Characterizing biodiversity in urban areas using remote sensing - Urban Remote Sensing: Monitoring, Synthesis and Modeling in the Urban Environment - page 281

20.5 Long-termmonitoring
of biodiversity in urban
green areas - methodology
development

biodiversity in urban areas and also the value of urban green
spaces for human recreation (Grahn and Stigsdotter, 2010) and
well-being (Fuller et al ., 2007). Thus, urban green areas and their
biodiversity are included in the Swedish Environmental Quality
Objectives (Governmental bill to Parliament, Prop. 2009/10:155).
The NILS methodology, based on hierarchical structure (see
Fig. 20.3), has been used as a model for the development for a
specific urban monitoring program called NILS Urban (National
Inventory of Landscape in Swedish urban areas, Fig. 20.3, Hed-
blom and Gyllin, 2009). A questionnaire was sent out by the
NILS Urban program to municipalities and governmental orga-
nizations asking what data could be important with respect to
the urban landscape; the responses revealed a great interest in
biodiversity-related topics such as long-termdata on urban green
habitats, species richness and fragmentation changes. Interest-
ingly, information about human requirements for urban green
areas was particularly emphasized (Hedblom and Gyllin, 2009).
Apparently, monitoring urban data relating to green areas have
many potential users, more than in, for example, forested and
agricultural areas, where one parcel of land could have one or
a few owners and users; urban areas might, therefore, be more
complex to monitor. The method developed for NILS Urban
illustrated some constraints and possibilities associated with an
urban monitoring program.
NILS Urban suggests a hierarchical level including remote
sensing and field inventories (Fig. 20.3). Froma national perspec-
tive, the previous method used in NILS with random 5 × 5km
landscape squares within cities would be enough to highlight
spatial-temporal differences. However, from a local (municipal)
perspective, it is of greater interest to cover the whole urban land-
scape in order to get detailed data relating to urban condensation
(infill development) and urban sprawl, to provide local planners
with information. However, to interpret aerial pictures manually
over large urban areas, for example, the city of Stockholm cover-
ing 400 km 2 , would be costly and time consuming. It is, therefore,
more cost-effective to use satellite images with automated inter-
pretation but lower resolution (see Fig. 20.3). Statistics Sweden
(2008) used the satellite SPOT 5 with a 10 m resolution and
automated interpreation of urban green areas, while NILS uses
manually interpreted infrared aerial photographs with a ground
resolution between 0.5 and 1.5 m (Allard et al ., 2003). Thus,
using manual interpretation is advantagous since it allows special
focusonfeaturessuchasvulnerablebiodiversityhotspots,for
example small ponds.
Although not yet used in monitoring, a different kind of
remote sensor data source could providemeasurements of species
movements from space. These possibilities are provided by the
ARGOS satellite tracking system, using relatively small transmit-
ters for studying larger animals, including mammals and reptiles.
For smaller animals (less than

A long term goal of urban ecology should be to uncover the
factors regulating the success or failure of species in inhab-
ited areas and use these factors to develop principles for the
design of urban landscapes compatible with nature (Turner,
2003). In order to reveal why species richness and abundance
fluctuate in urban ecosystems long-term data relating to species
abundance, habitat quality andhabitat quantity are needed. Long-
term data could provide valuable information not only about the
condition of single species, large ecosystems and the general
environment but also indirect effects on humans such as through
ecosystem services. A number of existing monitoring programs
are biodiversity-oriented, although most of them started fairly
recently. One of the programs that has been operational for
a long time is the British Countryside Survey (Haines-Young
et al ., 2003; Barr et al ., 2003). Monitoring programs have demon-
strated a decrease in many species of farmland birds in Europe
due to the intensification of agriculture (Wretenberg et al ., 2006).
This in turn has led to a demand that the EU needs to intro-
duce policies to protect or enhance bird diversity in agricultural
areas (Vickery, 2001; Pan European Common Bird Monitoring
Scheme, 2007). In Europe alone, historical photographs reveal
that urbanization has been the predominant agent of land cover
change since 1950 (Mucher, 2009). This process probably affects
both species richness and habitat quality. However, to date, no
national biodiversity monitoring program for urban green areas
exists.
National monitoring programs covering certain habitats have
existed for a long time, for example the Swedish forest moni-
toring program that began in 1923 (Fransson, 2009). In Europe
a coordinated program (EBONE) for monitoring biodiversity at
the national, region and European levels is under development
(Jongman et al ., 2006). In Sweden a nationwide environmental
protection program called NILS (National Inventory of Land-
scape in Sweden) has monitored the conditions and changes
in the landscape and recorded how these changes influence the
conditions for biodiversity since 2003 (Stahl et al ., 2010). The
program is founded by the Swedish Environmental Protection
Agency and is supposed to conduct data from year 2003 into
an indefinite future. The NILS program uses both remote sens-
ing and field studies and covers approximately 600 landscape
squares (5 5 km) that are randomly scattered (stratified in

certain regions) all over Sweden. Every fifth year an aerial pic-
ture is taken and field studies are conducted (see Stahl et al .,
2010 for details). The aerial pictures are manually interpreted
(see Fig. 20.3). However, despite this recent increase in moni-
toring programs covering whole landscapes and regions, only a
tiny proportion of the urban landscapes is included (Hedblom
and Gyllin, 2009). This small proportion of urban cover is not
enough to provide decision makers or urban planners with infor-
mation about the effects of fragmentation on biodiversity, not
even in a national context (Hedblom and Gyllin, 2009). There
is an increased awareness of the effects of fragmentation on

×

300 g), Wikelski et al . (2007)
proposed a small-animal satellite tracking system that would
enable the global monitoring of animals down to the size of the
smallest birds, mammals, marine life and eventually large insects.
The technique would utilize satellite-mounted radio-receivers for
tracking radio-tags weighing less than 1 g. This type of technique
will provide important new data that will allow quantitative
assessment of dispersal and migration and has the potential to
provide new insights into population dynamics and persistence.
This technique has great potential for analyzing how species use
the urban landscape.

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