This paper argues that the interplay of water, carbon and vegetationdynamics fundamentally links some global trends in the current andconceivable future Anthropocene, such as cropland expansion, freshwater use,and climate change and its impacts. Based on a review of recent literatureincluding geographically explicit simulation studies with the process-basedLPJmL global biosphere model, it demonstrates that the connectivity of waterand vegetation dynamics is vital for water security, food security and(terrestrial) ecosystem dynamics alike. The water limitation of net primaryproduction of both natural and agricultural plants – already pronounced inmany regions – is shown to increase in many places under projected climatechange, though this development is partially offset by water-saving directCO2 effects. Natural vegetation can to some degree adapt dynamically tohigher water limitation, but agricultural crops usually require some form ofactive management to overcome it – among them irrigation, soil conservationand eventually shifts of cropland to areas that are less water-limited dueto more favourable climatic conditions. While crucial to secure foodproduction for a growing world population, such human interventions inwater–vegetation systems have, as also shown, repercussions on the watercycle. Indeed, land use changes are shown to be the second-most importantinfluence on the terrestrial water balance in recent times. Furthermore,climate change (warming and precipitation changes) will in many regionsincrease irrigation demand and decrease water availability, impedingrainfed and irrigated food production (if not CO2 effectscounterbalance this impact – which is unlikely at least in poorly managedsystems). Drawing from these exemplary investigations, some researchperspectives on how to further improve our knowledge ofhuman–water–vegetation interactions in the Anthropocene are outlined.
展开▼
