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25-418: The western portion of the mountain range has pale green formations, differing from the eastern, steeply carved and striking brick-red volcanics. Landforms are diverse and range from valley floors and washes to steep-walled canyons, domed peaks, natural bridges, and eroded spires. The mountains mark a major direction change of the north-south Colorado, as it changes directions to southeast, then southwest around

50-614: A number of desert ecoregions that have a high degree of biodiversity and endemism : Drylands Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants ( evapotranspiration ). The United Nations Environment Program defines drylands as tropical and temperate areas with an aridity index of less than 0.65. One can classify drylands into four sub-types: Some authorities regard hyper-arid lands as deserts ( United Nations Convention to Combat Desertification - UNCCD) although

75-575: A number of the world's deserts include both hyper-arid and arid climate zones. The UNCCD excludes hyper-arid zones from its definition of drylands. Drylands cover 41.3% of the Earth's land surface, including 15% of Latin America , 66% of Africa , 40% of Asia , and 24% of Europe . There is a significantly greater proportion of drylands in developing countries (72%), and the proportion increases with aridity : almost 100% of all hyper-arid lands are in

100-541: A popular hiking location. Deserts and xeric shrublands Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature . Deserts and xeric ( Ancient Greek ξηρός xērós 'dry') shrublands form the largest terrestrial biome, covering 19% of Earth 's land surface area. Ecoregions in this habitat type vary greatly in the amount of annual rainfall they receive, usually less than 250 millimetres (10 in) annually except in

125-441: A rich array of habitats. Many of these habitats are ephemeral in nature, reflecting the paucity and seasonality of available water. Woody-stemmed shrubs and plants characterize vegetation in these regions. Above all, these plants have evolved to minimize water loss. Animal biodiversity is equally well adapted and quite diverse. The conversion of productive drylands to desert conditions, known as desertification , can occur from

150-482: A variety of causes. One is human intervention, including intensive agricultural tillage or overgrazing in areas that cannot support such exploitation. Climatic shifts such as global warming or the Milankovitch cycle (which drives glacials and interglacials ) also affect the pattern of deserts on Earth. Xeric shrublands can experience woody plant encroachment, which is the thickening of bushes and shrubs at

175-444: Is land having arid conditions. Arid and semi-arid lands have much higher evapotranspiration rates as compared to the precipitation along with high air temperature mainly during dry seasons, high and almost continuous isolation throughout the year, and the presence of dry gale-force winds. Based on spatial repartition of greenhouse gas emissions (GGE) in the atmosphere , it seems that Africa contributes marginally in comparison to

200-449: Is possible only from the north-east by way of a power line access road. This road may require high-clearance or four-wheel-drive vehicles. No permit is required for individual access, but a permit is required by the BLM for commercial or organized group access. Popular activities include hiking, horseback riding, hunting, camping, rock hounding , photography, and backpacking . Whipple Wash is

225-438: The desert bighorn sheep , mule deer , wild burro , coyote , black-tailed jackrabbit , ground squirrels , kangaroo rats , quail , roadrunners , owls , several species of rattlesnakes and lizards, and the threatened desert tortoise . The Whipple Mountains provide superior nesting and foraging habitat for a number of raptors ; including prairie falcon , golden eagle , red-tailed hawk , and Cooper's hawk . To protect

250-465: The Sahel area has been marked by climatic extremes with devastating consequences on natural resources, agricultural and pastoral activities, etc. In semi-arid lands, manifestations of climate change on communities and socio-economic activities are more diversified. The characterization and impact of the variability trend of rainfall depend on several random factors. Among the random factors, we can mention,

275-466: The characteristics of the climate. For instance, Mongi et al. (2010) consider semi-arid lands as places where the annual rainfall ranges between 500 and 800mm. Fabricius et al. on the other hand insist that the concept of aridity should also include conditions of aridity and semi-aridity. Furthermore, they consider that a huge part of the Sub-Saharan area covering around 40 countries on the continent

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300-771: The developing world. Nevertheless, the United States , Australia , and several countries in Southern Europe also contain significant dryland areas. Drylands are complex, evolving structures whose characteristics and dynamic properties depend on many interrelated interactions between climate , soil , and vegetation . The livelihoods of millions of people in developing countries depend highly on dryland biodiversity to ensure their food security and their well-being. Drylands, unlike more humid biomes, rely mostly on above ground water runoff for redistribution of water, and almost all their water redistribution occurs on

325-562: The dry season, using the available resources effectively. However, due to a variety of factors, this method has changed and been constrained. Challenges connected to demographics and climate change. The greatest issue in drylands, is land degradation which poses a huge danger to the world's capacity to end hunger. Drylands occupy around 2 million km² or respectively 90%, 75%, and 67% of Kenya, Tanzania, and Ethiopia respectively. More than 60 million people, or 40% of these countries’ population, live in drylands. The low level of precipitation and

