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Green Roofs – Urban Habitats for Ground-Nesting Birds and Plants

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18
Green Roofs – Urban Habitats for
Ground-Nesting Birds and Plants
Nathalie Baumann and Friederike Kasten
ZHAW Zurich University of Applied Sciences, Institute of Natural
Resource Sciences, W¨
adenswil, Switzerland
Summary
In this study, vegetation establishment and breeding success (from egg laying
tofledgling)onflatroofsinperi-urbanandindustrialzonesinSwitzerland
were examined. Seven green roofs in peri-urban and urban areas in different
Swiss cantons (Aargau, Berne, Zoug and Lucerne) where Vanellus vanellus
(Northern Lapwing) and Charadrius dubius (Little Ringed Plover) may breed
successfully were investigated. In addition, a ground site in an agricultural area
was used as a control or reference site. The project had two objectives: first,
to improve the vegetation of the roofs using different techniques – seed, hay
mulch (fresh and dry) and turf – and, second, to assess the development of the
vegetation in relation to improving the breeding success of, and habitat use
by, V. vanellus. Because the research project funding ended in July 2009, the
data presented in this chapter are from only one of the roof sites (Rotkreuz),
which provides a good overview. The data were obtained over three breeding
seasons. The initial results suggest that the improvement of green roof habitats
using fresh hay mulch produced a vegetation of 90100% in two seasons,
resulting in a remarkable increase in plant biomass. Results also show that
V. vanellus has begun to breed consistently, although as yet unsuccessfully on
Urban Biodiversity and Design, 1st edition.
Edited by N. M¨
uller, P. Werner and J. G. Kelcey. ©2010 Blackwell Publishing,
ISBN 978-1-4443-3266-7 (hb) and 978-1-4443-3267-4 (pb)
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Urban Habitats for Ground-Nesting Birds and Plants 349
green roofs. The results show that as a consequence of the improvement of
the vegetation, the chicks survived 510 days longer in the second year than
in the first year. The study has provided important information about the
habitat selection and behaviour of the adult and young birds, which is of value
in future urban research and green roof design.
urban biodiversity, extensive green roofs, ground-nesting birds, Vanellus vanellus,
breeding success, vegetation methods, Switzerland, ecological compensation areas
Introduction
Clergeau et al. (2006) state that the human population is growing and that the
extent of urban areas is expanding faster than the number of inhabitants. As a
consequence, large areas of agricultural and other land (including open areas
with damp soil) are being used for residential and industrial development.
This results in a threat to the existence of many plant and animal species in
Switzerland from habitat loss and fragmentation. However, extensive green
roofs can provide suitable compensation as a habitat for some animal and
plant species that are able to colonize roofs, adapt to the difficult conditions
and develop strategies for survival in ‘extreme’ local environments Brenneisen
(2003).
In 2005–2006, a literature search was carried out to obtain information
about the use of green roofs as a bird-breeding habitat. None of the literature
reported information about successful breeding; it also appeared that the
observation periods were too short, unsystematic and otherwise inadequate to
acquire reliable data about the behaviour of ground-nesting birds on roofs.
The research project reported in this chapter was devised to provide the
much-needed information. The main objectives of the 3-year (2006–2009)
project ‘Ecological compensation on roofs: vegetation and ground-nesting
birds’, funded by the Federal Office for the Environment (FOEN) were to
1. determine the breeding behaviour and success of ground-nesting birds
(adults and chicks);
2. find key factors to optimize the roof habitat for their needs (developing
guidelines for green roof design);
3. test different methods for the establishment and management of suitable
vegetation (local sources, sustainable and reasonably priced);
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350 Nathalie Baumann and Friederike Kasten
4. develop new technologies and systems for ecological compensation mea-
Q1
sures;
5. establish and improve the roof vegetation to enable Vanellus vanellus chicks
to grow and fledge successfully.
This chapter describes the research undertaken between 2006 and 2008
to analyse the vegetation and bird breeding at one of seven sites – Rotkreuz
(Canton Zoug, 3M Company and Sidler Transport AG). We predicted that
with good weather conditions and three growing seasons, the increase in
biomass of the improved habitats should result in sufficient insect production
to support chicks of the ground-nesting bird V. vanellus. In addition, we
examined whether there were any possibilities for assessing the suitability of
the surrounding area as breeding habitat for ground-nesting species and, if
so, whether we could encourage the birds to use more ‘natural’ habitats to
breed. We focused our analysis of breeding on observations of the behaviour
of breeding pairs and their chicks. The vegetation cover was assessed using the
phytosociological method of Braun-Blanquet (Dierschke, 1994).
Ground-nesting birds in Switzerland
In the last decade, ground-nesting birds appear to have adapted to breeding
on extensive flat roofs instead of agricultural areas. This secondary habitat
was chosen by V. vanellus following the loss of their former habitats such as
open areas, grasslands, fields, moors, bogs and heath, which have decreased
drastically throughout Switzerland during the last 100 years as a result of
improvements in land drainage (Schweizerische Vogelwarte Sempach, 2008).
In addition to V. vanellus, the other ground-nesting birds that were breeding
on flat roofs were Charadrius dubius (Little Ringed Plover), Alauda arvensis
(Eurasian Skylark) and Galerida cristata (Crested Lark). V. vanellus is native
to temperate Europe and Asia; 50% of the European population breed in
Britain, The Netherlands and North Germany. The species normally breeds
on cultivated land and in areas of low-growing or maintained vegetation. The
first clutch (three to four eggs) is laid in a scrape in the ground; the chicks’ hatch
after about 26 days of incubation. If the first brood is unsuccessful, the adult
birds are able to lay up to seven replacement clutches on a new site or on the
same site but several metres from the first nest. The chicks leave the nest early
and, after 42 days, are able to fly. From the first day of their leaving the nest, they
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Urban Habitats for Ground-Nesting Birds and Plants 351
have to forage and drink by themselves, which is a complex problem on roofs.
