Spatial patterns of soil δ 13C reveal grassland-to-woodland successional processes

Edith Bai, Thomas W. Boutton, Feng Liu, X. Ben Wu, Steve Archer

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Many grasslands and savannas around the world have experienced woody plant encroachment in recent history. In the Rio Grande Plains of southern Texas, subtropical woodlands dominated by C 3 trees and shrubs have become significant components of landscapes once dominated almost exclusively by C 4 grasslands. In this study, spatial variation of soil δ 13C to was used to investigate patterns of transformation. Previous research has shown that grassland-to-shrubland transitions are initiated when discrete, multi-species shrub clusters organized around a honey mesquite (Prosopis glandulosa) tree nucleus established in grassland. It is inferred from space-for-time substitution and modeling studies that as new shrub clusters are initiated and existing clusters enlarge, coalescence will occur, leading to the formation of groves; and that groves will eventually merge to form woodlands. The hypothesis that present-day mesquite groves represent areas where individual discrete shrub clusters have proliferated and coalesced was evaluated by comparing patterns of soil δ 13C within isolated shrub clusters (n=6) to those in nearby groves (n=3). Mean soil δ 13C within discrete clusters was lowest in the center (-23.3‰), increased exponentially toward the dripline (-20.1‰), and stabilized at a relatively high value approximately 15cm beyond the dripline (-18.9‰). The spatial structure of soil δ 13C in groves was consistent with that which would be expected to occur if present-day grove communities were a collection of what once were individual discrete clusters that had fused. As such, it provides direct evidence in support of conceptual and mathematical models derived from indirect assessments. However, spatial patterns of soil δ 13C suggest that groves are not simply a collection of clusters with respect to primary production and SOC turnover. This study illustrates how soil δ 13C values can be used to reconstruct successional processes accompanying vegetation compositional change, and its consequences for ecosystem function.

Original languageEnglish (US)
Pages (from-to)1512-1518
Number of pages7
JournalOrganic Geochemistry
Volume42
Issue number12
DOIs
StatePublished - Jan 2012

Fingerprint

woodland
grassland
shrub
Soils
soil
honey
shrubland
woody plant
coalescence
ecosystem function
Coalescence
savanna
Ecosystems
primary production
turnover
substitution
Substitution reactions
spatial variation
Mathematical models
vegetation

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

Spatial patterns of soil δ 13C reveal grassland-to-woodland successional processes. / Bai, Edith; Boutton, Thomas W.; Liu, Feng; Ben Wu, X.; Archer, Steve.

In: Organic Geochemistry, Vol. 42, No. 12, 01.2012, p. 1512-1518.

Research output: Contribution to journalArticle

Bai, Edith ; Boutton, Thomas W. ; Liu, Feng ; Ben Wu, X. ; Archer, Steve. / Spatial patterns of soil δ 13C reveal grassland-to-woodland successional processes. In: Organic Geochemistry. 2012 ; Vol. 42, No. 12. pp. 1512-1518.
@article{d57eaa5e15314435994127d11cfa96dc,
title = "Spatial patterns of soil δ 13C reveal grassland-to-woodland successional processes",
abstract = "Many grasslands and savannas around the world have experienced woody plant encroachment in recent history. In the Rio Grande Plains of southern Texas, subtropical woodlands dominated by C 3 trees and shrubs have become significant components of landscapes once dominated almost exclusively by C 4 grasslands. In this study, spatial variation of soil δ 13C to was used to investigate patterns of transformation. Previous research has shown that grassland-to-shrubland transitions are initiated when discrete, multi-species shrub clusters organized around a honey mesquite (Prosopis glandulosa) tree nucleus established in grassland. It is inferred from space-for-time substitution and modeling studies that as new shrub clusters are initiated and existing clusters enlarge, coalescence will occur, leading to the formation of groves; and that groves will eventually merge to form woodlands. The hypothesis that present-day mesquite groves represent areas where individual discrete shrub clusters have proliferated and coalesced was evaluated by comparing patterns of soil δ 13C within isolated shrub clusters (n=6) to those in nearby groves (n=3). Mean soil δ 13C within discrete clusters was lowest in the center (-23.3‰), increased exponentially toward the dripline (-20.1‰), and stabilized at a relatively high value approximately 15cm beyond the dripline (-18.9‰). The spatial structure of soil δ 13C in groves was consistent with that which would be expected to occur if present-day grove communities were a collection of what once were individual discrete clusters that had fused. As such, it provides direct evidence in support of conceptual and mathematical models derived from indirect assessments. However, spatial patterns of soil δ 13C suggest that groves are not simply a collection of clusters with respect to primary production and SOC turnover. This study illustrates how soil δ 13C values can be used to reconstruct successional processes accompanying vegetation compositional change, and its consequences for ecosystem function.",
author = "Edith Bai and Boutton, {Thomas W.} and Feng Liu and {Ben Wu}, X. and Steve Archer",
year = "2012",
month = "1",
doi = "10.1016/j.orggeochem.2010.11.004",
language = "English (US)",
volume = "42",
pages = "1512--1518",
journal = "Organic Geochemistry",
issn = "0146-6380",
publisher = "Elsevier Limited",
number = "12",

