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Appropriate spatial scale for potential woody cover observation in Texas savanna

  • Xuebin YangEmail author
  • Kelley Crews
  • Amy E. Frazier
  • Peter Kedron
Research Article
  • 60 Downloads

Abstract

Context

Potential woody cover, the upper bound of woody plant cover in savanna ecosystems, represents the end-point of woody plant encroachment and is highly relevant to the dynamics of savanna ecosystems.

Objectives

This study aims to identify the appropriate spatial scale for potential woody cover observation in the savanna of central Texas, USA.

Methods

The upper bound of woody plant cover was modeled over the east–west precipitation gradient of Texas savanna, at four different spatial scales respectively (30 m, 100 m, 250 m, and 500 m).

Results

The estimated upper bound of woody plant cover demonstrates a three-segment pattern across the precipitation gradient at all the four observation scales. The pattern begins with a low stable level and ends at a high stable level, with a linear transitional level in between. The magnitude of the upper bound under given precipitation conditions decreases with spatial scale, but stabilizes by 250 m scale.

Conclusions

A spatial scale between 250 and 500 m is recommended for potential woody cover observation. Water availability plays a more important role in limiting woody plant cover at larger spatial scales in savanna ecosystems. In addition, the scale dependency of upper bound woody plant cover is more pronounced in the arid region.

Keywords

Savanna Potential woody cover Scale dependency Encroachment Precipitation gradient Quantile regression 

Notes

Acknowledgements

Authors were supported by a grant to Kelley Crews from the National Science Foundation (BCS-0964596), a grant to Peter Kedron from the National Science Foundation EPSCoR program (OIA-1301789), and a grant to Amy Frazier and Peter Kedron from the NSF (BCS-1561021). Many thanks to the editor and reviewers, whose comments and suggestions greatly improved this manuscript.

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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Department of Plant PathologyKansas State UniversityManhattanUSA
  2. 2.Department of Geography and the EnvironmentThe University of Texas at AustinAustinUSA
  3. 3.Spatial Analysis Research Center (SPARC), School of Geographical Sciences and Urban Planning, Arizona State UniversityTempeUSA

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