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Carbon stocks and carbon accumulation in the earth's drylands have gained increasing attention. The winter-cold deserts of Middle Asia, i.e. in Kazakhstan, Uzbekistan, and Turkmenistan, cover an area of 2.5 million km2. Within these deserts, the two Saxaul species White Saxaul (Haloxylon persicum Bunge ex Boiss. & Buhse) and Black Saxaul (Haloxylon aphyllum (Minkw.) Iljin) are dominant woody species with a potential distribution area of about 500,000 km2. From the 1950s until today, the Saxaul vegetation has been degraded through logging and over-grazing. In this paper, we estimate the current and potential living above ground and below ground biomass of the Saxaul vegetation and its carbon stock. The living above ground biomass ranges between 1.5 t/ha and 3 t/ha. The potential carbon stocks above ground and below ground amount to 29.4–52.1 million t and 22–81.4 million t, respectively. Today, only 11%–28% of the potential biomass and carbon stock have remained. The carbon stock of the Saxaul vegetation is low compared to other ecosystems of the earth, but restoration and conservation of Saxaul vegetation is one way to sequester carbon through vegetation for Uzbekistan and Turkmenistan, which do not have much other woody vegetation.

The Haloxylon vegetation in Central Asia has undergone vast changes throughout the last century, which has lead to a strong degradation and desertification of the desert ecosystems in Kazakhstan, Uzbekistan, and Turkmenistan. In terms of combating desertification and restoration of ecosystems, two pilot-projects recently are aiming at the reforestation of Haloxylon ecosystems. Hereby, two of the internationally discussed climate change mitigation activities may be of higher relevance: (I) to sequester CO2 through afforestation and reforestation and (II) to substitute fossil fuels by sustainable utilization of regenerative bio-fuels. With particular focus on Central Asian desert ecosystems, the questions arose: (I) to which extent Haloxylon species – the dominant shrub species – sequester CO2, (II) what the recent carbon pool related to Haloxylon ecosystems is, and (III) in which magnitude the existing and/or reforested ecosystems could be utilized for bio-fuels sustainably. Therefore, this study aims at the derivation of allometric models including carbon contents for the two Haloxylon species in Central Asian desert ecosystems. A first application to measured transect data across Central Asia is carried out to reflect the recent biomass variability of the two study species. We found, that above- and below-ground biomass for both species is best modeled when taking growth height, basal area, and canopy area of shrubs into account (0.87

In Central Asia soil salinization is a wide-spread concern. Biomass harvested from the moderate salt-tolerant species Haloxylon aphyllum and Apocynum pictum can be used as fodder as well as for textile fibers and medicinal purposes, respectively. These plants offer opportunities to generate income from saline soils.

The Pamir Mountains in Tajikistan are sometimes called a mountain knot, because mountain chains from various directions meet. The various regions of the Pamir differ considerably. The eastern Pamir is a dry, arid, desert plateau, whereas other areas of the Pamir are strongly dissected and exhibit higher rainfalls. The vegetation cover in the east Pamir is very low; in the west Pamir, north Pamir, and Pamir-Alai, vegetation is more diverse and dense. Desertification, mainly by deforestation, overgrazing, and intensive gathering, is the main environmental impact in the Pamirs. Most of the areas need a strong restoration management system and require investment and much time for restoration. Improper land use by grazing, clearing, gathering, and overuse of soils, in combination with the dry climate of the Pamir, leads to the destruction of the vegetation, reduction of the vegetation cover, change of species composition, loss of biological diversity and productivity, and erosion of soil.

