We used a ground‐based approach to compute the pyrogenic carbon emissions from the Biscuit Fire, an exceptionally large wildfire, which in 2002 burned over 200,000 ha of mixed conifer forest in southwestern Oregon. A combination of federal inventory data and supplementary ground measurements afforded the estimation of preburn densities for 25 separate carbon pools at 180 independent locations in the burn area. Average combustion factors for each of these pools were then compiled from the postburn assessment of thousands of individual trees, shrubs, and parcels of surface and ground fuel. Combustion factors were highest for litter, duff, and foliage, lowest for live woody pools. Combustion factors also increased with burn severity as independently assessed from remote imagery, endorsing the use of such imagery in scaling emissions to fire area. We estimate the total pyrogenic carbon emissions from the Biscuit Fire to be between 3.5 and 4.4 Tg C (17 and 22 Mg C ha−1) depending on uncertainty in our ability to estimate preburn litter pools and mineral soil combustion with a central estimate of 3.8 Tg C (19 Mg C ha−1). We estimate that this flux is approximately 16 times the annual net ecosystem production of this landscape prior to the wildfire and may have reduced mean net biome production across the state of Oregon by nearly half in the year 2002.

In 1993, we located, measured, and tagged almost 1700 woody debris pieces on six streams in California's central Sierra Nevada. The stability, geomorphic function, and use by fish for cover of each piece were recorded. In 1994 and 1995, piece movement was quantified and new debris pieces were measured. In the 60 study reaches, debris was not influential in shaping channel morphology and fish cover. Although woody debris was often associated with habitat units, few pieces deflected flow or contributed to the formation of pools or steps. Fish used deep water as cover more often than debris or any other cover type. Medium-sized debris was, however, used in a greater proportion than its availability to fish. Little sediment was stored by debris, and five large pieces stored 85% of the sediment volume measured. Debris frequency and volume did not differ significantly by channel type. After a low stream flow year (1993)(1994), few pieces had moved and few new pieces were identified. After a high-flow season (1994)(1995), 31% of the pieces had either moved or were not found and new pieces represented over 5% of the originally surveyed volume of wood.

Gedney, Donald R.; Azuma, David L.; Bolsinger, Charles L.; McKay, Neil. 1999.

No abstract

We documented temperature stratification in a deep bedrock pool in the North Fork of the American River, described the diel movement of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta. and determined whether these trout used cooler portions of the pool. From July 30 to October 10, 1992, the main study pool and an adjacent pool were stratified (temperature differences between surface and bottom were as great as 4.5°Q on all but two days. Six rainbow and one brown trout equipped with temperature-sensitive radio transmitters used water with temperatures ranging from 12 to 19.3°C. During the late afternoon, when the widest range of water temperature was available, trout were found in temperatures up to 19.3°C even though cooler (14.5°C) water was available. Radio tracking indicated that fish were significantly more active and had significantly larger home ranges at night; fish were least active during the day. Because we found no evidence of subsurface seepage into the pool and water flowing into the pool was warmer than the pool's maximum temperature, we concluded that the geometry and depth of deep pools may moderate elevated summer water temperatures that can stress trout populations.