The standard green roof (for example, a lava pumice substrate colonized by
Sedum spp.) does not supply enough food for the chicks to survive and grow.
This is because vegetation is sparse and low growing; consequently, it does
not attract and support sufficient insects that can establish and develop their
life cycles (eggs, larvae, nymphs). A rich diversity and quantity of insectes
is necessary to support the chicks because they require to survive and grow
many insectes (larvae, nymphes etc). The development of the insectes biomass
depends on a large species and structural diversity of plants. The plant biomass
development is determined by the thickness and type of substrate. There is a
growing tendency in Switzerland for ground-nesting birds such as V. vanellus
(an endangered (EN) in the Red List of Swiss breeding birds; of least concern
in the International Union for Conservation of Nature (IUCN) Red List)
to regularly use flat roofs for breeding; therefore, it is of great importance
to optimize the design and construction of roofs to support and fulfil the
ecological needs of this and other species.
Methods
Sites and ground-nesting birds
We examined the roofs at seven sites where there had been single observations
of V. vanellus and C. dubius (see Figure 18.1). The sites were located in four
different Swiss Cantons (Aargau, Berne, Lucerne and Zoug). The surroundings
of the sites varied from urban to rural. From 2005 to 2008, the use of the roof
habitat for breeding by these two species was recorded from the end of March
until mid-July. From the time of arrival of the breeding pair, observations
were made weekly for 3 hours at the same time of the day. During the
breeding period, observations were made three times per week and when
the chicks hatched, the frequency was increased again (4 hours per day/site);
observation continued until they died, disappeared or fledged. Observations
of the replacement clutches were done using the same method. Observation
was made with binoculars (Nikon 10 ×42 mm) and telescopes (Nikon Field
scope EP, 13x - 56x). Foraging behaviour, movement patterns, habitat use and
other behavioural activities were recorded, together with information about
the habitat, vegetation and roof. So as not to disturb the birds significantly, the
observations were made primarily from adjacent buildings with good vantage
points (Baumann, 2006).
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352 Nathalie Baumann and Friederike Kasten
Figure 18.1 AmaleVanellus vanellus on the Rotkreuz roof, around March 2007
when the breeding season starts. The sparse vegetation of this roof comprises
moss, lichens, Sedum polster and very few herbs growing on bare gravel (2007,
N. Baumann).
In 2008, as a result of the problems caused by the 2007 drought and to
prevent a repetition of them, a rainwater irrigation system was installed and a
9m
2pond was constructed on each of the seven roofs to irrigate the vegetation,
provide water for the adult birds and the chicks and to create conditions that
would attract a large population of insects, for example, Chironomids and
other dipterans.
Vegetation
As suggested by K¨
ohler (2006), it is possible to create a relatively diverse
flora on extensive green roofs in inner cities as well as in rural areas. He
also suggests that plant diversity can be even higher if varied micro-climates
(especially sunny and shady areas) are created, initial plantings are enhanced
and a minimal amount of irrigation and maintenance is provided.
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Urban Habitats for Ground-Nesting Birds and Plants 353
From the start of the study, the roofs supported various vegetation types,
whichrangedfrommossesandlichensongraveltoSedum spp, Dianthus
carthusianorum, grass species and moss on lavapumice substrate. The land-
scape and vegetation design of four of the seven roofs could be improved by
increasing the vertical and horizontal structure of the vegetation and, there-
fore, the invertebrate biomass. It was, therefore, decided to test three methods
of doing so; first, by applying a hay mulch (dried or fresh and applied in
layers); second, sowing seed (a mixture of indigenous meadow plants specially
formulated for green roofs); and third, the laying of turves. All the three
techniques were applied to 4–6 cm of ‘ricoter’, which is a Swiss roof topsoil
substrate made from recycled material.
Rotkreuz roof (building of the companies: 3M and Sidler
Transport AG)
For the last decade, V. vanellus has been seen on the 40-year-old flat roof
(approximately 12,000 m2) of a building occupied by 3M and Sidler Transport
AG in the industrial zone of Rotkreuz (Canton Zoug) and close to the
A4 motorway. The protective waterproofing layer is of gravel without any
landscaping. Over the years, mosses, lichens, herbs and grasses established
spontaneously as a result of localized damp conditions. In February 2007, we
laid 15 circles (19.6 m2)and6semi-circles(9.8m
2)of46cmthick‘ricoter
to all of the roofs in the study; see Figure 18.2. On eight circles and two
semi-circles, we added 2-cm-thick turves; see Figure 18.3. The rest of the
ricoter ‘patches’ were sown with a small quantity of seed of Swiss indigenous
plants (annual and perennial herbs) with a high potential of water retention.
In June and July 2007, we added a layer of hay comprising alternate 3-cm deep
layers of freshly cut and dry hay to each of the five different turf circles. One
layer of 3-cm deep dry hay was applied to each of the four semi-circles; see
Figure 18.3 and 18.4.
Results
Use of the enhanced Rotkreuz roof by Vanellus vanellus
V. vanellus have returned to the Rotkreuz roof annually for about a decade,
and have produced about one to four clutches per year. The chicks hatched
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354 Nathalie Baumann and Friederike Kasten
Figure 18.2 Installation of circular patches of turf (2.5 cm deep) on the top of 4 cm
of ‘ricoter’, a Swiss compost recycling product developed for establishing rooftop
vegetation. The original ‘substrate’ on this roof was medium-sized gravel (2007,
N. Baumann).
successfully; in 2006 and 2007, they survived for 4–7 days – normally chicks
can only survive for 34 days on the remains of their egg yolk and without
finding food from elsewhere; if they do not do so, they die of starvation. In
2008, the chicks survived about 13 days – after that, only a few corpses were
found; it is assumed that the rest of the chicks were predated upon by raptors
or corvids (see Table 18.1).
