نتایج جستجو برای: forest stands

تعداد نتایج: 123621  

2015
Yacine Kouba Felipe Martínez-García Ángel de Frutos Concepción L. Alados Dusan Gomory

At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity...

2011
Jörgen Rudolphi Lena Gustafsson

The majority of managed forests in Fennoscandia are younger than 70 years old but yet little is known about their potential to host rare and threatened species. In this study, we examined red-listed bryophytes and lichens in 19 young stands originating from clear-cutting (30-70 years old) in the boreal region, finding 19 red-listed species (six bryophytes and 13 lichens). We used adjoining old ...

2009
S. Tuominen R. Haapanen

In Finland, the forest inventory for the forest management planning has traditionally been based on visual inventory by stands. In this method, the forest stands that are delineated on aerial photographs on the basis of their growing stock and site-related characteristics are measured or estimated in the field. The method is considered too labour-intensive, and it requires a large amount of fie...

2014
Hans Pretzsch Peter Biber Gerhard Schütze Enno Uhl Thomas Rötzer

Forest ecosystems have been exposed to climate change for more than 100 years, whereas the consequences on forest growth remain elusive. Based on the oldest existing experimental forest plots in Central Europe, we show that, currently, the dominant tree species Norway spruce and European beech exhibit significantly faster tree growth (+32 to 77%), stand volume growth (+10 to 30%) and standing s...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده جنگلداری و مهندسی چوب و کاغذ 1386

چکیده ندارد.

2009
Julia I. Burton Eric K. Zenner Lee E. Frelich Meredith W. Cornett

Forest scientists advocate the use of natural disturbance-based forest management for restoring the characteristics of old-growth forests to younger second-growth northern hardwood stands. However, prescriptions rely upon studies that have (1) not spanned the full range of conditions and species assemblages, and (2) focused primarily on contrasting old-growth andmature second-growth stands at a...

2004
T. Aschoff H. Spiecker

A method for extracting forest parameters is described in this paper. The 3D point clouds derived from phase difference laser scanners in forests were processed in a step-wise separation. The first step contains basic filter methods to reduce raw data which, separates isolated points or deletes those artefacts resulting from the ambiguity problem. The next step includes using algorithms to isol...

2006
José Ramón González

The present thesis deals with the inclusion of fire risk considerations into forest planning in Catalonia (North-East Spain). The first part of the thesis focused on the modeling the susceptibility of different kinds of forest to fire (Studies I, II, III and IV), and the second part on the inclusion of the acquired knowledge about fire risk into forest planning systems (Studies V and VI). The m...

Journal: :جنگل و فرآورده های چوب 0
وحید اعتماد استادیار گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران مرتضی مریدی دانشجوی کارشناسی ارشددانشگاه تهران کیومرث سفیدی استادیار دانشکده فناوری کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی

evaluating the forest stands structure in different development stages is one of the ways for better understanding the forest dynamics and its response to natural disturbances. this study was carried out in the compartment 319, kheiroud forest in order to quantify the structure properties of mixed beech stands in the stem exclusion phase. for this purpose, three one-hectare sample plots were se...

2011
James M. Guldin

Roughly 30 percent of the 200 million acres of forest land in the South supports stands dominated by southern pines. These are among the most productive forests in the nation. Adapted to disturbance, southern pines are relatively easy to manage with even-aged methods such as clearcutting and planting, or the seed tree and shelterwood methods with natural regeneration. In addition, most species ...

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