285
Ksiazek 2015; Salisbury et al. 2015), the use of horticultural cultivars has been
linked to a reduction in the forage value of planting for pollinators in general (Bates
et al. 2011; Salisbury et al. 2015). Moreover, the spread of alien invasive species
from gardens and parks is another significant issue in many parts of the world
(Reichard and White 2001; Russo et al. 2017). The conservation value of green
spaces that are popular with people can also be limited by significant levels of disturbance and degradation, which prevent native species from colonising and persisting (Brown and Grant 2005), and result in assemblages dominated by adaptable
generalists (Kowarik 2011) and the homogenisation of urban biodiversity (McKinney
2006). Even for human-nature interactions that people perceive as being good for
wildlife, such as the supplementary feeding of wild birds, we have little evidence as
to whether they deliver biodiversity conservation benefits (Fuller et al. 2008; Robb
et al. 2008; Jones 2018).
Despite this, suitable habitat within urban areas can support threatened and specialist species, and warrant conservation attention (Baldock et al. 2015; Ives et al.
2016). In developed regions, where intensive use of the wider landscape, particularly through agriculture, has resulted in species declines, urban areas have become
important for sustaining regional abundances of some species. Substantial proportions of the populations of some previously widespread and common species now
occur in urban green spaces (e.g. Beebee 1997; Gregory and Baillie 1998; Mason
2000; Bland et al. 2004; Peach et al. 2004; Speak et al. 2015; Ives et al. 2016;
Tryjanowski et al. 2017). For instance, over 600 species have been recorded in
Weißensee Jewish Cemetery in Berlin. It supports 25 plants, five bats and nine birds
that are species of conservation concern, and one of the lichens (Aloxyria ochrocheila) present on the site is considered very rare across the wider region. The cemetery therefore acts as an unintended refuge for a wide range of taxa (Buchholz et al.
2016).
12.2 Green Spaces Managed Primarily for Biodiversity
At the other end of the green space continuum are formal protected areas, now interpreted as a global conservation network, where the objective is to maintain and
enhance biodiversity (see MacKinnon et al. Chap. 16, this volume). Currently, there
are more than 200,000 protected areas globally, after a huge expansion of the network over the past few decades (Watson et al. 2014, Butchart et al. 2015). Some of
the earliest protected areas were preferentially designated in locations used heavily
for recreation (Pressey 1994), and some protected areas are still managed with
access and use by people as a primary management goal, such as many of the
National Parks in the UK (Smith 2013). However, this is usually the exception
rather than the rule for three inter-related reasons.
First, protected areas have overwhelmingly been established in areas not needed
for economic activity (Pressey 1994), so they are often sited at higher elevations, on
12 Biodiversity and Health: Implications for Conservation
Ksiazek 2015; Salisbury et al. 2015), the use of horticultural cultivars has been
linked to a reduction in the forage value of planting for pollinators in general (Bates
et al. 2011; Salisbury et al. 2015). Moreover, the spread of alien invasive species
from gardens and parks is another significant issue in many parts of the world
(Reichard and White 2001; Russo et al. 2017). The conservation value of green
spaces that are popular with people can also be limited by significant levels of disturbance and degradation, which prevent native species from colonising and persisting (Brown and Grant 2005), and result in assemblages dominated by adaptable
generalists (Kowarik 2011) and the homogenisation of urban biodiversity (McKinney
2006). Even for human-nature interactions that people perceive as being good for
wildlife, such as the supplementary feeding of wild birds, we have little evidence as
to whether they deliver biodiversity conservation benefits (Fuller et al. 2008; Robb
et al. 2008; Jones 2018).
Despite this, suitable habitat within urban areas can support threatened and specialist species, and warrant conservation attention (Baldock et al. 2015; Ives et al.
2016). In developed regions, where intensive use of the wider landscape, particularly through agriculture, has resulted in species declines, urban areas have become
important for sustaining regional abundances of some species. Substantial proportions of the populations of some previously widespread and common species now
occur in urban green spaces (e.g. Beebee 1997; Gregory and Baillie 1998; Mason
2000; Bland et al. 2004; Peach et al. 2004; Speak et al. 2015; Ives et al. 2016;
Tryjanowski et al. 2017). For instance, over 600 species have been recorded in
Weißensee Jewish Cemetery in Berlin. It supports 25 plants, five bats and nine birds
that are species of conservation concern, and one of the lichens (Aloxyria ochrocheila) present on the site is considered very rare across the wider region. The cemetery therefore acts as an unintended refuge for a wide range of taxa (Buchholz et al.
2016).
12.2 Green Spaces Managed Primarily for Biodiversity
At the other end of the green space continuum are formal protected areas, now interpreted as a global conservation network, where the objective is to maintain and
enhance biodiversity (see MacKinnon et al. Chap. 16, this volume). Currently, there
are more than 200,000 protected areas globally, after a huge expansion of the network over the past few decades (Watson et al. 2014, Butchart et al. 2015). Some of
the earliest protected areas were preferentially designated in locations used heavily
for recreation (Pressey 1994), and some protected areas are still managed with
access and use by people as a primary management goal, such as many of the
National Parks in the UK (Smith 2013). However, this is usually the exception
rather than the rule for three inter-related reasons.
First, protected areas have overwhelmingly been established in areas not needed
for economic activity (Pressey 1994), so they are often sited at higher elevations, on
12 Biodiversity and Health: Implications for Conservation