Western Journal of Applied Forestry

Frazey, Sharon, L.;Wilzbach, Margaret, A.

doi: 10.1093/wjaf/22.2.73pmid: N/A

Abstract Productivities of resident salmonids and upland and riparian forests in 22 small watersheds of coastal northern California were estimated and compared to determine whether: 1) upland site productivity predicted riparian site productivity; 2) either upland or riparian site productivity predicted salmonid productivity; and 3) other parameters explained more of the variance in salmonid productivity. Upland and riparian site productivities were estimated using Site Index values for redwood (Sequoia sempervirens) and red alder (Alnus rubra), respectively. Salmonid productivity was indexed by back-calculated length at age 1 of the largest individuals sampled and by total biomass. Upland and riparian site indices were correlated, but neither factor contributed to the best approximating models of salmonid productivity. Total salmonid biomass was best described by a positive relationship with drainage area. Length of dominant fish was best described by a positive relationship with percentage of hardwoods within riparian areas, which may result from nutrient and/or litter subsidies provided by red alder. The inability of forest productivity to predict salmon productivity may reflect insufficient variation in independent variables, limitations of the indices, and the operation of other factors affecting salmonid production. The lack of an apparent relationship between upland conifer and salmonid productivity suggests that management of land for timber productivity and component streams for salmonid production in these sites will require separate, albeit integrated, management strategies. forestry-fishery interactions, Site Index, red alder, redwood, resident salmonids This content is only available as a PDF. © 2007 by the Society of American Foresters

Teply,, Mark;McGreer,, Dale;Schult,, Dennis;Seymour,, Patrick

doi: 10.1093/wjaf/22.2.81pmid: N/A

Abstract Existing models for simulating large woody debris (LWD) loads of forest streams were adapted for forest conditions in northern Idaho. Effects of riparian management prescriptions implemented for streams within a habitat conservation planning area for bull trout and other sensitive species were evaluated based on riparian and instream LWD conditions observed along 58 randomly selected stream segments. A wood budgeting system presented by Welty et al. (2002. Riparian aquatic interaction simulator (RAIS): A model of riparian forest dynamics for the generation of large woody debris and shade. For. Ecol. Manage. 162:299–318) was employed through use of observed starting instream LWD loads and generalized depletion rates. LWD recruitment estimates were based on locally relevant growth and yield simulators, taper equations, and adjustments for tree fall directional bias. LWD loading, expressed as the number of qualifying pieces per 1,000 ft of stream, was examined under two scenarios: a no-harvest scenario and a harvest scenario. Results indicated no significant difference in the frequency distribution of simulated LWD loading between the no-harvest and harvest scenarios over a 100-year prediction period. Examination of our assumptions indicated that LWD loading was likely underestimated and less variable than would be expected. However, these assumptions had equal effects on each scenario, enabling us to confidently interpret the effects of timber harvest. The nature and extent of riparian forest harvesting evaluated in this simulation is similar to levels being considered elsewhere in the region. Therefore, simulation techniques demonstrated here could be applied elsewhere in the region for evaluating the potential effects of riparian management on fisheries resources. model, wood loading, riparian management This content is only available as a PDF. © 2007 by the Society of American Foresters

Menning, Kurt, M.;Stephens, Scott, L.

doi: 10.1093/wjaf/22.2.88pmid: N/A

Abstract Ladder fuels carry fire from the forest floor to the canopy and thereby may turn low-intensity fires into severe canopy fires. Attempts at assessing ladder fuels have been either expensive and spatially limited quantified approaches or unrepeatable and variable expert opinion strategies. We have developed a mixed semiquantitative, semiqualitative approach using a flow chart that systematizes observations and constrains judgments and decisionmaking. The ladder fuel hazard assessment (LaFHA) approach leads to ladder hazard ratings and some quantified observed data; it can be repeated across a very large area at relatively low cost and, because of the systematic and constrained approach, produces results that are mostly consistent and repeatable. Key attributes assessed are clumping of low aerial fuels, height to live crown base, and maximum gaps in vertical fuel ladders. Three field seasons of testing and implementing the LaFHA approach resulted in almost 4,000 observations. For the study area in the northern Sierra Nevada, California, more than a quarter of sites were rated high hazard and about 40% more were moderate risk. Data are presented on heights to live crown base and maximum gaps for each of the rated hazard categories. fire ecology, fire behavior, ladder fuels, fire hazard This content is only available as a PDF. © 2007 by the Society of American Foresters

