نتایج جستجو برای: felling

تعداد نتایج: 645  

Journal: :Croatian Journal of Forest Engineering 2022

Coppices are a major potential source of forest biomass in Spain, where they occupy around 4M ha. Quercus coppices mostly neglected because their high harvesting costs and the small size products. This makes them very interesting to test compare alternative means for utilizing resources an optimized way. Hence, comparative study motor-manual mechanized felling bunching was conducted when thinni...

Journal: :Asia Pacific Journal of Environment Ecology and Sustainable Development 2014

2014
José A. Reque Felipe Bravo

The effects of girdling were analysed in a sessile oak (Quercus petraea Matts. Leibl.) forest with an 80-year-old coppice with standard structure in northern Spain. The study evaluated the viability of girdling as an alternative to felling trees during crown thinning. Eighty-four direct competitors of selected future crop trees were girdled by double notching and peeling. Three years after gird...

2006
Karel Janák

Different methods of measuring and calculating the volume of logs in the forest after felling (“hand measuring”) and in log yards of sawmills (“electronic measuring”) give different results – volume of logs. The subject of this paper is the quantification of differences caused by the number and direction of scanning, by rounding and by volume calculation. The main results of measuring carried o...

2008
Satyaveer S. Chauhan Jean-Marc Frayret Luc LeBel Jean Favreau

We consider a two-echelon timber supply chain in which the first echelon consists of several stands to be harvested and the second echelon consists of mills to be procured with logs of different length. This problem aims at minimizing harvesting and transportation costs for one production period, while satisfying demand expressed as mix of volumes of specific log types. Harvesting cost, which i...

2014
Stefan Löfgren Ulf Grandin Sonja Stendera

Climate change is expected to cause an increased frequency of extreme events such as heavy floods and major storms. Such stochastic events have an immediate impact on surface water quality, but the long-term effects are largely unknown. In this study, we assess long-term monitoring data from two Swedish headwater catchments affected by extreme weather events. At one site, where nitrogen effects...

2009
Arun Kumar

The problems of the environmental management in river basins are treated as periphery problems. Though, these areas are often included in great reserves of natural resources of the nation, their contribution to the main land is quite often in terms of forest, water, wildlife, tourism and leisure industries. Forest and forest eco-systems of north-east India in general and Manipur in particular, ...

2007
Pamela A. Matson Peter M. Vitousek Maria Julia Mazzarino

We measured nitrogen transformations and loss following forest clearing in a relatively fertile tropical forest site. Nitrogen mineralization, nitrification, and amounts of ammonium and nitrate increased substantially in surface soils during the 6 mo following burning, then returned to background levels. The nitrogen content of microbial biomass declined to half its original value 6 mo after cl...

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