GENERAL APPROACH

The first step in developing a biodiversity management plan is to inventory the flora and fauna of the area.  Special attention is given to cataloging plant communities because these serve as the base for wildlife success, and plant community structure often predicts the types of wildlife that can reside there.  Plant community edges, the transition areas where two plant communities meet, is an important factor to wildlife.  These areas provide wildlife with the benefits of both plant communities, e.g. complex community structures, food, and additional cover.  Wildlife often congregate at edges because of greater resource availability and species richness.

The present status of the wildlife on Cal Poly properties was evaluated through presence/absence surveys of animal species and through plant community surveys and analyses.  These surveys were conducted by Cal Poly students recruited from the Departments of Biological Sciences and Natural Resource Management.  I coordinated the performance of these separate surveys and developed protocols to ensure continuity across studies.  Dr. Douglas Donaldson, Professor Emeritus, Biological Sciences, and Dr. Roger Gambs, Professor, Biological Sciences, served as the main faculty advisors on these projects.

Information from separate surveys was consolidated and analyzed to identify the conservation actions required to protect and preserve species present on the different parcels.  All management recommendations are directed toward establishing self-sustaining wildlife populations on the different properties.

Acreage and Edge Diversity Index

Acreage for plant communities was estimated using the established map scale and a Bryant transparency grid.  The Bryant transparency grid is based upon a system of dots with each dot representing a specific area, depending upon the map scale.  The scale of the Cal Poly agricultural maps is 1 inch² = 3.67 acres, thus 1 inch² on the Bryant Grid will contain 64 dots, with each dot equaling 0.057 acres.  The sum of all dots for a specific plant community denotes its estimated acreage.

Edge diversity index (EDI) is a number calculated using the map linear distance (or total perimeter) of the edge on a site and its corresponding acreage (Hanson 1997).  Linear distance was calculated using an opistometer to trace and record the length of edge.  This number, along with the acreage was placed into the formula:

where TP= total perimeter, A = acreage and p = 3.14.

The EDI indicates the amount of edge present in relation to a circle (EDI = 1), where the area is maximized in relation to edge.  For example, an area with an EDI of 1.50 has edge that is 50% better than a circle.