Arvicola terrestris Scherman est un rongeur fouisseur dont le regime alimentaire n'a ete que tres peu etudie bien que les degats qu'il occasionne dans les prairies soient tres importants, surtout lors des pullulations cycliques. Les methodes classiques d'investigations (analyses des contenus stomacaux, des reserves alimentaires, etc) ne rendent que partiellement comptes des choix reels. En outre, les travaux effectues sur le terrain ne permettent pas de tirer de conclusions precises sur le sujet, notamment en raison de la grande diversite des especes vegetales presentes. C'est pourquoi nous avons choisi une approche experimentale: un "essai en pature" adapte aux campagnols. L'experience s'est deroulee dans un terrarium de 6 x 3 m, dispose en pleine terre. Les campagnols places dans le terrarium avaient le choix entre 12 plantes, cultivees separement sur de petites parcelles. Ils pouvaient se nourrir, soit en surface, soit a partir de leurs galeries souterraines et restaient ainsi dans des conditions proches de celles de la prairie. Les preferences ont ete deduites selon trois methodes: la comparaison des quantites de matiere seche recoltees dans le terrarium et dans un temoin identique, l'observation des signes d'activite des campagnols et l'evolution du recouvrement de la vegetation dans chaque parcelle. Les trois ont donne des resultats semblables. Ce premier essai realise en 1986 a permis de mettre en evidence une nette preference pour Medicago sativa, Taraxacum officinale et Trifolium pratense; aucune des graminees presentees n'a ete tres appreciee malgre leur bonne qualite fourragere

This paper synthesizes the spatial and temporal relationship between forest cover and water, as well as its implications for food security in the northwestern highlands of Ethiopia. Different studies addressing the topic of land cover and hydrology have been reviewed. Analyses of 20–40 year long time series showed little and inconsistent relationships between forest cover change and hydrology on meso-scale (100–1000km2) watersheds. Spatial studies, however, showed stronger relationships between land cover and low flow features such as grasslands and woodlands. Interviews with local communities suggested land cover change impacts are more pronounced at smaller scale (<100km2) watersheds; which is consistent with observational studies on small scale watersheds and farm level plots. The stronger relationships between forests and hydrology at smaller scales suggests land management policies should be oriented to farm level conditions, where water is vital for the food security of subsistence farmers who comprise 86% of the population in the highlands.

The food–water–land–ecosystem (FWLE) nexus is fundamental for achieving sustainable development. This study examines the influence of urbanization on the FWLE nexus. Toward this end, land was deemed as an entry point. Therefore, the impact of urbanization on the nexus was explored based on changes in land use. We selected Shenzhen, a city in China, as the study area. First, a land change modeler was employed to analyze historical land-use changes from 2000 to 2010, to build transition potential submodels, and to project future land-use patterns for 2030 under a business-as-usual scenario. Second, based on land-use maps, we assessed habitat quality, water yield, and water supply from 2000 to 2030 using Integrated Valuation of Ecosystem Services and Tradeoffs. Moreover, crop production was estimated according to statistical materials. Finally, the study presents the analyses and discussion of the impacts of urbanization on ecosystem services related to the FWLE nexus. The results of land-use changes indicated that a significant expansion of artificial surfaces occurred in Shenzhen with varying degrees of decrease in cultivated land, forest, and grassland. Furthermore, habitat quality, water supply, and crop production decreased evidently due to rapid urbanization. In contrast, the total water yield indicated an upward trend owing to the increased water yield from increasing artificial surfaces, whereas water yield from other land-use areas declined, such as the forest and grassland. The results demonstrated a significant positive correlation between artificial surfaces and total water yield. However, negative correlations were observed in the interaction among habitat quality, water supply, and crop production. The study presented temporal and spatial assessments to provide an effective and convenient means of exploring the interactions and tradeoffs within the FWLE nexus, which, thus, contributed to the sustainable transformation of urbanization.

The roles of both landscape alteration and in-lake processes need to be considered in conservation strategies for shallow lakes in the prairie regions of North America. Here we focus on shallow lakes in west-central Minnesota, USA, highlighting the long-term ecological history and response to known landscape changes of a clear-water, macrophyte-dominated, shallow lake. Contemporary limnological data suggest the aquatic ecosystem has been very stable and fishless for the last ~15 years. Sediment proxies for primary production and ecological change confirm that a stable ecosystem likely prevailed for the last ~200 years. However, sedimentary indicators of catchment erosion detail a distinct response to land-use change during the conversion of native grassland to agricultural land, and following establishment of a protected waterfowl production area (WPA) around the lake. Post-WPA, the rate of sediment accrual decreased dramatically within 5–10 years and sources of organic matter were similar to those of the pre-settlement period. The aquatic ecosystem has been able to withstand nutrient enrichment and allochthonous inputs because stable trophic interactions have likely been in place for more than 200 years. We conclude that lack of hydrologic connectivity and isolated, small catchments are important factors in the promotion of clear-water shallow lake ecosystems, mainly because they prevent colonization by fish and associated ecological consequences. This study highlights the importance of managing both the landscape and in-lake processes to maintain stable, clear-water, shallow lakes.

