Contribution of private gardens to habitat availability, connectivity and conservation of the common pipistrelle in Paris

Abstract

Urban sprawl is one of the greatest global changes with major negative impacts on biodiversity and human well-being. Recent policies have acknowledged the value of urban green areas in counterbalancing such impacts. These policies aim to increase the ecological value of green areas, making cities more permeable to natural populations. However, they are largely focused on the role and management of public green areas, ignoring the role and potential of private green areas for urban ecological value.This study aims to evaluate the benefits of considering private green areas for conservation efforts in cities. Using data on bat activity and information on vegetation and building height, we quantify the respective role of public and private green areas in habitat availability and connectivity for the common pipistrelle in the city of Paris, France. Our results show that despite the low proportion of private green areas in Paris (36% of the total green areas), they still contributed up to 47.9% of bat habitat availability and decrease the resistance of the city matrix by 88%. The distribution in the city matrix and vegetation composition of those areas appeared especially beneficial for bat habitat availability and connectivity. The study demonstrates the importance of private green areas in the ecological value of cities in complementing the role of public green areas. Our results confirm the need to develop more inclusive urban conservation strategies that include both public and private stakeholders.HighlightsThe urban ecological value of private gardens outweighs that of public gardensThis is true for both habitat availability and connectivityBiodiversity policies in cities should also focus on private green areasInclusive conservation strategies are also needed in cities

Finding space for nature in cities: the considerable potential of redundant car parking

“…Our approach has promising biodiversity benefits, primarily by creating 'stepping stones' that link habitat patches for urban species, especially bees. As found in other connectivity studies, even small fragments of habitat can have a positive impact on mobility, particularly for species that may need to rest while dispersing [93][94][95][96][97][98][99][100] .…”

Urban ecological connectivity as a planning tool for different animal species

“…Urban environments are often highly fragmented landscapes, in which most habitat suitable for animal species, such as patches of remnant, semi-natural and managed vegetation, are surrounded by a matrix of residential, commercial and transportation land-uses that prioritise human activities. A high level of ecological connectivity within an urban landscape enables animals to move between patchy resources and allows post-breeding dispersal, maintaining gene flow and population viability (Braaker et al, 2014, 2017; Mimet et al, 2020; Ossola et al, 2019; Visscher et al, 2018). In contrast, a low level of ecological connectivity prevents the movement of individuals and genes, potentially leading to reduced genetic diversity, inbreeding depression and ultimately local extinction (Hanski, 1999; Keeley et al, 2017; LaPoint et al, 2015; Moilanen & Hanski, 2001; Teitelbaum et al, 2020).…”

“…For example, many bird species are able to disperse or commute across inter-patch distances of more than 100m (Shanahan et al, 2011; Silva et al, 2020; Tremblay & St. Clair, 2011), while amphibian species are likely to be impeded by traffic-heavy roads (Charry & Jones, 2009; Hamer, 2016; Jacobson et al, 2016). To measure connectivity more realistically for different species groups it is important to account for behaviour and ecology (Ersoy et al, 2019; Grafius et al, 2017; Lookingbill et al, 2022; Mimet et al, 2020; Teitelbaum et al, 2020; Tischendorf & Fahrig, 2000). Each species within a community has different habitat requirements and movement capabilities.…”

Creating ecologically sound buildings by integrating ecology, architecture and computational design

“…For many species, shelter can also be provided by man‐made structures, such as cavities in a building envelope (Gunnell et al, 2013). Thus, connectivity between patches is of overriding influence (Alberti, 2005; Mimet et al, 2020). Connectivity is strongly affected by urban form , that is, by the way in which patches that can be used by species are interspersed with buildings, roads and other human‐made structures.…”

“…Urban form is important at two spatial scales. At the city scale, urban morphology influences which organisms of the urban species pool can reach a given area within the city (Alberti, 2005; Mimet et al, 2020). At the local scale, local urban form determines which species can find the different resources they need to complete their life cycle (Fournier et al, 2020; Goddard et al, 2010).…”