Impacts of multiple stressors on ecosystem function: Leaf decomposition in constructed urban wetlands. (January 2016)

• Record Type: Journal Article
• Authors: Mackintosh, Teresa J.; Davis, Jenny A.; Thompson, Ross M.
• Is Part Of: Environmental pollution. Volume 208:Part A(2016)
• Page Start: 221
• Page End: 232
• Publication Date: 2016-01
• Subjects: Constructed wetlands -- Stormwater -- Metals -- Decomposition -- Leaf bags -- Metals -- Total imperviousness; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2015.08.038
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The impact of stormwater on stream biota is well documented, but less is known about the impacts on ecosystem processes, such as the breakdown of organic matter. This study sought to establish whether the degree of urbanisation affected rates of leaf-litter breakdown within constructed wetlands. A litter bag method was used to ascertain rate of decomposition along a gradient of urbanisation (total imperviousness, TI), in constructed wetlands in western and south-eastern Melbourne. A significant positive relationship between TI and breakdown rate was found in the south-eastern wetlands. The significant reduction in rate of invertebrate-mediated breakdown with increasing concentration of certain metals was consistent with other studies. However, overall there was an increase in rate of breakdown. Studies have shown that the effects of heavy metals can be negated if nutrient levels are high. Our results suggest that other parameters besides exposure to contaminants are likely to affect leaf litter breakdown. Highlights: There have been few studies on the effect of urbanisation on ecosystem function. Rate of leaf litter breakdown increased moving along a gradient of urbanisation. There was a reduction in invertebrate mediated breakdown with certain metals. Results suggest other parameters besides contaminants affect leaf litter breakdown. Abstract : Certain heavy metals led to a decrease in leaf litter breakdown; however overall, there was a positive relationship between breakdown and increasing urbanisation.