Self-Replication of Localized Vegetation Patches in Scarce Environments

Abstract

Desertification due to climate change and increasing drought periods is a worldwide problem for both ecology and economy. Our ability to understand how vegetation manages to survive and propagate through arid and semiarid ecosystems may be useful in the development of future strategies to prevent desertification, preserve flora—and fauna within—or even make use of scarce resources soils. In this paper, we study a robust phenomena observed in semi-arid ecosystems, by which localized vegetation patches split in a process called self-replication. Localized patches of vegetation are visible in nature at various spatial scales. Even though they have been described in literature, their growth mechanisms remain largely unexplored. Here, we develop an innovative statistical analysis based on real field observations to show that patches may exhibit deformation and splitting. This growth mechanism is opposite to the desertification since it allows to repopulate territories devoid of vegetation. We investigate these aspects by characterizing quantitatively, with a simple mathematical model, a new class of instabilities that lead to the self-replication phenomenon observed.

The interplay between facilitation and habitat type drives spatial vegetation patterns in global drylands

“…Similarly, large patches are considered dynamically instable due to competitive interactions between plants which tend to divide large patches (Bordeu et al 2016). Although the emergence of predominant scales is significant in our dataset, it does not explain a large proportion of the variation found (Fig.…”

“…The loss of both large and small patches is consistent with the emergence of a predominant scale associated with regularity, especially in sites following spotted patterns (Klausmeier 1999, von Hardenberg et al 2010. Similarly, large patches are considered dynamically instable due to competitive interactions between plants which tend to divide large patches (Bordeu et al 2016). Similarly, large patches are considered dynamically instable due to competitive interactions between plants which tend to divide large patches (Bordeu et al 2016).…”

“…Some abiotic variables, such as rainfall seasonality or soil texture, may exacerbate experienced water stress (Sala et al 1997) and affect infiltration rates thus, influencing spatial patterns (Deblauwe et al 2008, von Hardenberg et al 2010. Besides, clonal plants tend to generate regular patterns (Cosby 1960, Sheffer et al 2007, Cartenì et al 2012, Bordeu et al 2016. For instance, large species have a major influence on the emergence of PSDs Cortina 2005, Borthagaray et al 2012).…”

“…For instance, large species have a major influence on the emergence of PSDs Cortina 2005, Borthagaray et al 2012). Besides, clonal plants tend to generate regular patterns (Cosby 1960, Sheffer et al 2007, Cartenì et al 2012, Bordeu et al 2016. Indeed, contrasting dominant plant types, such as grasses versus shrubs, exhibit different ways of reproduction (e.g.…”

The Lefever–Lejeune nonlinear lattice: Convergence dynamics and the structure of equilibrium states

“…Besides the existence of Turing periodic patterns, the LL produces localized solutions such as isolated spots of vegetation, or groups of spots confined by the homogeneous zero vegetation [21]. Furthermore, the self-replication capabilities of the equation have been investigated, showing that for a particular regime of the aridity parameter in two spatial dimensions, a single circular vegetation patch can destabilize leading to an elliptical deformation, followed by patch multiplication [22]. This patch splitting phenomenon evolves in time until the system reaches a self-organized hexagonal pattern.In the above physical context, reaction-diffusion lattice systems can be used to model vegetation patterns dynamics, in a situation where space is viewed as a collection of patches (or cells).…”