title: A morphometric analysis of vegetation patterns in dryland ecosystems.
abstract: Vegetation in dryland ecosystems often forms remarkable spatial patterns. These range from regular bands of vegetation alternating with bare ground, to vegetated spots and labyrinths, to regular gaps of bare ground within an otherwise continuous expanse of vegetation. It has been suggested that spotted vegetation patterns could indicate that collapse into a bare ground state is imminent, and the morphology of spatial vegetation patterns, therefore, represents a potentially valuable source of information on the proximity of regime shifts in dryland ecosystems. In this paper, we have developed quantitative methods to characterize the morphology of spatial patterns in dryland vegetation. Our approach is based on algorithmic techniques that have been used to classify pollen grains on the basis of textural patterning, and involves constructing feature vectors to quantify the shapes formed by vegetation patterns. We have analysed images of patterned vegetation produced by a computational model and a small set of satellite images from South Kordofan (South Sudan), which illustrates that our methods are applicable to both simulated and real-world data. Our approach provides a means of quantifying patterns that are frequently described using qualitative terminology, and could be used to classify vegetation patterns in large-scale satellite surveys of dryland ecosystems.
authors.affiliation: College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4PS, UK; Department of Environment, Earth and Ecosystems, The Open University, Milton Keynes MK7 6AA, UK.
authors.forename: Luke
authors.identifier: 0000-0003-4347-2705
authors.initials: L
authors.lastname: Mander
authors.affiliation: Department of Environmental Sciences, Copernicus Institute of Sustainable Development , Utrecht University , PO Box 80115, Utrecht 3508 TC , The Netherlands.
authors.forename: Stefan C
authors.initials: SC
authors.lastname: Dekker
authors.affiliation: Department of Mathematics , Florida State University , Tallahassee, FL 32306 , USA.
authors.forename: Mao
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Mathematics , Florida State University , Tallahassee, FL 32306 , USA.
authors.forename: Washington
authors.initials: W
authors.lastname: Mio
authors.affiliation: Department of Plant Biology , University of Illinois , Urbana, IL 61801 , USA.
authors.forename: Surangi W
authors.initials: SW
authors.lastname: Punyasena
authors.affiliation: College of Life and Environmental Sciences , University of Exeter , Exeter EX4 4PS , UK.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Lenton
keywords: computational vision; ecohydrology; morphology; morphometrics; vegetation patterns