Elsevier

Landscape and Urban Planning

Volume 153, September 2016, Pages 28-39
Landscape and Urban Planning

Research paper
Approaches to urban vegetation management and the impacts on urban bird and bat assemblages

https://doi.org/10.1016/j.landurbplan.2016.04.011Get rights and content

Highlights

  • We examined three vegetation management approaches used in urban green spaces.

  • Bird and bat assemblages responded positively to increases in native plant richness.

  • Bird species richness increased with greater understorey vegetation volume.

  • Bat species richness increased with increasing density of trees >81 cm in diameter.

  • These measures can be implemented without compromising multiple uses of green space.

Abstract

To balance the needs of people and biodiversity in cities, local governments are increasingly incorporating green spaces and urban greening initiatives into urban planning frameworks. Despite this, there is little information on which vegetation features or management actions are most useful in supporting biodiversity within these green spaces. We assess the effect of three vegetation management approaches that are commonly suggested to improve outcomes for urban biodiversity, including: (1) increasing the proportion of native vegetation; (2) increasing the density of trees, and (3) increasing the volume or complexity of understorey vegetation. We use a network of 39 urban green spaces (including golf courses, public parks and residential neighbourhoods) to assess how these vegetation management approaches impact urban bird and bat communities. The richness of both birds and bats increased with an increase in the proportion of native plants, bird species richness increased with increasing volume of understorey vegetation, and increasing large tree density led to increased bat activity. Our study suggests that increasing native vegetation composition and understorey vegetation volume, and the retention of large trees are practical vegetation management approaches that improve outcomes for urban birds and bats. Our data also suggests that as urbanisation and infill development proceeds, retention of large green spaces (such as golf courses) will be critical for urban biodiversity conservation, as these areas supported a component of the bird and bat fauna which was not recorded in other green space types.

Introduction

Networks of green spaces can occupy substantial areas of land within a city (for example, ranging from 1.2–46% cover in European cities, Fuller & Gaston, 2009). However, green spaces are increasingly being lost to urban in-fill development in response to rising housing demand (Jim, 2004). Urban green spaces include both natural (remnant) or planted vegetation, on public and private land, such as residential gardens, recreation fields, public parks and reserves (Tzoulas et al., 2007). They can provide an array of ecosystem services to urban residents such as recreation, cooling, stormwater runoff reduction, noise reduction and carbon storage (Derkzen, van Teeffelen, & Verburg, 2015; Livesley, Ossola, Threllfall, Hahs, & Williams, 2015; Ossola, Hahs, & Livesley, 2015; Tzoulas et al., 2007), in addition to their enormous potential to support urban biodiversity (Bryant, 2006, Hahs et al., 2009; Sandström, Angelstam, & Mikusiński, 2006; Shwartz, Turbé, Julliard, Simon, & Prévot, 2014). Subsequently, there is global interest from city governments to manage urban green spaces so that they support people and biodiversity (Bryant, 2006, Sandstrom, 2002, Walmsley, 2006). However, despite the spread of urban greening initiatives (Walmsley, 2006), and recent growth of programs such as wildlife gardening (Goddard, Dougill, & Benton, 2010), and biodiversity-friendly park management schemes (Shwartz, Muratet, Simon, & Julliard, 2013), there is little empirical evidence to support the use of specific vegetation management regimes in urban green spaces to provide for an array of biodiversity and subsequent ecosystem services (Lin & Fuller, 2013).

