World's Saline Research Articles

The cost of addressing saline lake level decline and the potential for water conservation markets

The world's saline lakes are shrinking and human water diversions are a significant contributor. While there is increased interest in protecting the ecosystem services provided by these lakes, the cost of protecting water levels has not been estimated. To explore this question we consider the case of Great Salt Lake (Utah, USA) where human diversions from three rivers have caused the lake level to decline during the last century. Recent work has suggested the restoration of inflows is necessary to maintain a target elevation consistent with well-functioning ecosystems. We construct cost estimates of increasing water inflows using conservation cost curves for each river basin. We then compare the cost of uniform cutbacks to cap-and-trade systems which allow intra- and inter-basin trading. The cost of water to permanently implement uniform water right cutbacks to increase inflows by 20% above current levels is $37.4 million. Costs and cost-savings are sensitive to alternative allocation, inflow, and cost assumptions, and we estimate significant cost reductions from intra-basin water conservation markets (5–54% cost decrease) and inter-basin water conservation markets (22–57% cost decrease).

Decline of the world's saline lakes

Many of the world's saline lakes have been shrinking due to consumptive water use. The Great Salt Lake, USA, provides an example for how the health of and ecosystem services provided by saline lakes can be sustained. Many of the world's saline lakes are shrinking at alarming rates, reducing waterbird habitat and economic benefits while threatening human health. Saline lakes are long-term basin-wide integrators of climatic conditions that shrink and grow with natural climatic variation. In contrast, water withdrawals for human use exert a sustained reduction in lake inflows and levels. Quantifying the relative contributions of natural variability and human impacts to lake inflows is needed to preserve these lakes. With a credible water balance, causes of lake decline from water diversions or climate variability can be identified and the inflow needed to maintain lake health can be defined. Without a water balance, natural variability can be an excuse for inaction. Here we describe the decline of several of the world's large saline lakes and use a water balance for Great Salt Lake (USA) to demonstrate that consumptive water use rather than long-term climate change has greatly reduced its size. The inflow needed to maintain bird habitat, support lake-related industries and prevent dust storms that threaten human health and agriculture can be identified and provides the information to evaluate the difficult tradeoffs between direct benefits of consumptive water use and ecosystem services provided by saline lakes.

Reassessment of tissue Na+ concentration as a criterion for salinity tolerance in bread wheat

Wheat is the most important crop grown on many of world's saline and sodic soils, and breeding for improved salinity tolerance (ST) is the only feasible way of improving yield and yield stability under these conditions. There are a number of possible mechanisms by which cereals can tolerate high levels of salinity, but these can be considered in terms of Na(+) exclusion and tissue tolerance. Na(+) exclusion has been the focus of much of the recent work in wheat, but with relatively little progress to date in developing high-yielding, salt-tolerant genotypes. Using a diverse collection of bread wheat germplasm, the present study was conducted to assess the value of tissue Na(+) concentration as a criterion for ST, and to determine whether ST differs with growth stage. Two experiments were conducted, the first with 38 genotypes and the second with 21 genotypes. A wide range of Na(+) concentrations within the roots and shoots as well as in ST were observed in both experiments. However, maintenance of growth and yield when grown with 100 mM NaCl was not correlated with the ability of a genotype to exclude Na(+) either from an individual leaf blade or from the whole shoot. The K(+) : Na(+) ratio also showed a wide range among the genotypes, but it did not explain the variation in ST among the genotypes. The results suggested that Na(+) exclusion and tissue tolerance varied independently, and there was no significant relationship between Na(+) exclusion and ST in bread wheat. Consequently, similar levels of ST may be achieved through different combinations of exclusion and tissue tolerance. Breeding for improved ST in bread wheat needs to select for traits related to both exclusion and tissue tolerance.