Up to 2007, a minimum of 50 migrating individuals of V. vanellus were
frequently seen in autumn on the agricultural field, roosting in groups in front
of the building. Since June 2008, about 15 to 25 migrating individuals have
been observed while roosting on the roof.
Improvement of the vegetation on Rotkreuz roof with three
different methods
As described previously, in 2007 three vegetation methods, namely turf, seed
and hay, were applied for the improvement of the vegetation on a roof in
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Urban Habitats for Ground-Nesting Birds and Plants 355
Figure 18.3 Map of the Rotkreuz roof – the former gravel roof was revaluated with
a greening consisting of 15 circles and 6 semi-circles of vegetated surfaces. After two
vegetation seasons and despite a dry, hot spring in 2007, an interesting succession
of plants has developed since (Baumann).
Rotkreuz. As a result of the hot dry spring, by June 2007 (the end of the
V. vanellus breeding season) 90% of the vegetation and the substrate were dry,
despite being irrigated. Consequently, the vegetation was sparse and provided
little food and shelter for invertebrates, including insects and spiders. The
2008 survey showed a very good and beautiful layering of vegetation from near
the ground to 60 –80 cm high – typical meadow stratification. On assessment
using the Braun-Blanquet (Dierschke, 1994) method, it was found that
the vegetation cover of the patches was 90 100% (30% grass species); see
Figure 18.5. Some plant species on these circular patches were as follows:
Salvia pratensis (Meadow Clary)
Campanula rotundifolia (Harebell)
Stachys recta (Stiff Hedgenettle)
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356 Nathalie Baumann and Friederike Kasten
Figure 18.4 View of the roof in Rotkreuz just after the completion of the
vegetation improvement works (2007, N. Baumann).
Holcus lanatus (Yorkshire Fog)
Lolium multiflorum (Italian Ryegras)
Arenatherum elatium (Tall Oatgrass)
Discussion
Vanellus vanellus on the Rotkreuz roof
Ground-nesting bird species such as C. dubius and V. vanellus are under
strong anthropogenic pressure in Switzerland, and to a lesser degree in other
European countries. Increasing urbanization has led to the continuing loss and
fragmentation of their breeding habitat (swamps, wetlands and grassland).
However, they have shown, time and again, that they can adapt to the changes
and to the urban landscape. V. vanellus, for example, chooses intensively
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Urban Habitats for Ground-Nesting Birds and Plants 357
Table 18.1 Overview of all roof sites from 2005 to 2008 – in the first row, the three
breeding seasons on the Rotkreuz roof are illustrated. The dark grey fields state that
in those years no observations were made, which is because we did not know the
sites by that time.
2005 2006 2007 2008
Adult birds
Nest found
Chicks hatched (all clutches)
Chicks fledged
Chicks age (relative days number)
Chicks found dead
Replacement clutches
Adult birds
Nest found
Chicks hatched (all clutches)
Chicks fledged
Chicks age (relative days number)
Chicks found dead
Replacement clutches
Adult birds
Nest found
Chicks hatched (all clutches)
Chicks fledged
Chicks age (relative days number)
Chicks found dead
Replacement clutches
Adult birds
Nest found
Chicks hatched (all clutches)
Chicks fledged
Chicks age (relative days number)
Chicks found dead
Replacement clutches
Roof sites:
Rotkreuz
Shoppyland
OBI
Steinhausen
Emmen
Hünenberg
Flughafen
Zürich Kloten
(ZH)
“Natural” Reference site
Choller
6(8) 6 # 0 05? 1 ? 8? ? ? ? 22 109 0 5 614
63954001 8 4 4 0 4 0 0 2 7 3 0 1
46; 13
4 (6)
5
3? ?
260
0 0031100104230700 21203000
4 ? 2 2 1 4 0 5 ? 0 2 3 0 7 1 4 (6) 2 9 0 10 1 2
4 (6) 2 7 3 40; 6 3 1
4442403
3 (4)
3 (4) 2 4 (?) 0 ?? 4 2
85 0411 4 0 4 5 1 4 0 4 311 135 (6)137 (8)15
managed areas of agricultural land and in recent years it has begun to utilize
flat vegetated roofs.
In 2008, the chicks of V. vanellus that hatched on the roof survived almost
13 days. Compared to 4 days in the previous years, the survival period
increased by three times. This shows that the improvement in the species
composition and structure of the vegetation and the good weather conditions
(wet and humid) during the summer of 2007 produced a relatively high insect
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358 Nathalie Baumann and Friederike Kasten
Figure 18.5 In July 2008, students from our department classified the plants and
their cover percentage on the Rotkreuz roof during their environment analytics
project week (from Chr. Groeflin (2008) with permission).
biomass based on the assumption that the chicks were able to find food
sources elsewhere on the roof. However, because of the observation distance,
it was not possible to find out what they were eating. Autopsies of the stomach
content of chicks carried out by the Institute of Veterinary Bacteriology,
University of Zurich, failed to find any traces of insects in their guts. However,
the few corpses that were found were of 3- to 4-day-old chicks, which may
not have foraged but survived for a short time on the remains of the egg yolks.
It is impossible to draw conclusions from the autopsies because it is not clear
that the dead chicks starved to death. We assume that the other chicks, whose
bodies we could not find, were able to survive for 13 days because they found
some food.
An interesting observation was the use of the ponds by the adults and the
chicks. On land where chicks are rarely seen drinking at temporary pools or
small ponds they apparently need and use water on the roofs for drinking,
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Urban Habitats for Ground-Nesting Birds and Plants 359
for cooling and maybe for finding some invertebrates (for example, midge
larvae, Tubifex, etc.). This is a new parameter in our research considerations
and we hope to make more conclusive observations in 2009. There is little
data about the need for water, either on the ground or on roofs. Kooiker
(2000) mentioned that V. vanellus colonies have had a good breeding success
in habitats with no or only short vegetation and the absence of water bodies
such as small ponds, pools, ditches and damp mud surfaces.
