Pond density as a determinant of aquatic species richness in an urban landscape

Abstract

Social cues, such as eye gaze and pointing fingers, can increase the prioritisation of specific locations for cognitive processing. A previous study using a manual reaching task showed that, although both gaze and pointing cues altered target prioritisation (reaction times [RTs]), only pointing cues affected action execution (trajectory deviations). These differential effects of gaze and pointing cues on action execution could be because the gaze cue was conveyed through a disembodied head; hence, the model lacked the potential for a body part (i.e., hands) to interact with the target. In the present study, the image of a male gaze model, whose gaze direction coincided with two potential target locations, was centrally presented. The model either had his arms and hands extended underneath the potential target locations, indicating the potential to act on the targets (Experiment 1), or had his arms crossed in front of his chest, indicating the absence of potential to act (Experiment 2). Participants reached to a target that followed a nonpredictive gaze cue at one of three stimulus onset asynchronies. RTs and reach trajectories of the movements to cued and uncued targets were analysed. RTs showed a facilitation effect for both experiments, whereas trajectory analysis revealed facilitatory and inhibitory effects, but only in Experiment 1 when the model could potentially act on the targets. The results of this study suggested that when the gaze model had the potential to interact with the cued target location, the model's gaze affected not only target prioritisation but also movement execution.

Ecological Drivers of Cladoceran Diversity in the Central European City (Łódź, Poland): Effects of Urbanisation and Size of the Waterbody

“…An average of 28 and a total of 119 aquatic macroinvertebrate taxa were recorded from 37 ponds in the town of Halton, UK, however, this was lower than the wider landscape in the north west of England (Gledhill et al, 2008). The same study indicated that invertebrate biodiversity was higher in ponds in new town developments, where there was a higher density of ponds, than urban ponds in established, old urban areas (Gledhill et al, 2008). Common macroinvertebrate species can colonize even the most degraded urban ponds (Wood et al, 2003).…”

“…Previous research has highlighted urban ponds' considerable contribution to biodiversity (Gledhill et al, 2008;Hassall, 2014;Hassall and Anderson, 2015) whilst other studies have suggested that urban ponds are often ecologically poor and currently of little value to aquatic conservation (Noble and Hassall, 2014). …”

“…Research on the biodiversity of ephemeral ponds 'lags at least 50 years behind that of better known water body types' (Williams et al, 2001: 7) and urban ponds have also been very poorly studied due to their small size and the often misplaced assumption that they are of poor biodiversity value. These research gaps have recently been recognised and highlighted within the scientific literature (Gledhill et al, 2008;Chester and Robson, 2013;Hassall, 2014). There have been few studies into pond landscapes (pondscapes) and how their connectivity or isolation may influence biodiversity.…”

“…Urban and garden ponds are likely to play an increasingly important role in supporting and contributing to urban biodiversity and mitigating against urban biodiversity loss (Colding et al, 2009;Hassall and Anderson, 2015). An average of 28 and a total of 119 aquatic macroinvertebrate taxa were recorded from 37 ponds in the town of Halton, UK, however, this was lower than the wider landscape in the north west of England (Gledhill et al, 2008). The same study indicated that invertebrate biodiversity was higher in ponds in new town developments, where there was a higher density of ponds, than urban ponds in established, old urban areas (Gledhill et al, 2008).…”

“…Garden pond creation may offset pond loss in the wider landscape but they are unlikely to encompass the diversity of pond types and habitats in the wider landscape (Gaston et al, 2005a). Urban and garden ponds may contribute to and augment regional and urban species richness (Gaston et al, 2005b;Hassall and Anderson, 2015), act as refugia for aquatic taxa in urban spaces and as stepping stones between surface waters in the wider landscape (Gledhill et al, 2008).…”