نتایج جستجو برای: forest

تعداد نتایج: 106136  

2014
John W. Coulston Gregory A. Reams David N. Wear Kenneth Brewer

Quantifying the amount of forest and change in the amount of forest are key to ensure that appropriate management practices and policies are in place to maintain the array of ecosystem services provided by forests. There are a range of analytical techniques and data available to estimate these forest parameters, however, not all ‘forest’ is the same and various components of change have been pr...

Journal: :Ecological applications : a publication of the Ecological Society of America 2015
Nicholas M Fountain-Jones Gregory J Jordan Thomas P Baker Jayne M Balmer Tim Wardlaw Susan C Baker

In increasingly fragmented landscapes, it is important to understand how mature forest affects adjacent secondary forest (forest influence). Forest influence on ecological succession of beetle communities is largely unknown. We investigated succession and forest influence using 235 m long transects across boundaries between mature and secondary forest at 15 sites, sampling a chronosequence of t...

2015
Jorge Almeida

Forest algebras are defined for investigating languages of forests [ordered sequences] of unranked trees, where a node may have more than two [ordered] successors [9]. We show that several parameters on forests can be realized as forest algebra homomorphisms from the free forest algebra into algebras which retain the equational axioms of forest algebras. This includes the number of nodes, the n...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2006
Daniel J Twedt William B Uihlein A Blaine Elliott

The historical area of bottomland hardwood forest in the Mississippi Alluvial Valley has been reduced by >75%. Agricultural production was the primary motivator for deforestation; hence, clearing deliberately targeted higher and drier sites. Remaining forests are highly fragmented and hydrologically altered, with larger forest fragments subject to greater inundation, which has negatively affect...

Asadollah Shahbahrami Hamid Hassanpour Hamidreza Gorgani Firouzjaee,

At present, there is no conventional scientific method to evaluate the area of the burnt regions of forests and in this field, the related organizations use different methods and variables. Also, the speed in performing the processes of area computing and damage evaluation, especially in the extensive damaged forest regions is very slow; consequently, the expression of results takes more ti...

احمدیان, زهرا, تاسه, مجتبی, صیاد, احسان, غلامی, شایسته,

Assessment of forest structure and their spatial patterns are essential for managing and evaluation of forest ecosystems. This study was conducted at the Zagros forests in Kermanshah to evaluate the forest structural characteristics and their spatial distribution. Data was collected from 25 plots (400 m2) in a 100 m × 100 m systematic sampling grid. The spacing between plots was 50 m. In each p...

Journal: :international journal of advanced biological and biomedical research 2013
aboulghasem yousefi leila darvishi

increasing urbanisation and industrialisation have led to a dramatic reduction in forest area, and now only culturally protected remnants of natural forests and some new plantations remain in most areas of the north of iran. to investigate the status of the chemical and physical characteristics of soil under these remnant forests and assess the possible impacts of reforestation on soil properti...

Journal: :journal of insect biodiversity and systematics 0
ibrahim khalil al haidar department of zoology, university of chittagong, chittagong-4331, bangladesh md. farid ahsan department of zoology, university of chittagong, chittagong-4331, bangladesh syed abbas 61/2 north pirerbag, mirpur, dhaka-1216, bangladesh md. tarik kabir white-rumped vulture conservation in bangladesh project, iucn bangladesh

butterflies of the inani reserve forest were studied between may 2014 and may 2015. one hundred twenty five species of butterflies belonging to 84 genera and six families (hesperiidae, papilionidae, pieridae, lycaenidae, riodinidae and nymphalidae) were recorded during this study. the highest number of species comprised family nymphalidae (38 species, 30.4%) followed by lycaenidae (35 species, ...

Journal: :caspian journal of environmental sciences 2009
sh. mohammadnezhad kiasari

soil productivity and plant growth are usually affected by biological activities of earthworms. the objective of this study was a comparative evaluation of earthworm abundances in 20-year-old plantations of alder, oak, maple and cypress with the adjacent natural mixed broad-leaved deciduous forest in the caspian region of iran. in this research one sample plot, each 1 ha; was selected in every ...

Journal: :caspian journal of environmental sciences 2007
a. mahdavi r. naghdi

abstract the aim of this study was to evaluate the status of information on forest and data transfer and to identify the gaps in information and data flow in forestry sector in iran. the study evaluated the data and information flow in three levels (control offices level, provincial offices level and organizational offices level) using the document analysis and questioning (interviews and ques...

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