Understory

The Sugar Creek Research Natural Area is distinguished by its exceptional diversity of conifers, unsurpassed in the world. It is also notable for its well-developed and varied Sierran mixed-conifer forest on lower elevation slopes. The area occupies the entire upper watershed of Sugar Creek, thus including portions of all four major vegetation zones characteristic of the mid- to upper elevations of the eastern Klamath Mountains.The area is underlain entirely by granitic rock. Therefore, diversity of plant associations and species is not related to a diversity of parent materials, as is often t...

The purpose of this research was to develop a modeling system/framework for assessing forest management-related erosion at its sources and tracking sediment as it is transported from hillslopes to stream channels, and transported through a channel network to a watershed outlet. The ultimate goal was to develop a land management assessment tool capable of accurately assessing the primary impacts of spatiotemporally varied forest management practices on sediment yield and delivery at hillslope- and watershed-scales.The modeling framework developed consists of four components: 1) the TOpographic ...

Accurate assessment of forest management practices on sediment yield and delivery requires the use of physically based simulation models. Upland erosion rates are commonly simulated with the Water Erosion Prediction Project (WEPP) model. Since the WEPP was designed to evaluate erosion rates from fields and small watersheds without stream channels, it does not simulate hydrodynamics or sediment transport (especially important in watersheds larger than approximately one square mile). To resolve this problem, WEPP was linked via an interface program to CCHE1D, a one-dimensional, channel network, ...

We developed and evaluated a stratified index redd area method to estimate Chinook salmon Oncorhynchus tshawytscha, coho salmon O. kisutch, and steelhead O. mykiss escapement in several coastal streams in northern California based on the assumption that redd size is related to the number of redds a female builds. Sources of error in redd counts were identified, including the use of logistic regression to classify redd species (necessary due to temporal overlap in the spawning of these species in coastal northern California). Redd area escapement estimates were compared with estimates from more...

A part of the South Coast Ranges of California, and more specifically part of the San Rafael Mountains, Big Pine Mountain has one of the few well-developed examples of Sierra Nevada mixed conifer forest in this ecological province. The island-like mixed conifer forest at Big Pine Mountain are separated from similar forest on Madulce Peak and Pine Mountain (also known as Reyes Peak, a part of the Transverse Range) by about 5 and 16 miles (8 and 26 km), respectively. Mixed conifer forests are limited to the elevations above 5100 ft (1555 m) and are diverse and variable topographically and compos...

The Bridge Creek Research Natural Area is distinguished by its old growth Douglas-fir hardwood forest with a significant white fir and giant chinquapin element. It covers the majority (slightly under 80%) of the RNA. The forest is generally well developed, much of it being spared from even minor ground fires for over 150 years. Consequently, the multi-layer structure of the forest is typically very pronounced.Mature Douglas-fir forms an open canopy of trees up to 220 ft (67 m) tall and 6.5 ft (2 m) diameter at breast height (dbh). Beneath this is a sub-canopy of white fir, giant chinquapin, yo...

The lakes, numerous meadows, and predominant forest vegetation of red fir and mountain hemlock are the major features of Antelope Creek Lakes Research Natural Area.In the RNA, both the Butte and the Antelope Creek valleys were heavily glaciated. The four small lakes were created by morainal damming during the Pleistocene. Two lakes each occur in the Antelope and Butte Creek drainages. The Northern Antelope Creek Lake and both Butte Creek lakes appear to be formed by damming of lateral moraines, while the southern Antelope Creek Lake was formed in a cirque bowl following damming by a recessiona...

The L. E. Horton Research Natural Area is distinguished by an assemblage of plant associations that are underlain by ultramafic soil derived either from peridotite or gabbro. The entire RNA is within the Josephine Peridotite Body, a huge mass of peridotite, cumulate gabbro, diabase, and spilite. Forests on peridotite and serpentine show strikingly different patterns from those on adjacent metamorphic and granitic parent materials. The chemical imbalance of the ultramafic soils derived from this parent material is responsible for the open, stunted, scrubby and endemic-rich flora of the area.

The Long Canyon Research Natural Area (LCRNA) is one of two Forest Service areas chosen to preserve populations of this rare species endemic to the Southern Sierra Nevada province. The other area is the Bodfish Piute Cypress Botanical Area, which lies approximately nine miles (14.5 km) west-southwest of the Long Canyon stand.As with other cypresses in California, Piute cypress is a fire-adapted, serotinous-coned species, requiring fire for effective dispersal and regeneration. Fire history of each of the approximately 10 stands known varies. Some stands, such as the Back Canyon stand, are rela...

McAfee Research Natural Area (MRNA) is part of the largest continuous alpine steppe in California and the Great Basin, and is the most accessible large alpine area in California. It is unique due to the long history of research activities in the area. With the adjacent scientific facilities of WMRS and the concentration of scientific interest, the MRNA can be used as a control area for research done in the surrounding region and is valuable as a scientific research site for local (such as high-altitude environment and physiological processes related to reduced oxygen and increased ultraviolet ...