By Celeste Dodge, MS, Systems Ecologist
|Water returns to the landscape at |
Pepperwood's Weimar Falls
Pepperwood is studying the relationship between water availability and vegetation so our region's land and water managers can better prepare for what is expected to be a more arid future for California. The work we are conducting at our preserve gives organizations like the Sonoma County Water Agency and the US Geological Survey key data on not just variations in weather, but also how our soils, plants and animals are responding to these changing conditions.
|Volunteers learn how to collect data from rain gauges|
|Pepperwood's TBC3 team discussing best |
practices for monitoring soil moisture
By recording rainfall under the canopy at the forest monitoring plots, we are getting a pretty good sense of the environmental conditions experienced by seedlings in our forests. Total rainfall at these site varies by as much as 40% and is controlled by both canopy and topographic effects. At one site where there are particularly strong canopy effects, the rainfall we have measured thus far amounts to only 20% of the rainfall out our wettest location. We may decide to move our forest plot gauges out from under the canopy to a nearby grassland area to better understand the effects of topography alone next season. This will also make our data more valuable to forecasters. A nationwide citizen science project called the Community Collaborative Rain Hail and Snow Network collects backyard rain gauge data along these lines and uses it retroactively to improve weather models.
In addition to the new rain gauges, some of the forest monitoring plots are already equipped with instruments that collect data on leaf wetness, temperature, and humidity. Data from these instruments is relayed across the preserve by a wireless mesh network, a series of antennas that transmit across the preserve to a central computer.
|A mesh network sensor at a forest monitoring plot|
But measuring the amount of rain that falls is only one piece of the puzzle. We also need to determine what happens when it hits the ground. Pepperwood is one of only four sites in the entire Bay area equipped with soil moisture probes, which allow us to gain vital insights into the amount of water available to plants in the soil throughout the year. We currently have two sets of probes installed, and our goal is to install 10 sets of probes at two depths at our mesh network antennas before this year's spring dry-down occurs. This will give us a better sense of the heterogeneity of the preserve's hydrology, and will enable forecasters to better predict potential flood or mudslide events.