نتایج جستجو برای: canopy cover percentage

تعداد نتایج: 254028  

1998
Gregory P. Asner

to nadir-viewed vegetation reflectance data. Variability INTRODUCTION in tissue optical properties was wavelength-dependent. During the past several decades, the tools for vegetation For green foliage, the lowest variation was in the visible remote sensing have evolved significantly. Optical remote (VIS) spectral region and the highest in the near-infrared sensing has expanded from the use of p...

Journal: :Ambio 2011
Isla H Myers-Smith David S Hik Catherine Kennedy Dorothy Cooley Jill F Johnstone Alice J Kenney Charles J Krebs

Canopy-forming shrubs are reported to be increasing at sites around the circumpolar Arctic. Our results indicate expansion in canopy cover and height of willows on Herschel Island located at 70 degrees north on the western Arctic coast of the Yukon Territory. We examined historic photographs, repeated vegetation surveys, and conducted monitoring of long-term plots and found evidence of increase...

2011
G.vanN. du Toit H. A. Snyman

________________________________________________________________________________ Abstract Grazing levels and rotational schemes need to be tailored to each individual farm or pasture, and more studies are needed on the resilience of rangelands and on separating the effects of grazing and climate. The direct short-term impact of three rates of stocking (4, 8 and 16 Small Stock Units-SSU/ha) was ...

2016
Luke Wallace Arko Lucieer Darren Turner Juha Hyyppä Xinlian Liang

This study investigates the potential of unmanned aerial vehicles (UAVs) to measure and monitor structural properties of forests. Two remote sensing techniques, airborne laser scanning (ALS) and structure from motion (SfM) were tested to capture three-dimensional structural information from a small multi-rotor UAV platform. A case study is presented through the analysis of data collected from a...

Journal: :international journal of aquatic biology 0
arunkumar shetty department of p.g. studies and research in applied zoology, kuvempu university, shankaraghatta, 577 451 karnataka. mididodi venkateshwarlu department of p.g. studies and research in applied zoology, kuvempu university, shankaraghatta, 577 451. karnataka. murugan muralidharan sri paramakalyani centre for environmental scieces, manonmaniam sundaranar university, alwarkurichi, 627 412. tamilnadu

the fish assemblage and diversity in relation to water quality of three coastal rivers sita, swarna and varahi of udupi district, karnataka, india was studied. 71 species representing 7 orders, 20 families and 41 genera were recorded from 21 sites along the three rivers. species composition varied longitudinally in relation to the environmental factors of the habitat. the downstream change in t...

Journal: :جنگل و فرآورده های چوب 0
محمد شیخکانلوی میلان دانشجوی کارشناسی ارشد جنگل داری دانشکدة منابع طبیعی، دانشگاه گیلان، صومعه‏سرا، ایران ایرج حسن زاد ناورودی استادیار، عضو هیئت علمی گروه جنگل داری دانشکدة منابع طبیعی، دانشگاه گیلان، صومعه‏سرا، ایران محمد رسول نظری سندی دانشجوی کارشناسی ارشد جنگل داری دانشکدة منابع طبیعی، دانشگاه گیلان، صومعه‏سرا، ایران بهزاد بخشنده ناورود دانشجوی دکتری جنگل داری دانشگاه لرستان، خرم آباد، ایران

in order to study the effect of elevation on quantitative and qualitative characteristics of the humid forests of guilan shafaroud, series 17, 16 and 7 were selected that fall in to three height classes; class 1 (‏less than 500 m), class 2 (‏500 – 1000 m) and class 3 (‏1000 – 1600 m). in height class 1, 2 and 3 sample plots were determined as 4, 15 and 20 respectively and each sample plot was 0...

2014
Oumer S. Ahmed Steven E. Franklin Michael A. Wulder

Disclaimer: The PDF document is a copy of the final version of this manuscript that was subsequently accepted by the journal for publication. The paper has been through peer review, but it has not been subject to any additional copy-editing or journal specific formatting (so will look different from the final version of record, which may be accessed following the DOI above depending on your acc...

Rangeland management plan is one of the major means of management and utilization of rangelands in Iran. The formulation of these plans for the rangeland users should be studied from the ecological and socio-economic points of view. One of the main envisaged activities in almost all the management plans is the grazing system. An experiment was used to study the effects of three deferred grazing...

2011
Christopher H. R. Goatley David R. Bellwood

Canopies are common among autotrophs, increasing their access to light and thereby increasing competitive abilities. If viewed from above canopies may conceal objects beneath them creating a 'canopy effect'. Due to complexities in collecting 3-dimensional data, most ecosystem monitoring programmes reduce dimensionality when sampling, resorting to planar views. The resultant 'canopy effects' may...

Journal: :Journal of Korean Society for Geospatial Information System 2012

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