A copula bi-level fractional programming (CBFP) method is developed for planning the water–food–energy–ecology (WFEE) nexus system. CBFP has advantages in (i) dealing with ratio-objective problems, (ii) balancing the conflicts between hierarchical decision levels, and (iii) reflecting joint risks of correlated uncertain variables. Then, a CBFP–WFEE model is formulated to the Ili-Balkhash basin in Central Asia, in which 108 scenarios associated with different irrigation efficiencies, ecological-flow demands (EBW), and water–land resources have been examined. Solutions of water allocation, hydropower generation, and land-use pattern are obtained. Our major findings are as follows: (i) from 2021 to 2050, water allocation to livestock in East Kazakhstan would remarkably increase (by 40.9%) when water allocation to food is satisfied; (ii) hydropower generation would increase with the rising ecological flows and arable land resources; (iii) EBW is the key factor influencing the water inflow to the Balkhash Lake; (iv) the share of ecosystem water allocation would exceed 17.5% by 2050, and grassland area would rank in the first place of the ecosystem. Compared with conventional bi-level stochastic programming and single-level fractional programming models, the CBFP–WFEE model can achieve a higher ecosystem service value and higher efficiency of water–land resources, which can provide more feasible and sustainable alternatives for the WFEE nexus system. The obtained results can help balance the contradictions among water shortage, economic development, and ecology protection, as well as provide synergic management strategies for regional sustainability.

Human activities use more than half of accessible freshwater, above all for agriculture. Most approaches for reconciling water conservation with feeding a growing population focus on the cropping sector. However, livestock production is pivotal to agricultural resource use, due to its low resource-use efficiency upstream in the food supply chain. Using a global modelling approach, we quantify the current and future contribution of livestock production, under different demand- and supply-side scenarios, to the consumption of “green” precipitation water infiltrated into the soil and “blue” freshwater withdrawn from rivers, lakes and reservoirs. Currently, cropland feed production accounts for 38% of crop water consumption and grazing involves 29% of total agricultural water consumption (9990km³yr⁻¹). Our analysis shows that changes in diets and livestock productivity have substantial implications for future consumption of agricultural blue water (19–36% increase compared to current levels) and green water (26–69% increase), but they can, at best, slow down trends of rising water requirements for decades to come. However, moderate productivity reductions in highly intensive livestock systems are possible without aggravating water scarcity. Productivity gains in developing regions decrease total agricultural water consumption, but lead to expansion of irrigated agriculture, due to the shift from grassland/green water to cropland/blue water resources. While the magnitude of the livestock water footprint gives cause for concern, neither dietary choices nor changes in livestock productivity will solve the water challenge of future food supply, unless accompanied by dedicated water protection policies.

The Ecosystem Restoration Project (ERP) is a critical and urgent practice to achieve the land degradation neutrality (LDN) targets. However, an insufficient understanding of the balance between contrasting sectors of the food-water-ecosystem nexus results in ineffectiveness in supporting complex environmental management (CEM), leading to undesirable ERP failures. The Ordos Plateau case identified the nexus evolution and the non-linear interactions between sectors, which were expected to support adaptive strategy formulations for CEM and achieve win-win outcomes. Revegetation in drylands substantially boosted ecosystem restoration, alleviating soil erosion. However, the excessive reliance on returning cropland to woodland and grassland has caused a significant loss of arable and grazing land. During the initial period of ERPs, this exacerbated decline in grain and meat productivity. In addition, aggressive revegetation activities have also reduced runoff yield and depleted soil water resources. Water scarcity is recognized as the most challenging issue in dryland ecosystem restoration, heavily influencing the interactions between sectors and threatening the long-term sustainability of ERPs. To accommodate for regional water carrying capacity, ERPs should adopt and properly allocate the use of suitable plant species with a proven anti-drought capability and high survival ratios without additional human interventions. In addition, the evolution regimes, driving factors, critical thresholds, and complex feedbacks between the nexus sectors should be fully understood to address the water resources constraints and reconcile trade-offs. This would enable the prevention of ecosystem shifts to undesirable failures and inform timely and cost-effective CEM to achieve the LDN targets.

The paper presents lysimeter tests, which have been conducted since 1974 on the amount of water runoff from sodded soil profile under conditions of its diversified use and watering. On the tested area a major portion of the total yearly runoff from grasslands occurs during the growing season due to the amount and distribution of precipitation in this region (c.a. 68 of the total yearly precipitation falls during the growing season). Runoff values from grasslands recorded during the study period varied from 113.7 to 247.1 mm. A significant relationship has been found betwen the amount of water draining away from grassland soil profile and the amount of yield, which was caused either by a method of use (meadow, pasture or 8-15 cm high sward) or by the amount of applied nitrogen fertilization