نتایج جستجو برای: canopy cover perimeter

تعداد نتایج: 127446  

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2016
A C M Queiroz C R Ribas

We tested the hypothesis of a negative relationship between vegetation characteristics and ant species richness in a Brazilian open vegetation habitat, called candeial. We set up arboreal pitfalls to sample arboreal ants and measured the following environmental variables, which were used as surrogate of environmental heterogeneity: tree richness, tree density, tree height, circumference at the ...

Journal: :Revista de biologia tropical 2013
Eric J Fuchs Tatiana Robles James L Hamrick

The spatial distribution of individuals is a fundamental property of most species and constitutes essential information for the development of restoration and conservation strategies, especially for endangered plant species. In this paper we describe the spatial distribution of different size classes of the endangered tropical tree Guaiacum sanctum and the effect of canopy cover on spatial aggr...

2005
Malcolm L. Bryant Shirish Bhat Jennifer M. Jacobs

The temporal variability of interception losses was measured for contrasting forest communities in the southeastern United States. Throughfall was measured simultaneously at Fort Benning in western Georgia for the five forest communities that are characteristic of the region. The measured interception losses over the study period were 22.3, 18.6, 17.7, 17.6, and 17.4% of the total precipitation...

2014
David M J S Bowman Harry J MacDermott Scott C Nichols Brett P Murphy

A grass-fire cycle in Australian tropical savannas has been postulated as driving the regional decline of the obligate-seeding conifer Callitris intratropica and other fire-sensitive components of the regional flora and fauna, due to proliferation of flammable native grasses. We tested the hypothesis that a high-biomass invasive savanna grass drives a positive feedback process where intense fir...

2007
Mark Chopping Gretchen G. Moisen Lihong Su Andrea Laliberte Albert Rango John V. Martonchik Debra P.C. Peters

A rapid canopy reflectance model inversion experiment was performed using multi-angle reflectance data from the NASA Multi-angle Imaging Spectro-Radiometer (MISR) on the Earth Observing SystemTerra satellite, with the goal of obtainingmeasures of forest fractional crown cover, mean canopy height, and aboveground woody biomass for large parts of south-eastern Arizona and southern New Mexico (N20...

Journal: :Remote Sensing 2018
Richard Makanza Mainassara Zaman-Allah Jill E. Cairns Cosmos Magorokosho Amsal Tarekegne Mike Olsen Boddupalli M. Prasanna

In the crop breeding process, the use of data collection methods that allow reliable assessment of crop adaptation traits, faster and cheaper than those currently in use, can significantly improve resource use efficiency by reducing selection cost and can contribute to increased genetic gain through improved selection efficiency. Current methods to estimate crop growth (ground canopy cover) and...

2008
C. Y. Lo L. C. Chen

To understand the biomass condition in the forestry areas, the detection for individual trees becomes an important topic. For forestry management, the canopy may be described with several parameters, e.g., number of stems, stand position, tree height, timber volume, canopy cover, etc. Traditional methods rely on field measurements, imagery, and radar data to derive the canopy information. Follo...

2014
Yi-Huei Chen Elva J. H. Robinson

Climate change may affect ecosystems and biodiversity through the impacts of rising temperature on species' body size. In terms of physiology and genetics, the colony is the unit of selection for ants so colony size can be considered the body size of a colony. For polydomous ant species, a colony is spread across several nests. This study aims to clarify how climate change may influence an ecol...

2002
D. B. LOBELL G. P. ASNER

The dependence of vegetation re ectance on sun and sensor geometry can potentially provide information on canopy properties, but also may be a source of unmodelled systematic error in single-angle remote sensing measurements. In this study, we investigated the angular variability of re ectance measurements from the NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), and the resultin...

2004
E B Spurr B Warburton

Stem density, basal area, vegetation cover and vegetation surface area were compared as measures of the proportions of plant species present in North Okarito Forest, South Westland, for use in determining bird preferences for plant species. In general, stem density estimates of the proportions of canopy species were about 10 times lower than basal area estimates. The converse was true for estim...

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