Much of our understanding of the value of urban green spaces for biodiversity has come from studies of urban birds (Magle, Hunt, Vernon, & Crooks, 2012; McDonnell and Hahs, 2008, Shwartz et al., 2014). Birds are the most frequently studied urban taxa, probably because they are prevalent across many habitats, conspicuous, easy to observe and have wide public appeal (Larsen, Bladt, Balmford, & Rahbek, 2012; Shwartz et al., 2013). Birds are a significant component of the urban fauna, and 20% of global bird species can be found in cities (Aronson et al., 2014). Studies of urban birds have increased our understanding of ways to design and manage urban green spaces to conserve bird assemblages, however, it is unclear if this understanding is equally relevant to other taxa. The size of urban green spaces, and the density, size and origin of trees within them, have been consistently shown to positively influence the richness and diversity of urban bird assemblages (Chace & Walsh, 2006; Fontana, Sattler, Bontadina, & Moretti, 2011; Ikin, Knight, Lindenmayer, Fischer, & Manning, 2013; Shanahan, Miller, Possingham, & Fuller, 2011; Shwartz et al., 2013; Stagoll, Lindenmayer, Knight, Fischer, & Manning, 2012; White, Antos, Fitzsimons, & Palmer, 2005). Urban green space with a greater diversity of habitat elements, including understorey and overstorey canopy vegetation, leaf litter, logs and long grass, have also been shown to benefit bird assemblages (Evans, Newson, & Gaston, 2009; Shwartz et al., 2013; Stagoll, Manning, Knight, Fischer, & Lindenmayer, 2010). Scientists recommend that urban landscape managers can improve bird habitat by retaining large trees (Stagoll et al., 2012), increasing the proportion of native vegetation (Chace & Walsh, 2006), and improving habitat complexity or diversity (Shwartz et al., 2013). However, unless other fauna respond to green space attributes in the same way as birds, these vegetation management actions may not lead to improved outcomes for urban biodiversity more broadly.

Insectivorous bats are one such group that are commonly found in urban environments (Russo & Ancillotto, 2015), and are highly mobile. Previous studies examining urban bat assemblages have largely focussed on landscape factors, demonstrating that bat assemblages are more diverse in landscapes with larger patches of green space (Avila-Flores and Fenton, 2005, Gehrt and Chelsvig, 2003), and respond positively to increases in the cover of vegetation and density of trees at the landscape scale (Basham, Law, & Banks, 2011; Hale, Fairbrass, Matthews, & Sadler, 2012; Luck, Smallbone, Threlfall, & Law, 2013; Threlfall, Law, & Banks, 2012). Site level factors suggested to be beneficial to bat assemblages include the presence of large trees (Basham et al., 2011), tree hollows (Basham et al., 2011), and an abundant supply of nocturnal invertebrates (Avila-Flores & Fenton, 2005). However, few studies have investigated ways to design and manage urban green spaces to specifically promote bat assemblages (Smith & Gehrt, 2010). This issue is particularly pressing in Australia, where cities have been found to be disproportionately important for the conservation of threatened species in comparison to non-urban regions (Ives et al., 2016). In Australia, several threatened species of birds, bats and other vertebrate fauna, have been found to rely heavily on resources provided by urban landscapes (Ives et al., 2016, Threlfall et al., 2012).

To improve our understanding of the ways in which urban green spaces can be managed to support an array of taxa, we investigated the relationship between bird and bat assemblages and vegetation attributes throughout a network of large and small urban green spaces in Melbourne, Australia. Taking a multi-taxa approach can reveal important differences in the way biodiversity responds to urban environments (Beninde, Veith, & Hochkirch, 2015; MacGregor-Fors et al., 2015), enabling the development of more sophisticated approaches to green space management in both public and private spaces. We selected bats as a comparative taxa to birds due to their ubiquity in Australian cities (Caryl et al., 2014; Hourigan, Catterall, Jones, & Rhodes, 2010; Luck et al., 2013, Scanlon and Petit, 2008, Threlfall et al., 2012), and because their mobility and their insectivorous diet make them potentially highly responsive to the way vegetation is managed in urban areas, particularly as invertebrates are known to be influenced by various aspects of urban vegetation (Beninde et al., 2015). Additionally, bats have been proposed as potential bio-indicators in urban environments (Russo & Ancillotto, 2015), making it critical to compare their response to other more commonly studied taxa.

