Quantifying the effect of catchment land use and water nutrient concentrations on freshwater river and stream biodiversity

Abstract

ABSTRACT1. A major threat to freshwater taxon diversity is the alteration of natural catchment Land use into agriculture, industry or urban areas and the associated eutrophication of the water. In order to stop freshwater biodiversity loss, it is essential to quantify the relationships between freshwater diversity and catchment Land use and water nutrient concentrations.2. A literature survey was carried out on biodiversity data from rivers and streams. Fish and macroinvertebrates were selected as focal groups as they are widely used as indicator species of river and stream health. Only published data were selected that (a) compared data found at impaired sites with a pristine reference situation (either in time or space), (b) clearly defined the stressors studied (Land use cover and/or nutrient concentrations), and (c) clearly defined biodiversity (number of native species, species lists or IBI-scores).3. The number of native taxa found in each study was transferred in an index of relative taxon richness (RTR) ranging from 0 (severely altered) to 100 (pristine reference conditions). Only those taxa were included that were (at least) present in the most pristine situation. This made it possible to combine, compare and analyse results from different studies. Catchment Land use was expressed as the percentage of non-natural Land use (agriculture, industry, housing or mining). As a measure of nutrients, the concentrations of NO 3 , NH 4 , PO 4 , total N and total P in the river and stream water were used.4. Over 240 published articles have been studied, but only 22 met the criteria described above and could be used for further analysis.5. This study showed that altered catchment Land use has a major effect on freshwater biodiversity and that the rate of species loss is serious; on average every 10% of lost natural catchment Land use cover leads to a loss of almost 6% ( AE 0.83) of the native freshwater fish and macroinvertebrate species.

Environmental factors – spatial and temporal variation of chironomid communities in oceanic island streams (Azores archipelago)

“…This type of impact contrasts with the impacts of urbanization which are mainly related to direct effects of point source pollution, hydromorphological and biological impacts (Brasher, 2003;Feld and Hering, 2007;Mykra¨et al, 2007;Munne´and Prat, 2009;Weijters et al, 2009). The physicochemical gradient of temperature, pH and conductivity in this study illustrates the indirect, combined effect of multiple mechanisms operating over several spatial scales describing natural biotic and abiotic gradients, changes in land use an organic enrichment .…”

Influences of natural and anthropogenic factors on surface and groundwater quality in rural and urban areas

“…Changes in landscape pattern induced by human activities have major impacts on river conditions (Allan 2004;Bhat et al 2006;Hopkins 2009). Land use and land cover change is strongly correlated with water chemistry parameters (Hunsaker and Levine 1995;Tran et al 2010), the species diversity of freshwater fish and macro-invertebrates (Hopkins 2009;Weijters et al 2009), and sediment metal concentrations (Hollister et al 2008). Highly fragmented urban land uses, with a large proportion of impervious surfaces, tend to increase river flow and negatively affect water quality (Sliva and Williams 2001;Brabec 2009;Lee et al 2009).…”

Influence of invasiveAcer negundoleaf litter on benthic microbial abundance and activity in the littoral zone of a temperate river in Lithuania

“…Riparian ecosystems are highly vulnerable to exotic plant invasion (Hood and Naiman, 2000) due to their milder microclimatic conditions and the frequent natural and anthropogenic disturbances that create diverse niches to support invasive species (Chytry et al, 2008). Shifts from native to exotic trees may alter the quality of leaf litter inputs into water body, thus causing effects on quantity and quality of nutrients (Molinero and Pozo, 2006), biotic communities (Weijers et al, 2009) and ecosystem functioning (Martinez et al, 2013). Several studies have been performed to examine invasive species effects on leaf decomposition rates in aquatic ecosystems by litterbags method, but still have found mixed effects (Swan et al, 2008;Marano et al, 2013;Serra et al, 2013).…”