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Natural landscapes are spatial-temporal ensembles of landforms and species in interaction with their physical environment. Ecosystems are simply their arbitrary, yet coherent subsets, where the individual components are grouped into functional compartments linked by energy and matter transfer and species interaction. Ecosystems can only persist through a cascade of energy, from higher levels (e.g., solar radiation) to heat, where multiple forms of work can be performed, and without any further work, can only dissipate. Because ecosystems must increase their organization to prevent such an inexorable flow towards degradation and disorder, we say that they can only exist far from equilibrium.

Badlands are landforms that occur all over the World. In the Mediterranean region, badlands are found in both dry (arid and semi‐arid) and wet (subhumid and humid) environments, and are characterized by complex hydro‐geomorphological dynamics, high intense erosion processes and extreme sediment yield. Understanding the impact of Global Change is key to predict the on‐site and off‐site effects on badland dynamics, particularly its consequences on bedrock weathering, on sediment yield and delivery and on plant colonization. Here, conducting a systematic literature review, we analyzed an extensive database and identified the main climate‐drivers affecting the hydro‐geomorphological dynamics in Mediterranean badlands (based on non‐metric multidimensional scaling and structural equation modeling analysis). Later, we examined the main impacts expected from climate change forecasting in the near future, and we explored the interactions between badlands response to climate variation. In Mediterranean badlands, weathering processes are mainly related to wetting–drying cycles and freeze–thaw cycles in dry and wet badlands, respectively. In both environments, rainfall amount appears as the main driver for runoff response, and rainfall amount and rainfall intensity for erosion dynamics. Future climate scenarios forecast a decrease in annual rainfall, number of rainfall events and frost days, and in soil moisture, and an increase in rainfall intensity. These changes will have direct hydro‐geomorphological implications with direct and indirect effects on badland dynamics. This may result in a decrease in annual runoff in dry badlands, but the occurrence of more frequent extreme events would increase soil erosion and could negatively affect biological soil crust. In wet badlands, weathering and erosion processes may decrease, and a stabilization of the slopes, with consequently improved vegetation growth, may be expected. In addition, the forecasted changes must be taken into acco

[No abstract available]

Arid and semi-arid ecosystems are characterized by patchy vegetation and variable resource availability. The interplant spaces of these ecosystems are very often covered by cyanobacteria-dominated biocrusts, which are the primary colonizers of terrestrial ecosystems and key in facilitating the succession of other biocrust organisms and plants. Cyanobacterial biocrusts regulate the horizontal and vertical fluxes of water, carbon and nutrients into and from the soil and play crucial hydrological, geomorphological and ecological roles in these ecosystems. In this paper, we analyze the influence of cyanobacterial biocrusts on water balance components (infiltration-runoff, evaporation, soil moisture and non-rainfall water inputs (NRWIs)) in representative semiarid ecosystems in southeastern Spain. The influence of cyanobacterial biocrusts, in two stages of their development, on runoff-infiltration was studied by rainfall simulation and in field plots under natural rainfall at different spatial scales. Results showed that cover, exopolysaccharide content, roughness, organic carbon, total nitrogen, available water holding capacity, aggregate stability, and other properties increased with the development of the cyanobacterial biocrust. Due to the effects on these soil properties, runoff generation was lower in well-developed than in incipient-cyanobacterial biocrusts under both simulated and natural rainfall and on different spatial scales. Runoff yield decreased at coarser spatial scales due to re-infiltration along the hillslope, thus decreasing hydrological connectivity. Soil moisture monitoring at 0.03 m depth revealed higher moisture content and slower soil water loss in plots covered by cyanobacterial biocrusts compared to bare soils. Non-rainfall water inputs were also higher under well-developed cyanobacterial biocrusts than in bare soils. Disturbance of cyanobacterial biocrusts seriously affected the water balance by increasing runoff, decreasing soil moisture and