Bunnell, Fred, L.;Goward,, Trevor;Houde,, Isabelle;Björk,, Curtis

doi: 10.1093/wjaf/22.2.94pmid: N/A

Abstract In many areas Bryoria lichen is a major winter food for deer and caribou. We examined the role of western larch (Larix occidentalis) seed trees in retaining arboreal lichens and encouraging recolonization of regenerating stands by Bryoria. Although exposed to desiccation, Bryoria was sustained in significant amounts in larch seed trees. Other than a reduction near roads, apparently by alkaline road dust, arboreal forage lichens were relatively uniformly distributed throughout the regenerating stands. There was little difference in abundance up to 135 m from the source tree. The sorediate form of the lichens did better on lodgepole pine (Pinus contorta), and larger, nonsorediate fragments were more abundant on western larch. We attribute the difference to bark pH. Scattered western larch seed trees were effective at retaining lichens and facilitating recolonization of the regenerating stand. biodiversity, ungulate winter forage This content is only available as a PDF. © 2007 by the Society of American Foresters

Poage, Nathan, J.;Marshall, David, D.;McClellan, Michael, H.

doi: 10.1093/wjaf/22.2.99pmid: N/A

Abstract Reineke's (1933) maximum stand-density index (SDImax) was determined for 40 unthinned, fully stocked, even-aged, hemlock-spruce stands in southeast Alaska. A nonlinear model was used to identify objectively the linear portions of the stands' self-thinning trajectories for analysis. The objectives of the present study were (1) to use the modeled slopes and intercepts to determine the mean SDImax of the stands and (2) to identify stand and site factors associated with the variability observed in SDImax. The mean SDImax of the 40 hemlock-spruce stands in southeast Alaska was 619. Individually, none of the stand or site factors examined accounted for >30% of the variability observed in SDImax when all 40 stands were analyzed together. Although the spruce proportion of total stand basal area of most stands increased over time and the hemlock proportion of total stand basal area of most stands decreased over time, SDImax was not related to species proportion or changes in species proportion over time. stand-density index, self-thinning, Tsuga heterophylla, Picea sitchensis, Alaska, Pacific Northwest This content is only available as a PDF. © 2007 by the Society of American Foresters

Filip, Gregory, M.;Schmitt, Craig, L.;Scott, Donald, W.;Fitzgerald, Stephen, A.

doi: 10.1093/wjaf/22.2.105pmid: N/A

Abstract Tree mortality in western conifer forests is a complex process involving several related factors. Conifer mortality tends to be more common in high-elevation forests where stress from weather, insects, and disease result in higher rates of mortality and in the drier interior forests where mortality from fire, insects, and disease are common. Immediate mortality from fire damage may be obvious, but currently there is considerable controversy about labeling fire-injured green trees as dead that have a high probability of experiencing delayed mortality. Trees die when carbohydrates used in respiration exceed those produced in photosynthesis or water movement is impaired, the tree desiccates, and photosynthesis ceases. Immediate or delayed tree mortality may be directly due to biotic or abiotic causes and may be affected by previous damage, current condition (vigor), and attack by secondary agents such as bark beetles. A particular pathogen or insect usually attacks, damages, or kills only one portion of a tree. Trees that are damaged or attacked by pests and expected to have a dead or nonfunctional root system or a nonfunctional stem within 5 years may be considered either dead or death is imminent. Numerous studies have produced logistic regression equations or other statistical models to help determine probability of tree survival. We define and propose that a “dead tree” designation is justified for most species when at least three of the four quadrants from around the base of the root collar has cambium, inner bark, or phloem that are discolored and dead. For large ponderosa pines, a dead tree has all four quadrants with dead cambium. wildfire damage, mortality models, bark beetles, root disease, tree physiology, tree death, cambial death, delayed mortality This content is only available as a PDF. © 2007 by the Society of American Foresters

Brown, Kevin, R.;Courtin,, P.J.

doi: 10.1093/wjaf/22.2.116pmid: N/A

Abstract The effects of nutrient additions on growth of the red alder (Alnus rubra Bong.) are not well known. We examined the growth and nutritional responses of 10 young (0–4 years old at time of fertilization) red alder plantations on eastern Vancouver Island to additions of phosphorus (P), added as triple super phosphate, and a blended fertilizer (F) containing elements other than nitrogen (N), P, and calcium (Ca). Site fertility classes ranged from poor to very rich and soil moisture regime classes ranged from moderately dry to very moist. Nutrients were added in single-tree plots and responses were measured for up to 3 years after fertilization. In plantations fertilized within 1 year of planting, P additions increased heights (average of 17%), basal diameters (28%), and stem volumes (68%) over a 3-year period and increased 1st-year foliar concentrations of P, N, and S. The fertilizer supplying other elements also increased concentrations of N and S, along with potassium (K), boron (B), zinc (Zn), and manganese (Mn), but increased volume by only 16%. These data suggest that deficiencies of P are more likely to limit the growth of young red alder than are deficiencies of other elements. Older plantations (more than 2 years postplanting) were less responsive to fertilization than were younger plantations (less than 2 years postplanting). Growth of young red alder appears limited by P availability when soil Bray-P and foliar P concentrations are less than approximately 12 mg kg−1 and 2 g kg−1, respectively. red alder, phosphorus, nutrition, plantations This content is only available as a PDF. © 2007 by the Society of American Foresters

