The UN’s Climate Change Conference that will open on November 1 in Glasgow, Scotland is expected to evoke global interest in this subject. Israel will be represented by a very large delegation, which will be headed by Prime Minister Naftali Bennett, environmental Protection Minister Tamar Zandberg, Energy Minister Karine Elharrar, and some 120 representatives from the government, Knesset ministries, municipalities, universities, companies, and the media. 

Climate change and the prospect of more frequent and intense climate extremes such as prolonged droughts and heavy rains threaten many services that plants provide to humans. Experts are worried about a change in plant community structure, with key species being displaced by others and a decline in the diversity of plants, as well as animals. 

The great complexity of ecosystems, reflected in part by their hierarchy of organizational levels, interferes with attempts to disentangle ecosystem responses to climate extremes that involve mechanisms operating at different organizational levels.

Scientists at Ben-Gurion University (BGU) of the Negev in Beersheba have identified a positive aspect of that complexity – it holds promise for reducing harmful effects of prolonged droughts by providing diverse pathways of response by the ecosystem. They developed and studied a mathematical model that captures a response mechanism operating at the population level – self-organization of plants in spatial and a response mechanism operating on the ground. It represents a community shift from species investing in growth to species investing in tolerating water stress.

Using this model to study the interplay between the two mechanisms, Prof. Ehud Meron of the Blaustein Institutes for Desert Research, his postdoctoral fellows Dr. Bidesh Bera and Dr. Jamie Bennett, and his former doctoral student Dr. Omer Tzuk uncovered three surprising insights. 

These are that spatial self-organization acts to reverse community-structure changes induced by water stress; that it buffers the impact of further stress and that it generates multi-stability of alternative ecosystem states and suggests new forms of ecosystem management that integrate the need for provisioning ecosystem services with the need to conserve community structure.

Their findings were reported in the peer-reviewed journal e-Life under the title “Linking spatial self-organization to community assembly and biodiversity.” 

“The structure of plant communities – their composition and diversity – forms the foundation of many ecosystem services on which human well-being crucially depends,” the researchers wrote. “These include provisioning services such as food, freshwater, wood, and fiber; regulating services such as flood regulation and water purification; cultural services such as recreation and aesthetic enjoyment; and supporting services such as soil formation, photosynthesis, and nutrient cycling. These services are at risk due to potential changes in the composition and diversity of plant communities as a result of global warming and the development of drier climates. Understanding the factors that affect community structure in varying environments calls for integrated studies of mechanisms operating at different levels of organization.” 

“These insights highlight the need to consider essential aspects of ecosystem complexity – spatial self-organization in this case – when addressing possible responses of ecosystems to climate extremes and devising management forms for ecosystems at risk,” stressed Meron “We focused on drylands, but spatial self-organization also occurs in wetlands such as hydric [saturated with water] peat bogs and salt marshes or undersea in seagrass meadows. Similar conclusions may hold for these systems as well,” Meron concluded.