Challenges in adaptive management of riparian coastal ecosystems

Adaptive management is the attractive notion that we can learn about natural systems as we manage them. Carl Walters succinctly calls adaptive management "learning by doing". More specifically, he describes adaptive management as "a concerted effort to integrate existing interdisciplinary experience and scientific information into dynamic models that attempt to make predictions about the impacts of policy alternatives."

I can't address all issues Walters raises in the article, but there are definately a few worth highlighting. When Walters introduced the article talking about the importance of creating accurate ecological models, I expected him to laud this approach for answering important management questions. I was surprised then, when Walters pointed out several weaknesses in ecosystem modeling. In fact, he argued that there is too much modeling and not enough field experimentation. Walters laments that few of the adaptive-management planning processes have moved beyond the modeling stage to the field experimentation. He suggests that a disproportiante amount of energy has been dedicated to model refinement, and not field testing.

Walters also argues that more complex models are not necessarily better at providing accurate predictions. Error can be compounded multiplicatively, or the model may fail for being reductionists, while giving the appearance of being wholistic.

As I consider applying the principles of adaptive management to the management of the Llobregat watershed, it was useful for me to think about what problem needs to be modeled. Walters suggests four types of models for riparian and coastal ecosystems:

(1) A hydrodynamic submodel for space-time variation in water flows [water volume]
(2) A hydrochemistry submodel for transport and transformation of key chemical variables such as nutrients and sediments [water quality]
(3) "Lower trophic level" submodels for primary, invertebrate, and small "forage" fish production
(4) Population dynamics submodels for key animal indicator species.

As it stands today, I would probably be most interested in looking at (2) water quality.

Walters is unabashed at pointing out how scientists position themselves strategically to obtain funding research. "An emergent principle of adaptive management is that, for every difficult functional relationship, there is a scientist willing to claim the ability to measure it for you if you will provide enough research money to measure details of how the relationship arises."

Another key point is that the Adaptive Environmental Assessment and Management process (AEAM) helps take bad propositions off the table. By narrowing down the field of policy prescriptions, adaptive management permits managers to be more strategic in testing potential measures.

Walters concludes calling for "more creative thinking about how to make management experimentation an irresistible opportunity". He also ends with a few really good questions, including one particuarly relevant for me: "Why is the development of innovative methods for large-scale monitoring not usually considered a good research topic, especially for aspiring graduate students?"

Walters, C. 1997. Challenges in adaptive management of riparian coastal ecosystems. Conservation Ecology [online]1(2):1. Available from the Internet. URG:http://www.consecol.org/vol1/iss2/art1