نتایج جستجو برای: subalpine ecosystems

تعداد نتایج: 47057  

2007
Michael A. Battaglia Wayne D. Shepperd

Before European settlement of the interior west of the United States, coniferous forests of this region were influenced by many disturbance regimes, primarily fires, insects, diseases, and herbivory, which maintained a diversity of successional stages and vegetative types across landscapes. Activities after settlement, such as fire suppression, grazing, and logging significantly altered these d...

2015
Marion Boutin Thierry Lamaze Florian Couvidat André Pornon

Deposition of reactive nitrogen (N) from the atmosphere is expected to be the third greatest driver of biodiversity loss by the year 2100. Chemistry-transport models are essential tools to estimate spatially explicit N deposition but the reliability of their predictions remained to be validated in mountains. We measured N deposition and air concentration over the subalpine Pyrenees. N depositio...

2001
Prince George

The Aleza Lake Shelterwood Case Study is a recent introduction of uniform shelterwood methods to interior spruce-subalpine fir forests in central British Columbia. The goal of this operational trial is to test spruce shelterwood prescriptions designed for local conditions, and to monitor and report on post-harvest silvicultural results. Potential risks and operational disadvantages are also bei...

Journal: :Environmental entomology 2009
Susan E Elliott

Bees feed almost exclusively on nectar and pollen from flowers. However, little is known about how food availability limits bee populations, especially in high elevation areas. Foraging distances and relationships between forager densities and resource availability can provide insights into the potential for food limitation in mobile consumer populations. For example, if floral resources are li...

Journal: :The New phytologist 2016
Roberto A Geremia Mihai Pușcaș Lucie Zinger Jean-Marc Bonneville Philippe Choler

The effect of plant species composition on soil microbial communities was studied at the multiregional level. We compared the soil microbial communities of alpine natural grasslands dominated by Carex curvula and anthropogenic subalpine pastures dominated by Nardus stricta. We conducted paired sampling across the Carpathians and the Alps and used Illumina sequencing to reveal the molecular dive...

Journal: :The New phytologist 2014
Paul V Dunnette Philip E Higuera Kendra K McLauchlan Kelly M Derr Christy E Briles Margaret H Keefe

Wildfires can significantly alter forest carbon (C) storage and nitrogen (N) availability, but the long-term biogeochemical legacy of wildfires is poorly understood. We obtained a lake-sediment record of fire and biogeochemistry from a subalpine forest in Colorado, USA, to examine the nature, magnitude, and duration of decadal-scale, fire-induced ecosystem change over the past c. 4250 yr. The h...

2015
Thomas A. Minckley Robert K. Shriver Bryan N. Shuman T. A. MINCKLEY R. K. SHRIVER B. SHUMAN

Paleoecological records indicate that subalpine forests in western North America have been resilient in response to multiple influences, including severe droughts, insect outbreaks, and widely varying fire regimes, over many millennia. One hypothesis for explaining this ecosystem resilience centers on the disruption of forest dynamics by frequent disturbance and climatic variability, and the re...

Journal: :The Science of the total environment 2010
Markus Egli Giacomo Sartori Aldo Mirabella Daniele Giaccai Filippo Favilli Daniel Scherrer Rolf Krebs Evelyne Delbos

We investigated the effect of organic matter and weathering on the lability and solid phase speciation of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) in two contrasting subalpine regions in the Italian Alps. Cr, Ni and Cu could be linked to weathering. This was not the case for Pb. Since organic matter (OM) influences the solid phase speciation of heavy metals, the total organic C and N content, the ...

2013
Jeffrey G. Holmquist Jutta Schmidt-Gengenbach Sylvia A. Haultain

Conclusions regarding disturbance effects in high elevation or high latitude ecosystems based solely on infrequent, long-term sampling may be misleading, because the long winters may erase severe, short-term impacts at the height of the abbreviated growing season. We separated a) long-term effects of pack stock grazing, manifested in early season prior to stock arrival, from b) additional pack ...

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