METHODOLOGY

How was the Conservation Lands Network created? 

Through a science-based conservation planning process that uses a systematic approach to identify areas important for biological diversity. For more information about the methodology employed in this project, download Chapter 3: Approach and Methodology here.  

Conservation planning typically involves the following steps (Groves 2003):

1. Identify conservation targets.
2. Compile information and identify data gaps.
3. Analyze existing protected lands for their contribution to biodiversity goals.
4. Set goals for conservation.
5. Evaluate the viability and ecological integrity of conservation targets.
6. Design a network of conservation lands to meet the goals.

The Coarse Filter / Fine Filter Approach to Conservation Planning

The project used the coarse filter/fine filter approach to conservation planning as illustrated below. The coarse filter analysis comprised a vegetation representation analysis (or gap analysis) that inventoried all vegetation types, established percentage conservation goals for each vegetation type, evaluated the extent of protection afforded by existing protected lands, and then calculated acreage goals for each vegetation type based on the gaps in protection.  The underlying assumption of the coarse filter gap analysis is that if sufficient acreage of all vegetation types is preserved, then the majority of biodiversity elements will also be preserved.  Appendix C is a table showing the vegetation type acreage goals.

Conservation planning software (called Marxan) combined the vegetation type conservation goals with numerous other variables (e.g., existing protected lands, rarity rank, population density, distance to roads) to define the boundaries of the Coarse Filter Conservation Lands Network.  Chapter 4: Coarse Filter: Vegetation of the full report provides a detailed description of the methods used to develop the Coarse Filter Conservation Lands Network.

To capture species that may not have been covered by the coarse filter analysis, a fine filter analysis was used to refine the Coarse Filter Conservation Lands Network. Focus team experts selected fine filter conservation target species including plants, mammals, fish, amphibians, reptiles, invertebrates, and abiotic elements such as unique soil types, streams, and ponds. The configuration of the Coarse Filter Conservation Lands Network was adjusted to incorporate sufficient habitat for these fine filter target species.  Fine filter targets can be reviewed by going to the Tables page.

Much more detail about the selection of coarse and fine filter targets can be found in Chapters 3 to 8 of the full report that can be downloaded from the Reports page.

Once targets were selected, focus team members also identified key viability factors -listed below - that must be managed for species survival.  A description of these factors, their impacts, and management recommendations can be found in Chapter 9: Conservation Target Viability and on the Managing for Biodiversity page.

Viability Factors: 

1. Climate Change and Bay Area Microclimates

2. Atmospheric Nitrogen Deposition

3. Fire

4. Ecological Succession

5. Flood and Drought

6. Landslides and Erosion

7. Invasive Plants

8. Non-native Animals

9. Pathogens and Disease

Because the Conservation Lands Network is dynamic, it will be revised approximately every two years so that newly conserved areas, updated human impacts, and other new data – as well as advances in the conservation planning process itself – can be factored into the network configuration, recommendations, and tools.