TY - JOUR
T1 - Inconsistent outcomes of heterogeneity-based management underscore importance of matching evaluation to conservation objectives
AU - McGranahan, Devan Allen
AU - Engle, David M.
AU - Fuhlendorf, Samuel D.
AU - Winter, Stephen L.
AU - Miller, James R.
AU - Debinski, Diane M.
N1 - Funding Information:
We acknowledge the following support: the Iowa State Wildlife Grants program through the United States Fish and Wildlife Service Wildlife and Sport Fish Restoration Program (#T-1-R-15); the Joint Fire Science Program (#201814G905); the USDA Cooperative State Research, Education and Extension Service National Research Initiative (#2006-35320-17476); the Oklahoma Agricultural Experiment Station ; and the Mellon Foundation through the Associated Colleges of the South environmental post-doctoral scholar program . We appreciate the contributions of R. Harr, R. Limb, B. Allred, J. Kerby, M. Kirkwood, P. Dixon, C. Goad and K. Pazdernick.
PY - 2013/8
Y1 - 2013/8
N2 - Conservation policy often incentivizes managers of human-impacted areas to create landscape heterogeneity to maximize biodiversity. In rangeland, patchy disturbance regimes create landscape heterogeneity (patch contrast), but outcomes of heterogeneity-based management are rarely tested for a universal response. We analyzed four habitat variables - vegetation structure, plant functional group composition, litter cover, and bare ground - from five experimental rangelands in Oklahoma and Iowa, USA. We tested for response consistency to heterogeneity-based management across and within locations. We calculated effect sizes for each variable to compare patch contrast on pastures managed for heterogeneity (patch burn-grazing) and pastures managed for homogeneity (grazing with homogeneous fire regimes). Effects varied considerably across and within locations. Effects of heterogeneity-based management were positive for all variables at only three of five experimental rangeland locations. No location showed a consistent pattern of positive effect across all four variables, although one location showed no effect for any variable. At another location, we found a positive effect of heterogeneity-based management on litter cover and bare ground, but no effect on vegetation structure and plant functional group composition. We discuss effect variability and how the fire-grazing interaction applies to rangeland management and conservation. Although it is accepted practice to use heterogeneity-based management to increase rangeland habitat diversity, managers should also confirm that evaluation metrics match desired conservation outcomes.
AB - Conservation policy often incentivizes managers of human-impacted areas to create landscape heterogeneity to maximize biodiversity. In rangeland, patchy disturbance regimes create landscape heterogeneity (patch contrast), but outcomes of heterogeneity-based management are rarely tested for a universal response. We analyzed four habitat variables - vegetation structure, plant functional group composition, litter cover, and bare ground - from five experimental rangelands in Oklahoma and Iowa, USA. We tested for response consistency to heterogeneity-based management across and within locations. We calculated effect sizes for each variable to compare patch contrast on pastures managed for heterogeneity (patch burn-grazing) and pastures managed for homogeneity (grazing with homogeneous fire regimes). Effects varied considerably across and within locations. Effects of heterogeneity-based management were positive for all variables at only three of five experimental rangeland locations. No location showed a consistent pattern of positive effect across all four variables, although one location showed no effect for any variable. At another location, we found a positive effect of heterogeneity-based management on litter cover and bare ground, but no effect on vegetation structure and plant functional group composition. We discuss effect variability and how the fire-grazing interaction applies to rangeland management and conservation. Although it is accepted practice to use heterogeneity-based management to increase rangeland habitat diversity, managers should also confirm that evaluation metrics match desired conservation outcomes.
KW - Fire-grazing interaction
KW - Habitat management
KW - Meta-analysis
KW - Patch burn-grazing
KW - Pyric-herbivory
KW - Rangeland biodiversity
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U2 - 10.1016/j.envsci.2013.03.005
DO - 10.1016/j.envsci.2013.03.005
M3 - Article
AN - SCOPUS:84877045598
SN - 1462-9011
VL - 31
SP - 53
EP - 60
JO - Environmental Science and Policy
JF - Environmental Science and Policy
ER -