Factors of global change affecting plants act at different levels of the ecological hierarchy

Abstract

SUMMARYPlants and ecosystems worldwide are exposed to a wide range of chemical, physical, and biological factors of global change, many of which act concurrently. As bringing order to the array of factors is required in order to generate an enhanced understanding of simultaneous impacts, classification schemes have been developed. One such classification scheme is dedicated to capturing the different targets of global change factors along the ecological hierarchy. We build on this pioneering work, and refine the conceptual framework in several ways, focusing on plants and terrestrial systems: (i) we more strictly define the target level of the hierarchy, such that every factor typically has just one target level, and not many; (ii) we include effects above the level of the community, that is, there are effects also at the ecosystem scale that cannot be reduced to any level below this; (iii) we introduce the level of the landscape to capture certain land use change effects while abandoning the level below the individual. We discuss how effects can propagate along the levels of the ecological hierarchy, upwards and downwards, presenting opportunities for explaining non‐additivity of effects of multiple factors. We hope that this updated conceptual framework will help inform the next generation of plant‐focused global change experiments, specifically aimed at non‐additivity of effects at the confluence of many factors.

Studying interactions among anthropogenic stressors in freshwater ecosystems: A systematic review of 2396 multiple‐stressor experiments

“…To better understand, predict and manage multiple stressors in natural systems, some experimental designs will be more useful than others. Studies, particularly with communities of species, that report multiple biological responses across levels of organization can help to identify if stressor interactions at one level are causing non‐additive responses at another (Rillig, Lehmann, et al., 2023; Simmons et al., 2021). Furthermore, more long‐term experiments that study adaptation to stressors or the trajectory of communities following the removal of stressors (only ca.…”

Stress combination: from genes to ecosystems

“…The authors discuss deficiencies in phosphorous combined with other essential elements, such as nitrogen, iron, and zinc, as well as with non-essential elements such as aluminum and sodium. Rillig et al (2024) describe in their review a new classification scheme that captures the different targets of global change factors along the ecological hierarchy. The authors discuss how effects can propagate across the levels of the ecological hierarchy, upwards and downwards, presenting new opportunities for explaining the non-additivity of effects of multiple factors.…”

Mycorrhization enhances plant growth and stabilizes biomass allocation under drought

“…The limited data available on the role of AM fungi in plant response to multiple global change factors hinder our ability to explore the potential mitigating effects. Furthermore, the number of global change factors significantly impacts soil functions and plant community dynamics(Rillig et al, 2019(Rillig et al, , 2024. Given this, we call for more studies to test the potential role of AM fungi in plant responses in the context of the simultaneous occurrence of multiple global change factors.…”