The Ecology of Plant Interactions: A Giant with Feet of Clay

Abstract

Community ecologists value the phenomenological observation of plant biotic interactions because they provide assumptions to make predictions of other ecosystem features, such as species diversity, community structure, or plant atmospheric carbon uptake. However, a rising number of scientists claim for the need of a mechanistic understanding of plant interactions, due to the limitations that a phenomenological approach raises both in empirical and modeling studies. Scattered studies take a mechanistic approach to plant interactions, but we still lack an integrated theoretical framework to start approaching holistically. In this Review and Synthesis, we present a comprehensive foundation for the study of the mechanisms underpinning the net interaction between two plants. First, we recapitulate the elementary units of plant interactions, i.e. all the known biophysical processes affected by the presence of an influencing plant and the possible phenotypic responses of influenced plants to these processes. Following, we discuss how a net interaction between two plants may emerge from the simultaneous effect of these elementary units. We then touch upon the spatial and temporal variability of this net interaction, and scrutinize how that variability may be linked to the underlying biophysical processes. We conclude by arguing how these processes can be integrated in a mechanistic framework for plant interactions, and why it must necessarily focus on the individual scale, incorporate the spatial structure of the community, and explicitly account for environmental factors.

Physiological responses to light explain competition and facilitation in a tree diversity experiment

“…The microclimate could also have altered photosynthesis directly in ways our light–response measurements did not capture because we controlled the chamber microclimate. Water stress was seldom very severe in any treatment (Figure ), but even modest differences could have changed the timing of stomatal closure (Brodribb et al., 2003). Greater light exposure may also have raised leaf temperature in monoculture (Schymanski et al., 2013), perhaps pushing leaves above thermal optima for photosynthesis.…”

Application of active acoustic transducers in monitoring and assessment of terrestrial ecosystem health—A review

“…Acoustic tomographs can also be used to study the density and distribution of roots systems (Mary et al, 2015). Plant root allocation can depend on environmental factors such as soil resources and competition, so studying spatial distributions of root systems can provide valuable insight into the overall plant community health (Cabal et al, 2020; Cahill et al, 2010). Acoustic waves travel through plant roots at a much higher velocity than they do through air or soil, thus the travel time of sound pulses moving through wood underground informs on the vicinity of the roots (Alani & Livia, 2020).…”

Enhanced species coexistence in Lotka-Volterra competition models due to nonlocal interactions

“…First, we have studied additive and non-additive influence ranges separately. However, nonlocal interactions with additive and non-additive influence ranges may act simultaneously, such as in allelopathic plants that also compete for resources through their roots (Cabal et al, 2020, Schenk, 2006. Our model easily allows exploring these scenarios by adequately tuning the integral terms in the model equations.…”