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Biocrusts are critical biological components of drylands and play an important role in soil carbon (C) cycling. However, the effect of biocrusts on soil CO 2 exchange across global gradients of temperature and moisture is poorly understood. Moreover, their response to climate change remains highly uncertain. Bayesian hierarchical meta-analyses were performed on 47 published studies to quantify the impact of biocrusts on net soil exchange (NSE) of carbon- the difference between respiration and photosynthesis. Meta-analyses were also used on 23 studies to examine the effects of experimental warming on NSE in biocrusts. Meta-regressions further explored the thermal and wetness sensitivities of biocrust NSE and potential adaptation of biocrust responses to climate change. The development of biocrusts in dryland soils significantly increased NSE by 66.5 [22.2, 112.2] g C m−2yr−1, despite seasonal fluctuations, indicating a net loss of carbon to the atmosphere. Experimental warming, on average, increased biocrust NSE by 22.9 [-0.1, 40.8] g C m−2yr−1 per °C. However, across the spatial climate gradient, aridity limited the effects of warming, while high temperature decreased the thermal sensitivity of biocrust NSE, thus supporting the thermal adaptation of biocrusts. These results emphasize the critical role of biocrusts in modulating soil carbon exchange in response to climate warming across drylands, with particularly high thermal sensitivity in cool and moist regions. This highlights the need to incorporate biocrusts into global carbon budgets and models for a comprehensive understanding of their impact on the carbon cycle. • Biocrusts increase soil CO2 efflux by 66.5 g C m-2yr-1 in drylands worldwide. • Climate warming increases CO2 efflux in biocrust soil by 22.9 g C m-2yr-1 per °C. • Thermal adaptation reduces thermal sensitivity of biocrust carbon efflux. [ABSTRACT FROM AUTHOR]

Highlights • Calibrating parameters is necessary for dynamic vegetation model in local scale. • Potential forest areas will decrease, while potential steppe areas will increase. • Existing land use pattern should be adjusted to adapt to climate change. • Shrubs have larger area and higher habitat suitability than forests. • Results could guide decision makers in developing effective revegetation plans. Abstract Global concern about the restoration of vegetation ecosystems has recently increased. Potential natural vegetation (PNV) and climate adaptation concepts should be integrated into revegetation programs to achieve sustainable ecosystems. The Yanhe Basin in the Loess Plateau of China (7687 km2) has been subjected to intense human activity for centuries. It was selected as the study area because vegetation degradation and restoration are occurring there. The objectives of this study were to (1) evaluate whether the current vegetation pattern is appropriate, and (2) provide a restoration plan for future revegetation programs based on PNV and habitat suitability patterns simulated by the dynamic vegetation model LPJ-GUESS. Current work focused on the parameter calibration and high-resolution climate data of the model over the study area. The comparisons of model performances in the PNV pattern and productivity indicated that parameter calibration was necessary for the model application. PNV of the Yanhe Basin may shift by 21.37–29.67% from 1981–2010 to 2071–2100, mainly in the southern part. Forests may decrease and steppes may increase as the climate becomes drier in the future. Comparisons between an existing land use map and the current PNV pattern indicated that only 40.8% of the forestland was coincident with the current PNV pattern, whereas grassland was a more suitable vegetation type for the rest of the terrain. In contrast, 83.1% of the grassland aligned with the current PNV pattern. Therefore, 16.9% remains to be forested. Current forestland and grassland patterns should be adjusted to cope with future climate change. Broadleaf summer-green shrubs covered a larger area and had higher habitat suitability than forests; they might be the most suitable woody plants for revegetation of the Yanhe Basin. The applied research approach could be extended to other regions undergoing similar revegetation programs and help promote sustainable vegetation management. [ABSTRACT FROM AUTHOR]

Highlights: [•] We investigate mechanism of hydraulic redistribution (HR) in relatively shallow tree roots. [•] We model the climate, vegetation, and soil controls on HR in shallow tree roots. [•] We investigate the effect of HR on the water stress of trees and grasses. [ABSTRACT FROM AUTHOR]