}

TY - JOUR

T1 - Spatial patterns of soil δ 13C reveal grassland-to-woodland successional processes

AU - Bai, Edith

AU - Boutton, Thomas W.

AU - Liu, Feng

AU - Ben Wu, X.

AU - Archer, Steve

PY - 2012/1

Y1 - 2012/1

N2 - Many grasslands and savannas around the world have experienced woody plant encroachment in recent history. In the Rio Grande Plains of southern Texas, subtropical woodlands dominated by C 3 trees and shrubs have become significant components of landscapes once dominated almost exclusively by C 4 grasslands. In this study, spatial variation of soil δ 13C to was used to investigate patterns of transformation. Previous research has shown that grassland-to-shrubland transitions are initiated when discrete, multi-species shrub clusters organized around a honey mesquite (Prosopis glandulosa) tree nucleus established in grassland. It is inferred from space-for-time substitution and modeling studies that as new shrub clusters are initiated and existing clusters enlarge, coalescence will occur, leading to the formation of groves; and that groves will eventually merge to form woodlands. The hypothesis that present-day mesquite groves represent areas where individual discrete shrub clusters have proliferated and coalesced was evaluated by comparing patterns of soil δ 13C within isolated shrub clusters (n=6) to those in nearby groves (n=3). Mean soil δ 13C within discrete clusters was lowest in the center (-23.3‰), increased exponentially toward the dripline (-20.1‰), and stabilized at a relatively high value approximately 15cm beyond the dripline (-18.9‰). The spatial structure of soil δ 13C in groves was consistent with that which would be expected to occur if present-day grove communities were a collection of what once were individual discrete clusters that had fused. As such, it provides direct evidence in support of conceptual and mathematical models derived from indirect assessments. However, spatial patterns of soil δ 13C suggest that groves are not simply a collection of clusters with respect to primary production and SOC turnover. This study illustrates how soil δ 13C values can be used to reconstruct successional processes accompanying vegetation compositional change, and its consequences for ecosystem function.

AB - Many grasslands and savannas around the world have experienced woody plant encroachment in recent history. In the Rio Grande Plains of southern Texas, subtropical woodlands dominated by C 3 trees and shrubs have become significant components of landscapes once dominated almost exclusively by C 4 grasslands. In this study, spatial variation of soil δ 13C to was used to investigate patterns of transformation. Previous research has shown that grassland-to-shrubland transitions are initiated when discrete, multi-species shrub clusters organized around a honey mesquite (Prosopis glandulosa) tree nucleus established in grassland. It is inferred from space-for-time substitution and modeling studies that as new shrub clusters are initiated and existing clusters enlarge, coalescence will occur, leading to the formation of groves; and that groves will eventually merge to form woodlands. The hypothesis that present-day mesquite groves represent areas where individual discrete shrub clusters have proliferated and coalesced was evaluated by comparing patterns of soil δ 13C within isolated shrub clusters (n=6) to those in nearby groves (n=3). Mean soil δ 13C within discrete clusters was lowest in the center (-23.3‰), increased exponentially toward the dripline (-20.1‰), and stabilized at a relatively high value approximately 15cm beyond the dripline (-18.9‰). The spatial structure of soil δ 13C in groves was consistent with that which would be expected to occur if present-day grove communities were a collection of what once were individual discrete clusters that had fused. As such, it provides direct evidence in support of conceptual and mathematical models derived from indirect assessments. However, spatial patterns of soil δ 13C suggest that groves are not simply a collection of clusters with respect to primary production and SOC turnover. This study illustrates how soil δ 13C values can be used to reconstruct successional processes accompanying vegetation compositional change, and its consequences for ecosystem function.

UR - http://www.scopus.com/inward/record.url?scp=83955162976&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=83955162976&partnerID=8YFLogxK

U2 - 10.1016/j.orggeochem.2010.11.004

DO - 10.1016/j.orggeochem.2010.11.004

M3 - Article

AN - SCOPUS:83955162976

VL - 42

SP - 1512

EP - 1518

JO - Organic Geochemistry

JF - Organic Geochemistry

SN - 0146-6380

IS - 12

ER -