نتایج جستجو برای: and vegetation data including canopy cover of annuals

تعداد نتایج: 24175190  

2015
Gemma Rutten Andreas Ensslin Andreas Hemp Markus Fischer Lucas C.R. Silva

In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure o...

2000
A. Lotsch

Land cover maps are widely used to parameterize the biophysical properties of plant canopies in models that describe terrestrial biogeochemical processes. In this paper, we describe the use of supervised classification algorithms to generate land cover maps that characterize the vegetation types required for LAI and FAPAR retrievals from MODIS and MISR. As part of this analysis, we examine the ...

Ferula pseudalliacea (Bitter asafetida) is an endemic medicinal plant grown in the center of Iran, which is used in pharmaceutical industries. There is less report about its habitat characteristics and distribution in Iran. So, this research was conducted to study the effects of topography and soil properties on distribution of this species in Yazd Province, Iran in 2016 and 2017. Two habitats ...

2000
Scott N. Martens David D. Breshears Clifton W. Meyer

The understory light environment is a key determinant of vegetation pattern and ecosystem processes, and varies spatially perhaps more than any resource used by plants. Understory light varies along gradients of vegetation structure that range from grassland with no woody canopy cover to forest with nearly complete woody canopy cover. Spatial variability in understory light is largely determine...

ژورنال: علوم آب و خاک 2008
باغستانی , ناصر , ثواقبی, محمد حسین , رحیمیان , محمد حسن , عبداللهی, جلال ,

The present study discusses a method used to produce updated information about vegetation cover in arid and semi-arid zones, using RS data and GIS technique. In this method, Landsat ETM+ data in 2002 was collected in an area of about 60000 ha in Nodoushan basin, Yazd, Iran. To collect the necessary ground data, 50 sites of different vegetation types were selected and the percentage of vegetatio...

Journal: :جنگل و فرآورده های چوب 0
کورش نظرپور فرد دانشجو وحید اعتماد استاد مجید مخدوم استاد منوچهر نمیرانیان استاد

this study aims at assessing the impact of land use change (from forest areas to forest parks) on some silvicultural characteristics of stands under recreational land use in boloran natural forest park, kuhdasht. for this purpose, three zones including non-recreation, extensive recreation and intensive recreation regions were chosen. in each zone 30 sample plots in a systematic random design (1...

Journal: :مرتع و آبخیزداری 0
شفق رستگار استادیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری حسین بارانی دانشیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان علی دریجانی استادیار دانشکده اقتصاد کشاورزی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان واحدبردی شیخ دانشیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان جمشید قربانی دانشیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری محمد قربانی استاد دانشکده اقتصاد کشاورزی، دانشگاه فردوسی مشهد

vegetation cover as the main factor affecting the water erosion plays an important role in preventingsoil loss. to this end, for better understanding the impact of vegetation cover on soil erosion andsediment yield over the major existing geological formations in the summer rangelands of balade inthe mazandaran province, rainfall simulation studies have been carried out using a portable rainfal...

2002
Janet Franklin Frank W. Davis Paul Lefebvre

T h e effect of variable tree canopy cover, shadows, and topography on Thematic Mapper (TM) data was examined for blue oak (Quercus douglasii) woodland and wooded grassland on rugged terrain in central California. Thematic Mapper data were analyzed from September 1986 (trees in leaf, grass understory senescent) and December 1984 (trees leafless, grasses emerging. Tree cover measured in 84 60 m ...

ژورنال: مرتع 2023

Background and objective: Today, the use of predictive models of plant species distribution plays an important role in the assessment, restoration, protection and development of rangeland ecosystems. It is one of the important tools to obtain information about the causes of species distribution and habitat suitability for plant species. In this research, using multivariate analysis, the ecologi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - پژوهشکده علوم انسانی و اجتماعی 1390

this study attempts to investigate the effect of peers’ revision in comparison to that of the teacher, and whether peers’ comments and teachers’ comments facilitate students’ revision? if yes, which one is more effective? also attempts have been made to see which aspects of language are more highlighted by peers versus teachers when commenting. besides, it is investigating the student’s attitud...

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