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Agriculture significantly contributes to greenhouse gas emissions and thus to climate change, directly through farm operations and indirectly through the energy needed to produce input materials, most prominently fertiliser, as well as through nitrous oxide (N2O) emissions from soils. Agriculture is the largest consumer of phosphorus, which is a non-renewable resource. Cotton accounts for one third of all natural and synthetic fibres of the total textile production. Today, Xinjiang, China, has become one of the most important cotton producers with highest yields worldwide. The aim of this study was to calculate the carbon (climate footprint and energy footprint) and phosphorus footprint of this high yielding cotton production and compare it to a theoretical production of an alternative fibre from Apocynum (local name: Kendyr or Kutra), which is a bast fibre plant native in Xinjiang and Central Asia. The data of the cotton production was collected through farm interviews during six years in Xinjiang. The data for Apocynum was compiled by literature from field experiments in the former Soviet Union. Cotton fibres, mainly due to high fertiliser inputs, caused a climate footprint of 4.43 kg CO2e/kg fibre, an energy footprint of 30.90 MJ/kg fibre, and a phosphorus footprint of 101 g P/kg fibre. The footprints of Apocynum are significantly lower with a climate footprint of 1.93 kg CO2e/kg fibre, an energy footprint of 21.85 MJ/kg fibre, and a phosphorus footprint of 1.6 g P/kg fibre. In cotton production, 63.9% of the climate footprint and 68.4% of the energy footprint are attributed to fertiliser production. Soil emissions of N2O account for another 22.2% of the climate footprint of cotton. The biggest potential to reduce carbon and phosphorus footprints of cotton production lie in reduced fertiliser application and re-use of plant residues. In the case of Apocynum, 65.1% of the climate footprint and 64.1% of the energy footprint are attributed to chemical treatment of the fibres in the extraction process.

Following the desiccation of the Aral Sea, Lake Balkhash has become the largest lake of Central Asia with an area of 17,000 km 2 . 70%–80% of the annual inflow into Lake Balkhash is delivered by the Ile River. The Ile Delta, 8000 km 2 large, is the largest natural delta and wetland complex of Central Asia and therefore is of crucial significance for the biodiversity of that region. In this paper, we reviewed the literature available with regard to vegetation, fauna, and biodiversity of the Ile River Delta and South Lake Balkhash Ramsar Site , in order to identify threats and research gaps. Threats are reduced runoff of the Ile River due to increasing water consumption upstream, overfishing, fires ignited by local people, logging for fuel wood collection, over-grazing, and water pollution from upstream. Major research gaps to be addressed are: 1) impact of reduced discharges of the Ile River on the wetland ecosystems and associated changes in livestock grazing, 2) impact of reduced discharges on spawning grounds for fish, 3) upper harvest limits for the fishery, and 4) regrowth of riparian woodlands.

A significant part of the world's largest river basins are located in areas of arid and semi-arid climate, such as the Amu Darya, Jordan, Murray-Darling, Yellow River, and Aksu-Tarim river basin. These river basins are experiencing water scarcity resulting in conflicts between upstream and downstream, conflicts between water users, and degradation of the natural ecosystems. Therefore, in many river basins, including the Aksu-Tarim river basin, water quota systems have been established, in order to allocate water under scarcity. The Aksu-Tarim river basin (NW China) has developed into one of the most important cotton production areas worldwide. In this paper, we aim at assessing the water consumption through irrigated agriculture, mainly cotton, and natural vegetation in the Aksu-Tarim river basin against the background of this water quota system. Firstly, we map the evapotranspiration (ETa) as water consumption of irrigated agriculture and natural vegetation in the Aksu-Tarim river basin. Secondly, we calculate water balances and relate them to the water quota system. We employed the remote sensing method Simplified Surface Energy Balance Index (S-SEBI), in order to map ETa based on MODIS satellite images for the growing seasons 2009, 2010, and 2011. Thereby, the MODIS products 8-day land surface temperature (MOD11A2), 16-day albedo (MCD43A3), and 16-day NDVI (MOD13A1) were used. The ETa of cotton ranges from 884 to 1198 mm. The ETa of the natural vegetation of a total coverage ranges from 715 in 2009 to 960 mm in 2011, clearly following the annual runoff of the Aksu and Tarim River. The water balance of the Aksu-Tarim river basin is −3.25 to −3.73 km3, 0.1–0.53 km3, and −3.55 to −4.12 km3 in 2009, 2010, and 2011, respectively. The water quotas along the Aksu River and the upper reaches of the Tarim are exceeded by water consumption, while the quotas along the middle and lower reaches are not met. Considerable amounts of groundwater, including fossil groundwater, are exploited for irrigation along the Aksu and Tarim River, which must be regarded as exploitation of a non-renewable resource.

