Historically, arid and desert ecosystems have been little studied as they are considered of little interest. In addition, most of the countries where these environments are found tend to have less consolidated scientific infrastructures. These conditions have generated a knowledge gap regarding these ecosystems.
However, this trend is beginning to change. New research recently published in the Ecology & Evolution section of the prestigious journal Nature has shown that arid regions can provide valuable information on how temperate systems will adapt to climate change.
changes in ecosystems
In the study, an analysis was made of the ecological mechanisms that take place in dry ecosystems and from there, a model of its dynamics on a global scale was created. The results of the analysis, led by Professor José Marc Grünzweig of the Hebrew University of Jerusalem, show unprecedented changes in up to 12 different mechanisms associated with drylands. These mechanisms are directly related to environmental factors such as solar radiation, the intermittent availability of water or high temperatures, factors that climate change is altering, and that profoundly affect the functioning of the ecosystem.
It is to be expected that these mechanisms observed in arid zones will come into play in wetter and colder regions, historically not limited by water.
A significant increase in the extent of arid zones is expected, as well as a drastic reduction of up to 74% of soil moisture in areas that are not considered arid today. Some of these mechanisms are activated as soon as microclimatic thresholds are crossed, however, others have a slow and gradual response that depends on a combined set of local climatic conditions.
According to the forecasts of the study, these changes may influence the development and renewal of vegetation, as well as the flow of water and energy in ecosystems, the cycle of carbon and many other nutrients, and plant production. of ecosystems and even in the decomposition of organic matter.
Consequences on ecosystem services
Climate change is causing infrequent and extreme weather events, such as droughts and heat waves, to become more extreme and more frequent. Ultimately, and as the research shows, alterations in the mechanisms underlying the functioning of ecosystems will have immediate consequences on the contribution of nature to people, in what are called ecosystem services.
Large regions widely used for agricultural, livestock and forestry purposes will be affected by these changes. Furthermore, much of the areas involved are densely populated; The loss of ecosystem services, added to the lack of water in these new regions, can seriously jeopardize the well-being of the societies of these regions.
adaptation to arid life
In a scenario like the one presented, it has also been studied how species and ecosystems will adapt to life in arid zones. The research shows an ambiguous effect: while some observed mechanisms may buffer other impacts associated with anthropogenic climate change, many others may amplify them and even act synergistically, thereby increasing their importance.
Each type of ecosystem will have different adaptive capacity. For example, ecosystems that form primary forests, with a dense tree canopy and complex food webs, show greater ecological inertia that slows down changes. Trees have an acclimatizing effect that, through different mechanisms, reduces the incidence of extreme temperatures. The broader and bushier the canopy, the softer the effects, and the more time the ecosystem has to adapt to the changes. However, in grassland-type ecosystems, much more exposed to insolation and with greater water loss, much more drastic changes are observed.
This type of research provides new knowledge that can contribute to improving the adaptive capacity of societies to withstand climatic extremes and their impact on nature and on socioeconomic systems. This knowledge, the researchers suggest, “can be passed on to stakeholders to inform and direct environmental policy in their efforts to adapt to the human and nature consequences of climate change.”
Grunzweig, JM et al. 2022. Dryland mechanisms could widely control ecosystem functioning in a drier and warmer world. Nature Ecology & Evolution, 6(8), 1064-1076. DOI: 10.1038/s41559-022-01779-y