نتایج جستجو برای: hyrcanain forests

تعداد نتایج: 39403  

2015
Gillian Petrokofsky Plinio Sist Lilian Blanc Jean-Louis Doucet Bryan Finegan Sylvie Gourlet-Fleury John R Healey Barbara Livoreil Robert Nasi Marielos Peña-Claros Francis E Putz Wen Zhou

Background: Currently, about 400 million hectares of tropical moist forests worldwide are designated production forests, about a quarter of which are managed by rural communities and indigenous peoples. There has been a gradual impoverishment of forest resources inside selectively logged forests in which the volume of timber extracted over the first cutting cycle was mostly from large, old tree...

Journal: :Journal of environmental management 2003
Heinrich Spiecker

In Europe temperate forests play a prominent role in timber production, nature protection, water conservation, erosion control and recreation. For centuries temperate forests in Europe have been affected by forest devastation and soil degradation. Applying great efforts to eliminate the severe wood shortage of those days, countermeasures were taken during the last 150 years by regenerating and ...

2013
Steffen Boch Daniel Prati Dominik Hessenmöller Ernst-Detlef Schulze Markus Fischer

Lichens are a key component of forest biodiversity. However, a comprehensive study analyzing lichen species richness in relation to several management types, extending over different regions and forest stages and including information on site conditions is missing for temperate European forests. In three German regions (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin), the so-called Biodiversi...

Journal: :Environmental health and preventive medicine 2010
Eeva Karjalainen Tytti Sarjala Hannu Raitio

This review aims to contribute to the ongoing discussion about human health, global change, and biodiversity by concentrating on the relationships between forests and human health. This review gives a short overview of the most important health benefits that forests provide to humans, and the risks that forests may pose to human health. Furthermore, it discusses the future challenges for the re...

2015
Tomasz Durak Roma Durak Ewa Węgrzyn Konrad Leniowski Brian J. Palik Eric J. Jokela

The Carpathians are Eastern Europe’s largest contiguous forest ecosystem and a hotspot of biodiversity. However, not much is known about changes in species diversity in these forests. Here we investigate the long-time changes in the diversity of plant communities in the Eastern Carpathian beech forests. We also inquire about the similarity of plant communities between managed and protected fore...

2003
DAVID A. WHITE

The woody communities of seven of the most intact bottomland hardwood forests of southeastern Louisiana are described. The seven forests are on old levee ridges associated with past distributaries of the Mississippi River. The communities were divided by diameter size class into overstory (~10.0 cm dbh) and understory (3.0 cm 2 10.0 cm dbh). The overstory (27 species) and understory (24 species...

2014
Meghan G. Midgley Richard P. Phillips

Temperate forests receive some of the highest rates of nitrogen (N) deposition in the world. While numerous studies have investigated the effects of N enrichment on forests, there is little consensus on why some forests become N saturated while others do not. To investigate this, we used a multi-factor metaanalysis to simultaneously estimate the relative importance of several environmental, exp...

Journal: :CoRR 2016
Marvin N. Wright Theresa Dankowski Andreas Ziegler

The most popular approach for analyzing survival data is the Cox regression model. The Cox model may, however, be misspecified, and its proportionality assumption is not always fulfilled. An alternative approach is random forests for survival outcomes. The standard split criterion for random survival forests is the log-rank test statistics, which favors splitting variables with many possible sp...

2017
Kok-Boon Neoh Lee-Jin Bong Ahmad Muhammad Masayuki Itoh Osamu Kozan Yoko Takematsu Tsuyoshi Yoshimura

Fire has become a common feature in tropical drained peatlands, and it may have detrimental impacts on the overall biodiversity of the forest ecosystem. We investigated the effect of fire on termite and ant assemblages and the importance of remnant forest in restoring species diversity in fire-impacted tropical peat swamp forests. The species loss of both termites and ants was as high as 50% in...

Journal: :Tree physiology 2013
Xuhui Zhou Yuling Fu Lingyan Zhou Bo Li Yiqi Luo

Tropical forests play a crucial role in regulating regional and global climate dynamics, and model projections suggest that rapid climate change may result in forest dieback or savannization. However, these predictions are largely based on results from leaf-level studies. How tropical forests respond and feedback to climate change is largely unknown at the ecosystem level. Several complementary...

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