Tecate Cypress

Tecate cypress (Hesperocyparis forbesii) is a rare tree found in only four isolated locations in southern California and northern Baja California, Mexico. In California, it grows in the Santa Ana, Guatay, Otay, and Tecate Mountains, where it is part of the chaparral community. A relic of a cooler, wetter era, the species now persists in scattered refuges. The Santa Ana Mountains are home to its northernmost population in a highly urbanized region of California.

Though the Tecate cypress is fire-dependent, increasing frequency of human-caused wildfires prevents young trees from maturing and reproducing, thus threatening its future. Its health is an important indicator of wildfire impacts, especially as climate change alters fire regimes.

This assessment found that the overall condition of this species is caution, with an unchanging trend based on the metrics of spatial extent (area occupied by Tecate cypress), fire frequency, and post-burn regeneration (seedling-to-tree-skeleton ratio). While its spatial extent condition is good, fire frequency is of significant concern and post-burn regeneration is in a condition of caution.

Aside from fire frequency, which has been well documented, data gaps impact our overall confidence in these metrics. Important information gaps and management needs include competition with invasive species; ground-habitat-suitability models; an updated fire risk assessment; and an overall, long-term monitoring program to document tree health, density, size, age, cone production, and seedling recruitment.