Wuliangsuhai Lake is one of the largest wetlands in Inner Mongolia, China, half covered by large and highly productive Common Reed (Phragmites australis) stands. However, benefits from current utilization practices do not cover the costs of harvesting. Against this background, Wuliangsuhai Lake is taken as a case study for the assessment of the potential use of reed biomass for energy production. Taking into account, both the present and the potential reed availability, four scenarios are considered, i.e. (1) a decentralized application in household stoves, (2) a centralized reed supplied combined heat and power gasification, (3) a direct combustion plant and (4) a co-firing in existing coal plants. Two field campaigns have been conducted firstly collect information about the current situation of the reed and coal market and secondly to measure reed above-ground biomass. The suitability of reed for thermochemical conversion processes has been evaluated by means of chemical-physical, calorimetric, and thermal analyses of the samples. The potential energy production is valued regarding the profitability on the current Chinese energy market. Possible subsidies for reed as a renewable resource are taken into account. The evaluation has shown that reed has the potential to act as an energy feedstock. In relation to the considered study site, reed energy use can be profitable on the household level, in CHP combustion plants and in co-combustion. Gasification CHP plants are not economic feasible under current conditions. The results show that reed can be a sustainable alternative to highly health and environment damaging coal.

Common reed (Phragmites australis (Cav.) Trin. ex Steud.) is a key wetland species with cosmopolitan distribution. In this study, we examined nitrogen (N) and phosphorus (P) stoichiometry in reed organs, using data of 28 samples from Wuliangsuhai Lake and 17 samples from the wetlands of the city of Zhangye, both located in northern China. Our results showed that the average N and P contents and N:P ratio of the whole plant (geometric mean of mass ± standard deviation) were 14.1 ± 5.3 mg g−1, 0.95 ± 0.54 mg g−1, and 16 ± 5, respectively. These values exhibited significant differences among the organs of reed, including the flowers, leaves, stems, roots, and rhizomes, ranging on average from 6.4 ± 4.2 (stem) to 31.4 ± 5.2 mg N g−1 (leaf), from 0.652 ± 0.647 (stem) to 2.05 ± 0.33 mg P g−1 (flower), and from 10 ± 6 (stem) to 24 ± 4 (leaf) on N:P ratio. The N content closely co-varied with P content within and across organs, and interestingly, P content was more variable than N content. The N and P contents of the whole reed plant, stems, and rhizomes were positively correlated with the availability of these nutrients in water and sediment, but were relatively stable in leaves and flowers. Structural organs probably perform a buffering function of storing N and P in plants. All such stoichiometric patterns can influence the reed bed stand structures such as stem density, stem height, and basal diameter, and may contribute to the wide distributions of reed species in various environments. Our findings are applicable to the management of reed-dominated wetlands.

To investigate the influence of groundwater and river dynamics on genetic diversity and clonal growth of Populus euphratica forests along the Tarim river system (Xinjiang Prov., China), we genotyped nine old stands in three study areas of various distance to the main river. Using seven microsatellite loci, 850 genotypes were found among 1701 analyzed trees, with 204 of these comprising at least two trees. Population genetic analyses revealed a low degree of genetic differentiation (Dest = 0.014, Gst = 0.005), and no restriction to gene flow between stands. The forests can therefore be described by the infinite island model of gene flow. Stands in the three study areas differed strongly in clonality: in area I 82% of all trees grew from root suckers, clones averagely comprised 10.5 ± 2.0 trees; figures in area II were 45% and clones of 4.5 ± 1.0 trees, respectively. Area III had the largest trees, but was almost non-clonal (less than 3% of all trees were root suckers). By measuring current ground water depth and reconstructing river courses over more than one century, the varying ground water supply was identified as the most likely reason for the different degree of clonal growth. Neither survival nor lifespan of a stand depends on clonal growth. In the harsh environments inhabited by P. euphratica, the most important function of clonal growth may be the enhanced reproductive impact of large clones.

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