A knowledge base to assess site suitability for ecological field stations Frank W. Davis (PI), David Stoms, Jennifer McDonald Biogeography Lab Institute for Computational Earth System Science University of California at Santa Barbara September, 1999 A case study for the UC Natural Reserve System at UC Merced

Research Reserve Networks Many agencies designate sites for research reserves (e.g., LTER, MAB, RNA, NRS). There is a need for a systematic (“top-down”) procedure for selecting new sites based on formal criteria. Many programs face the dilemma of conflicting objectives as potential sites seldom excel in all criteria. There is a need for a method for assessing and ranking sites based on multiple and often conflicting criteria.

A Top-Down Procedure for UC-NRS Development of a new UC campus near Merced has stimulated interest in locating a new NRS reserve. We used this opportunity to develop a generic top-down procedure for selecting new NRS sites based on UC guidelines. This procedure consists of three phases from regional screening to recommendation of a specific parcel(s). The first step is to translate the UC guidelines for NRS acquisition into a logical network that assesses site suitability.

UC Guidelines Knowledge Base UC-NRS published a set of guidelines for assessing the suitability of sites as candidate reserves. How these guidelines should be measured is only generally prescribed. We have defined specific variables to quantify these descriptive criteria, which become more detailed as the scope of the assessment is narrowed in subsequent phases.

Three Phase Procedure

Phase 1 Objectives Translate the University guidelines into a knowledge base of broad-scale spatial criteria to rate the suitability of planning units within a planning region Apply the model to a planning region around the new UC Merced campus to identify a smaller area that would be further assessed in Phase 2.

EMDS Site suitability was assessed using the Ecosystem Management Decision Support (EMDS) system, which consists of a knowledge base development tool (Netweaver), a GIS extension (ArcView) and an assessment system.

Planning Units The planning region includes the westside of the southern Sierra Nevada ecoregion plus a part of the San Joaquin Valley. As Phase 1 encompasses a large region (63,000 sq km), the assessment was made for 1,395 medium-sized planning units (Calwater watersheds in the Sierra Nevada and 6x6 mile townships in the San Joaquin Valley). These planning units are larger than a typical UC NRS site, but are approriate for applying the UC guidelines at a regional scale.

The NRS guidelines were translated into a logic network, starting with three primary criteria-- scientific, academic and administrative suitability. To be rated as highly suitable, the site must receive relatively high scores for ALL three suitability criteria. Site is Highly Suitable

Scientifically Suitable The guidelines define scientific suitability as a combination of a site’s integrity and the significance of its habitat. Thus we interpreted these two criteria as separate subnetworks, joined by an AND node, which evaluates the degree to which a site has both integrity and significant habitat.

Ecosystems Have Integrity The guidelines say “natural relationships should be intact” and “reserves should be of sufficient size.” We have interpreted these statements with two variables from the GIS database: 1) the proportion of a planning unit affected by roads and 2) the area of native habitat. The range of data values are assessed into relative suitability scores. ROADSIZE

Habitat is Significant The Significance network evaluates whether a site has a “large diversity of habitats” OR “special features” such as rare species. The more habitats or special features a site has, the greater its significance. DIVERSERARE

Academically Suitable “Sites close to campus … make a correspondingly higher contribution to the NRS.” Academic suitability was therefore based on the travel time to a site from the UC- Merced campus, with the highest suitability for sites within two hours. Although the guidelines state that sites with current and potential research uses are more academically useful, data were not available for the entire study region. TRAVEL

Administratively Suitable The guidelines define administrative suitability as a combination of a site’s ability to fill representation gaps and increase the geographic balance of the NRS. Thus we interpreted these two criteria as separate subnetworks. In addition, the guidelines look for favorable acquisition terms and ease in administering a site. However, we deferred applying these criteria until Phase 2, where we will assess individual parcels.

