نتایج جستجو برای: arid rangelands

تعداد نتایج: 20677  

2017
Susan J. Prichard Camille S. Stevens-Rumann Paul F. Hessburg

Across the globe, rising temperatures and altered precipitation patterns have caused persistent regional droughts, lengthened fire seasons, and increased the number of weather-driven extreme fire events. Because wildfires currently impact an increasing proportion of the total area burned, land managers need to better understand reburns – in which previously burned areas can modify the patterns ...

2012
Elizabeth G. King Trenton E. Franz Kelly K. Caylor

In the semi-arid rangelands of north central Kenya, the abundance of grasses has declined over recent decades. Concomitantly, the native succulent herb Sansevieria volkensii has greatly proliferated in many areas. Landscape structure has thus shifted from contiguous herbaceous cover to large, dense stands of S. volkensii with interpatches of bare or sparsely vegetated ground. Local pastoralists...

2017
Jason Barnetson Stuart Phinn Peter Scarth Robert Denham

Suitable measures of grazing impacts on ground cover, that enable separation of the 1 effects of climatic variations, are needed to inform land managers and policy makers across the arid 2 rangelands of the Northern Territory of Australia. This work developed and tested a time-series, 3 change-point detection method for application to time series of vegetation fractional cover derived 4 from La...

Journal: :Remote Sensing 2015
Andreas Tewes Frank Thonfeld Michael Schmidt Roelof J. Oomen Xiaolin Zhu Olena Dubovyk Gunter Menz Jürgen Schellberg

Image time series of high temporal and spatial resolution capture land surface dynamics of heterogeneous landscapes. We applied the ESTARFM (Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model) algorithm to multi-spectral images covering two semi-arid heterogeneous rangeland study sites located in South Africa. MODIS 250 m resolution and RapidEye 5 m resolution images were fused to ...

2006
M. D. Nosetto

The large global extension of arid and semi-arid regions together with their widespread degradation give these areas a high potential to sequester carbon. We explored the possibilities of semi-arid ecosystems to sequester carbon by means of rangeland exclusion and afforestation with Pinus ponderosa in NW Patagonia (Argentina). We sampled all pools where organic carbon accumulates in a network o...

Journal: :Remote Sensing 2016
Olena Dubovyk Tobias Landmann Andreas J. Dietz Gunter Menz

Currently there is a lack of quantitative information regarding the driving factors of vegetation dynamics in post-Soviet Central Asia. Insufficient knowledge also exists concerning vegetation variability across sub-humid to arid climatic gradients as well as vegetation response to different land uses, from natural rangelands to intensively irrigated croplands. In this study, we analyzed the en...

2007
A. A. AL-DOSS A. M. ASSAEED

Hammada elegans is a widely distributed shrub in arid rangelands. It has a potential for reseeding. Identification of reliable and easy to measure growth attributes will help in monitoring seedling survival and establishment in reseeding projects. The aim of this study is to identify seedling growth attribute(s) that can be used to predict survival and establishment of H. elegans using simple c...

Dr. Abbasali Sanadgol is an associate professor in rangelands and forests research institute, IRAN, He is retired now. He earned his undergraduate and master degrees in natural resources and range management in 1976 and 1992 respectively from natural resources faculty of Tehran University and worked as a natural resources and range management researcher for 29 years at education and research ag...

Journal: :محیط شناسی 0
الناز نوروزی اقدم سید محمودرضا بهبهانی علی رحیمی خوب حسین عقیقی

soil moisture is one of the critical parameters in climatic, ecological and hydrological modeling and vegetation growth. soil moisture is important for environmental studies but due to ground-based point measurement of soil moisture is expensive and impractical for watershed measurement, this parameter is not be used widely to simulate and predict models. overall and uniform view on different p...

Journal: :مرتع و آبخیزداری 0
مریم آذرخشی استادیار دانشگاه تربت‏ حیدریه، دانشکدة کشاورزی و منابع طبیعی، ایران محمد مهدوی استاد دانشگاه تهران، دانشکدة منابع طبیعی، ایران حسن احمدی استاد دانشگاه تهران، دانشکدة منابع طبیعی، ایران حسین ارزانی استاد دانشگاه تهران، دانشکدة منابع طبیعی، ایران جلیل فرزادمهر استادیار دانشگاه تربت‏ حیدریه، دانشکدة کشاورزی و منابع طبیعی، ایران

plants cover composition, condition, trend, production, and grazing capacity of the rangeland change annually. in this research, the role of temporal rainfall distribution on rangeland production was assessed. this research had down in the rangelands of ilam (with semiarid to semi humid climate) and qom and markazi (with arid to semiarid climate) provinces. by attention on plant cover maps in e...

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