In this article, we develop a unifying framework for the understanding of spatial vegetation patterns in heterogeneous landscapes. While much recent research has focused on self-organised vegetation the prevailing view is still that biological patchiness is mostly due to top-down control by the physical landscape template, disturbances or predators. We suggest that vegetation patchiness in real landscapes is controlled both by the physical template and by self-organisation simultaneously, and introduce a conceptual model for the relative roles of the two mechanisms. The model considers four factors that control whether vegetation patchiness is emerged or imposed: soil patch size, plant size, resource input and resource availability. The last three factors determine the plant-patch size, and the plant-to-soil patch size ratio determines the impact of self-organisation, which becomes important when this ratio is sufficiently small. A field study and numerical simulations of a mathematical model support the conceptual model and give further insight by providing examples of self-organised and template-controlled vegetation patterns co-occurring in the same landscape. We conclude that real landscapes are generally mixtures of template-induced and self-organised patchiness. Patchiness variability increases due to sourcesink resource relations, and decreases for species of larger patch sizes.
Emerged or imposed: a theory on the role of physical templates and self-organisation for vegetation patchiness / Sheffer, Efrat; von Hardenberg, Jost; Yizhaq, Hezi; Shachak, Moshe; Meron, Ehud. - In: ECOLOGY LETTERS. - ISSN 1461-023X. - 16:2(2013), pp. 127-139.
|Titolo:||Emerged or imposed: a theory on the role of physical templates and self-organisation for vegetation patchiness|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1111/ele.12027|
|Appare nelle tipologie:||1.1 Articolo in rivista|