Integrating biodiversity in urban planning

Abstract

The scientific literature on the subject of urban biodiversity is sparse, but as a result of the Rio conference and the subsequent pressure on local governments to establish Agenda 21 programmes, it nevertheless has to be taken into account. This raises the question as to whether the tools that urban planners have at their disposal are sufficient and, if not, what the potential consequences of biodiversity integrated into the urban planning process might be. In some cases there is a danger that integration could actually counteract its purpose, for example, when planners in different municipalities take the same routine measures to enhance local biodiversity, thereby decreasing biodiversity on a regional scale. This risk increases with the growing tendency to regard biodiversity purely as a quantity, disregarding local qualities because species numbers are not high enough. To avoid the risk of a special "planner's biodiversity" as a result of temporary trends in biodiversity policy, there might be cases when certain aspects of biodiversity should be left out of the plans as an attempt to preserve some unique urban habitats which normally appear as a result of "non-planning". A recurring phenomenon is the use of only partly tested ecological theories, for example, the theory of island biogeography, as if they were absolute truths. This is close to gambling and may lead to unpredictable consequences in the future. These and other issues regarding urban biodiversity and planning in a theoretical perspective are discussed in this paper. It is concluded that a regional perspective is crucial when dealing with biodiversity locally.

 

Background

As stated by Margerum (1997): "Integrated approaches are emerging as the new paradigm in environmental planning and management." Considering that biological diversity (or biodiversity) has been on everybody's lips since the Convention on Biological Diversity was signed in 1992 (UNEP, 1992), an attempt to argue in favour of biodiversity integrated in environmental planning of different kinds - including urban planning - is not particularly controversial, especially as it is expressly stated as a directive in the convention. There are, of course, positive and negative sides to such an approach. The purpose of this paper is to discuss urban biodiversity planning in general and to identify some of the factors that must be considered when integrating biodiversity in the process of planning urban environments, with particular emphasis on Sweden.

 

Biodiversity

The major problem with biodiversity in general is that most people interpret the concept differently, which of course is due to the lack of substance in the "official" definition as written in the Convention texts. It is far too vague and generalised to be of any practical use in a planning situation: "Biological diversity means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems." In short, life on Earth. Theoretically the biodiversity of a certain area would be the number of genes (or rather, alleles) present, since all other levels depend on this. For all practical purposes, however, such a definition is impossible. You rarely have the means to go below the species level, and very often (on a larger scale) you have to contend with the ecosystem level. So it is never possible actually to measure biodiversity directly, especially since some organism groups are never or rarely included in investigations, for example, bacteria, protists, algae, most fungi, etc (Embley et al., 1994; O'Donnell et al., 1994; Hugenholtz and Pace, 1996; Staley, 1997). This may be one of the reasons why biodiversity is never said to have "changed" until some really major, preferably visible, change has occurred.

Nothing is said about the temporal aspect of biodiversity in the Convention text. Again, there is a theoretical momentary biodiversity, i.e. the biodiversity during an infinitesimal interlude. For practical reasons, biodiversity is always integrated over a period of time: a year, a decade or a few decades, even though this is rarely expressed explicitly. Peck (1998) states that "… to fully describe biodiversity, information over a period of time is necessary." In this case, ecological processes are included in the definition of biodiversity, which is another example of making the concept more difficult to grasp.

The Convention aims at conserving biodiversity, which is even more problematic, since biodiversity (no matter how it is defined or interpreted) is the result of ecological processes, with or without human intervention. Thus, to conserve biodiversity in a certain area, you must also conserve the ecological processes - with the same degree of human intervention - which have produced the desired "amount" or "quality" of biodiversity.

 

Urban biodiversity

Most people interpret biodiversity intuitively, as vaguely connected with rare species and visual variation and the amount of vegetation, i.e. a cultural concept where experience, emotions, education, and cultural background are some of the major factors. A common notion is that biodiversity is something you have outside the city boundaries, whereas "green open space", "parks", "gardens" etc. (i.e. structural or cultural concepts where biodiversity is not considered relevant) are found within. This is also reflected in different planning strategies: in rural areas biodiversity is treated as an important factor in nature conservation, whereas in urban areas it is often merely treated as an aspect of conserved "nature fragments" or newly created "wildlife" areas. Biodiversity is rarely mentioned in connection with traditional green areas such as parks, gardens etc. This is a natural side effect of the emphasis on conservation in the convention on biological diversity, since both by tradition and necessity conservation concentrates on endangered species in their natural habitats.

