Precipitation recycling, where evapotranspiration (ET) from the land surface contributes to precipitation within the same region, is a critical component of the water cycle. This process is especially important for the US Corn Belt, where extensive cropland expansions and irrigation activities have significantly transformed the landscape and affected the regional climate. Previous studies investigating precipitation recycling typically relied on analytical models with simplifying assumptions, overlooking the complex interactions between groundwater hydrology and agricultural management.
View Article and Find Full Text PDFIn the vegetation root zone, infiltration () parts in two directions with distinct Earth-system functions. One goes up as evapotranspiration ( + ), returning to the atmosphere (short-circuiting) and affecting short-term weather/climate and the carbon cycle. The other goes down as deep drainage (), flushing the regolith, mobilizing nutrients/contaminates and dissolved minerals into aquifers and rivers, eventually reaching the ocean (long-circuiting) thus regulating global biogeochemical cycles and long-term climate.
View Article and Find Full Text PDFLand degradation is a complex socio-environmental threat, which generally occurs as multiple concurrent pathways that remain largely unexplored in Europe. Here we present an unprecedented analysis of land multi-degradation in 40 continental countries, using twelve dataset-based processes that were modelled as land degradation convergence and combination pathways in Europe's agricultural (and arable) environments. Using a Land Multi-degradation Index, we find that up to 27%, 35% and 22% of continental agricultural (~2 million km) and arable (~1.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2023
Forest-savanna boundaries are ecotones that support complex ecosystem functions and are sensitive to biotic/abiotic perturbations. What drives their distribution today and how it may shift in the future are open questions. Feedbacks among climate, fire, herbivory, and land use are known drivers.
View Article and Find Full Text PDFGlobal warming is expected to alter wildfire potential and fire season severity, but the magnitude and location of change is still unclear. Here, we show that climate largely determines present fire-prone regions and their fire season. We categorize these regions according to the climatic characteristics of their fire season into four classes, within general Boreal, Temperate, Tropical and Arid climate zones.
View Article and Find Full Text PDFVegetation modulates Earth's water, energy and carbon cycles. How its functions might change in the future largely depends on how it copes with droughts. There is evidence that, in places and times of drought, vegetation shifts water uptake to deeper soil and rock moisture as well as groundwater.
View Article and Find Full Text PDFContinued deforestation in the Amazon forest can alter the subsurface/surface and atmospheric branches of the hydrologic cycle. The sign and magnitude of these changes depend on the complex interactions between the water, energy, and momentum budgets. To understand these changes, we use the weather research and forecasting (WRF) model with improved representation of groundwater dynamics and the added feature of Amazonian moisture tracers.
View Article and Find Full Text PDFPlant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle.
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