Transition from connected to fragmented vegetation across an environmental gradient: Scaling laws in ecotone geometry

Michael T. Gastner, B. Oborny, D. K. Zimmermann, Gunnar Pruessner

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

A change in the environmental conditions across space-for example, altitude or latitude-can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, "step length" across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the " hull edge." We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/ 4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a piñon-juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change.

Original languageEnglish
JournalAmerican Naturalist
Volume174
Issue number1
DOIs
Publication statusPublished - Jul 2009

Fingerprint

Fractals
ecotones
ecotone
environmental gradient
hull
hulls
Mesons
Juniperus
vegetation types
vegetation type
geometry
vegetation
Climate Change
Ecosystem
connectivity
fractal dimensions
cans
woodlands
woodland
environmental conditions

Keywords

  • Environmental gradient
  • Fractal geometry
  • Landscape connectivity
  • Patch dynamics
  • Tree line

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Medicine(all)

Cite this

Transition from connected to fragmented vegetation across an environmental gradient : Scaling laws in ecotone geometry. / Gastner, Michael T.; Oborny, B.; Zimmermann, D. K.; Pruessner, Gunnar.

In: American Naturalist, Vol. 174, No. 1, 07.2009.

Research output: Contribution to journalArticle

@article{4acaf7460be14503b0edd9c6a9780e6c,
title = "Transition from connected to fragmented vegetation across an environmental gradient: Scaling laws in ecotone geometry",
abstract = "A change in the environmental conditions across space-for example, altitude or latitude-can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, {"}step length{"} across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the {"} hull edge.{"} We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/ 4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a pi{\~n}on-juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change.",
keywords = "Environmental gradient, Fractal geometry, Landscape connectivity, Patch dynamics, Tree line",
author = "Gastner, {Michael T.} and B. Oborny and Zimmermann, {D. K.} and Gunnar Pruessner",
year = "2009",
month = "7",
doi = "10.1086/599292",
language = "English",
volume = "174",
journal = "American Naturalist",
issn = "0003-0147",
publisher = "University of Chicago",
number = "1",

}

TY - JOUR

T1 - Transition from connected to fragmented vegetation across an environmental gradient

T2 - Scaling laws in ecotone geometry

AU - Gastner, Michael T.

AU - Oborny, B.

AU - Zimmermann, D. K.

AU - Pruessner, Gunnar

PY - 2009/7

Y1 - 2009/7

N2 - A change in the environmental conditions across space-for example, altitude or latitude-can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, "step length" across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the " hull edge." We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/ 4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a piñon-juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change.

AB - A change in the environmental conditions across space-for example, altitude or latitude-can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, "step length" across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the " hull edge." We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/ 4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a piñon-juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change.

KW - Environmental gradient

KW - Fractal geometry

KW - Landscape connectivity

KW - Patch dynamics

KW - Tree line

UR - http://www.scopus.com/inward/record.url?scp=66849142466&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66849142466&partnerID=8YFLogxK

U2 - 10.1086/599292

DO - 10.1086/599292

M3 - Article

C2 - 19426110

AN - SCOPUS:66849142466

VL - 174

JO - American Naturalist

JF - American Naturalist

SN - 0003-0147

IS - 1

ER -