نتایج جستجو برای: canopy cover

تعداد نتایج: 122030  

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...

1999
R. Z. Wang

Effects of mowing and grazing on a Leymus chinensis grassland in the Songnen plain of northeastern China were studied using eight replicates of four grazing and mowing treatments. Canopy cover and biomass of the dominant species (L. chinensis) were lower, and cover of the halophyte Suaeda corniculata higher, on grazed than ungrazed; ungrazed plots showed a response to mowing, but not grazing; s...

Journal: :ecopersia 0
sedigheh zarekia forest and rangeland research division, yazd agriculture and natural resources research and education center, areeo, yazd, iran ali ashraf jafari rangeland research division, research institute of forests and rangelands, areeo, tehran, iran taghi mirhaji rangeland research division, research institute of forests and rangelands, areeo, tehran, iran

this research aimed to evaluate the effect of planting seasons (autumn and spring) on 10 accessions of two species of astragalus effusus and astragalus brachyodontus in the field condition (homand absard station, damavand). after preparing the seedbed, the plant species were planted on two lines in 2 m, where the spacing between the lines of each accession was 0.5 m, and the spacing between the...

2013
Gina S. Lovasi Jarlath P.M. O’Neil-Dunne Jacqueline W.T. Lu Daniel Sheehan Matthew S. Perzanowski Sean W. MacFaden Kristen L. King Thomas Matte Rachel L. Miller Lori A. Hoepner Frederica P. Perera Andrew Rundle

BACKGROUND Urban landscape elements, particularly trees, have the potential to affect airflow, air quality, and production of aeroallergens. Several large-scale urban tree planting projects have sought to promote respiratory health, yet evidence linking tree cover to human health is limited. OBJECTIVES We sought to investigate the association of tree canopy cover with subsequent development o...

Journal: :Revista Brasileira de Geografia Física 2020

2015
Joanne C. White Piotr Tompalski Nicholas C. Coops Michael A. Wulder Eric J. Jokela

Digital aerial photogrammetry (DAP) is emerging as an alternate data source to airborne laser scanning (ALS) data for three-dimensional characterization of forest structure. In this study we compare point cloud metrics and plot-level model estimates derived from ALS data and an image-based point cloud generated using semi-global matching (SGM) for a complex, coastal forest in western Canada. Pl...

2018
Jose A. Jimenez-Berni David M. Deery Pablo Rozas-Larraondo Anthony (Tony) G. Condon Greg J. Rebetzke Richard A. James William D. Bovill Robert T. Furbank Xavier R. R. Sirault

Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the abilit...

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