The factors that control the survival of V. vanellus chicks and their relative
importance remain unknown. We assume that these factors are likely to
include weather conditions, limited vegetation cover and, therefore, a low
biomass of plants and invertebrates. The adult birds were observed wanting
to leave the roof the parent birds were seen flying up and down trying to
encourage the chicks to move to another more suitable foraging site, which is
impossible for them to do from a roof top. This behaviour is similar to ground
observations by Kooiker and Buckow (1997), who found that adult V. vanellus
with chicks change sites if the vegetation becomes too high and/or if there is
insufficient food.
V. vanellus are remarkably faithful to a breeding site; consequently, if they
start to breed on a flat , they will return despite being unsuccessful in rearing
the first and subsequent broods. Another important observation is that groups
of 15–25 birds use the Rotkreuz roof from June to September as a roosting
site on their migration south – it is the only roof site where we have seen this
behaviour.
Establishment of vegetation on the Rotkreuz roof
In summary, the techniques used are valuable in establishing or enhancing
grassland vegetation on roofs. There was no displacement despite strong
winds. The thickness of the turf or hay layer plays a determinant role in the
establishment of the vegetation. In addition, hay has a positive effect on
the development of vegetation, particularly during hot weather in springtime.
The transportation of hay to roofs is slightly complex, but not impossible
(Tausendpfund, 2008).
In 2008, after only two growing seasons of the improved habitats exercise,
90–100% plant cover had been established using the hay method, which is a
great success, considering the harsh conditions on a roof. Unfortunately, in
2007, April and May were dry and hot months; consequently about 90% of
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360 Nathalie Baumann and Friederike Kasten
the established vegetation dried out just at the time the birds were breeding
and the chicks hatching. As a result of the wet summer in 2007, the vegetation
recovered well and plant growth improved in 2008 with a good vegetation
biomass with some faunal food source (insects, spiders and other small
animals), which is particularly important for young precocial birds.
The usefulness of applying or establishing vegetation on roofs with fresh
or dry hay is not well known. In this process, grass is used together with
ripe seeds from surrounding areas in order to create a meadow-like roof.
It has been proved from use at ground level that this method offers a very
good alternative to the use of commercial seed mixes. The method is also
beneficial in providing a nucleus of invertebrate species, which is important
for the development of the roof-meadow as a natural habitat. The success of
the natural seeding mostly depends on the species, composition of the hay and
on the time when it was cut and applied. In addition, displacement of the hay
from the roof by the wind or even the reverse – the transfer, by wind, of seed
from the surrounding area onto the roof – may play a role in the composition
of the roof vegetation.
The fresh hay method appears to be a good method of establishing rooftop
vegetation. When applied on a layer of 34 cm thickness, the plant species
grow well. The mulch also acts as a humus basis, retaining water and providing
a habitat for insects, which is important on roofs in hot and dry season.
Because the trials only started in 2007, we are not yet able to present (in this
chapter) the comprehensive results of all the main areas of our research.
Perspectives: green roofs, a suitable breeding habitat?
It is not yet possible to determine whether a sustainable habitat can be created
on roofs using these new techniques or whether it is better to create and
manage new habitats on the ground. Nevertheless, it is important to create
and enhance habitats on the ground but it is not always possible to do so.
In such cases, grassland and other habitats can be created on extensive flat
roofs to compensate for or supplement habitats on the ground by providing,
amongst other things, opportunities for breeding areas for ground-nesting
birds. To do this will involve the development of further and better procedures
for the development of rooftop vegetation. In the following years, we intend
to examine many or all of these issues.
In summary, the improvements in the layout of the roof vegetation allow
us to respond rapidly to changing weather conditions, which is an influential
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Urban Habitats for Ground-Nesting Birds and Plants 361
parameter in determining the successful establishment of the plant and animal
biomass. The weather conditions from April to July 2008 were almost perfect.
We assume that more broods will be observed and that the chicks will survive
longer – at a new green roof site (not described in this chapter); three chicks
even fledged successfully. On the first day after the young birds had fledged,
we were only able to find one of the three – it was seen with its parents in an
agricultural field near the roof site. After 3 more days, we were unable to find
either the remaining young bird or the adult birds. We assume that the first
two of the three young birds were caught by a ground-living predator that
frequently hunts in peri-urban areas. The same fate may have been suffered
by the third young bird. However, none of the corpses of the three young
birds were found, consequently; it is equally plausible to assume that one or a
combination of the young birds flew away. With this ‘milestone’ we can prove,
for the first time, that sufficient food for the chicks of ground-nesting birds
can be provided in roof vegetation if the conditions on the roof are suitable
and good. That means that the vegetation and some areas on the roof can
store water and keep the substrate humid – we consider that this is the key,
finding enough substrate to enable invertebrates to undergo their life cycles at
an optimum rate. The roofs can be improved as breeding habitats for birds by
the creation of humid areas using irrigation during the summer months and
on dry, hot days in order to attract sufficient insects.
The 2009 season is likely to be interesting; as a result of the experiences and
observations during the previous years, we will be able to concentrate on and
give greater attention to the effects of the improvements on plant and animal
biomass and their impact on hatching of the eggs and survival of the chicks.
Acknowledgements
We are grateful to the Federal Office for the Environment (FOEN), to all the
different partners (substrate producers, companies, building owners, commu-
nity and canton offices, etc.), and private persons who joined, participated and
supported us in this project and made it possible for us to realize the project
successfully.
