Show simple item record

dc.creatorRatajczak, Zak
dc.creatorD'Odorico, Paolo
dc.creatorNippert, Jesse B.
dc.creatorCollins, Scott L.
dc.creatorBrunsell, Nathaniel A.
dc.creatorRavi, Sujith
dc.date.accessioned2021-12-06T20:37:28Z
dc.date.available2021-12-06T20:37:28Z
dc.date.issued2016-11-05
dc.identifier.citationRatajczak, Z., D'Odorico, P., Nippert, J.B., Collins, S.L., Brunsell, N.A. and Ravi, S. (2017), Changes in spatial variance during a grassland to shrubland state transition. J Ecol, 105: 750-760. https://doi.org/10.1111/1365-2745.12696
dc.identifier.issn1365-2745
dc.identifier.doihttp://dx.doi.org/10.34944/dspace/7125
dc.identifier.urihttp://hdl.handle.net/20.500.12613/7146
dc.description1. State transitions are changes in ecosystem structure and self-reinforcing feedbacks that are initiated when an exogenous driver variable crosses a threshold. Reversing state transitions is difficult and costly. While some state transitions are relatively rapid, many take years to decades. Outside of theoretical models, very little is known about slower state transitions and how they unfold in time and space. 2. We quantified changes in spatial variance as a mesic grassland ecosystem shifts to a shrub-dominated state, using long-term experiments and simulations that maintain grasslands with annual fires or initiate a state transition to shrub dominance by decreasing fire frequency. 3. In the experiments, the susceptibility to state transitions varied substantially in space. In the less frequent fire treatment, some plots became shrub-dominated around year 20 and grass extirpations began in year 25, but a third of the plots were still grass-dominated in year 37. Variable rates of state transition resulted in increasing spatial variance of grass cover over time, whereas shrub cover variance decreased. In the annually burned treatment, grasses remained dominant and the spatial variance of grass cover declined. 4. In a separate experiment, less frequent fires were maintained for 23 years and then switched to annual fires. The switch to annual fires occurred shortly after grass variance started to increase and a majority of these plots quickly returned to a grass dominated state. 5. In simulations, spatial variance remained low and average grass cover was high under frequent fires. If fire frequency decreased below a threshold, the ecosystem transitioned to shrubland, with a transient increase in the spatial variance of grass cover during the transition between states. 6. Synthesis. Spatial variability in the rate and susceptibility to state transitions is indicative of a system with a patchy spatial structure, high spatial heterogeneity and low connectivity between patches. Increases in spatial variance can serve as an indication that some patches have begun a state transition and that management interventions are needed to avoid widespread transitions. This is one of the first empirical examples where altering management after an increase in spatial variance prevented state transitions.
dc.format.extent11 pages
dc.languageEnglish
dc.language.isoeng
dc.relation.ispartofFaculty/ Researcher Works
dc.relation.haspartJournal of Ecology, Vol. 105, No. 3
dc.relation.isreferencedbyWiley
dc.rightsAll Rights Reserved
dc.subjectBush encroachment
dc.subjectEarly warning signs
dc.subjectForecasting
dc.subjectLeading indicators
dc.subjectLong-term
dc.subjectNon-equilibrium
dc.subjectRegime shifts
dc.subjectResilience
dc.subjectShrub encroachment
dc.subjectTransient dynamics
dc.titleChanges in spatial variance during a grassland to shrubland state transition
dc.typeText
dc.type.genreJournal article
dc.description.departmentEarth and Environmental Science
dc.relation.doihttps://doi.org/10.1111/1365-2745.12696
dc.ada.noteFor Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu
dc.description.schoolcollegeTemple University. College of Science and Technology
dc.creator.orcidRavi|0000-0002-0425-9373
dc.temple.creatorRavi, Sujith
refterms.dateFOA2021-12-06T20:37:28Z


Files in this item

Thumbnail
Name:
Ravi-JournalArticle-2016.pdf
Size:
1018.Kb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record