular mycorrhizal fungal community     

《Applied soil ecology》2013

Arbuscular mycorrhizal fungi (AMF) community composition and species richness are affected by several factors including soil attributes and plant host. In this paper we tested the hypothesis that conversion of tropical Amazon forest to pasture changes taxonomic composition of AMF community but not community species abundance and richness. Soil samples were obtained in 300 m × 300 m plots from forest (n = 11) and pasture (n = 13) and fungal spores extracted, counted and identified. A total of 36 species were recovered from both systems, with 83% of them pertaining to Acaulosporaceae and Glomeraceae. Only 12 species were shared between systems and spore abundance of the majority of fungal species did not differ between pasture and forest. Spore abundance was significantly higher in pasture compared to forest but both systems did not differ on mean species richness, Shannon diversity and Pielou equitability. Species abundance distribution depicted by species rank log abundance plots was not statistically different between both systems. We concluded that conversion of pristine tropical forest to pasture influences the taxonomic composition of AMF communities while not affecting species richness and abundance distribution.  相似文献