References
Baumann, N. (2006) Ground-nesting birds on green roofs in Switzerland: preliminary
observations. Urban Habitats, 4(1), 37–50, ISSN 1541 7115.
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Brenneisen, S. (2003) ¨
Okologisches Ausgleichspotenzial von extensiven Dachbegr¨
unun-
gen Bedeutung f¨
ur den Arten- und Naturschutz und die Stadtentwicklungsplanung.
Dissertation, Geographisches Institut, Universit¨
at Basel. Basel, Switzerland.
Clergeau, P., Croci, S., Jokim¨
aki, J., Kaisanlahit-Jokim¨
aki, M.-L. & Dinetti, M.
(2006) Avifauna homogenisation by urbanisation: analysis at different European
latitudes. Biological Conservation, 127, 336–344.
Dierschke, H. (1994) Pflanzensoziologie: Grundlagen und Methoden. Ulmer, Stuttgart.
K¨
ohler, M. (2006) Green roofs and biodiversity: long-term vegetation research on two
extensive green roofs in Berlin. Urban Habitats, 4(1), 3 –26, ISSN 1541-7115.
Kooiker, G. (2000) Kiebitzbrutpl¨
atze in Mitteleuropa: Entscheidungen in schwieriger
Situation. Der Falke, 47, 338–341.
Kooiker, G. & Buckow, C.V. (1997) Der Kiebitz: Flugk¨
unstler im Offen Land.Aula
Verlag, Wiesbaden.
Schweizerische Vogelwarte Sempach (2008) Species Profiles. http://www.vogelwarte.ch.
[retrieved 30 May 2008].
Tausendpfund, D. (2008) Dachbegr¨
unung mit Heumulchverfahren. G’plus, 11, 34 –35.
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Queries in Chapter 18
Q1. We have shortened the Running head. Please confirm if it is fine.
... Research on alternative green roof systems which have used deeper substrates, undulating topography, and a variety of vegetation ('biodiverse' roofs), has shown that even modest modifications to the 'standard' green roof design can result in a wider variety of species utilising a roof (Brenneisen 2006;Köhler 2006;Gong 2007;Kadas 2007;Baumann & Kasten 2010;Tonietto et al. 2010). Key to the success of these studies was the technique of incorporating biomimicry into the design of green roofs by incorporating habitat features typical of regionally important habitats for nature conservation. ...
... With an increasing body of evidence to suggest that green roofs are able to support broad biodiversity if designed appropriately (Brenneisen 2006;Köhler 2006;Gong 2007;Kadas 2007;Baumann & Kasten 2010;Tonietto et al. 2010) and increasing recognition that rich biodiversity in cities can have enormous potential to mitigate the effects of climate change making them more sustainable and resilient (Secretariat of the Convention on Biological Diversity 2012) why are the majority of green roofs still incorporating industrial standard sedum systems rather than biomimicry of typically regional habitat of conservation value? ...
Technical Report
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- Transitioning Towards Urban Resilience and Sustainability (TURAS) is an FP7 funded European-wide research and development programme with the aim of enabling European cities and their rural interfaces to build vitally-needed resilience in the face of significant sustainability challenges through Knowledge Transfer Partnerships. - The increasing proportion of people living in urban areas has led to a range of environmental issues and sustainability challenges. In order to ensure that urban living is sustainable and that cities have the resilience to cope with environmental change these challenges must be met. - Restoration and re-creation of green infrastructure in urban areas is a potential solution to many of these challenges and in high density urban areas with little usable space at ground level, roof level green infrastructure has perhaps the greatest potential to contribute to re-greening urban areas. - Given the increasing recognition that the natural environment can provide goods and services of benefit to humans and the planet (‘ecosystem services’), and that these services can provide resilience for urban areas, the European Commission is now advocating well-planned green infrastructure that provides opportunities to protect and enhance biodiversity. - In order to maximise biodiversity, and the associated ecosystem services, in urban areas it is necessary to incorporate local and regional environmental context into the design of urban green infrastructure. - Unfortunately, the majority of green roof installations in London, across Europe and beyond are ‘off-the-shelf’ industry standard systems predominantly designed for aesthetics and stormwater attenuation and an assumption is made that by installing something green a range of additional ecosystem services will be restored. - The resulting lack of plant diversity and habitat structure means that these green roof systems offer restricted biodiversity and associated ecosystem service benefits and mean that opportunities are missed for supporting urban biodiversity and building the associated resilience that biodiversity can provide. - In order to ensure that further opportunities are not missed, it is necessary to take a local view of key ecosystems and habitats and incorporate these into green roof design using biomimicry. - The following report details a Knowledge Transfer Partnership (KTP) established in Barking Riverside (London, UK) between Barking Riverside Ltd, the London Borough of Barking and Dagenham, Livingroofs.org, the University of East London and the Institute for Sustainability to establish whether there is a ‘cost’ associated with shifting away from industrial standard green roofs designed for SuDs towards more biodiverse systems designed based on regional habitat characteristics. - An investigation was carried out using trial green roof test systems to compare the effect on performance in terms of a number of ecosystem services of moving away from an industrial standard sedum system to a more biodiverse green roof system comprising wildflowers typical of the Barking Riverside development area and of value to regional biodiversity of national conservation importance. - Of the ecosystem service performances monitored, summarised results of water attenuation, thermal and biodiversity performance are included in the report. - Rather than demonstrating an ecosystem service cost associated with moving away from industrial standard systems, the biodiverse green roof systems performed as well as or superior to the equivalent sedum systems for water attenuation and thermal insulation and far out-performed the sedum systems in terms of supporting a diverse flora. - Results from the investigation are being fed into the design of green roofs throughout the Barking Riverside development. - It is hoped that this KTP will act as a blue print for use throughout the TURAS partnership and beyond to promote the use of biomimicry of regional habitat of conservation value in the design of green roofs to maximise urban biodiversity.
