Exploration of Fens in Carpenter Valley
By Jennifer Buck-Diaz
The rattling calls of three sandhill cranes echoed across Carpenter Valley as ecologists from the CNPS Vegetation Program investigated a large fen/meadow complex last August. Soon, in lower Carpenter Valley, north of the town of Truckee, more than 1,000 acres of lush meadow and forest will be protected through ownership by the Truckee Donner Land Trust and a conservation easement held by The Nature Conservancy.
Carpenter Valley is perched more than 6,000 feet above sea level and includes a large meadow surrounded by patches of big sagebrush (Artemisia tridentata) and conifer forest dominated by lodgepole pine (Pinus contorta). Lemmon’s willow (Salix lemmonii) lines the banks of the North Fork Prosser Creek which meanders through the site. With funding provided by The Nature Conservancy, CNPS assessed and delineated fen habitats within the meadow and adjacent forest. Fens are groundwater-fed, peat-accumulating systems with perennially saturated soils. You know you’re standing in one when the cool water begins to slowly seep through your shoes and into your socks. You may even feel a floating sensation as you walk, or feel the ground move beneath if you bounce.
We mapped about 30 acres of fen habitat in this area by a process of identifying wetland plant species, sampling the vegetation, digging soil cores, identifying saturated peat soils, and using a soil probe to delineate the habitat edge. A soil probe slips easily through the thick layers of peat in a fen, and you can feel the edges of this habitat by a gritty sound and the resistance of the probe as it hits mineral soil. Numerous mosses and liverworts were sent off for expert identification and small soil samples were analyzed to confirm the necessary levels of organic carbon content (>18%). We identified more than 130 vascular plants and 9 bryophytes/lichens; some of our favorites included gentians (Gentiana newberryi, Gentianopsis simplex), hooded ladies tresses (Spiranthes romanzoffiana), and marsh grass of Parnassus (Parnassia palustris). A new plant to us was star duckweed (Lemna triscula), an almost translucent triangular-shaped floating leaf that accumulates in the thin channels that braid through the meadow.
Five rare taxa were found in Carpenter Valley, and only a few non-native grasses were detected during two visits on the site including cheat grass (Bromus tectorum), Kentucky blue grass (Poa pratensis) and timothy (Phleum pratense). The fens of Carpenter Valley are highly rated for conservation significance because they are relatively undisturbed, and they support rare taxa and vegetation types. Additional surveys of fen vegetation in this region will contribute to a better understanding of these rare natural community types and augment additional data regarding the statewide diversity of fen/wetland vegetation.
To learn more about the Campaign to Conserve Lower Carpenter Valley click here: http://northernsierrapartnership.org/carpentervalley/. If you’re interested to know more about fen habitat, contact Jennifer Buck-Diaz at jbuck@cnps.org.