نتایج جستجو برای: unmanaged forest

تعداد نتایج: 106735  

   Biomass measurement is important in terms of ecological and economical evaluation of the structure and conditions of habitat and can provide an estimate for carbon sequestration in different organs of tree. In order to assess the amount of biomass in harvested and unmanaged Beech stands, two compartments (511 and 514) of Safaroodchr('39')s forest  were selected. A plot of 6.25 hectare from e...

Journal: :Remote Sensing 2014
Stephan Getzin Robert S. Nuske Kerstin Wiegand

Gap distributions in forests reflect the spatial impact of man-made tree harvesting or naturally-induced patterns of tree death being caused by windthrow, inter-tree competition, disease or senescence. Gap sizes can vary from large (>100 m) to small (<10 m), and they may have contrasting spatial patterns, such as being aggregated or regularly distributed. However, very small gaps cannot easily ...

Journal: :MCFNS 2009
Klaus Gadow Chun Yu Zhang Xiu Hai Zhao

Approximately 3000 million ha of the world’s forests have been classified as productive, and are subject to some kind of management. Considering their environmental and social importance, the managed forest ecosystems are not receiving as much scientific attention as the few remaining unmanaged ones. This is especially true in the growing urban landscapes where managed forest ecosystem provide ...

Journal: :Journal of environmental quality 2005
Richard Lowrance Joseph M Sheridan

Managed riparian forest buffers are an important conservation practice but there are little data on the water quality effects of buffer management. We measured surface runoff volumes and nutrient concentrations and loads in a riparian buffer system consisting of (moving down slope from the field) a grass strip, a managed forest, and an unmanaged forest. The managed forest consisted of sections ...

Journal: :محیط زیست طبیعی 0
زهرا نوری دانشجوی دکترای جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران جهانگیر فقهی دانشیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران قوام الدین زاهدی امیری دانشیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران رامین رحمانی دانشیار گروه جنگلداری، دانشگاه گرگان، ایران

the aim of this study is to investigate the tree species&apos; diversity in a region with no management planning and introduce the calculated indices as the norm for sustainability assessment. dbh of all tree individuals, and their stories were recorded in the inventory grid (75 m × 100 m) sample plots. subsequently, richness, evenness (simpson, smith & wilson) and heterogeneity (simpson, shann...

2007
Hakan Oguz R. Srinivasan

We used the SLEUTH urban growth model, closely coupled with a land transition model, to simulate future urban growth in the Houston metropolitan area, one of the fastest growing metropolises in the United States during the past three decades. The model was calibrated with historical data extracted from a time series of satellite images. Three specific scenarios are designed to simulate the spat...

Journal: :Science 2009
Phillip J van Mantgem Nathan L Stephenson John C Byrne Lori D Daniels Jerry F Franklin Peter Z Fulé Mark E Harmon Andrew J Larson Jeremy M Smith Alan H Taylor Thomas T Veblen

Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29 years among regions. Increa...

2017
Norimasa Takayama Akio Fujiwara Haruo Saito Masahiro Horiuchi

We investigated the influence of forest management on landscape appreciation and psychological restoration in on-site settings by exposing respondents to an unmanaged, dense coniferous (crowding) forest and a managed (thinned) coniferous forest; we set the two experimental settings in the forests of the Fuji Iyashinomoroi Woodland Study Center. The respondents were individually exposed to both ...

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