• Energy Research

AbstractScientific innovation is overturning conventional paradigms of forest, water, and energy cycle interactions. This has implications for our understanding of the principal causal pathways by which tree, forest, and vegetation cover (TFVC) influence local and global warming/cooling. Many identify surface albedo and carbon sequestration as the principal causal pathways by which TFVC affects global warming/cooling. Moving toward the outer latitudes, in particular, where snow cover is more important, surface albedo effects are perceived to overpower carbon sequestration. By raising surface albedo, deforestation is thus predicted to lead to surface cooling, while increasing forest cover is assumed to result in warming. Observational data, however, generally support the opposite conclusion, suggesting surface albedo is poorly understood. Most accept that surface temperatures are influenced by the interplay of surface albedo, incoming shortwave (SW) radiation, and the partitioning of the remaining, post‐albedo, SW radiation into latent and sensible heat. However, the extent to which the avoidance of sensible heat formation is first and foremost mediated by the presence (absence) of water and TFVC is not well understood. TFVC both mediates the availability of water on the land surface and drives the potential for latent heat production (evapotranspiration, ET). While latent heat is more directly linked to local than global cooling/warming, it is driven by photosynthesis and carbon sequestration and powers additional cloud formation and top‐of‐cloud reflectivity, both of which drive global cooling. TFVC loss reduces water storage, precipitation recycling, and downwind rainfall potential, thus driving the reduction of both ET (latent heat) and cloud formation. By reducing latent heat, cloud formation, and precipitation, deforestation thus powers warming (sensible heat formation), which further diminishes TFVC growth (carbon sequestration). Large‐scale tree and forest restoration could, therefore, contribute significantly to both global and surface temperature cooling through the principal causal pathways of carbon sequestration and cloud formation.

The results of a broader notion of value for measuring ecosystem services (ESs) are presented, as recently demanded by R. Costanza, with attention to the biophysical, thermodynamic aspects of value. The unifying basis in any ecosystem is the solar energy inflow and the growing efficiency of its use with higher stages of self-organized succession processes. The authors utilize two methods of nonmarket valuation (Biotope Valuation Method, Energy-Water-Vegetation Method) which show the range of the environmental values of nature, from how costly it is for nations to restore the quality of a landscape (biotopes as specific habitats for specific species) to their real abilities to replace the core supporting and regulating services of ecosystems (climatizing service, water-retention service, oxygen production, habitats for biodiversity). The role of natural forests and wetlands as the most effective solar energy users is shown and compared with agricultural lands and other human-altered ecosystem groups. A comparison of ESs value ratios with the welfare-method results of Costanza’s team shows much higher importance of natural forests as the best climatic and water regulators in sustainable landscape decision-making. The authors show that it is not the replacement-cost method that overestimates, but rather, preferential methods that underestimate the values of ESs.

Abstract East African wetlands are naturally dominated by papyrus, the world's fastest growing herbaceous plant, reaching up to 5 m in height and 3 kg m−2 of standing biomass per year. While its provisioning services are well-known, papyrus plays a less evident role in supporting tropical swamp ecosystems by controlling nutrient balances as well as hydrological flows, and through the provision of critical biotopes vital for the reproduction of insects, fishes and birds, including a small number of endemic species. Claims are made condemning papyrus for enhancing water loss, yet only few proper evapotranspiration studies have been carried out. Conflicting evidence indicates that papyrus swamps could be important in regulating local climate through evapotranspiration and hold significant potential in climate mitigation through carbon sequestration and carbon storage as peat. These benefits may become soon severely eroded because papyrus swamps are degrading rapidly due to direct exploitation, to agricultural encroachment, and to extensive trampling and feeding by cattle. We review papyrus ecosystem services, with a focus on its role on biodiversity enhancement and regulating functions. We present new evidence, showing an inverse temperature gradient within papyrus swamps, indicative of an optimised water retention capacity, with examples from Lake Naivasha and Lake Victoria. Better understanding of papyrus regulating services should underpin papyrus restoration as an ecohydrological tool to improve water quality, to moderate local climate by regulating the water cycle, to provide base material for a variety of provisioning ecosystem services, to enhance biotope structure and to support biodiversity.

Destabilization of the water cycle threatens human lives and livelihoods. Meanwhile our understanding of whether and how changes in vegetation cover could trigger abrupt transitions in moisture regimes remains incomplete. This challenge calls for better evidence as well as for the theoretical concepts to describe it. Here we briefly summarise the theoretical questions surrounding the role of vegetation cover in the dynamics of a moist atmosphere. We discuss the previously unrecognized sensitivity of local wind power to condensation rate as revealed by our analysis of the continuity equation for a gas mixture. Using the framework of condensation-induced atmospheric dynamics, we then show that with the temperature contrast between land and ocean increasing up to a critical threshold, ocean-to-land moisture transport reaches a tipping point where it can stop or even reverse. Land-ocean temperature contrasts are affected by both global and regional processes, in particular, by the surface fluxes of sensible and latent heat that are strongly influenced by vegetation. Our results clarify how a disturbance of natural vegetation cover, e.g., by deforestation, can disrupt large-scale atmospheric circulation and moisture transport. In view of the increasing pressure on natural ecosystems, successful strategies of mitigating climate change require taking into account the impact of vegetation on moist atmospheric dynamics. Our analysis provides a theoretical framework to assess this impact. The available data for Eurasia indicate that the observed climatological land-ocean temperature contrasts are close to the threshold. This can explain the increasing fluctuations in the continental water cycle including droughts and floods and signifies a yet greater potential importance for large-scale forest conservation. 25 pages, 5 figures, and 1 table

This article shows how to restore Central European natural capital effectively. Water in the landscape is primarily sustained by vegetation and soil, most effectively by natural forests and only secondarily by artificial reservoirs. The authors document these facts using a case study from the Želivka River basin (Švihov reservoir), which collects surface water for the metropolitan region of Prague and Central Bohemia. With the Energy-Water-Vegetation Method, the authors demonstrate that the cultural human-changed landscape of the Želivka river basin is able to utilize only about 60% of its solar energy potential. In 1.5% of the territory of the Czech Republic, society annually loses supporting ecosystem services at a level higher than 25% of the annual GDP of the CR 2015. Water retention in the landscape needs to be re-evaluated and addressed in accordance with the thermodynamic principles of life and ecosystem functioning in the biosphere. It is necessary to begin restoring the most efficient natural capital in the landscapes and to return the broad-leaved deciduous forests by intelligent forestation methods to the cultural landscape to the extent justified; this is especially true of the Želivka River basin, which is Czechia’s biggest surface drinking-water collecting area.