Planting grass filter strips: Does it influence the structure and function of riparian habitats of agricultural headwater streams?

Abstract

Grass filter strips are strips of cool or warm season grasses planted adjacent to agricultural streams to reduce nutrient, pesticide, and sediment input. This conservation practice is the most frequently planted riparian buffer type in the United States. Previous studies have not evaluated how grass filter strips alter the structure and function of riparian habitats of agricultural streams. Our objective was to examine the research hypothesis that planting grass filter strips will influence the structure and function of riparian habitats of channelized agricultural headwater streams. We sampled riparian vegetation, quantified coarse particulate organic matter input and nutrient input, and measured water temperature within two unplanted riparian habitat sites, two riparian habitat with grass filter strips sites, and two forested riparian habitat sites of agricultural headwater streams in central Ohio. Forested riparian habitats exhibited greater percent maximum frequency of woody vegetation and reduced water temperatures than unplanted riparian habitats and grass filter strips. Forested riparian habitats also exhibited greater canopy cover, woody vegetation taxa richness, and coarse particulate organic matter input than grass filter strips and greater riparian widths and woody vegetation abundance than unplanted riparian habitats. Grass filter strips did not differ in structure and function from unplanted riparian habitats. We conclude that planting grass filter strips does not influence the structure and function of riparian habitats of channelized agricultural headwater streams.

Evaluating the Effects of Riparian Habitat Type on Nutrient Concentrations in Agricultural Headwater Streams

“…The seasonal DOC concentrations in the forested streams were the greatest during the fall, which highlights the effect of seasonal leaf litter and other allochthonous inputs from the forested riparian buffers on DOC concentrations. Smiley and Rumora (2015) documented within our study sites that the input of leaf litter and other types of coarse particulate organic matter within riparian corridors of forested streams was greater than that of the nonforested streams. Leaf litter is a seasonally significant source of stream DOC (Stanley et al.…”

“…Thus, the stream selection criteria and experimental design summarized below have been described in previous publications derived from the preliminary results from the first eight years of this study (Smiley et al. 2009, 2011; Smiley and Rumora 2015). We selected eight streams (Figure 1) using the following a priori habitat criteria: (1) first‐ or second‐order streams; (2) dominant land use in the watershed was row‐crop agriculture; and (3) the presence of either unplanted riparian habitats, grass filter strips, or forested riparian habitats.…”

“…This study is one component of a long-term multiphased project conducted to document the effects of planting grass filter strips on the physical, chemical, and biotic characteristics of channelized agricultural headwater streams (Smiley et al 2009Smiley and Rumora 2015). Thus, the stream selection criteria and experimental design summarized below have been described in previous publications derived from the preliminary results from the first eight years of this study (Smiley et al 2009Smiley and Rumora 2015). We selected eight streams (Figure 1) using the following a priori habitat criteria: (1) firstor second-order streams; (2) dominant land use in the watershed was row-crop agriculture; and (3) the presence of either unplanted riparian habitats, grass filter strips, or forested riparian habitats.…”

“…The Upper Big Walnut Creek watershed is located in central Ohio (Figure 1) and is one of 14 watersheds in the U.S. that is part of the USDA Agricultural Research Service's Conservation Effects Assessment Project Watershed Assessment Study (Smiley et al 2009;Lizotte et al 2021). The Upper Big Walnut Creek lies within the humid continental, hot summer climate region of the U.S. and air temperatures in the watershed are typically the coldest in January and the warmest in July (King et al 2008;Smiley and Rumora 2015). Precipitation in the watershed varies annually and seasonally (Table S1).…”

“…This study is one component of a long-term multiphased project conducted to document the effects of planting grass filter strips on the physical, chemical, and biotic characteristics of channelized agricultural headwater streams (Smiley et al 2009Smiley and Rumora 2015). Thus, the stream selection criteria and experimental design summarized below have been described in previous publications derived from the preliminary results from the first eight years of this study (Smiley et al 2009Smiley and Rumora 2015).…”