Towards a simple global-standard bioassay for a key ecosystem process: organic-matter decomposition using cotton strips

作者：Fanny Colas, Guy Woodward, Francis J. Burdon, François Guérold, Éric Chauvet, Julien Cornut, Aurélie Cébron, Hugues Clivot, Michaël Danger, M. Danner, Christophe Pagnout, Scott D. Tiegs · 发表于：Ecological Indicators · 年份：2019 · DOI：10.1016/j.ecolind.2019.105466 · 被引用次数：42 · 研究领域：Freshwater macroinvertebrate diversity and ecology、Microbial Community Ecology and Physiology、Aquatic Invertebrate Ecology and Behavior

Cotton-strip bioassays are increasingly used to assess ecosystem integrity because they provide a standardized measure of organic-matter decomposition – a fundamental ecosystem process. However, several different cotton-strip assays are routinely used, complicating the interpretation of results across studies, and hindering broader synthesis. Here, we compare the decay rates and assemblages of bacteria and fungi colonizing the three most commonly used cotton materials: Artist’s canvas, Calico cloth, and Empa fabric. Cotton strips from each material type were incubated in 10 streams that span a wide range of physicochemical properties across five ecoregions. Additionally, to evaluate responses to environmental stress without potentially confounding biogeographical effects, we deployed identical bioassays in five streams across an acidification gradient within a single ecoregion. Across all streams decomposition rates (as tensile strength loss [TSL]) differed among the three cotton materials; Calico cloth decomposed fastest (time to 50% TSL [T50] = 16.7 d), followed by the Empa fabric (T50 = 18.3 d) and then Artist’s canvas (T50 = 21.4 d). Despite these differences, rates of TSL of the three cotton materials responded consistently to variation in environmental conditions; TSL of each fabric increased with stream temperature, dissolved-nutrient concentrations and acid-neutralizing capacity, although Artist’s canvas and Calico cloth were more sensitive than Empa fabric. Microbial...