Treesearch

The impacts of logging on near-surface hydrologic response at the catchment and watershed scales were examined quantitatively using numerical simulation. The simulations were conducted with the Integrated Hydrology Model (InHM) for the North Fork of Caspar Creek Experimental Watershed, located near Fort Bragg, California. InHM is a comprehensive physics-based hydrologic-response model. The North Fork watershed (including 11 tributary catchments) is the site of an ongoing study monitoring the impacts of forest practices. InHM was parameterized and calibrated using existing data and new...

The current conditions of many seasonally dry forests in the western and southern United States, especially those that once experienced low- to moderate-intensity fire regimes, leave them uncharacteristically susceptible to high-severity wildfire. Both prescribed fire and its mechanical surrogates are generally successful in meeting short-term fuel-reduction objectives such that treated stands are more resilient to high-intensity wildfire. Most available evidence suggests that these objectives are typically accomplished with few unintended consequences, since most ecosystem components...

Sediment production has been measured for nearly half a century at the Caspar Creek Experimental Watersheds. Examination of this sediment record provides insights into the relative magnitudes and durations of sediment production from management practices including road construction, selection harvest and tractor skidding, and later road decommissioning. The 424-ha South Fork was harvested under standards that applied before passage of the 1973 Forest Practice Act. Regression analysis of annual suspended sediment loads on peak flows indicates that sediment production roughly doubled, with a...

Monitoring of large woody debris (LWD) in the two mainstem channels of the Caspar Creek Experimental Watersheds since 1998, combined with older data from other work in the watersheds, gives estimates of channel wood input rates, survival, and outputs in intermediate-sized channels in coastal redwood forests. Input rates from standing trees for the two reaches over a 15 year period varied from a high of 28 m3/km/yr in the North Fork (in 1995) to a low of 0.12 m3/km/yr in the South Fork (from 2000 to 2002). Rates in the South Fork, where a second-growth forest was selectively logged in the...

California's coastal salmon and steelhead populations are listed under California and Federal Endangered Species Acts; both require monitoring to provide measures of recovery. Since 2004 the California Department of Fish and Game and NOAA Fisheries have been developing a monitoring plan for California¡¯s coastal salmonids (the California Coastal Salmonid Monitoring Plan- CMP). The CMP will monitor the status and trends of salmonids at evolutionarily significant regional scales and provide population level estimates. For the CMP, data to evaluate adult populations are collected using a...

Initial increases in dry-season flow after selective logging of second-growth coast redwoods (Sequoia sempervirens) in the 424 ha South Fork Caspar Creek watershed disappeared by 7 years after logging ended, and low flows then dropped to below expected values for the next 20 years. During the16 years after clearcut logging in the 473 ha North Fork watershed, late summer flows increased to nearly twice those expected and then declined to pre-treatment levels on a trajectory that suggests further decline is likely. This contrast in dry-season flow responses is consistent with expected...

Landslides have been mapped at least annually in the 473 ha North Fork Caspar Creek watershed since 1985, allowing evaluation of landslide distribution, characteristics, and rates associated with second-entry partial clearcut logging of 1989 to 1992. Comparison of sliding rates in logged and forested areas shows no appreciable difference for streamside slides (size range: 7.6 to 380 m3). However, the incidence of large landslides, including both streamside and upslope slides of 98 to 4900 m3, varied by treatment. Such slides displaced 12 m3/yr per km2 of unlogged forest but showed rates...

Invasive non-native species can create especially problematic restoration barriers in subtropical and tropical dry forests. Native dry forests in Hawaii presently cover less than 10% of their original area. Many sites that historically supported dry forest are now completely dominated by non-native species, particularly grasses. Within a grass-dominated site in leeward Hawaii, we explored the mechanisms by which non-native Pennisetum setaceum, African fountain grass, limits seedlings of native species. We planted 1,800 seedlings of five native trees, three native shrubs, and two native...

Sampling with different plot types and sizes was simulated using tree location maps and data collected in three even-aged coast redwood (Sequoia sempervirens) stands selected to represent uniform, random, and clumped spatial patterns of tree locations. Fixed-radius circular plots, belt transects, and variable-radius plots were installed by simulation. Bootstrap sample means, coefficient of variation (CV), and 95 percent confidence intervals were calculated for sample estimates of eight important stand parameters. Percent CV models depicted sample precision and enable calculation of minimum...

The effects of long-term silvicultural thinning on soil C and N content are not well known. We evaluated the impact of periodic thinnings on soil C and N pools in a 134-yr-old red pine (Pinus resinosa Ait.) forest in Minnesota, and a 104 yr-old northern hardwood forest in Wisconsin. The red pine stands had five thinning regimes (13.8, 18.4, 22.7, 27.6, 32.1 m2 ha-1 residual basal area [BA]), which were cut five or seven times over 46 yr. The northern hardwood stands had three residual basal area treatments (13.8, 17.2, 20.6 m2 ha-1) that were thinned five times over 50 yr. Our results...