Yosemite Valley California Black Oak Preservation
In 2013, the six sites where restoration will occur are:
• Bridalveil Straight
• El Cap Meadow
• Schoolyard/Yosemite Village
• Ahwahnee Meadow
• Stoneman Meadow
In these six groves (sites) dominated by California black oak, locally collected acorns will be planted in the ground during the period February - April in 2013. Acorns will not be planted within the adjacent meadows far from existing black oak groves, but within and next to the existing black oak groves. The number of acorns planted at each site varies by the number of acorns collected from the site and the number of existing adult black oaks at the site. In total, over all six sites approximately 150-200 pairs of acorns will be planted for each of the two years of the project. Each pair will consist of side-by-side plantings. Around one of each pair, an above ground cylindrical, deer exclusion cage and below ground cylindrical cage will be placed to protect the emerging seedling from mammals. This cylindrical exclusion cage is made from steel four inch x four inch mesh fencing that is five feet tall. The cylinder is secured to the ground with a metal t-post. The other side of each pair will receive no deer exclusion cage. For the below ground cages, a hand auger will be used to dig a hole approximately 12 inches deep and six inches wide. A cylindrical non-galvanized steel wire cylinder will then be placed in the hole and the hole filled with the soil excavated. A small identification tag will be placed on each cage. In summary, for the 150-200 pairs of acorn plantings over all six sites for each year, each will have one above ground cage that is four feet in diameter and five feet tall. Half of those cages will be a smaller cylindrical cage that is sunk 12 inches into the ground and extends two feet above ground. On one to several cages per grove, a small (~five inch x seven inch) laminated sign will be placed informing visitors of the project, its purpose, and recognition of the Yosemite Conservancy. The sign will read: "This is a native California black oak research and restoration project conducted by the National Park Service and supported by the Yosemite Conservancy. These cages will be protecting growing seedlings in an effort to promote recruitment of new trees into these groves and enhance this important ecological and cultural resource." Above ground deer and rodent exclusion cages will stay in place until the oak seedling grows to at least six feet tall over a period of approximately five to ten years. When the young oak reaches this height, all material will be removed and the tree will be tagged for further monitoring. In 2014, the planting locations will be the same, but may include some new sites, depending on where acorns will be collected.
This project proposes to restore iconic and ecologically and culturally important California black oak groves within Yosemite Valley. Previous research found that these groves are slowly declining as adults die and are not being replaced naturally by younger trees. Young seedlings that are not surviving are likely succumbing to over browsing by an overabundant deer population as well as predation by rodents. Acorns will be collected from trees and then planted in winter 2013 and 2014 in selected groves. Once planted, one half of the acorns will receive protection from deer and rodents in the form of above ground and below ground wire cages. This process will be repeated for a second year in 2014. The growth and survival of the emerging seedlings will be tracked over the two year period. Over the two year period, approximately 300-400 new seedlings will be established in the groves in an effort to slowly restore these important populations.