© Copyright 2000 by the Massachusetts Institute of Technologyand Yale University

Volume 3, Number 2 & 3

❙ I N D U S T R I A L E C O S YS T E M S A N D E C O - I N D U S T R I A L P A R K S

Journal of Industrial Ecology 11

Famously, industrial ecologists look to biologi-cal ecosystems as analogies or metaphors in

the study of production and consumption. A keydeterminant of natural or indigenous ecosystemsthat has garnered increasing attention at local andinternational levels is that of biodiversity. Interest-ingly this characteristic has not attracted as muchattention in the study of industrial ecosystems.

Some ecologists argue that it is the diversenature of an ecosystem which is central to itssustainability. This diversity enables some redun-dancy in function, which, in turn, supports thestability and resilience of thesystem. Other ecologists con-tend that the more importantfeature is interconnectedness,that is, the number of connec-tions between diverse popula-tions of species. The hypothesisis that the more connectionswhich exist, the more stableand resilient an ecosystem islikely to be.

The waste exchanges in themuch discussed industrial symbiosis inKalundborg, Denmark are relatively limited innature and small in number. Yet, even so, thereis some evidence that the connections have posi-tively influenced the socio-economic stability ofthe town and its industries, improved the effi-ciency of some material use and enhanced envi-ronmental quality. And, although Kalundborg’s

symbiotic relationships began emerging twenty-five years ago, it continues to evolve.

In Kalundborg, many of the connections oc-cur primarily at a few key levels of the “foodweb” normally seen in an ecosystem. These lev-els include those of producers and consumers, inwhich the Asnaes Power Station might beviewed as a producer—generating steam, wasteheat, gypsum, and fly ash—and the other indus-tries are primary and secondary consumers. Inbiological systems, materials are cycled by acomplex web of species that includes not only

producers and consumers, butalso scavengers and decompos-ers. The latter are critical tothe cycling of elements andcompounds that are the build-ing blocks for species at otherlevels in the web. Scavengersand decomposers occur innatural ecosystems as thou-sands, if not millions, of spe-cies. Some of these are larger,such as crows and crabs, but

many of these are small bacterial and fungal spe-cies, somewhat analogous to the small businessesin the industrial system.

Arguably, an eco-industrial park should bemore than material exchanges or symbioses in-volving only the large-volume materials and thelarge industries in a spatially defined area. Thereare thousands of materials that flow through anindustrial park which eventually become prod-ucts and wastes. Some of the products are usedin neighboring communities and then becomewaste. In Kalundborg, only a few materials are

Exploring the AnalogyFurtherRaymond P. CôtéSchool for Resource and Environmental StudiesDalhousie UniversityHalifax, Nova Scotia, Canada

Scavengers and decompos-ers—that is, more “biodiver-sity”—could increase thecycling [in industrial ecosys-tems] of other materials thatmay be available and valu-able in smaller quantities.

❙ I N D U S T R I A L E C O S YS T E M S A N D E C O - I N D U S T R I A L P A R K S

12 Journal of Industr ial Ecology

the subject of symbioses among the larger indus-tries. Scavengers and decomposers—that is,more “biodiversity”—could increase the cyclingof other materials that may be available andvaluable in smaller quantities. In Kalundborg weare beginning to see the addition of new “spe-cies” that perform these functions. A new com-pany, A/S Bioteknisk Jodrens, has recentlymigrated into the area.

A variety of niches can be filled, includingbusinesses that reuse, refurbish, repair, rent,remanufacture, and recycle, which would increasethe connectedness in Kalundborg and elsewhere.In industrial terms, these niches are likely to befilled by small and medium-sized businesses. InBurnside Industrial Park, Dartmouth, Nova Scotia,approximately 12% of the 1,300 businesses per-form these functions and assist in cycling materialswithin the park and the neighboring community.

If the analogy holds, the addition of thesefunctions—whether seen as increasing diversity

or interconnectedness or both—should enhancethe resiliency and the stability of bothKalundborg and Burnside. From a socio-eco-nomic perspective, employment will be createdand maintained, and from an ecological point ofview, these activities will reduce the amount ofmaterials discharged into the water, soil, and air.Rapid changes in the economic structure of anindustrial park, such as the loss of an anchor in-dustry or loss of critical functions, will cause so-cial upheaval and may, in turn, have ecologicalimplications. Networking among businesses willenhance the stability of the park and some re-dundancy will foster a more resilient ecosystem.

Address correspondence to:Prof. Raymond CôtéSchool for Resource and Environmental StudiesDalhousie UniversityHalifax, Nova Scotia Canadarcote@IS.Dal.ca