Application of ecological performance measures to a natural area acquisition program in Portland, Oregon

Background/Question/Methods

A 2006 bond measure provided $227.4 million to safeguard water quality, protect fish and wildlife habitat and ensure access to nature for future generations in the Metro region. The bond measure called for an independent citizen oversight committee to review the Natural Areas Program, looking at how decision-making occurs and how business is conducted. Among other questions, the committee must answer:  Are the program results on track? Oversight Committee members and Metro staff developed performance measures to evaluate land acquisitions against goals identified in the bond measure and present the information in a simple, graphical format. Staff had less than two months to develop and present draft measures that were grounded in science and could be applied to the 27 acquisition target areas and their diverse habitats and landscape settings.

Results/Conclusions

A total of 11 performance measures were developed; six focus on water quality and wildlife habitat benefits and the other five on public and financial benefits. The six measures for water quality and wildlife habitat are water quality, existing or potential wildlife habitat quality, rare habitats and species, fish habitat, habitat area size and habitat connectivity. The water quality metric ranks acquisitions’ value based on proximity to water features and the degree to which they store water, trap sediment, reduce flood damage, recharge groundwater and control pollution. Wildlife habitat quality scoring is based on a wildlife habitat assessment model that considers food, cover, human disturbance and important habitat features. The rare habitats and species rankings use the Oregon Biodiversity Information Center’s rankings and the Oregon Conservation Strategy. Regional (StreamNet) and local knowledge is used to determine whether acquisitions protect native fishes, especially salmonids, and their habitat. The last two measures address habitat patch size and connectivity, refining a literature review with local research for this urban setting.

The science-based measures were synthesized to rank acquisitions high, medium or low for each metric. By condensing complex information into a ranking system, the performance measures convey important information to non-technical audiences simply and consistently. The bar charts are easy to read and interpret. The measures can be applied to multiple acquisitions and rolled up to summarize progress by target area as new information becomes available or key nearby parcels are acquired. Since their implementation, the performance measures have worked well. The Oversight Committee has reviewed progress with individual acquisitions, by bond measure target area and by the overall program.