J. Patrick Donnelly , Kelsey Jensco , John S. Kimball , Johnnie N. Moore , David Ketchum , Daniel P. Collins , David E. Naugle
{"title":"Beneficial ‘inefficiencies’ of western ranching: Flood-irrigated hay production sustains wetland systems by mimicking historic hydrologic processes","authors":"J. Patrick Donnelly , Kelsey Jensco , John S. Kimball , Johnnie N. Moore , David Ketchum , Daniel P. Collins , David E. Naugle","doi":"10.1016/j.agee.2024.109051","DOIUrl":null,"url":null,"abstract":"<div><p>Ranching in the American West has long relied on riparian ecosystems to grow grass-hay to feed livestock in winter and during drought. Producers seasonally flood grasslands for hay production using stream diversions and low-tech flood-irrigation on riparian floodplains. Inundation mimics natural processes that sustain riparian vegetation and recharge groundwater. The recent doubling in use of more efficient irrigation approaches, such as center-pivot sprinklers, threatens to accelerate climate change impacts by unintentionally decoupling more inefficient, traditional practices that sustain riparian systems. To assess ecosystem services provided by flood-irrigation hay production, we developed an exhaustive spatial inventory of grass-hay production and combined it with monthly surface water distributions modeled from satellite data. Surface water data were classified by wetland hydroperiod and used to estimate the proportion of wetlands supported by grass-hay production in the Intermountain West, USA. Elevation and proportion of grass-hay relative to other irrigated lands were enumerated to examine differences in their positions and abundance within landscapes. Lastly, we overlaid the delineated grass-hay wetlands with LANDFIRE pre-Euro-American Settings layer to quantify the efficacy of flood irrigation in mimicking the conservation of historical riparian processes. Findings suggest that inefficient grass-hay irrigation mirrored the timing of natural hydrology, concentrating ∼93% of flooded grasslands in historical riparian ecosystems, affirming that at large scales, this ranching practice, in part, mimics floodplain processes sustaining wetlands and groundwater recharge. Despite representing only 2.5% of irrigated lands, grass-hay operations supported a majority (58%) of temporary wetlands, a rare and declining habitat for wildlife in the Intermountain West. Tolerance for colder temperatures confined grass-hay production to upper watershed reaches where higher value crops are constrained by growing degree days. This novel understanding of grass-hay agroecology highlights the vital role of working ranches in the resilience and stewardship of riparian systems.</p></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":null,"pages":null},"PeriodicalIF":6.0000,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Agriculture, Ecosystems & Environment","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167880924001695","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Ranching in the American West has long relied on riparian ecosystems to grow grass-hay to feed livestock in winter and during drought. Producers seasonally flood grasslands for hay production using stream diversions and low-tech flood-irrigation on riparian floodplains. Inundation mimics natural processes that sustain riparian vegetation and recharge groundwater. The recent doubling in use of more efficient irrigation approaches, such as center-pivot sprinklers, threatens to accelerate climate change impacts by unintentionally decoupling more inefficient, traditional practices that sustain riparian systems. To assess ecosystem services provided by flood-irrigation hay production, we developed an exhaustive spatial inventory of grass-hay production and combined it with monthly surface water distributions modeled from satellite data. Surface water data were classified by wetland hydroperiod and used to estimate the proportion of wetlands supported by grass-hay production in the Intermountain West, USA. Elevation and proportion of grass-hay relative to other irrigated lands were enumerated to examine differences in their positions and abundance within landscapes. Lastly, we overlaid the delineated grass-hay wetlands with LANDFIRE pre-Euro-American Settings layer to quantify the efficacy of flood irrigation in mimicking the conservation of historical riparian processes. Findings suggest that inefficient grass-hay irrigation mirrored the timing of natural hydrology, concentrating ∼93% of flooded grasslands in historical riparian ecosystems, affirming that at large scales, this ranching practice, in part, mimics floodplain processes sustaining wetlands and groundwater recharge. Despite representing only 2.5% of irrigated lands, grass-hay operations supported a majority (58%) of temporary wetlands, a rare and declining habitat for wildlife in the Intermountain West. Tolerance for colder temperatures confined grass-hay production to upper watershed reaches where higher value crops are constrained by growing degree days. This novel understanding of grass-hay agroecology highlights the vital role of working ranches in the resilience and stewardship of riparian systems.
期刊介绍:
Agriculture, Ecosystems and Environment publishes scientific articles dealing with the interface between agroecosystems and the natural environment, specifically how agriculture influences the environment and how changes in that environment impact agroecosystems. Preference is given to papers from experimental and observational research at the field, system or landscape level, from studies that enhance our understanding of processes using data-based biophysical modelling, and papers that bridge scientific disciplines and integrate knowledge. All papers should be placed in an international or wide comparative context.