Cool-season whole-plant gas exchange of exotic and native semiarid bunchgrasses

Erik P. Hamerlynck, Russell L. Scott, Greg A Barron-Gafford, Michelle L. Cavanaugh, M. Susan Moran, Travis E. Huxman

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The success of invasive aridland plants may depend on their utilization of precipitation not fully exploited by native species, which could lead to seasonally altered ecosystem carbon and water fluxes. We measured volumetric soil water across 25-cm profiles (θ 25cm) and springtime whole-plant water- and carbon-fluxes of the exotic Lehmann lovegrass (Eragrostis lehmanniana) and a native bunchgrass, bush muhly (Muhlenbergia porteri), following typical (55 mm in 2009) and El Niño-enhanced accumulations (154 mm in 2010) in a SE Arizona savanna. Across both years, θ 25cm was higher under lovegrass plots, with similar evapotranspiration (ET) between lovegrass and bush muhly plots. However, in 2010 transpiration (T) was higher in bush muhly than lovegrass, implying higher soil evaporation in lovegrass plots maintained similar ET. Net ecosystem carbon dioxide exchange (NEE) was similar between lovegrass and bush muhly plots in 2009, but was more negative in bush muhly plots following El Niño, indicating greater CO 2 assimilation. Ecosystem respiration (R eco) and gross ecosystem photosynthesis (GEP) were similar between lovegrass and bush muhly plots in 2009, but were higher in bush muhly plots in 2010. As a result, lovegrass plots reduced ecosystem water-use efficiency (WUE e = NEE/ET), while bush muhly WUE e remained constant between 2009 and 2010. Concurrent whole-plant WUE (WUE p = GEP/T) did not change in lovegrass plots, but increased in bush muhly plots between these years. We concluded that cool-season precipitation use is not a component of Lehmann lovegrass invasive success, but that the change in ET partitioning and attendant shifts in cool-season WUE e may increase interannual variation in ecosystem water- and carbon-exchange dynamics in the water-limited systems it dominates.

Original languageEnglish (US)
Pages (from-to)1-11
Number of pages11
JournalPlant Ecology
DOIs
StateAccepted/In press - 2012

Fingerprint

gas exchange
water use efficiency
Eragrostis lehmanniana
evapotranspiration
ecosystems
ecosystem
carbon
Muhlenbergia
water
photosynthesis
ecosystem respiration
carbon flux
savannas
evaporation
assimilation (physiology)
transpiration
savanna
native species
indigenous species
annual variation

Keywords

  • Bush muhly
  • Evapotranspiration
  • Lehmann lovegrass
  • Photosynthesis
  • Respiration
  • Savanna
  • Soil water

ASJC Scopus subject areas

  • Ecology
  • Plant Science

Cite this

Hamerlynck, E. P., Scott, R. L., Barron-Gafford, G. A., Cavanaugh, M. L., Susan Moran, M., & Huxman, T. E. (Accepted/In press). Cool-season whole-plant gas exchange of exotic and native semiarid bunchgrasses. Plant Ecology, 1-11. https://doi.org/10.1007/s11258-012-0081-x

Cool-season whole-plant gas exchange of exotic and native semiarid bunchgrasses. / Hamerlynck, Erik P.; Scott, Russell L.; Barron-Gafford, Greg A; Cavanaugh, Michelle L.; Susan Moran, M.; Huxman, Travis E.

In: Plant Ecology, 2012, p. 1-11.

Research output: Contribution to journalArticle

Hamerlynck, Erik P. ; Scott, Russell L. ; Barron-Gafford, Greg A ; Cavanaugh, Michelle L. ; Susan Moran, M. ; Huxman, Travis E. / Cool-season whole-plant gas exchange of exotic and native semiarid bunchgrasses. In: Plant Ecology. 2012 ; pp. 1-11.
@article{937a104017f34b72906e0c0ee529034c,
title = "Cool-season whole-plant gas exchange of exotic and native semiarid bunchgrasses",
abstract = "The success of invasive aridland plants may depend on their utilization of precipitation not fully exploited by native species, which could lead to seasonally altered ecosystem carbon and water fluxes. We measured volumetric soil water across 25-cm profiles (θ 25cm) and springtime whole-plant water- and carbon-fluxes of the exotic Lehmann lovegrass (Eragrostis lehmanniana) and a native bunchgrass, bush muhly (Muhlenbergia porteri), following typical (55 mm in 2009) and El Ni{\~n}o-enhanced accumulations (154 mm in 2010) in a SE Arizona savanna. Across both years, θ 25cm was higher under lovegrass plots, with similar evapotranspiration (ET) between lovegrass and bush muhly plots. However, in 2010 transpiration (T) was higher in bush muhly than lovegrass, implying higher soil evaporation in lovegrass plots maintained similar ET. Net ecosystem carbon dioxide exchange (NEE) was similar between lovegrass and bush muhly plots in 2009, but was more negative in bush muhly plots following El Ni{\~n}o, indicating greater CO 2 assimilation. Ecosystem respiration (R eco) and gross ecosystem photosynthesis (GEP) were similar between lovegrass and bush muhly plots in 2009, but were higher in bush muhly plots in 2010. As a result, lovegrass plots reduced ecosystem water-use efficiency (WUE e = NEE/ET), while bush muhly WUE e remained constant between 2009 and 2010. Concurrent whole-plant WUE (WUE p = GEP/T) did not change in lovegrass plots, but increased in bush muhly plots between these years. We concluded that cool-season precipitation use is not a component of Lehmann lovegrass invasive success, but that the change in ET partitioning and attendant shifts in cool-season WUE e may increase interannual variation in ecosystem water- and carbon-exchange dynamics in the water-limited systems it dominates.",
keywords = "Bush muhly, Evapotranspiration, Lehmann lovegrass, Photosynthesis, Respiration, Savanna, Soil water",
author = "Hamerlynck, {Erik P.} and Scott, {Russell L.} and Barron-Gafford, {Greg A} and Cavanaugh, {Michelle L.} and {Susan Moran}, M. and Huxman, {Travis E.}",
year = "2012",
doi = "10.1007/s11258-012-0081-x",
language = "English (US)",
pages = "1--11",
journal = "Plant Ecology",
issn = "1385-0237",
publisher = "Springer Netherlands",