Emmingham,, Wm;Fletcher,, Rick;Fitzgerald,, Stephen;Bennett,, Max

doi: 10.1093/wjaf/22.2.124pmid: N/A

Abstract We consider tree and stand response to low, crown, and no thinningof well-differentiated, naturally regenerated even-aged Douglas-firstands over 15 years on a moderately productive Cascade Mountains siteand over 10 years on a highly productive Oregon Coast Range site.Regardless of treatment, trees in dominant and codominant crown classescontinued growing at preinitiation rates and contributed 92–100% ofstand growth 5–15 years later. Most leave trees in suppressed crownclasses died during the first 10 years and suppressed and intermediatecrown classes contributed little to stand growth because survivorscontinued to grow slowly. Low thinning remains the most reliablethinning method for increasing stand volume in high-quality trees.Crown or selection thinning may be used to achieve certain objectivesif managers carefully use information about response of trees invarious crown classes. Growth rates of residual stands will depend onthe amount of residual growing stock and the degree to which it iscomprised of vigorously growing dominant and codominant trees.Residual subordinate trees may provide snags but few living trees insmall-diameter classes. Implications for management of the Douglas-firare discussed. stand differentiation, thinning strategies, relative density, crownclass This content is only available as a PDF. © 2007 by the Society of American Foresters

Parker, Robert, T.;Maguire, Douglas, A.;Marshall, David, D.;Cochran,, Pat

doi: 10.1093/wjaf/22.2.134pmid: N/A

Abstract Mechanical harvesting and associated logging activities have the capacity to compact soil across large portions of harvest units, but the influences of compaction on long-term site productivity are not well understood. Previous research in central Oregon has shown that volcanic ash soils compact readily under both compression and vibration loads, resulting in long-term alteration in soil density and a decline in tree growth. In this study, soil strength (SS) and tree growth were assessed in areas subject to repeated timber harvesting with the objective of quantifying the relationship between ponderosa pine (Pinus ponderosa Laws.) growth and SS. Two thinning treatments (felled only versus felled and skidded) in 70- to 80-year-old ponderosa pine stands were replicated at three sites in 1991. Subsequent 5-year growth in diameter, height, and volume of residual trees were assessed with respect to SS measured by a recording penetrometer. Felled and skidded plots had 44% higher SS values than felled-only plots (P = 0.05). Although no treatment effect on growth was detected at the plot level, diameter, height, and volume growth of individual trees within plots declined significantly as average SS within a 30-ft zone of influence increased from approximately 800 to 2,500 kPa. Results show the potential use of SS measurements for monitoring impacts of harvesting operations on tree growth. site productivity, tree growth, ponderosa pine, compaction, volcanic ash, bulk density This content is only available as a PDF. © 2007 by the Society of American Foresters

Christian, Linda, E.;Brackley, Allen, M.

doi: 10.1093/wjaf/22.2.142pmid: N/A

Abstract This study examines production rates and costs for felling and helicopter yarding on eight units harvested in accordance with ecologically based silvicultural prescriptions in southeast Alaska. The prescriptions included harvesting to create gaps, harvesting to leave trees in clumps, individual tree selection, and combinations of these treatments. In combination, the treatments represented five levels of basal area (BA) retention. The levels of retention had irregular spatial arrangements caused by gaps and clumps that ranged from 0% retention (clearcut) to 75% of BA retained. Turn time (TT), as adjusted to a standardized distance, and turn weight were used as the basis for estimating productivity. There were statistically significant differences in adjusted TT, depending on the treatment. Areas with higher levels of removal tended to have lower adjusted TTs. With the exception of one unit with a short yarding distance, average turn weights increased as levels of retention decreased. Weighted average cost per thousand board feet (mbf) harvested was $322. The cost per mbf for cutting and yarding together ranged from $305 to $353. logging costs, partial cut, yarding, Tongass This content is only available as a PDF. © 2007 by the Society of American Foresters