This is, however, an artificial and arbitrary way of regarding urban biodiversity. It could be argued that even the most cultural areas contain animal life that may be worth preserving (Wiren, 1994; Wiren, 1994). Furthermore, it could be argued that many of the introduced species should be incorporated in the local flora, especially in urban areas, and especially since a great deal of the domesticated plants have a long history in the country or region (Jansson and Lorentzon, 1996; Persson et al., 1998) and may have become genetically unique. In short, some domesticated species may well fit into the "red lists". This has to do with the fact that the boundary between nature and culture is relative and different for each individual (Larsen, 1992).

The extreme would be to regard all urban environments as no different from any other environments and to regard all species, no matter their origin, as equal. This should appeal to theoretical ecologists, since built-up areas could be regarded as colonies of human beings living in symbiosis with other organisms and introducing species simply another way for them to be dispersed. There is, however, a strong emphasis on conservation in most matters regarding biodiversity, so in general, certain species are regarded as "worth" more than others, for example, because they are rare or because they have an important function in the ecosystem (Harper and Hawksworth, 1994). There could also be historical or cultural reasons for preferring some species at other species' expense.

 

Estimating biodiversity

Hawksworth (1995) presents an ambitious set of measurement methods, along with a thorough discussion on measurements and estimations of biodiversity. They are, however, aimed at researchers in ecology or taxonomy and not particularly well suited for planning purposes. Methods directly aimed at urban biodiversity planning usually focus on the ecosystem (or biotope/habitat), since you can get quick results for rather large areas that way (Sukopp and Weiler, 1988; Gyllin and Hammer, 1997; Frey, 1998; Löfvenhaft and Ihse, 1998; Müller, 1998; Weber and Bedê, 1998). A problem with such an approach is that biotopes (however they are defined) need to be calibrated with regardto the composition of species, to make investigations comparable and informative. Without such a calibration, results rely too much on documented knowledge about biotope types. Such knowledge about urban biotopes is very limited, which leaves prejudice and downright guessing as very unsatisfactory solutions.

Investigating the composition of species is, however, time-consuming and difficult and is perhaps not always worth the effort. A way of at least estimating the biodiversity structure of an area would be to use functional groups of organisms instead of species (Körner, 1993; Lavorel et al., 1998; Pausas, 1999; Walker et al., 1999). It has been suggested (Körner, 1993) that carefully selected functional groups can be even more informative than species. Unfortunately there are as yet no fully developed methods available.

 

Planning urban biodiversity

One of the problems with biodiversity is its dependence on scale which is also connected with the question as to whether biodiversity is a "quantity" or a "quality". If it were interpreted as simply quantity, you would get the absurd effect that you could increase the biodiversity on a local scale, while actually decreasing it on a regional scale. This would be achieved simply by exchanging a rare, but poor, habitat for a richer, but more common habitat. The local biodiversity would increase, since you get more species, but the regional biodiversity would decrease, since you have lost a rare habitat and possibly some rare species along with it. The conclusion of this must be that although the Biodiversity Convention text implies that biodiversity is a quantitative, measurable variable, the spirit of this Convention implies a more qualitative approach. Thus, in a planning situation, you must choose which interpretation of "biodiversity" to favour - not necessarily the one that yields the highest scores of species richness. If all local planners were to carry the purely quantitative approach to its extreme (perhaps in an attempt to score points for their respective local Agenda 21 programmes), the result would be something of a "Tragedy of the Commons" (Hardin, 1997), i.e. the benefits for the local biodiversity would be devastating for the regional biodiversity. Of course, this may be a purely academic problem, but it should nevertheless be considered, since some local planners at least never go beyond the administrative borders of their authority. There is a danger that temporary trends in policy on biodiversity could encourage planners to establish an artificial "planner's biodiversity", with little concern for the existing and seemingly "trivial" local biodiversity.

There are a number of problems concerning communication between planners and researchers, which is understandable since planners need absolute answers and practical tools to aid them in the planning process, whereas researchers never provide absolute answers and both theory and practical instruments are in a state of constant change. Planners also tend to be conservative about the tools they actually use, since they need them on a long-term basis or perhaps even into the distant future: the time elapsing between initiation and implementation of a plan might be considerable. There is a danger that such an approach produces unwanted results, since planners often have to rely on proposed methods that have never been tested in a practical situation. The most obvious example is the common recommendation to use methods based on the theory of island biogeography (MacArthur and Wilson, 1967), a practice that has been subjected to a great deal of criticism over the last decades (Gilbert, 1980; Janzen, 1983; Simberloff et al., 1992; Beier and Noss, 1998). Despite this, such recommendations are still made rather frequently (cf. Linehan et al., 1995; Umeå kommun, 1998; Jonsson et al., 1999), which means that delicate local conditions demanding perceptive handling may be overruled by standardised recommendations about the form and size of patches of land.

