Grazing Increases Soil Warming in Headwater Wetlands: Importance to Land Managers and Water Users

Abstract

The earth’s mountains continue to lose water. Glaciers are melting and mountain snow/rain balance tilts increasingly liquescent. Water is running off sooner—sometimes overfilling reservoirs, causing flooding, and setting the stage for late-season shortages. One adaptive strategy is to recover and enhance water-storage capacities of headwater riparian systems. Grazing, a common use of headwater lands, affects both soils and vegetation. To better understand how grazing might affect water storage and other ecosystem services of high elevation riparian wetlands, we measured soil-profile temperatures, soil organic matter (SOM), and phytomass at six sites in the upper Sweetwater River sub-basin of Wyoming, USA, where fence lines allowed us to contrast grazing management. We found grazed wetlands consistently had warmer soils than fenced wetlands. We found added evidence that SOM is important in both soil temperature control and water-storage potential of wetlands. We review evidence that warmer soil temperatures and drying cause loss of SOM with the implied concomitant C losses through erosion and emissions. We recommend land managers of temperate-climate headwater systems consider the need to end growing seasons with full stands of riparian vegetation to reduce soil warming and to build organic matter—particularly on lands where municipalities and other downstream water users are seeking long-term increases in water yields and less flooding.

How Wide, How Much? A Framework for Quantifying Economic and Ecological Trade-Offs of Altering Riparian Width on Agricultural Land

“…RBZs facilitate and regulate the provision of energy across a catchment (Singh et al, 2021) and create a buffer that can prevent the runoff of excess sedimentation, pollutants and nutrients into a waterway (Cordeiro et al, 2020;Li et al, 2018;Phogat et al, 2019). This buffering capacity of RBZs can reduce the impact of anthropogenic land uses, such as intensive agriculture (Booth et al, 2021;Grudzinski et al, 2020;Smith et al, 2013) and urbanisation (Sarker et al, 2008) on water quality. The shade created by riparian canopy also serves to regulate in-stream temperatures (Albertson et al, 2018) and has significant influence over in-stream plant and algal growth (Alberts et al, 2018).…”