Responses of terrestrial ecosystems to climate change have been explored in many regions worldwide. While continued drying and warming may alter process rates and deteriorate the state and performance of ecosystems, it could also lead to more fundamental changes in the mechanisms governing ecosystem functioning. Here we argue that climate change will induce unprecedented shifts in these mechanisms in historically wetter climatic zones, towards mechanisms currently prevalent in dry regions, which we refer to as ‘dryland mechanisms’. We discuss 12 dryland mechanisms affecting multiple processes of ecosystem functioning, including vegetation development, water flow, energy budget, carbon and nutrient cycling, plant production and organic matter decomposition. We then examine mostly rare examples of the operation of these mechanisms in non-dryland regions where they have been considered irrelevant at present. Current and future climate trends could force microclimatic conditions across thresholds and lead to the emergence of dryland mechanisms and their increasing control over ecosystem functioning in many biomes on Earth.

全球许多地区都在探索陆地生态系统对气候变化的响应。虽然持续的干燥和变暖可能会改变过程速率并恶化生态系统的状态和性能，但它也可能导致管理生态系统功能的机制发生更根本的变化。在这里，我们认为气候变化将导致历史上较为潮湿的气候区的这些机制发生前所未有的转变，转向目前在干旱地区普遍存在的机制，我们称之为“旱地机制”。我们讨论了影响生态系统功能多个过程的 12 种旱地机制，包括植被发育、水流、能量收支、碳和养分循环、植物生产和有机物分解。然后，我们检查了这些机制在目前被认为无关紧要的非旱地地区运作的罕见例子。当前和未来的气候趋势可能迫使微气候条件跨越阈值，并导致旱地机制的出现及其对地球上许多生物群落中生态系统功能的日益控制。