The aim of our study was to investigate how local scale vegetation management in urban green spaces influences bird and bat assemblages. To do this we examined the effect of three local scale vegetation management approaches: (1) increasing the proportion of native vegetation; (2) increasing the density of trees, and (3) increasing the volume or complexity of understorey vegetation. The ecological responses we examined were measures of the bird and bat assemblage relevant to biodiversity-friendly management goals, including species richness of bird and bat assemblages, bird breeding activity, and the activity and richness of bat species previously classified as being urban sensitive (Threlfall et al., 2012). We expected that birds would respond strongly to differences in native and exotic vegetation in different green spaces, as found by previous Australian studies (White et al., 2005). In contrast, we expected that bats would respond more strongly to structural aspects of urban vegetation, such as tree density and size, rather than the composition of vegetation per se (Kalcounis, Hobson, Brigham, & Hecker, 1999).

Section snippets

Study area

We sampled birds and bats within three types of urban green spaces in south-east Melbourne, including: (1) golf courses, (2) public parks and (3) residential neighbourhoods (e.g. front gardens and streetscapes). Melbourne is home to four million residents, and this region has been experiencing rapid urban expansion since the late 1800’s (Victorian Department of Sustainability and Environment 2005). Residential neighbourhoods typically comprise low density single story detached houses. Golf

Results

We recorded 71 bird species that were not considered ‘water-dependant’. Rainbow Lorikeet Trichoglossus haematodus, Australian Magpie Cracticus tibicen and Little Raven Corvus mellori, were recorded in every green space surveyed (n = 39). Golf courses supported significantly greater bird species richness, including a greater proportion of insectivorous species, in comparison to public parks and residential neighbourhoods (Table 1). Native bird breeding activity was significantly higher in golf

Discussion

Urban green space networks have huge potential to contribute to urban biodiversity conservation (Shwartz et al., 2014). Altering vegetation management practices in these green spaces could significantly improve outcomes for biodiversity (Shwartz et al., 2013). We examined three local scale vegetation management approaches that are suggested to positively influence both bird and bats: (1) increasing the proportion of native vegetation; (2) increasing the density of large trees, and (3)

Conclusions

We found that three local scale vegetation management approaches commonly suggested to improve outcomes for urban biodiversity have significant, positive impacts to several aspects of urban bird and bat assemblages. However, our results also highlight the importance of considering multiple components of vegetation management in order to support a broader range of biodiversity. Importantly, we found that these benefits extend to activities likely to impact population fitness of birds (e.g.

Acknowledgements

We thank participating residents, municipalities and golf courses for granting access to their properties and our volunteer field assistants. This study was funded by the Australian Research Council (LP110100686), the Australian Research Centre for Urban Ecology of the Royal Botanic Gardens Victoria and the Australian Golf Course Superintendents Association. We particularly acknowledge John Geary and BirdLife Australia for their assistance.

References (77)

  • M.D. Adams et al.

    Reliable automation of bat call identification for eastern new south wales, australia, using classification trees and anascheme software

    Acta Chiropterologica

    (2010)
  • M.F.J. Aronson et al.

    A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers

    Proceedings of the Royal Society B: Biological Sciences

    (2014)
  • R. Avila-Flores et al.

    Use of spatial features by foraging insectivorous bats in a large urban landscape

    Journal of Mammalogy

    (2005)
  • R. Basham et al.

    Microbats in a ‘leafy' sydney urban landscape: are they persisting, and what factors influence their presence?

    Austral Ecology

    (2011)
  • J. Beninde et al.

    Biodiversity in cities needs space: A meta-analysis of factors determining intra-urban biodiversity variation

    Ecology Letters

    (2015)
  • S. Bhullar et al.

    Arthropods on street trees: a food resource for wildlife

    Pacific Conservation Biology

    (2000)
  • T. Bjerke et al.

    Vegetation density of urban parks and perceived appropriateness for recreation

    Urban Forestry & Urban Greening

    (2006)
  • M.M. Bryant

    Urban landscape conservation and the role of ecological greenways at local and metropolitan scales

    Landscape and Urban Planning

    (2006)
  • K.T. Burghardt et al.

    Impact of native plants on bird and butterfly biodiversity in suburban landscapes

    Conservation Biology

    (2009)
  • F.M. Caryl et al.

