Browsing Promotes Drought Resistance of Wyoming Big Sagebrush in a Working Rangeland

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management Pub Date : 2025-02-25 DOI:10.1016/j.rama.2025.01.006

Ashley Tribitt , Lauren M. Porensky , Sally E. Koerner , Kimberly J. Komatsu , Kurt Reinhart , Kevin Wilcox

{"title":"Browsing Promotes Drought Resistance of Wyoming Big Sagebrush in a Working Rangeland","authors":"Ashley Tribitt , Lauren M. Porensky , Sally E. Koerner , Kimberly J. Komatsu , Kurt Reinhart , Kevin Wilcox","doi":"10.1016/j.rama.2025.01.006","DOIUrl":null,"url":null,"abstract":"<div><div>Droughts are projected to become more extreme and more frequent throughout the remainder of the 21st century. Our ability to sustain rangeland functioning relies on understanding the interactive effects of extreme drought and herbivory on vegetation. Here, we report on an experiment in northeast Wyoming, USA that simulated five levels of drought intercepting 0 %, 25%, 50%, 75%, or 99% of ambient rainfall for two years. These treatments were crossed with two grazing intensity (50%, 70% utilization) and two browsing intensity (background, +50% leader removal) treatments. We measured canopy volume changes, leader growth, and leaf water potential on a dominant shrub, <em>Artemisia tridentata</em> ssp. <em>wyomingensis</em> (Beetle & Young), to test three major predictions: (1) canopy volume and leader growth decline with greater drought magnitude, (2) heavy grazing reduces the effects of drought magnitude, and (3) heavy browsing amplifies effects of drought magnitude. Under ambient browsing intensity, extreme drought caused Wyoming big sagebrush (Beetle & Young) canopies to shrink. Interestingly, this effect went away in our heavy browsing treatment, despite overall negative effects of heavy browsing on shrub canopies and leader survival. We show that this drought-buffering effect may be driven by reduced leaf-level water stress in droughted, heavily browsed shrubs compared with droughted, ambiently browsed shrubs; this may have resulted from lower early-season leaf area leading to lower transpiration-related water loss. This potential mechanism for drought resistance in sagebrush steppe highlights the importance of maintaining intact food webs, despite perceived deleterious effects of herbivores for plant abundance and growth. To promote sustainability of sagebrush and other shrub-dominated ecosystems in face of extreme precipitation change, it may be necessary for land managers and policy makers to prioritize conservation of native herbivores within ecosystems.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"100 ","pages":"Pages 27-37"},"PeriodicalIF":2.4000,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Rangeland Ecology & Management","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1550742425000156","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ECOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Droughts are projected to become more extreme and more frequent throughout the remainder of the 21st century. Our ability to sustain rangeland functioning relies on understanding the interactive effects of extreme drought and herbivory on vegetation. Here, we report on an experiment in northeast Wyoming, USA that simulated five levels of drought intercepting 0 %, 25%, 50%, 75%, or 99% of ambient rainfall for two years. These treatments were crossed with two grazing intensity (50%, 70% utilization) and two browsing intensity (background, +50% leader removal) treatments. We measured canopy volume changes, leader growth, and leaf water potential on a dominant shrub, Artemisia tridentata ssp. wyomingensis (Beetle & Young), to test three major predictions: (1) canopy volume and leader growth decline with greater drought magnitude, (2) heavy grazing reduces the effects of drought magnitude, and (3) heavy browsing amplifies effects of drought magnitude. Under ambient browsing intensity, extreme drought caused Wyoming big sagebrush (Beetle & Young) canopies to shrink. Interestingly, this effect went away in our heavy browsing treatment, despite overall negative effects of heavy browsing on shrub canopies and leader survival. We show that this drought-buffering effect may be driven by reduced leaf-level water stress in droughted, heavily browsed shrubs compared with droughted, ambiently browsed shrubs; this may have resulted from lower early-season leaf area leading to lower transpiration-related water loss. This potential mechanism for drought resistance in sagebrush steppe highlights the importance of maintaining intact food webs, despite perceived deleterious effects of herbivores for plant abundance and growth. To promote sustainability of sagebrush and other shrub-dominated ecosystems in face of extreme precipitation change, it may be necessary for land managers and policy makers to prioritize conservation of native herbivores within ecosystems.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Rangeland Ecology & Management 农林科学-环境科学

CiteScore

4.60

自引率

13.00%

发文量

审稿时长

12-24 weeks

期刊介绍： Rangeland Ecology & Management publishes all topics-including ecology, management, socioeconomic and policy-pertaining to global rangelands. The journal''s mission is to inform academics, ecosystem managers and policy makers of science-based information to promote sound rangeland stewardship. Author submissions are published in five manuscript categories: original research papers, high-profile forum topics, concept syntheses, as well as research and technical notes. Rangelands represent approximately 50% of the Earth''s land area and provision multiple ecosystem services for large human populations. This expansive and diverse land area functions as coupled human-ecological systems. Knowledge of both social and biophysical system components and their interactions represent the foundation for informed rangeland stewardship. Rangeland Ecology & Management uniquely integrates information from multiple system components to address current and pending challenges confronting global rangelands.