نتایج جستجو برای: canopy cover perimeter

تعداد نتایج: 127446  

2005

We used snow fences and small (1m) open-topped fiberglass chambers (OTCs) to study the effects of changes in winter snow cover and summer air temperatures on arctic tundra. In 1994, two 60m long, 2.8m high snow fences, one in moist and the other in dry tundra, were erected at Toolik Lake, Alaska. OTCs paired with unwarmed plots, were placed along each experimental snow gradient and in control a...

2005
K. F. HUEMMRICH

Monthly measurements of leaf area index (LAI) and the fraction of absorbed photosynthetically active radiation (fAPAR) taken at approximately monthly intervals were collected along three 750 m transects in a Kalahari woodland near Mongu in western Zambia. These data were compared with MODIS NDVI (MOD13, Collection 3) and MODIS LAI and fAPAR products (MOD15, Collection 3) over a 2 year period (2...

2016
Anne C. S. McIntosh S. Ellen Macdonald Sylvie A. Quideau

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these ...

2004
Timothy N. McPherson Michael J. Brown Steven J. Burian

Describing urban terrain and land use/land cover (LULC) characteristics accurately is an essential element in environmental modeling, assessment and management. Urban terrain and LULC information are especially important in meteorological modeling applications, such as simulations of atmospheric flow over cities, defining surface energy budgets, and fate and transport studies of urban contamina...

2012
David M. Williams Amy Dechen Quinn William F. Porter

Advances in animal tracking technologies have reduced but not eliminated positional error. While aware of such inherent error, scientists often proceed with analyses that assume exact locations. The results of such analyses then represent one realization in a distribution of possible outcomes. Evaluating results within the context of that distribution can strengthen or weaken our confidence in ...

2013
Huifeng Hu Benjamin O. Knapp G. Geoff Wang Joan L. Walker

We installed a field experiment to support the development of protocols to restore longleaf pine (Pinus palustris Mill.) to existing mature loblolly pine (P. taeda L.) stands at Camp Lejeune, NC. Seven canopy treatments included four uniform and three gap treatments. The four uniform treatments were defined by target residual basal area (BA) [control (uncut), BA9, BA4.5, and BA0 (clearcut) m2/h...

2003
Peter T. Soulé Paul A. Knapp Henri D. Grissino-Mayer

We examine changes in canopy cover for adult western juniper from the 1960s to 1994 in central Oregon using repeat aerial photography. We compare changes at four sites with a land-use history of minimal anthropogenic disturbance to changes on adjacent sites that have a disturbance history more typical of central Oregon rangelands. Canopy cover increased at all sites, but afforestation on sites ...

2017
Pangzhen Zhang Xiwen Wu Sonja Needs Di Liu Sigfredo Fuentes Kate Howell

Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit zone to reduce the leaf photosynthetic area, and to increase sunlight exposure of grape bunches. Apical leaf removal is not commonly practiced, and therefore its influence on canopy structure and resultant wine aroma is not well-studied. Th...

آذرنیوند, حسین, عرفانزاده, رضا , غضنفریان, فاطمه,

This study aimed to investigate the effect of canopy trees and shrubs: Pistacia atlantica, Amygdalus scoparia, Amygdalus eburnean on the species diversity and richness of soil seed bank. Ten individuals of each species were selected and one quadrate was established in and outside of crown canopy of each species. In each plot, soil samples were collected from 0-5 and 5-10 cm depths. GLM was appl...

2005
M. Biradar Chandrashekhar Sameer Saran P. L. N. Raju P. S. Roy

Monitoring of forest cover is an essential tool for sustainable management of natural resources. Woody green cover can better maintained and managed by identification of forest gaps and their subsequent refilling. Forest canopy density mapping is one of the tools used to identify such canopy openings and most useful parameter to consider in the planning and implementation of afforestation and r...

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