... Tüm bu akustik özellikleri ile yapı bünyelerindeki açık ve yeşil mekânların kentsel ortamdaki ses düzeyini önemli ölçüde düşürmeye katkıları olduğu tespit edilmiştir(Azkorra vd. 2014, Renterghem 2017.Yapı bünyelerindeki açık ve yeşil mekânların yukarıdaki tüm katkıları yerine getirirken sahip oldukları toprak hacimleri ile de bölge canlıları ve bitkileri için habitat oluşturdukları da ortaya çıkmıştır(Dunnett ve Kingsbury 2004, Monsma 2011, Baumann 2010, Kadas 2006, Grant 2006). Yukarıda özetlenen tüm araştırma verileri, kentleşme sonucunda yapılar ve sert yüzeyler ile kaplanmış olan hektarlarca büyüklükteki yeryüzü alanlarının, yukarıdaki tüm katkıları sağlayan yapı bünyelerindeki açık ve yeşil mekânlar ile bitkiler ve canlılara yeniden habitat durumuna gelmeye başlayabileceğini ortaya koymaktadır. ...
Thesis
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The aim of this thesis study is to propose a method that will set an example for all cities, and that will enable the multi-storey mass housing structures in the city of Ankara to be produced with living spaces more related to nature and to contribute positively to the existing urban environment. In order to achieve this aim, the historical process of the production of "housing" and "open and green spaces in buildings" in cities around the world and in Ankara has been examined in detail from technical and theoretical perspectives. Following this examination, the open and green spaces system in low-density city settlements was used as an example model, and a theoretical idea was developed to produce an open and green spaces system that could be included in the multi-storey mass housing buildings in the city of Ankara. The theoretical idea developed was applied on three multi-storey mass housing examples in Ankara, and the open and green spaces system proposal for multi-storey mass housing structures in the city of Ankara was revealed as a finding. Then, the system that emerged as a finding was examined and compared with the components that make up the open and green spaces system in low-density city settlements and selected examples in cities around the world. Subsequently, the changes that need to be made in the design method while the system in question was put into practice were revealed. As a final step, changes that need to be made in the field of legislation and policy proposals that need to be developed in order to put all these studies into practice were put forward. As a result, the effects of the emerged open and green spaces system on nature and people were evaluated. As a result of the evaluation, it has been observed that the system in question has revealed the potential to create positive effects on nature and people, which can be a turning point.
... gravel, sand mounds, dead wood) on the same roof (e.g. Baumann and Kasten 2010;Bates et al. 2013;Thuring and Grant 2016;Catalano 2017). In Switzerland, even natural soils of varying depth are used for green roofs larger than 500 m 2 (Brenneisen 2006). ...
Chapter
Green roofs can mitigate negative environmental effects of urban densification to some extent, but they are often covered by species-poor Sedum mixtures with a low value for biodiversity. By combining a habitat template and a seed-provenance approach, we review the suitability of plant species from regionally occurring dry sandy grasslands (Koelerio-Corynophoretea) for extensive roof greening in northwestern Germany. Since 2015, we have studied the effects of species introduction on vegetation dynamics on experimental mini-roofs. Treatments included sowing seeds of regional native origin in two densities (1 g and 2 g/m²) and the transfer of raked material from an ancient dry grassland area classified as Natura 2000 site. The applied raked material contained diaspores of 27 vascular plant species (including seven threatened species) and vegetative fragments of grassland-specific mosses and lichens. Since 2018, we have tested more species-rich seed mixtures in a large-scale experiment on a roof of 500 m² with different engineered green-roof substrates and layering. In 2019, a green roof of 10,200 m² was established in cooperation with a local enterprise to support regional native biodiversity. In this chapter, we summarise the most important results of our studies and discuss how to support regional native biodiversity on green roofs.
... Buffam, Mitchell, & Durtsche, 2016;Medlock & Vaux, 2014) to more than 20 years later (Guderyahn, Smithers, & Mims, 2016). Some GI are unmanaged and vegetation communities follow successional processes through time, such as an abandoned rooftop that over time is colonized by lichens, mosses and forbs (Baumann & Kasthen, 2010;Drake, Grimshaw-Surette, Heim, & Lundholm, 2018). Many of the surveyed GI types are relatively young (<10 years) and thus the effects on urban biodiversity may not yet be fully realized. ...
Article
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The development of buildings and other infrastructure in cities is viewed as a threat to local biodiversity and ecosystem functioning because natural habitat is replaced. However, there is momentum for implementing green infrastructure (GI), such as green roofs, wetland detention basins and community gardens, that partially offset these impacts and that benefit human health. GI is often designed to explicitly support ecosystem services, including implied benefits to biodiversity. The effects of GI on biodiversity have been rarely quantified, but research on this topic has increased exponentially in the last decade and a synthesis of the literature is needed. Here, we examined 1,883 published manuscripts and conducted a meta‐analysis on 33 studies that were relevant. We determined whether GI provides additional benefits to biodiversity over conventional infrastructure or natural counterparts. We also highlighted research gaps and identified opportunities to improve future applications. We determined that GI significantly improves biodiversity over conventional infrastructure equivalents, and that in some cases GI had comparable measures of biodiversity to natural counterparts. Many studies were omitted from these analyses because we found GI research has generally neglected conventional experimental design frameworks, including controls, replication or adequate sampling effort. Synthesis and applications. Our synthesis identified that taxa specificity is an important consideration for green infrastructure (GI) design relative to the more common measurements at the community level. We also identified that ignoring multi‐trophic interactions and landscape‐level patterns can limit our understanding of GI effects on biodiversity. We recommend further examination of species‐specific differences among infrastructures (i.e. green, conventional or natural equivalents) or using functional traits to improve the efficacy of GI implementation on urban biodiversity. Furthermore, we encourage policy makers and practitioners to improve the design of GI to benefit urban ecosystems because of the potential benefits for both humans and global biodiversity.
