Restoration of wet meadows to enhance Gunnison sage‐grouse habitat and drought resilience in arid rangelands

Abstract

The arid sagebrush landscape of the Gunnison Basin, Colorado is home to the federally threatened Gunnison sage‐grouse (GUSG; Centrocercus minimus) and is expected to become hotter and drier with a changing climate. Wet meadows within the sagebrush ecosystem are a critical lifeline for wildlife and livestock, particularly during drought years, yet they occupy less than 2% of the landscape. Our objective was to enhance wet meadow drought resiliency by slowing the water down, reconnecting floodplains, and increasing wetland vegetation. Indirectly we also aimed to enhance GUSG habitat and improve rangeland condition. Between 2012 and 2020, we constructed nearly 900 low‐tech restoration structures (Zeedyk structures), across seven drainageways with wet meadows. Six of these years were drought years. We used a before‐after‐control‐impact design to assess vegetation response. Vegetation data were collected on 135 randomly selected treated and 30 control transects. We found that 75% of ephemeral units and all of perennial units achieved or surpassed the wetland plant cover management goal of a 4% yearly increase. This led to an average enhancement of 40% in wetland plant cover in the treated drainageways. There was a significant positive difference between treated and control transects in 50% of the drainageways, regardless of hydroperiod status. The low‐tech restoration structures were effective at rewetting perennial and ephemeral wet meadows within the arid landscape, even during a megadrought, and reduced non‐native invasive weeds in all but one of the treated units. Forbs and grasses critical to sage‐grouse and important to livestock operations increased in 67% of the units.