Logging mills. Millionaire’s mansions. Hillside vineyards. These are a few examples of how the land that is now Bear Creek Redwoods Open Space Preserve was utilized by people before Midpen acquired it in 1999. Today, a 12-acre former Christmas tree farm still remains within this public open space preserve as part of its storied history of human uses. While not an obvious scar on the land, the overgrown and densely packed commercially bred Douglas fir trees, which are genetically distinct from local native Douglas firs, have replaced the area’s natural biodiversity.
Restoring the natural environment is a keystone of Midpen’s mission. Recently, we began a project to restore the tree farm site to more natural conditions by removing most of the planted former Christmas trees and invasive species, implementing erosion control measures and eventually reseeding and planting the site with an array of native trees and plants.
The ultimate long-term goal is to transform the area back into a native oak woodland featuring species like coast live oak, California black oak, tanoak, redwood and Pacific madrone.
“While it may seem counterintuitive to remove trees to support the health of a forest, this site is far from what you would see in a natural forest. It lacks the structural and species diversity that provide quality habitat for native wildlife and promote wildland fire resiliency,” Midpen forest ecologist and project manager Ari Camponuri said. “Biodiversity is the backbone of forest resiliency. A healthy forest is a mosaic featuring a variety of types of trees that vary in size, spacing and stages of development.”
Camponuri’s vision for the site stands in stark contrast to the overgrown thicket of long-forgotten Christmas trees that dominate the site today, inhibiting light from reaching the forest floor and leading to a dearth of understory plants.
In 2019, Midpen successfully restored a less than 2-acre area of this former tree farm as a pilot project that is now being scaled up. The current phase of the project underway now will complete the full site restoration within the next several years.
Also at this site, Midpen is partnering with a graduate student from San José State University who is researching the ideal conditions for oak tree growth. This area of study is increasingly important as the plant disease sudden oak death threatens oak woodlands throughout the Santa Cruz Mountains and beyond. Cognizant of this disease, which is unfortunately widespread throughout Bear Creek Redwoods Preserve, staff and contractors are required to regularly sanitize boots, equipment and machinery to prevent further spread.
The restoration work is conducted with respect for local wildlife. Just before the removal of the former Christmas trees began, the on-site biologist spotted several dusky-footed woodrat nests, pausing work until their nests were relocated. This compacted an already tight work window, which is limited by nesting birds in the spring and the onset of winter.
Natural forests include standing dead trees, called snags, that provide important habitat particularly for birds. To replicate this diversity of habitat, a few select former Christmas trees will be left standing but will be “girdled,” resulting in the death of the tree over time.
“When you walk through this overgrown former tree farm, you can see it’s not a natural forest,” Camponuri explained as she pointed out the lack of understory plants, intertwining branches and dense, uniform rows of trees competing for sunlight. “By restoring this site to a native oak woodland, over time it will be much healthier, more resilient and full of life.”
This article was originally published in the Winter Views 2023 newsletter under, O Christmas Tree! Returning a Former Tree Farm to its Roots.