... In addition, they aid endangered species conservation (Brenneisen, 2005;Gedge & Kadas, 2005); (Kadas, 2010) and facilitate the movement of organisms by connecting to other urban landscapes (Braaker, Ghazoul, Obrist, & Moretti, 2014). Furthermore, design strategies to enhance the ecological value of green roofs have been discussed in experimental research investigating soil types and depth (Brenneisen, 2004;Dunnett, Nagase, & Hallam, 2008), and vegetation structure diversity (Baumann & Kasten, 2010;Gedge & Kadas, 2005;Köhler, 2006;Madre, Vergnes, Machon, & Clergeau, 2013). In short, viewed from the highly-urban context of Singapore where there is an abundance of roof-space, green roofs can be promising components of the enhancement of biodiversity in the city-state. ...
Article
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While much of the land in Singapore has been urbanized, green roofs have the potential to be part of an urban ecosystem where limited human interference can promote natural processes. This study observes the establishment of flora and fauna communities on two newly installed green roofs using a mix of seeding, transplantation and spontaneous colonization installation methods and operating under minimal management over a period of 16 months. Recorded here are plant compositions and spatial distributions of flora growth of 64 species over this period. The minimally managed green roofs in this study possess increased plant species richness, highlighting a way to enhance urban diversity in a tropical city.
... One such benefit is their potential to restore biodiversity in urban landscapes (Gedge, 2001;Grant et al., 2003;Sadler et al., 2011;Ishimatsu and Ito, 2013;Madre et al., 2014). There is an increasing body of evidence demonstrating that green roofs are able to support high biodiversity if designed appropriately (Brenneisen, 2006;Kadas, 2007;Baumann and Kasten, 2010;Tonietto et al., 2011) and increasing recognition that rich biodiversity in cities can have enormous potential to mitigate the effects of climate change through the enhancement of urban resilience and sustainability (Niemelä, 2014). ...
... The species requires gravelly areas with sparse vegetation for food resources, and colonized many derelict sites with spontaneous vegetation after World War Two. Redevelopment of London is rendering this habitat type rare, but these can be recreated on "biodiverse" or rubble roofs (Baumann & Kasten 2010). Rubble roofs create the right conditions for the bird but also exhibit spontaneous dynamics in the plant community, which, while usually seeded initially with wild flower mixes (Kadas 2006), develops an appearance characteristic of ground-level urban wildlands in contrast to more typical succulentdominated green roofs (Kadas 2006). ...
Article
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Green roofs and other constructed environments represent novel ecosystems, yet have potential to contribute to biodiversity conservation goals. Constructed ecosystems are intentionally managed to produce specific services, and thus could be viewed as highly artificial or controlled. Yet all constructed ecosystems exhibit spontaneous dynamics, as community structure changes due to internal or external ecological processes. While all green roofs have some element of design and human control over ecological trajectories, the level of ongoing management can vary greatly. I discuss “wildness” as a characteristic of green roofs in response to their spontaneous dynamics after initial setup, and their potential to provide ecosystem services related to human psychological well-being, aesthetics and habitat for biodiversity. This approach suggests new design possibilities in interaction with spontaneous ecosystem dynamics and highlights a need for greater ecological understanding of green roof systems.
... While some green roofs have been colonized by rare plant species (Madre et al. 2014), this claim relates primarily to rare fauna. Some green roofs in England and Switzerland have been designed to mimic the open rocky nesting habitats for rare birds such as black redstart Phoenicurus ochruros Gmelin and Northern lapwing Vanellus vanellus Linnaeus (Baumann & Kasten 2010). Green roofs have also been designed to support rare lizards (Earth Pledge 2005). ...
Conference Paper
Background/Question/Methods Greens roofs are often promoted as novel habitats that can be used to increase the biodiversity of cities, particularly in dense urban cores. Many regulatory standards or certification programs for buildings now incorporate green roofs for their biodiversity value. However, the success of green roofs designed for biodiversity has rarely been evaluated and the claims of positive biodiversity outcomes could sometimes be criticised as a ‘green wash’ applied by building developers and architects. Using the scientific literature, books detailing green roof projects and published conference proceedings, we reviewed and quantified the ecological motivations cited by green roof projects that aim to increase biodiversity. Results/Conclusions The most frequent was ecological restoration or creation of habitat but provision of habitat for rare species and pollinators, ecological compensation for habitat destroyed at ground level and the development of ecological corridors or linkages were also cited. The validity of these motivations are critically reviewed against current ecological theory and evidence from urban ecology studies. Green roofs can be used to increase urban biodiversity but to do so current green roof industry practices and designs must change.
Article
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Bu makalede, günümüz koşularında sahip olduğumuz bilgilerin ışığında, yapı bünyelerinde üretilebilecek olan açık ve yeşil mekânların yapılma gerekliliği ile ilgili bir durum değerlendirmesi yapılmıştır. Değerlendirme, literatür taraması ile ulaşılan aşağıda özetlenmiş olan verilerin karşılaştırılması ve tartışılması ile yapılmıştır. Yapı bünyelerindeki açık ve yeşil mekânların bir yandan kentleşme ile zarar görmüş doğanın yeniden üretilmesi konusunda önemli katkılar oluştururken, diğer yandan da kentlilerin sağlıkları ve refahları ile yapı zarfının performansı üzerinde olumlu etkiler oluşturdukları görülmüştür. Tüm bu olumlu etkilerinin yanında yapı bünyelerindeki açık ve yeşil mekânların yapılarda ilave yükler ve daha karmaşık tasarım ve uygulama süreçleri ortaya çıkardıkları da görülmüştür. Yapı bünyelerinde üretilebilecek olan açık ve yeşil mekânların ortaya çıkardığı olumsuzlukların temelde bilgi eksiklikleri ve maliyet artışlarından kaynaklandığı görülmüştür. Bilgi eksikliklerinin eğitim çalışmaları ile tamamlanabileceği, maliyet artışlarının ise kentlilerin sağlıkları ve refahlarındaki artışlar ile telafi edilebileceği görülmüştür. Değerlendirmenin sonucu olarak özellikle yoğun yapılaşmış kentsel bölgelerdeki yapı bünyelerinde açık ve yeşil mekânların üretilmesi gerekliliği ortaya çıkmıştır.
