Search

Abstract MARAS (Monitoring of Arid and Semiarid Regions) consists of 379 ground monitors in Patagonia, a 624.500 km2 semiarid area of southern Argentina and Chile. The objective of this paper was to describe the system and analyze four variables of the initial data base. Floristic composition, diversity and cover were analyzed with intercept lines (500 points). Patches (resource-sinks areas) and Interpatches (areas that loose resources) were described using Gap intercept lines (50 m). Eleven Landscape Functional Analysis indicators were recorded in 10 interpatches: Soil stability, Infiltration and Nutrient cycling. Vegetation Cover was 43 ± 2%, Richness 15 ± 7 species/monitor, Interpatch Size 154 ± 134 cm and LFA Stability Index 46 ± 1%. Cover, Richness and Stability maps had bimodal distribution and maximum in S and NE areas, following rainfall gradients. Variability analysis shows that cover estimations are within 5% error at site and regional scales. Graphical analysis of single monitors shows observational biases in interpatch size and LFA Stability index. Richness estimations correlate significantly with α diversity (R2 = 0.80). Analysis of 5-year change in 115 monitors shows significant reductions in cover and interpatch length, especially N of the region. These base line evaluations enable analysis of future changes that were not possible with multiple techniques and isolated data bases. Highlights • 379 ground monitors of vegetation and soil were installed in Patagonia. • Six teams in two countries shared a single protocol and data base. • Errors of estimations at site and regional scales are acceptable. • Contour maps of main variables show gradients associated to aridity. • This baseline enables future change evaluation. [ABSTRACT FROM AUTHOR]

With their modest rainfall, arid regions are characterized by relatively fewer species than the better-watered biomes. But this makes it all the more important that the biodiversity that is present in arid environments be given even higher priority; for each species lost from an arid region, the percentage of loss for the region''s biodiversity is much higher than in more species-rich regions. And some species, such as bees and ants, are particularly diverse in arid habitats. Realizing the importance of biodiversity in the arid regions where they live, local people have devised numerous ways of limiting their impact. Historically, such regions have been especially subject to changes in climate, which affect productivity; these changes have often been accompanied by conflicts. The paper will describe these from various parts of the arid world, as a basis for comparison. The paper will also examine economic issues relating to biodiversity in arid lands, focusing especially on the relationship between biodiversity and various kinds of development projects. The major challenges in implementing the Convention on Biological Diversity (CBD) in arid lands lie not so much in the biology of the species concerned, but rather in the social, economic, and political arenas within which people operate. We need to build a broader constituency for conserving biodiversity, extend the responsibility for conserving biodiversity far beyond government, bring local people into the conservation movement, ensure that sufficient information is available to those who need it, restore degraded ecosystems, and stimulate far greater public support for biodiversity. [Copyright &y& Elsevier]

Mammalian species inhabiting arid landscapes exhibit various levels of mobility in order to cope with unpredictable spatiotemporal dispersion of resources. However, the space use and ranging behavior of many species in drylands is poorly understood, especially for large carnivores in Asia. Accommodating the long-distance movements of mammalian carnivores is a major challenge in conservation, particularly for threatened and highly mobile species. The Asiatic cheetah Acinonyx jubatus venaticus , a critically endangered subspecies found only in arid areas of Iran, exhibits high levels of mobility. In the absence of satellite collars, this paper outlines ranging patterns of the majority of the Asiatic cheetah’s known population. A total of 17 independent cheetahs (11 males; 6 females) were detected with camera traps that were deployed on eight reserves between January 2011 and May 2016. The animals displayed extensive movements (up to 217 km between furthest known locations) and at least nine adult cheetahs were known to move between multiple reserves in central Iran. This mobility may follow a “nomadic” ranging pattern, a non-sedentary behavior with irregular timing and movement directions. The ranging behavior documented here must be considered when designing monitoring efforts to determine population and occupancy trends for this wide-ranging elusive carnivore. Although preliminary, our results show that improving protection beyond the current network of cheetah reserves, particularly along corridors, should be a top priority to safeguard the persistence of the Asiatic cheetah. [ABSTRACT FROM AUTHOR]

The rating of biodiversity in arid and semiarid regions on the basis of ecological function and genetic traits of adaptation to severe environmental stresses produces significantly higher values, than that based solely on the commonly applied structural criteria of forms of life and levels of organization. The indirect driving forces of biodiversity impoverishment listed in the Global Biodiversity Strategy that are particularly effective in arid and semi-arid regions are (a) population growth, (b) economic systems and policies that fail to value the environment and its natural resources; (c) inequity in the ownership, management and flow of benefits from both the use and conservation of biological resources; and (d) weakness in legal and institutional systems. The most effective direct human impacts are (a) habitat destruction and fragmentation, (b) overexploitation of biological resources, (c) biological invasion, and (d) agriculture. The problem in arid and semiarid regions, particularly in developing countries, is exacerbated by the lack of knowledge and awareness, the paucity of research, and the diminishing number of competent systematists.This paper discusses the theoretical and practical aspects of each of the indirect driving forces, and the direct human impacts on biodiversity, and reviews case studies related to these impacts, with special reference to those carried out in arid and semiarid regions. These studies include monitoring of the human impact on land cover by remote sensing, effects of landuse on species diversity, impact of habitat fragmentation by summer resorts on coastal dunes, consequences of protection from grazing on biodiversity, comparison of biodiversity in nature reserves and the traditional ema system with that of nearby territories, and the impact of desertification on animal life and endangered species. Case studies also include the tools applied for biodiversity conservation in arid and semiarid lands with special emphasis on endangered species, restoration of degraded habitats and their biodiversity, the significance of nature reserves and captive breeding, the importance of conserving the populations below the species level throughout their geographical range of distribution, and ecotonal biodiversity. [Copyright &y& Elsevier]