350-679: The eastern perimeter of the range. The highest point of the mountains, and the Whipple Mountains Wilderness is Whipple Mountain at 4,131 feet (1,259 m). The two major habitats here are the Sonoran xeric bush scrub with creosote bush , and Sonoran thorn forest with Velvet mesquite . The dominant vegetation-type is commonly referred to creosote bush scrub , with palo verde , desert Ironwood , smoketree , and numerous species of cacti including cholla , saguaro , foxtail , and prickly pear . Wildlife species include

375-440: The expense of grasses. This process is often caused by unsustainable land management practices, such as overgrazing and fire suppression, but can also be a consequence of climate change . As a result, the shrublands' core ecosystem services are affected, including its biodiversity, productivity, and groundwater recharge. Woody plant encroachment can be an expression of land degradation. The World Wide Fund for Nature highlights

400-523: The fragile and rare habitats of the Whipples, wheeled and motorized vehicles are excluded from the entire wilderness area. Hiking and horseback riding are the primary means of accessing the interior of the range. The most frequently used route for these activities lies in Whipple Wash ( see photo ) which bisects the range from southwest to northeast. Motorized access to the boundary of the wilderness

425-499: The high degree of variability in the climatic conditions limit the possibilities for rainfed crop production in these areas. Countries like Burkina Faso, Botswana, Iraq, Kazakhstan, Turkmenistan and the Republic of Moldova, are 99% covered in areas of dry and sub-humid lands. The biodiversity of dry and sub-humid lands allows them to adapt to the unpredictable rainfall patterns that lead to floods and droughts. These areas produce

450-445: The intrinsic value of biological diversity and recognized the severity of global biodiversity loss and degradation of ecosystems. The East African drylands cover about 47% of land areas and are home to around 20 million people. Pastoralists who rely on cattle for both economic and social well-being constitute the majority of rural inhabitants in the drylands. Pastoralists use strategic movement to gain access to pasture during

475-570: The margins. Generally evaporation exceeds rainfall in these ecoregions. Temperature variability is also diverse in these lands. Many deserts, such as the Sahara , are hot year-round, but others, such as East Asia's Gobi Desert , become quite cold during the winter. Temperature extremes are a characteristic of most deserts. High daytime temperatures give way to cold nights because there is no insulation provided by humidity and cloud cover. The diversity of climatic conditions, though quite harsh, supports

500-432: The nature and the critical thresholds of extreme events, the frequency of these extremes according to regions, the precision of data used, and the results of mathematical simulations, and propagation. The state of scientific knowledge has allowed for the identification of the principal manifestations of climate change on the development of socio-economic activities in semi-arid lands. These manifestations are: an increase in

525-413: The occurrence of dry sequences that can happen at any time in space and time during the actual period; Dry and violent winds associated with very scarce rainfall that prevent enough humidification of the soils; making difficult the development of the whole vegetal life; In semi-arid lands where pastoralism is the principal activity, the main adaptation measures are an early departure to transhumance ,

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550-522: The reduction of the size of the herd, a change in the management of water, and diversification of paths of transhumance. This allows breeders to safeguard their livestock and prevent huge losses as was the case in the drought of the seventies. Breeders purchase stock for the livestock or simply stock it. They become proactive (engage in trade, real estate, guarding, transport) in certain countries like Burkina Faso, Senegal, Mali, and Kenya . These adaptation strategies allow them to be more resilient to

575-421: The rest of the world. Africa generates on average less than 4% of GGE produced in the world. Comparative data on GGE per person show that Europeans and Americans generate about 50 to 100 times more gas than Africans (Thiam, 2009). Based on the consequences caused by variability and climate change, it appears that African populations are more vulnerable than others. To illustrate, the trend of reduced rainfall in

600-606: The surface. Dryland inhabitants' lifestyle provides global environmental benefits which contribute to halt climate change , such as carbon sequestration and species conservation. Dryland biodiversity is equally of central importance as to ensuring sustainable development , along with providing significant global economic values through the provision of ecosystem services and biodiversity products. The UN Conference on Sustainable Development Rio+20 , held in Brazil in June 2012, stressed

625-627: The vast amount the world's crops and livestock . Even further than producing the vast majority of crops in the world, it is also significant because it includes many different biomes. Biomes include: Semi-arid lands can be found in several regions of the world. For instance in places such as Europe, Mexico, Southwestern parts of the U.S, Countries in Africa that are just above the equator , and several Southern countries in Asia. According to literature, arid and semi-arid lands are defined based on

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