Defoliation increased above-ground productivity in a semi-arid grassland

Matthew R. Loeser, Timothy E. Crews, Thomas D Sisk

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

In light of the continuing debate regarding overcompensation we studied the responses of above-ground biomass in a high-elevation, semi-arid grassland to defoliation, defoliation history, and livestock grazing. The above-ground annual net primary productivity (ANPP) was measured over 2 years in one-hundred twenty, 1-m2 plots that were exposed to single- and multi-year defoliation and grazing treatments. Plant communities showed an average increase in ANPP of 31%-45% due to a single defoliation event. The most conservative estimate of average ANPP of defoliated subplots was 29.4 g m-2 greater than the non-defoliated controls. A history of defoliation, due to clipping or grazing, lessened the magnitude of the compensatory response, but above-ground overcompensation of biomass was still observed, ranging on average from 17% to 26%. One dominant species, squirreltail grass [Elymus elymoides (Raf.) Swezeyi], accounted for nearly one-third of the community-level increases in ANPP. In contrast to above-ground patterns, below-ground root production of squirreltail did not increase in response to defoliation events. These results suggest that the above-ground production of high-elevation, semi-arid grasslands in the American Southwest may be temporarily increased through certain grazing events, and may help explain shifts in species dominance in grasslands exposed to long-term grazing by livestock.

Original languageEnglish (US)
Pages (from-to)442-447
Number of pages6
JournalJournal of Range Management
Volume57
Issue number5
StatePublished - Sep 2004

Fingerprint

defoliation
grasslands
grassland
grazing
productivity
primary productivity
aboveground biomass
livestock
Elymus elymoides
aboveground production
Southwestern United States
clipping
history
plant community
plant communities
grass
grasses
biomass

Keywords

  • ANPP
  • Clipping
  • High-elevation grasslands
  • Overcompensation
  • Root biomass
  • Squirreltail
  • Western wheatgrass

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology

Cite this

Defoliation increased above-ground productivity in a semi-arid grassland. / Loeser, Matthew R.; Crews, Timothy E.; Sisk, Thomas D.

In: Journal of Range Management, Vol. 57, No. 5, 09.2004, p. 442-447.

Research output: Contribution to journalArticle

Loeser, Matthew R. ; Crews, Timothy E. ; Sisk, Thomas D. / Defoliation increased above-ground productivity in a semi-arid grassland. In: Journal of Range Management. 2004 ; Vol. 57, No. 5. pp. 442-447.
@article{bf9c2405775646039fa0b815dbcd3484,
title = "Defoliation increased above-ground productivity in a semi-arid grassland",
abstract = "In light of the continuing debate regarding overcompensation we studied the responses of above-ground biomass in a high-elevation, semi-arid grassland to defoliation, defoliation history, and livestock grazing. The above-ground annual net primary productivity (ANPP) was measured over 2 years in one-hundred twenty, 1-m2 plots that were exposed to single- and multi-year defoliation and grazing treatments. Plant communities showed an average increase in ANPP of 31{\%}-45{\%} due to a single defoliation event. The most conservative estimate of average ANPP of defoliated subplots was 29.4 g m-2 greater than the non-defoliated controls. A history of defoliation, due to clipping or grazing, lessened the magnitude of the compensatory response, but above-ground overcompensation of biomass was still observed, ranging on average from 17{\%} to 26{\%}. One dominant species, squirreltail grass [Elymus elymoides (Raf.) Swezeyi], accounted for nearly one-third of the community-level increases in ANPP. In contrast to above-ground patterns, below-ground root production of squirreltail did not increase in response to defoliation events. These results suggest that the above-ground production of high-elevation, semi-arid grasslands in the American Southwest may be temporarily increased through certain grazing events, and may help explain shifts in species dominance in grasslands exposed to long-term grazing by livestock.",
keywords = "ANPP, Clipping, High-elevation grasslands, Overcompensation, Root biomass, Squirreltail, Western wheatgrass",
author = "Loeser, {Matthew R.} and Crews, {Timothy E.} and Sisk, {Thomas D}",
year = "2004",
month = "9",
language = "English (US)",
volume = "57",
pages = "442--447",
journal = "Rangeland Ecology and Management",
issn = "1550-7424",
publisher = "Society for Range Management",
number = "5",

}

TY - JOUR

T1 - Defoliation increased above-ground productivity in a semi-arid grassland

AU - Loeser, Matthew R.

AU - Crews, Timothy E.

AU - Sisk, Thomas D

PY - 2004/9

Y1 - 2004/9

N2 - In light of the continuing debate regarding overcompensation we studied the responses of above-ground biomass in a high-elevation, semi-arid grassland to defoliation, defoliation history, and livestock grazing. The above-ground annual net primary productivity (ANPP) was measured over 2 years in one-hundred twenty, 1-m2 plots that were exposed to single- and multi-year defoliation and grazing treatments. Plant communities showed an average increase in ANPP of 31%-45% due to a single defoliation event. The most conservative estimate of average ANPP of defoliated subplots was 29.4 g m-2 greater than the non-defoliated controls. A history of defoliation, due to clipping or grazing, lessened the magnitude of the compensatory response, but above-ground overcompensation of biomass was still observed, ranging on average from 17% to 26%. One dominant species, squirreltail grass [Elymus elymoides (Raf.) Swezeyi], accounted for nearly one-third of the community-level increases in ANPP. In contrast to above-ground patterns, below-ground root production of squirreltail did not increase in response to defoliation events. These results suggest that the above-ground production of high-elevation, semi-arid grasslands in the American Southwest may be temporarily increased through certain grazing events, and may help explain shifts in species dominance in grasslands exposed to long-term grazing by livestock.

AB - In light of the continuing debate regarding overcompensation we studied the responses of above-ground biomass in a high-elevation, semi-arid grassland to defoliation, defoliation history, and livestock grazing. The above-ground annual net primary productivity (ANPP) was measured over 2 years in one-hundred twenty, 1-m2 plots that were exposed to single- and multi-year defoliation and grazing treatments. Plant communities showed an average increase in ANPP of 31%-45% due to a single defoliation event. The most conservative estimate of average ANPP of defoliated subplots was 29.4 g m-2 greater than the non-defoliated controls. A history of defoliation, due to clipping or grazing, lessened the magnitude of the compensatory response, but above-ground overcompensation of biomass was still observed, ranging on average from 17% to 26%. One dominant species, squirreltail grass [Elymus elymoides (Raf.) Swezeyi], accounted for nearly one-third of the community-level increases in ANPP. In contrast to above-ground patterns, below-ground root production of squirreltail did not increase in response to defoliation events. These results suggest that the above-ground production of high-elevation, semi-arid grasslands in the American Southwest may be temporarily increased through certain grazing events, and may help explain shifts in species dominance in grasslands exposed to long-term grazing by livestock.

KW - ANPP

KW - Clipping

KW - High-elevation grasslands

KW - Overcompensation

KW - Root biomass

KW - Squirreltail

KW - Western wheatgrass

UR - http://www.scopus.com/inward/record.url?scp=15944395095&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=15944395095&partnerID=8YFLogxK

M3 - Article

VL - 57

SP - 442

EP - 447

JO - Rangeland Ecology and Management

JF - Rangeland Ecology and Management

SN - 1550-7424

IS - 5

ER -