Deserts, Land Use and Desertification.- River Diversion, Irrigation, Salinization, Desertification - an Inevitable Succession.- I: The Aral Sea Crisis.- The Aral Sea Crisis Region.- Flora of the Dry Seafloor of the Aral Sea.- Vegetation Dynamics on the Dry Seafloor of the Aral Sea.- Methods of Conservation and Restoration of Vegetation Cover on the Aral Sea Coast.- Vegetation Dynamics on the Syrdarya Delta and Modern Land Use.- Ecological Basis for Botanical Diversity Conservation within the Amudarya and Syrdarya River Deltas.- The Tugai Forests of Floodplain of the Amudarya River: Ecology, Dynamics and Their Conservation.- Soil Crusts in the Amudarya River Delta: Properties and Formation.- Irrigation and Land Degradation in the Aral Sea Basin.- Ecology of the Aqueous Medium in the Area Surrounding the Aral Sea.- Potable Water: Research into Seasonal Changes and Conditions in the Aral Sea Region.- II: Salt Stress.- Halophytes on the Dry Sea Floor of the Aral Sea.- Halophytes: Structure and Adaptation.- Environmental State and an Analysis of Phytogenetic Resources of Halophytic Plants for Rehabilitation and Livestock Feeding in Arid and Sandy Deserts of Uzbekistan.- Salinity: A Major Enemy of Sustainable Agriculture.- III: Impact of Grazing.- Remarkable Differences in Desertification Processes in the Northern and Southern Richtersveld (Northern Namaqualand, Republic of South Africa).- Colour Plates.- How Grazing Turns Rare Seedling Recruitment Events to Non-Events in Arid Environments.- Vegetation Degradation in Northeastern Jordan.- Impact of Grazing on the Vegetation of South Sinai, Egypt.- Arid Rangeland Management Supported by Dynamic Spatially Explicit Simulation Models.- IV: Desertification Processes and Monitoring.- Remote Sensing of Surface Properties. The Key to Land Degradation and Desertification Assessments.- Evaluation of Potential Land Use Sites in Dry Areas of Burkina Faso with the Help of Remote Sensing.- Degradation of the Vegetation in the Central Kyzylkum Desert (Uzbekistan).- Modern Geomorphological Processes on the Kazakhstanian Coast of the Caspian Sea and Problems of Desertification.- Anthropogenic Transformation of Desert Ecosystems in Mongolia.- Assessment of the Modern State of Sand-Desert Vegetation in Kazakhstan.- V: Reclamation.- Water-Harvesting Efficiency in Arid and Semiarid Areas.- The Effects of Landscape Structure on Primary Productivity in Source-Sink Systems.- Sedimentary Environments in the Desiccated Aral Sea Floor: Vegetation Recovery and Prospects for Reclamation.- Seeding Experiments on the Dry Aral Sea Floor for Phytomelioration.- Rehabilitation of Areas of Irrigation Now Derelicted Because of Strong Salinization in Ecologically Critical Zones of Priaralia.- Desert Soil Recultivation and Monitoring of (Phyto-) Toxicity: Pilot Project in Three Phases Lasting for 4 Years.- Contributions to a Sustainable Management of the Indigenous Vegetation in the Foreland of Cele Oasis - A Project Report from the Taklamakan Desert.- The Control of Drift Sand on the Southern Fringe of the Taklamakan Desert - an Example from the Cele-Oasis.- The Role of Biological Soil Crusts on Desert Sand Dunes in the Northwestern Negev, Israel.- Restoration of Disturbed Areas in the Mediterranean - a Case Study in a Limestone Quarry.- Indigenous Agroforestry for Sustainable Development of the Area around Lake Nasser, Egypt.- Ziziphus - a Multipurpose Fruit Tree for Arid Regions.- Root Morphology of Wheat Genotypes Grown in Residual Moisture.- Field Studies in Solar Photocatalysis for Detoxification of Organic Chemicals in Waters and Effluents.- VI: National Programs.- Activity of the Consulting Centre to Combat Desertification in Turkmenistan.- Desertification in China and Its Control.- Environmental Problems of the Southern Region of Kazakhstan.- National Strategy and Action Plan to Combat Desertification in Kazakstan.- VII: Social and Economic Aspects.- Economic-Demographic Strategies and Desertification: Interactions in Low-Income Countries.- Final Remarks.

In 1999, the dry sea floor of the Aral Sea had an area of about 40 000 km2. The new land is being steadily invaded by plants. The list of the flora consists of 266 species. It is a young immigration flora (40 years old) that established under harsh habitat conditions. Adjacent to the former coastline there are mostly sandy soils which already are free of salt. They are replaced on younger sea floor areas by mixed sandyloamy or loamy coastal and marsh solonchaks. The family Chenopodiaceae was dominant on the solonchaks of the dry sea floor from the 1970s, 1980s and 1990s. The share of the Chenopodiaceae in the flora amounts to 28.2% (75 species). Along the former coastline on the sands of the dry sea floor from the 1960s the Polygonaceae (Calligonum), Fabaceae (Astragalus), psammophilous Chenopodiaceae and some representatives of the Poaceae play a major role. The composition of the flora and of the important families is discussed.