    Continuous predictors of species distributions support categorically stronger inference than ordinal and nominal classes: an example with urban bats

    Landscape Ecology

    (2014)
  • J.F. Chace et al.

    Urban effects on native avifauna: a review

    Landscape and Urban Planning

    (2006)
  • A. Chao et al.

    Coverage-based rarefaction and extrapolation: standardizing samples by completeness rather than size

    Ecology

    (2012)
  • M.L. Derkzen et al.

    Quantifying urban ecosystem services based on high‐resolution data of urban green space: an assessment for rotterdam, The Netherlands

    Journal of Applied Ecology

    (2015)
  • J.A. Dunster

    The role of arborists in providing wildlife habitat and landscape linkages throughout the urban forest

    Journal of Arboriculture

    (1998)
  • K.L. Evans et al.

    Habitat influences on urban avian assemblages

    Ibis

    (2009)
  • J. Fischer et al.

    The disproportionate value of scattered trees

    Biological Conservation

    (2010)
  • J.A. Fitzsimons et al.

    When more is less: urban remnants support high bird abundance but diversity varies

    Pacific Conservation Biology

    (2011)
  • S. Fontana et al.

    How to manage the urban green to improve bird diversity and community structure

    Landscape and Urban Planning

    (2011)
  • R.A. Fuller et al.

    The scaling of green space coverage in european cities

    Biology Letters

    (2009)
  • S.D. Gehrt et al.

    Bat activity in an urban landscape: patterns at the landscape and microhabitat scale

    Ecological Applications

    (2003)
  • P. Gibbons et al.

    Tree hollows and wildlife conservation in Australia

    (2002)
  • M.A. Goddard et al.

    Scaling up from gardens: biodiversity conservation in urban environments

    Trends in Ecology & Evolution

    (2010)
  • A.K. Hahs et al.

    A global synthesis of plant extinction rates in urban areas

    Ecology Letters

    (2009)
  • J.D. Hale et al.

    Habitat composition and connectivity predicts bat presence and activity at foraging sites in a large UK Conurbation

    PLoS One

    (2012)
  • P.J. Higgins et al.

    Handbook of Australian New Zealand & Antarctic birds

    (1990)
  • S. Hodgkison et al.

    The efficacy of small-scale conservation efforts, as assessed on australian golf courses

    Biological Conservation

    (2007)
  • S.C. Hodgkison et al.

    The conservation value of suburban golf courses in a rapidly urbanising region of australia

    Landscape and Urban Planning

    (2007)
  • C.L. Hourigan et al.

    The diversity of insectivorous bat assemblages among habitats within a subtropical urban landscape

    Austral Ecology

    (2010)
  • Hsieh, T.C., Ma, K.H., Chao, A., 2013, Inext online: Interpolation and extrapolation (version...
  • K. Ikin et al.

    The influence of native versus exotic streetscape vegetation on the spatial distribution of birds in suburbs and reserves

    Diversity and Distributions

    (2013)
  • C.D. Ives et al.

    Cities are hotspots for threatened species

    Global Ecology and Biogeography

    (2016)
  • C.Y. Jim

    Green-space preservation and allocation for sustainable greening of compact cities

    Cities

    (2004)
  • M.C. Kalcounis et al.

    Bat activity in the boreal forest: importance of stand type and vertical strata

    Journal of Mammalogy

    (1999)
  • F.W. Larsen et al.

    Birds as biodiversity surrogates: will supplementing birds with other taxa improve effectiveness?

    Journal of Applied Ecology

    (2012)
  • D.S. Le Roux et al.

    Reduced availability of habitat structures in urban landscapes: implications for policy and practice

    Landscape and Urban Planning

    (2014)
  • D.S. Le Roux et al.

    The future of large old trees in urban landscapes

    PLoS One

    (2014)
  • S. Lehvavirta et al.

    Natural regeneration of trees in urban woodlands

    Journal of Vegetation Science

    (2002)
  • B.B. Lin et al.

    Sharing or sparing? How should we grow the world's cities?

    Journal of Applied Ecology

    (2013)
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