}

TY - JOUR

T1 - Cool-season whole-plant gas exchange of exotic and native semiarid bunchgrasses

AU - Hamerlynck, Erik P.

AU - Scott, Russell L.

AU - Barron-Gafford, Greg A

AU - Cavanaugh, Michelle L.

AU - Susan Moran, M.

AU - Huxman, Travis E.

PY - 2012

Y1 - 2012

N2 - The success of invasive aridland plants may depend on their utilization of precipitation not fully exploited by native species, which could lead to seasonally altered ecosystem carbon and water fluxes. We measured volumetric soil water across 25-cm profiles (θ 25cm) and springtime whole-plant water- and carbon-fluxes of the exotic Lehmann lovegrass (Eragrostis lehmanniana) and a native bunchgrass, bush muhly (Muhlenbergia porteri), following typical (55 mm in 2009) and El Niño-enhanced accumulations (154 mm in 2010) in a SE Arizona savanna. Across both years, θ 25cm was higher under lovegrass plots, with similar evapotranspiration (ET) between lovegrass and bush muhly plots. However, in 2010 transpiration (T) was higher in bush muhly than lovegrass, implying higher soil evaporation in lovegrass plots maintained similar ET. Net ecosystem carbon dioxide exchange (NEE) was similar between lovegrass and bush muhly plots in 2009, but was more negative in bush muhly plots following El Niño, indicating greater CO 2 assimilation. Ecosystem respiration (R eco) and gross ecosystem photosynthesis (GEP) were similar between lovegrass and bush muhly plots in 2009, but were higher in bush muhly plots in 2010. As a result, lovegrass plots reduced ecosystem water-use efficiency (WUE e = NEE/ET), while bush muhly WUE e remained constant between 2009 and 2010. Concurrent whole-plant WUE (WUE p = GEP/T) did not change in lovegrass plots, but increased in bush muhly plots between these years. We concluded that cool-season precipitation use is not a component of Lehmann lovegrass invasive success, but that the change in ET partitioning and attendant shifts in cool-season WUE e may increase interannual variation in ecosystem water- and carbon-exchange dynamics in the water-limited systems it dominates.

AB - The success of invasive aridland plants may depend on their utilization of precipitation not fully exploited by native species, which could lead to seasonally altered ecosystem carbon and water fluxes. We measured volumetric soil water across 25-cm profiles (θ 25cm) and springtime whole-plant water- and carbon-fluxes of the exotic Lehmann lovegrass (Eragrostis lehmanniana) and a native bunchgrass, bush muhly (Muhlenbergia porteri), following typical (55 mm in 2009) and El Niño-enhanced accumulations (154 mm in 2010) in a SE Arizona savanna. Across both years, θ 25cm was higher under lovegrass plots, with similar evapotranspiration (ET) between lovegrass and bush muhly plots. However, in 2010 transpiration (T) was higher in bush muhly than lovegrass, implying higher soil evaporation in lovegrass plots maintained similar ET. Net ecosystem carbon dioxide exchange (NEE) was similar between lovegrass and bush muhly plots in 2009, but was more negative in bush muhly plots following El Niño, indicating greater CO 2 assimilation. Ecosystem respiration (R eco) and gross ecosystem photosynthesis (GEP) were similar between lovegrass and bush muhly plots in 2009, but were higher in bush muhly plots in 2010. As a result, lovegrass plots reduced ecosystem water-use efficiency (WUE e = NEE/ET), while bush muhly WUE e remained constant between 2009 and 2010. Concurrent whole-plant WUE (WUE p = GEP/T) did not change in lovegrass plots, but increased in bush muhly plots between these years. We concluded that cool-season precipitation use is not a component of Lehmann lovegrass invasive success, but that the change in ET partitioning and attendant shifts in cool-season WUE e may increase interannual variation in ecosystem water- and carbon-exchange dynamics in the water-limited systems it dominates.

KW - Bush muhly

KW - Evapotranspiration

KW - Lehmann lovegrass

KW - Photosynthesis

KW - Respiration

KW - Savanna

KW - Soil water

UR - http://www.scopus.com/inward/record.url?scp=84862989068&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84862989068&partnerID=8YFLogxK

U2 - 10.1007/s11258-012-0081-x

DO - 10.1007/s11258-012-0081-x

M3 - Article

AN - SCOPUS:84862989068

SP - 1

EP - 11

JO - Plant Ecology

JF - Plant Ecology

SN - 1385-0237

ER -