Within a relatively short period, less than a half century, the area of salt deserts in Central Asia has grown by about 60 000 km2. The process of salt desertification is tremendously active in the region of the former Aral Sea. The coastal plain and the dry sea floor of the Aral Sea are an evident model for studying salt desertification. The vast occurrence of salinization processes is the main reason for a very diverse halophytic flora on the dry sea floor. In comparison to other ecophysiological life forms, halophytes thrive on saline soils and are able to grow even on rather strongly salinized substrates. Investigation of the adaptive mechanisms of the various halophyte types is essential for an adequate species composition for phytomelioration of these saline soils. Phytomelioration by artificial planting on the dry sea floor for more rapid closure of the vegetation cover is a great need to minimize the widespread negative effects of salt desertification.

The term Aral Sea crisis region covers the lower stretches of the rivers Amudarya and Syrdarya, where the effects of the diversion of the river water from the Amudarya and Syrdarya are a blatant case. The drying of the Aral Sea, according to the Scientific Board for Global Environmental Changes of the German Federal Republic (WBGU), was declared the greatest environmental disaster caused by mankind in this century by changing the regional water budget. The disintegration into smaller water bodies is reality. Meanwhile the knowledge and information basis on the status of land degradation and on current activities in the crisis region is still insufficient. Up-to-date information on monitoring of land use and of the situation of the ecosystems in the crisis region is important, since the ecological situation is very dynamic and unstable. Degradation and desertification are threatening the whole population of the area and endangering their basis of living.

Deserts are arid areas on the globe where plant growth is scarce. The lack of water during longer periods is due to climatic conditions. This is known from all parts of the climatic temperature zones of the globe. Deserts and their adjacent semidesertic regions, such as the Sahara, the Negev and Sinai, the Namib, the Atacama and Altiplano, Central Australia, the Mohave in Southwestern USA, the Kyzylkum and Aralkum, and the Kawir in Iran and the Afghan deserts often exhibit severe changes in their environmental design according to human impact. Fluvial and aeolian soil erosion, enhanced salinity by waterlogging, pollution by pesticides and other toxics, thus, the loss of productive areas, are some of the severe effects of inadequate use by man Desertification often takes place by this human influence in ecotopic areas where a shift to desertic conditions by a slight change in environmental factors may cause a severe additional degradation.

The dry sea floor of the Aral Sea at present is a huge open salt flat. The enhancement of vegetation cover by means of phytomelioration is a realistic way for stabilization of the dry sea floor surface. This will support the natural processes of vegetative and generative propagation and the creation of seed banks for natural dissemination. Two experimental plots were established for identification of perspective plants for phytoreclamation of saline soils. Seeding experiments were started on two kinds of different ecological environments. Seeds of perennial and annual halophytes: Halocnemum strobilaceum, Haloxylon aphyllum, Halostachys caspica, Climacoptera aralensis, etc. were sowed. Experiment has shown that sandy soils have more favourable conditions for implementation of phytomeliorative measures than clay soils; the aridity of the first vegetation period plays a major role on the establishment of seedlings and saplings; species from local flora are more effective for phytoreclamation.

The dry sea floor of the Aral sea is a new terrestrial surface, where plants (including seedbank) and animals have not existed before, and it is actively populated by organisms. The dry sea floor (Aralkum desert) is the largest area worldwide where a primary succession takes place. Unintentionally, mankind has created a huge experiment, an experimental set, a laboratory of nature with thousands of local events. The new knowledge on vegetation dynamics in the Aralkum desert, which is a mosaic of sand and salt desert ecosystems, is very important for the understanding of the ecosystem dynamics in the whole Central Asian area. The succession on the dry sea floor has continued for 40 years. We are able to determine the age of the drying and of the ecosystems. This is important to identify major mechanisms that determine the rate and direction of ecosystem changes on the dry sea floor. The distribution and dynamics of the vegetation and ecosystems were surveyed along some new transects. On the dry sea floor barchan and salt deserts have spread. The present and future development of the drying sea is characterized by the creation of salt desert flats. Along the former coast line the inhabitants of adjacent villages are using the dry sea floor more and more as grazing area and for hay production.