Parkwide Meadow Vital Sign Data Collection

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Resources Management and Science and the Inventory and Monitoring Program propose to implement a long-term meadow monitoring program within Yosemite National Park. The purpose of this study is to inform the NPS about the current and long-term condition of meadows in Yosemite. The goals of this program are to collect long-term data to assess the hydrologic, biotic and ecological integrity of wet meadows. Approximately 50-60 study meadows will be chosen throughout Yosemite to span the range of elevations, watershed bedrock types, and history of Pleistocene glaciations that occurs within the park. In each study meadow the depth to the water table, vegetation composition, and invertebrate composition will be analyzed during 2007, and regularly for several decades afterwards.

Three types of data will be collected during this project: (1) hydrologic data including depth to the water table, (2) a complete list of plant species present and a measure of the canopy coverage of each species, (3) composition and biomass of invertebrates.

One of the most critical measures in wetland monitoring is depth to the water table at critical times of the year. Wetland types such as fens, wet meadows, and marshes have distinctive hydrologic regimes, and the persistence of suitable hydrologic conditions is essential for their long-term sustainability. One simple ground water monitoring well will be installed in each meadow. The well will consist of a small diameter (1.25 inch) section of slotted PVC pipe, typically 1 to 1.5 m long, that sticks up above the ground about 6 inches. The pipe is placed into a hand-augered hole, approximately 2 inches in diameter. The hole is then backfilled with native soil, including the plug of turf that was first removed with a shovel. The vegetation is allowed to grow back around the well. The PVC is painted to match the surrounding area, capped, and numbered with a permanent tag inside the well. Wells allow researchers and technicians to visit a meadow, find the exact site where the water table was previously measured, remove the cap and measure the water table depth without site disturbance and in a relatively short visit. Water table depth provides a definitive record of hydrologic conditions at the same location from week to week, month to month, year to year, or decade to decade. The need for each well will be reevaluated at least once every ten years.

The sampling design for the selection of meadows and the data collection will be statistically robust. The data collected during this project will reside with the NPS Inventory and Monitoring program and Yosemite.

The project will include site-specific consultation with the Park Archeologist to avoid impacts to archeological sites and consultation with the Park Botanist to avoid impacts to special status plant species.