Search

Invertebrates comprise the most diversified animal group on Earth. Due to their long evolutionary history and small size, invertebrates occupy a remarkable range of ecological niches, and play an important role as "ecosystem engineers" by structuring networks of mutualistic and antagonistic ecological interactions in almost all terrestrial ecosystems. Urban forests provide critical ecosystem services to humans, and, as in other systems, invertebrates are central to structuring and maintaining the functioning of urban forests. Identifying the role of invertebrates in urban forests can help elucidate their importance to practitioners and the public, not only to preserve biodiversity in urban environments, but also to make the public aware of their functional importance in maintaining healthy greenspaces. In this review, we examine the multiple functional roles that invertebrates play in urban forests that contribute to ecosystem service provisioning, including pollination, predation, herbivory, seed and microorganism dispersal and organic matter decomposition, but also those that lead to disservices, primarily from a public health perspective, e.g., transmission of invertebrate-borne diseases. We then identify a number of ecological filters that structure urban forest invertebrate communities, such as changes in habitat structure, increased landscape imperviousness, microclimatic changes and pollution. We also discuss the complexity of ways that forest invertebrates respond to urbanisation, including acclimation, local extinction and evolution. Finally, we present management recommendations to support and conserve viable and diverse urban forest invertebrate populations into the future. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems are under threat from habitat loss, partly due to urban expansion. However, some elements of urban freshwaters are already integral parts of the urban landscape and so are more resilient to loss, representing opportunities for the enhancement of freshwater resources within cities. This study investigated the biodiversity value of the Leeds-Liverpool Canal in Leeds, UK, in relation to its landscape context. Specifically, we tested the hypotheses that (i) biodiversity value is lowest nearest to the urban core, and (ii) the pattern of canal locks structured ecological communities. Nutrients, metals and dissolved carbon all existed at relatively low concentrations, contrary to what is often seen in urban water bodies, although concentrations were higher in the urban core. This gradient of chemical stress was associated with a decline in macroinvertebrate diversity towards the city centre, which manifested as pollution-sensitive taxa being excluded from this area. Community structures were found to vary between groups of sampling sites separated by locks, suggesting that locks may act as barriers for aquatic invertebrates by restricting dispersal. The results in this study indicate that canals in urban areas can be high-quality habitats, despite the associated anthropogenic stressors, and locks may represent a unique model for researching relationships between connectivity and community structure. [ABSTRACT FROM AUTHOR]