BIODIVERSITY HOTSPOTS by Jake Ruygt

This article originally appeared in the Summer 2026 Napa Valley Chapter CNPS newsletter.

Over the last few decades, experts have puzzled over a strategy to preserve the diversity of life on earth as we face increasing impacts from development, invasive species, and climate change.

What has emerged is a method of analyzing the distribution of plant and animal species based on where they are most concentrated and where they are at most risk. Currently, there are 36 recognized global biodiversity hotspots. These areas each support at least 1500 plant species and have lost about 70% of the “primary vegetation.” Combined, the 36 hotspots cover less than 2.5% of the total land area on Earth but support as much as 60% of all species. The California Floristic Province is one of the recognized hotspots. In 1982, the Nature Conservancy published a map of biodiversity in the United States. It brings focus to the concentration of species in California, with Napa County ranking as a high point within the state’s heat map.

In 2022, the Montreal Global Diversity Framework called for protecting 30% of the world’s land area, preserving the diversity of habitats and species by the year 2030. The California Native Plant Society has developed a program to meet that goal in California. A group of over 30 scientists have studied the maps and the numbers in California and have developed a system of evaluating “durably” conserved lands relative to vegetation diversity and habitat connectivity. Some of the most under-conserved habitats that can be found in Napa County include grasslands, blue oak woodland, valley oak woodland and blue oak-foothill pine woodland. Hardwood Forest and Conifer Forest are faring a bit better but have not yet met the 30% goal.

As we continue to see losses in Napa County due to development, we need to take a closer look at what portions of these habitats survive and respond to further development of these habitats in the county. Adequate conservation and management of natural habitat provides the necessary connectivity to permit plants and wildlife to flourish. These goals and issues need to be incorporated into the Napa County General Plan, up for consideration later this year.