@misc{10481/64199,
year = {2020},
url = {http://hdl.handle.net/10481/64199},
abstract = {Understanding the causes and effects of spatial vegetation patterns is a fundamental problem in
ecology, especially because these can be used as early predictors of catastrophic shifts such as
desertification processes. Empirical studies of the vegetation cover in some areas such as drylands
and semiarid regions have revealed the existence of vegetation patches of broadly diverse sizes. In
particular, the probability distribution of patch sizes can be fitted by a power law, i.e. vegetation
patches are approximately scale free up to some maximum size. Different explanatory
mechanisms, such as plant–plant interactions and plant-water feedback loops have been proposed
to rationalize the emergence of such scale-free patterns, yet a full understanding has not been
reached. Using a simple model for vegetation dynamics, we show that environmental temporal
variability—a well-recognized feature of semiarid environments—promotes in a robust way (i.e.
for a wide range of parameter values) the emergence of vegetation patches with broadly distributed
cluster sizes. Furthermore, this result is related to a percolation phenomenon that occurs in an
intermittent or fluctuating way. The model also reveals that the power-law exponents fitting the
tails of the probability distributions depend on the overall vegetation-cover density, in agreement
with empirical observations. This supports the idea that environmental variability plays a key role
in the formation of scale-free vegetation patterns. From a practical viewpoint, this may be of
importance to predict the effects that changes in environmental conditions may have in real
ecosystems. From a theoretical side, our study sheds new light on a novel type of percolation
phenomena occurring under temporally-varying external conditions, that still needs further work
to be fully characterized.},
organization = {Spanish Ministry and Agencia Estatal de investigacion (AEI) 	
FIS2017-84256-P},
organization = {Junta de Andalucia},
organization = {European Union (EU)

A-FQM-175-UGR18
SOMM17/6105/UGR},
publisher = {IOP PUBLISHING LTD},
keywords = {Scale invariance},
keywords = {Power laws},
keywords = {Percolation},
keywords = {Spatial patterns},
keywords = {Multiplicative noise},
title = {Intermittent percolation and the scale-free distribution of vegetation clusters},
doi = {10.1088/1367-2630/ab9f6e},
author = {Villa Martín, Paula and Domínguez-García, Virginia and Muñoz Martínez, Miguel Ángel},
}