The functional response and resilience in small waterbodies along land‐use and environmental gradients

Abstract

There is growing recognition of the essential services provided to humanity by functionally intact ecosystems. Freshwater ecosystems are found throughout agricultural and urban landscapes and provide a wide range of ecosystem services, but globally they are also amongst the most vulnerable. In particular, ponds (lentic waters typically less than 2 ha), provide natural flood management, sequester carbon and hold significant cultural value. However, to inform their management it is important to understand (1) how functional diversity varies in response to disturbance and (2) the link between biodiversity conservation and ecosystem function. In this study, a meta-analysis of seven separate pond studies from across England and Wales was carried out to explore the effect of urban and agricultural land-use gradients, shading, emergent vegetation, surface area and pH upon groups of functionally similar members of the macroinvertebrate fauna. Functional effect groups were first identified by carrying out a hierarchical cluster analysis using body size, voltinism and feeding habits (18 categories) that are closely related to biogeochemical processes (e.g. nutrient and carbon recycling). Secondly, the influence of the gradients upon effect group membership (functional redundancy-FR) and the breadth of traits available to aid ecosystem recovery (response diversity) was assessed using species counts and functional dispersion (FDis) using 12 response traits. The effect of land-use gradients was unpredictable, whilst there was a negative response in both FR and FDis to shading and positive responses to increases in emergent vegetation cover and surface area. An inconsistent association between FDis and FR suggested that arguments for taxonomic biodiversity conservation to augment ecosystem functioning are too simplistic. Thus, a deeper understanding of the response of functional diversity to disturbance could have greater impact with decision-makers who may relate better to the loss of ecosystem function in response to environmental degradation than species loss alone.

Dynamic of Dominant Plant Communities in Kettle Holes (Northeast Germany) during a Five-Year Period of Extreme Weather Conditions

“…groups gained + groups lost total number o f groups observed ∈ both years (2) Proportional appearance (gain rates; G) and disappearance (loss rates; L), as well as change of dominant groups (turnover rates; T) were calculated relative to the total number of dominance groups counted across the respective sampling years. Calculations were based on presence-absence data for the full set of sites, using the R codyn package v. 2.0.5 [52] and following Anderson [53].…”

“…We monitored 14 out of more than 1500 kettle holes located in the "AgroScapeLab Quillow" (ASLQ, Leibniz Centre for Agricultural Landscape Research (ZALF)) that covers the catchment of the river Quillow with an area of about 170 km 2 . This landscape laboratory is located in the lowlands of northeast Germany and part of a hummocky young moraine landscape.…”

“…The understanding of ecosystem functioning in small, highly variable wetland ecosystems such as potholes or kettle holes requires sufficient knowledge about their spatiotemporal dynamics [1][2][3]. This is even more important under climate change conditions where changing precipitation patterns cause extreme weather conditions [4].…”

Integridad biótica de charcas en humedales patagónicos: valoración de métricas del paisaje, encuadre ambiental y respuestas comunitarias

“…El pastoreo y desmonte para ganadería y agricultura, y el desarrollo urbano/industrial han generado un impacto importante sobre la base de los recursos acuáticos en vastas áreas del planeta (Allan, 2004;Villagran-Mella et al, 2006). Estos cambios en el uso del suelo han producido la degradación de los ecosistemas de agua dulce, induciendo cambios sustanciales en las propiedades fisicoquímicas del agua y determinando la pérdida de la biodiversidad (Akasaka et al, 2010;Thornhill et al, 2018). Asimismo, los resultados de un número importante de estudios sugieren que los cambios en el uso del suelo contribuyen al cambio climático local y regional (Houghton et al, 1999, Chase et al, 2000, Claussen et al, 2001, Defries et al, 2002, Brovkin et al, 2004, así como también al calentamiento global (Houghton et al, 1999;Lambin et al, 2001).…”

“…No obstante, otros estudios argumentan que los factores a escala local como el tamaño de las charcas, el hidroperíodo, el tipo de sustrato y la química del agua son los que principalmente definen la composición de las especies en los humedales (Tarr et al, 2005;Gascón et al, 2009;Kutschker et al, 2014;Hill et al, 2015;2017). En línea con estos hallazgos, Thornhill et al (2018) evidenciaron que los factores locales como el área del humedal, la vegetación emergente, y el pH tuvieron una influencia más fuerte y consistente sobre la diversidad de invertebrados que los gradientes de uso del suelo considerados (urbanización y agricultura) en charcas de Inglaterra y Gales. Para la Patagonia Argentina, Epele et al, (2019) demostraron que la variación composicional (i.e., diversidad beta) de los invertebrados en las charcas era fuertemente explicada por las características locales de los cuerpos de agua, tales como la cobertura de plantas, el oxígeno disuelto y la conductividad, y por las variables climáticas como la temperatura ambiental, más que por las características del paisaje como la cobertura del suelo alrededor de las charcas (100 m buffer).…”