Article
Green roofs are known to mitigate the negative effects of urban consolidation by offering diverse ecosystem functions compared to non-vegetated roofs. However, the support for native biodiversity might be improved by using native plant species. In a mesocosm experiment, we studied the suitability of three commercial green-roof growth substrates for the establishment of 27 native plant species from the dry sandy grasslands of northwestern Germany over the course of four years. The substrates were mineral-based, but differed in the layering of organic matter. Total establishment rates reached 44–59% in Year 4, indicating the general suitability of the substrates. During the first weeks after seeding, with light irrigation, the vascular plant cover was greater in the similar substrates Zincolit® Plus (Z) and Zincolit® Plus-Leicht (ZL) with their compost-based organic mulch layers than in the substrate Sedumteppich (ST) with its organic matter evenly admixed with the mineral aggregates. In Years 2 and 3, however, the vascular plant cover was greater in the ST substrate, likely due to the better availability of water and nutrients from the organic matter compared to the dry surface-mulch layer variants Z and ZL. After severe drought events, there was a decline in plant cover that was more pronounced in the ST substrate, likely representing a trade-off between lush growth and a susceptibility to drought. An indicator-species analysis revealed differences in species composition between the ST and Z/ZL substrates. Annual plant species were indicators of the ST substrate. Perennials, such as Thymus pulegioides and Achillea millefolium, were typical of the Z and ZL substrates. In addition to the general suitability of the tested standard substrates for target species establishment, the study indicated that a combination of different layers of substrate components resulted in different vegetation patterns that may have a positive effect on green-roof biodiversity.
Article
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In this paper, I evaluated the long-term vegetation dynamics of two extensive green roof (EGR) installations in Berlin. The first, installed on two inner-city residential buildings in 1985, consisted of 10 sections ("sub-roofs") with a combined area of 650 square meters. The 10 sub-roofs differed in exposure and slope. Ten plant species were initially sown on the sub-roofs. Observations were made twice yearly (with a few exceptions) from 1985 to 2005. Altogether, 110 species were observed over the 20-year time period; however, only about 10 to 15 of these were dominant over the long term and could be considered typical EGR flora in Berlin. Allium schoenoprasum was the dominant plant species over the entire time period on all sub-roofs. Festuca ovina, Poa compressa, and Bromus tectorum were also typically present over the course of the study. Statistical tests revealed that weather-related factors such as temperature and rainfall distribution were the most important factors affecting floral diversity. The size, slope, and age of the sub-roofs had no significant statistical influence on plant species richness. This EGR installation was virtually free of technical problems after 20 years. The success of this low-maintenance green roof is a good argument for greater extension of green roof technology in urban areas. The EGR of the second study was installed in 1986, but investigation of the flora only began in 1992. Observations were again made twice yearly until 2005. The six roofs studied were on top of a cultural center located in a park area in the Berlin suburbs, and they were irrigated during the first few years to support plant establishment. These EGRs had a higher degree of species richness than the inner-city ones. These early German projects in urban ecology demonstrate that relatively diverse EGRs are possible on city buildings. They also show that species richness can be increased with a minimal amount of irrigation and maintenance. And they suggest that enhanced initial plantings, the creation of microclimates (shaded and sunny areas), and the presence of surrounding vegetation also increase plant diversity.
Article
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Bird species in Switzerland are threatened by habitat loss and fragmentation due to increasing urbanization. New research is showing that green roofs can provide food habitat for some bird species. But little research has been done on the potential of green roofs for providing nesting locations for birds, particularly ground-nesting species. This preliminary two-year study (part of a larger, multiyear project) examined the breeding success of the little ringed plover (Charadrius dubius) and northern lapwing (Vanellus vanellus) on flat green roofs in five sites in Switzerland surrounded by varied levels of development. Results show that northern lapwings have begun to breed consistently, though as of yet unsuccessfully, on some green roofs. Because the observation time was short, the available data are incomplete. Nonetheless, they show certain tendencies with regard to the habitat selection and behavior of young and adult birds—important information that can be applied to future research and green roof design.
Okologisches Ausgleichspotenzial von extensiven Dachbegrünungen-Bedeutung für den Arten-und Naturschutz und die Stadtentwicklungsplanung
  • S Brenneisen
Brenneisen, S. (2003) ¨ Okologisches Ausgleichspotenzial von extensiven Dachbegrünungen-Bedeutung für den Arten-und Naturschutz und die Stadtentwicklungsplanung.
Kiebitzbrutplätze in Mitteleuropa: Entscheidungen in schwieriger Situation
  • G Kooiker
Kooiker, G. (2000) Kiebitzbrutplätze in Mitteleuropa: Entscheidungen in schwieriger Situation. Der Falke, 47, 338-341.
Der Kiebitz: Flugkünstler im Offen Land
  • G Kooiker
  • C V Buckow
Kooiker, G. & Buckow, C.V. (1997) Der Kiebitz: Flugkünstler im Offen Land. Aula Verlag, Wiesbaden.
Dachbegrünung mit Heumulchverfahren. G'plus
  • D Tausendpfund
Tausendpfund, D. (2008) Dachbegrünung mit Heumulchverfahren. G'plus, 11, 34-35.