 

Integrating biodiversity in urban planning

As stated earlier, one of the aims with the convention of biological diversity is to integrate biodiversity in the planning process. Although urban environments are not the main issue in this convention, they are nevertheless included. Integrating biodiversity into the urban planning process could be beneficial in many ways, but there are certain traps to be avoided. The risk associated with standardised approaches and a mechanical way of thinking may be high. This could increase the development of a "planner's biodiversity" as mentioned above, as well as the use of "unproven" ecological models.

On the other hand, a constant awareness of the "green dimension" of urban environments at all stages of the planning process and a smoother handling of biodiversity matters is also likely to develop. Instead of creating "flashy" biodiversity project areas, the entire city would be a "biodiversity area", perhaps more discreet, but also more useful to most people. Integration could also counteract the tendency towards a "planner's biodiversity" through the close connection between biodiversity and cultural, historical and other aspects, so encouraging planners in biodiversity to adopt a more natural and adapted perspective.

Another aspect of planning urban biodiversity is the value placed on "non-planned" elements, i.e. objects that are often the most highly regarded by conservationists, such as abandoned industries, parts of parking lots, edge zones etc. Such areas often display a strange mix of species, either ephemeral or specific to a very limited area. When biodiversity is fully integrated into the relevant urban planning processes, an awareness of such areas could actually threaten them through misguided attempts to "improve" them. This can be seen as a parallel to preferred playground areas for children, i.e. the difference between areas that children prefer, and areas that planners think they prefer. Perhaps such areas should remain "non-planned", for children as well as for local biodiversity and thus be deliberately excluded from integration into the planning process.

 

Concluding remarks

Some of the suggestions and discussion in this paper are highly theoretical and should not be regarded as serious warnings, but merely as a basis for further discussion. Experience in Swedish local planning makes it clear that a regional perspective when dealing with local biodiversity is absolutely crucial and that tactical, rather than strategic, considerations govern much of the present decision-making concerning Swedish urban biodiversity. Full integration into the urban planning process could be one way of improving urban biodiversity planning and counteract some of the potential problems, bearing in mind that some aspects would perhaps be better off if they were left out of those plans and that local conditions (with a regional perspective) in most cases should outweigh the use of "unproven" theoretical models that need much more research before being operational. Of course, the use of corridors is certainly worth the effort in many cases, but the crucial point is that this should be decided for each individual case after careful consideration and their usefulness should not be taken for granted.

 

References

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Embley, T. M., Hirt, R. P., Williams, D. M., 1994. Biodiversity at the molecular level: The domains, kingdoms and phyla of life. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 345, 21-33.

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This paper will appear elsewhere in full during 2000 - contact author

Integrating biodiversity in urban planning
Mats Gyllin
Department of Landscape Planning, Alnarp, Swedish University of Agricultural Sciences

Communication in
Urban Planning

Göteborg Conference Papers - Oct 1999
 

Workshops for Environmental Innovations (Eijk et al)

Communication and Urban Green (Lindholm)

Integrating Biodiversity (Gyllin)

User participation in Public Park Administration (Delshammer)

Making Outdoor Places for Children (Kylin)

The Home Street (Staffans)

Identification of ecological potentials (Guldager et al)

Evaluation and Dialogue (Sager)

A Communicative Planning Methodology (Stromberg)

Rationality Revisited (Lapintie)

Planning deconstructed and rebuilt as discourse analyses
(Orrskog)

 

"Whereof one cannot speak, thereof one must be silent"
(Birgersson)

 
Background

Biodiversity

Urban biodiversity

Estimating biodiversity

Planning urban biodiversity

Integrating biodiversity

Conclusion

References

CLICK A SECTION

 
Background

Biodiversity

Urban biodiversity

Estimating biodiversity

Planning urban biodiversity

Integrating biodiversity

Conclusion

References

CLICK A SECTION

Menu of Conference Papers

 

 
Background

Biodiversity

Urban biodiversity

Estimating biodiversity

Planning urban biodiversity

Integrating biodiversity

Conclusion

References

CLICK A SECTION

Menu of Conference Papers

 

 
Background

Biodiversity

Urban biodiversity

Estimating biodiversity

Planning urban biodiversity

Integrating biodiversity

Conclusion

References

CLICK A SECTION

Menu of Conference Papers

 

Background

Biodiversity

Urban biodiversity

Estimating biodiversity

Planning urban biodiversity

Integrating biodiversity

Conclusion

References

CLICK A SECTION
Menu of Conference Papers

 

Menu of Conference Papers

 

European Research Network - Urban density and Green Structure

Proceedings of the Gothenburg Conference:
Communication in Urban Planning - Oct 1999

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