نتایج جستجو برای: eg percentage of canopy cover

تعداد نتایج: 21181098  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه خلیج فارس - دانشکده مهندسی 1393

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

2007
Chad S. Boyd Jon D. Bates Rick F. Miller

Sagebrush cover is often estimated with the use of the line intercept method. However, a lack of standardized protocols may lead to variable estimates of sagebrush canopy cover. Our objectives were to determine the influence of gap size on 1) sagebrush canopy cover estimates, 2) time needed to read a transect, and 3) among-observer variability in sagebrush canopy cover estimates. We utilized 5-...

Journal: :environmental resources research 2014
hossein varasteh moradi mohamed zakaria scott . k. robinson

forest fragmentation results in a loss of forest interior and an increase in edge habitat. we studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a 1248-ha lowland rainforest patch in peninsular malaysia. birds and environmental variables such as vegetation structure and litter depth were detected within a 25-m radius of each of...

جباری, سمیه , جعفری, رضا, خواجه‌الدین, سید جمال‌الدین , سلطانی, سعید,

The objective of the present study was to investigate the pasture vegetation changes using satellite data in Semirom, Isfahan province. This study was conducted in 2004 as a wet year and 2009 as a dry year. The WiFS and AWiFS satellite images were acquired and used for the year 2004 and 2009, respectively. First, the vegetation percentage was simultaneously measured in the two years. Then, cons...

Journal: :journal of rangeland science 2015
amir mirzaei mossivand farshad keivan behjou ehsan zandi esfahan ardavan ghorbani

the aim of this study was to assess the regional effects of fire on the surface cover and forage production of mountainous rangelands of delfan county, lorestan province, iran. the fire took placed in june 2007 with significant effects on the vegetation characteristics in the study area. four fire affected sites were selected for sampling and a close area without fire was considered as control....

Journal: :مرتع و آبخیزداری 0
سید مرتضی ابطحی استادیار، پژوهش بخش تحقیقات منابع طبیعی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اصفهان، سازمان تحقیقات، آموزش و ترویج کشاورزی

the purpose of this study was to investigate vegetation dynamics and range conditions considering the climatic conditions and soil properties in doolat gharin in the south of isfahan province of an area equal to 25 square kilometer. for this purpose, after determining vegetation types and associated species, the type of rangeland utilization, grazing season, the type of livestock and other rele...

The Moroccan locust (Dociostaurus maroccanus Thunberg) is one of the most important species of locusts in Iran and many parts of the world, which causes great damage to pastures and agricultural products every year. Since a main part of the life cycle of this insect is spent in pastures, recognizing the relationship between locusts and plant properties are important in the rangeland management ...

2013
John W. Coulston Dennis M. Jacobs Chris R. King

Quantifying tree canopy cover in a spatially explicit fashion is important for broad-scale monitoring of ecosystems and for management of natural resources. Researchers have developed empirical models of tree canopy cover to produce geospatial products. For subpixel models, percent tree canopy cover estimates (derived from fi ne-scale imagery) serve as the response variable. The explanatory var...

2006
LUIS SCHIESARI

1. The gradient in pond canopy cover strongly influences freshwater species distributions. This study tested the effects of canopy cover on the performance of two species of larval anurans, a canopy cover generalist (Rana sylvatica, the wood frog) and an open-canopy specialist (R. pipiens, the leopard frog), and tested which factors co-varying with canopy cover mediate these effects. 2. A field...

Journal: Desert 2012
E. Janfaza M. Biniaz M. Jafari M. Karimpour Reyhan M.J. Nematolahi

Relationships between soil factors and vegetation types in playa of Damghan was investigated. Six vegetationtypes including Artemisia.sieberi, Arundo. sp, Artemisia.sieberi-Peganum.harmala, Alhagi.cammelerom,Artemisia.sieberi-petropyron.sp, Tamarix.passerinoides-Halocnemum strobilaceum. One bare land was recognized inthe study area and the research was conducted within mentioned types. Canopy p...

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