Representation Is Increased The Representation network evaluates whether a site fills “NRS habitat voids” OR “habitat voids in reserve programs administered by other agencies”. The guidelines do not describe how the voids are to be identified nor what measures will determine when adequate representation has been achieved. We developed two quantitative measures that are described on the following slides. NRSPCAVULNCOM

Environmental Distance The environmental variability of California was characterized by a statistical analysis of climate, elevation, and soil factors. The environment of every location in the state was compared to the network of existing NRS reserves. Sites that are more similar to an existing reserve (shorter environmental distance) appear in darker shades. The less well- represented environments are brighter, such as the mid- elevation conifer zone in the Sierra Nevada.

Vulnerability Index California Gap Analysis used a simplified scoring approach to rank sites based on the level of protection and threat to their biodiversity. Sites with large proportions of highly vulnerable plant communities outside of existing managed areas scored highest. These high- ranking sites would contribute the most to filling gaps in California’s reserve network.

Balance Is Increased “It is important that the NRS be distributed geographically around the state.” Balance was therefore based on a planning unit’s geographic distance from existing NRS reserves. NRSDIST

Assessment of Existing NRS Reserves Representativeness and suitability were assessed for the existing NRS reserves. This indicated how well the potential sites in the planning region compare to existing reserves deemed highly suitable by less formal means. The existing reserves tend to represent similar coastal environments near campuses. Environments that are less well- represented include conifer forests in the Sierra Nevada and Northern Coast Ranges and deserts.

Suitability of NRS Reserves The suitability values range from moderately high to very low. The highest ranking reserves (such as the Jepson Prairie Preserve, top) tend to satisfy all three criteria-- scientific, academic and administrative suitability. The lower scoring reserves (such as the Kendall-Frost Marsh Reserve, bottom) tend to be excellent in some criteria, but score poorly in at least one. University of California Jepson Prairie Preserve

NRS Suitability Example The Kendall-Frost Mission Bay Marsh Reserve received a low overall suitability score, despite its high academic suitability, as a result of its small size, high degree of roadedness, and its similarity to other NRS reserves. In contrast, the Jepson Prairie Preserve is relatively undisturbed, and is fairly unique compared to other NRS reserves. It is important to note that these assessments reflect the characteristics of the watershed or township containing the reserve, not the reserve itself.

The three criteria create quite different planning region suitability maps. Scientifically, the best sites are in the High Sierra. Academically suitable sites are located in close proximity to Merced. Only a few scattered sites are considered highly administratively suitable. Assessment of Planning Region

The overall suitability values range from completely false to moderately true. No planning unit was totally suitable according to our logic. The highest values in the planning region are comparable to the best NRS reserves. We will focus the Phase 2 assessment on the planning units enclosed by the bold, black line. Site Suitability Assessment

Phase 2 Study Region The Phase 2 planning region is concentrated around the Merced campus. It covers a broad elevational gradient (top) containing wetlands, grassland, foothill oak woodland and mid- elevation conifer forest (bottom). Mixed Conifer Chaparral Hardwoods Grasslands Agriculture Subalpine Urban >

Coordination Opportunities There are many managed areas already designated (blue) in the Phase 2 planning region. The NRS may have an opportunity to contribute to a series of reserves across the ecological gradient of the west slope of the Sierra Nevada.

Existing Managed Areas within the Phase 2 Region

Direction for Phase 2 We propose to assess planning units within the smaller Phase 2 planning region. The knowledge-base will have the same general structure. However, the details of the criteria and the logic network at its lower levels are expected to change. The goal of the second phase will be to select a small number of parcels for further site-specific evaluation and possible nomination to the NRS in Phase 3.

Highlights We developed a systematic, quantitative decision support tool that integrates multiple, conflicting criteria. This tool is a three phase procedure with regional screening, parcel assessment and final site evaluation. In applying it to the Merced planning region, we identified a set of planning units that appear to be comparable to existing NRS reserves.