نتایج جستجو برای: forest trees

تعداد نتایج: 184211  

2005
Robert Griffiths Michael Madritch Alan Swanson

In many areas, chemical and biological characteristics of soils change when trees colonize meadows. To determine if the invasion of high meadows by forests in the central Cascade Mountains of Oregon altered soil properties, we measured soil properties along transects from mountain meadows through transition zones, where trees were becoming established, into mature forest. The differences observ...

Journal: :Ecology letters 2012
William A Hoffmann Erika L Geiger Sybil G Gotsch Davi R Rossatto Lucas C R Silva On Lee Lau M Haridasan Augusto C Franco

Fire shapes the distribution of savanna and forest through complex interactions involving climate, resources and species traits. Based on data from central Brazil, we propose that these interactions are governed by two critical thresholds. The fire-resistance threshold is reached when individual trees have accumulated sufficient bark to avoid stem death, whereas the fire-suppression threshold i...

2013
Erhan Caliskan

Forest roads are the base infrastructure foundation of forestry operations. These roads entail a complex engineering effort because they can cause substantial environmental damage to forests and include a high-cost construction. This study was carried out in four sample sites of Giresun, Trabzon(2) and Artvin Forest Directorate, which is in the Black Sea region of Turkey. The areas have both st...

2013
James H. Derzon Aaron A. Alford

Forest plots provide an effective means of presenting a wealth of information in a single graphic. Whether used to illustrate multiple results in a single study or the cumulative knowledge of an entire field, forest plots have become an accepted and generally understood way of presenting many estimates simultaneously. This article explores advanced uses of the forest plot with the intent of hig...

Journal: :Molecular ecology 2003
Christopher W Dick Gabriela Etchelecu Frédéric Austerlitz

Tropical rainforest trees typically occur in low population densities and rely on animals for cross-pollination. It is of conservation interest therefore to understand how rainforest fragmentation may alter the pollination and breeding structure of remnant trees. Previous studies of the Amazonian tree Dinizia excelsa (Fabaceae) found African honeybees (Apis mellifera scutellata) as the predomin...

1999
I. R. Ball D. B. Lindenmayer H. P. Possingham

This paper describes a deterministic computer model for simulating forest dynamics. The model predicts the long-term dynamics of hollow-bearing trees which occur in a single-species (monotypic) forest stand under an array of different timber harvesting regimes over a time scale of centuries. It is applied to a number of different timber harvesting scenarios in the mountain ash (Eucalyptus regna...

Journal: :محیط زیست طبیعی 0
فاطمه بهادری خسروشاهی دانش آموخته کارشناسی ارشد، شرکت مهندسان مشاور آب و عمران فراز اندیش، ایران افشین علیزاده شعبانی استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران محمد کابلی استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران محمود کرمی استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران پدرام عطارد استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران میترا شریعتی دانش آموخته کارشناسی ارشد، دانشکده منابع طبیعی، دانشگاه تهران، ایران

the aim of this study was to develop a methodology to identify suitable habitat of the eurasian nuthatch (sitta europea) at kheyrood forest, northern alborz, iran. this study was carried out during spring to summer 2008. with attention to the area and topographic condition of kheyrood forest, patom, namkhane, gorazbon, cheler and baharbon were selected as data collecting series. the present stu...

2016
H. Eden W. Cottee-Jones Omesh Bajpai Lal B. Chaudhary Robert J. Whittaker

Forest restoration is an increasingly important tool to offset and indeed reverse global deforestation rates. One low cost strategy to accelerate forest recovery is conserving scattered native trees that persist across disturbed landscapes and which may act as seedling recruitment foci. Ficus trees, which are considered to be critically important components of tropical ecosystems, may be partic...

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