نتایج جستجو برای: arid zones
تعداد نتایج: 63858 فیلتر نتایج به سال:
tourism as a growing industry needs special attention in developing countries. during last decades, nature based tourism has been growing faster than other tourism fields and it seems to grow even faster. ever growing demand for nature based tourism emphasizes the necessity of a holistic planning for preserving environment against degradation. objective of this study is to present a nature base...
This research discusses some of the issues encountered while developing a set of WGEN parameters for Chile and advice for others interested in developing WGEN parameters for arid climates. The WGEN program is a commonly used and a valuable research tool; however, it has specific limitations in arid climates that need careful consideration. These limitations are analysed in the context of genera...
A brief analysis on the distribution range of some of the species dominating in the arid and extra arid regions of North Africa and Arabian Peninsula is presented. These species are belonging to three phytogeographical categories namely: Saharo-Sindian, Sudano-Deccanian and Tropical African-Indian elements. Species included for this study are either disjunct or they have a wider distribution, s...
Multilocus clines between Müllerian mimetic races of Heliconius butterflies provide a classic example of the maintenance of hybrid zones and their importance in speciation. Concordant hybrid zones in the mimics Heliconius erato and H. melpomene in northern Peru were carefully documented in the 1980s, and this prior work now permits a historical analysis of the movement or stasis of the zones. P...
J. Kihara et al. (eds.), Improving Soil Fertility Recommendations in Africa using the Decision Support System for Agrotechnology Transfer (DSSAT), DOI 10.1007/978-94-007-2960-5_3, © Springer Science+Business Media Dordrecht 2012 Abstract Africa is the continent with the lowest fertilizer use per hectare notwithstanding the fact it possesses geologically old, infertile and degraded soils. This c...
INTRODUCTION An understanding of the feeding ecology of the red-billed quelea (Quelea quelea) is necessary for a comprehensive assessment of the potential impact of this species on cereals development. Queleas are reported to subsist primarily on wild Gramineae (Ward 1965a; Gaston 1976), but their mobility and tendency to feed in large aggrega-tions readily adapts them to becoming a major cerea...
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