Timber Harvesting Activities Research Articles

A phylogeographic perspective on endemism in the Alexander Archipelago of southeast Alaska

Conservation plans for the North Pacific Coast are beginning to acknowledge that the old-growth forests remaining on the extensive archipelagos of the region may require a new management paradigm. Extensive timber harvesting activities on these islands may impact wildlife populations and be particularly detrimental to the large number of endemics. Because insular biotas have suffered a disproportionate number of documented extinctions worldwide, the documentation of taxonomic validity and spatial distribution of endemics should be a priority for management efforts. To date, few North Pacific coastal endemics have been reevaluated since their original descriptions. This study provides an independent view of endemism in the Alexander Archipelago of southeast Alaska through a phylogeographic assessment of eight species of mammals ( Sorex monticolus, Glaucomys sabrinus, Microtus longicaudus, Clethrionomys rutilus, Clethrionomys gapperi, Martes americana, Mustela erminea, Ursus americanus). The molecular data (mitochondrial sequence variation of the cytochrome b gene) suggest a dynamic history of faunal interchange in the region. While some purported endemics show minimal levels of genetic divergence from other conspecific populations, other taxa appear to be more divergent than recognized by current taxonomy. Some species in the region are comprised of multiple clades or evolutionarily significant units. These reciprocally monophyletic lineages may be the result of multiple Holocene invasions (neoendemics) or they may have persisted in refugia (paleoendemics) in the region during Pleistocene glacial advances. This emerging historical perspective should have direct implications for the management of these endemic taxa.

HISTORICAL CHANGES IN POOL HABITATS IN THE COLUMBIA RIVER BASIN

An historical stream survey (1934–1945) was compared with current surveys (1987–1997) to assess changes in pool frequencies in the Columbia River Basin. We surveyed 2267 km of 122 streams across the basin, representing a wide range of lithologies, stream sizes, land use histories, ownerships, and ecoregions. Based on pool classes inherited from the historical surveys, the frequencies of large (≥20 m2 and ≥0.9 m depth) and deep (≥20 m2 and ≥1.8 m depth) pools have decreased significantly (P < 0.01) since the 1930s. We classified streams as natural or commodity based on their watershed management and land use histories. Natural streams were in watersheds minimally affected by human activities (e.g., wilderness or roadless designation, limited entry), with only 12% having roads in riparian areas. Commodity streams were defined as having watersheds managed predominantly for extraction of resources via timber harvest, livestock grazing, and other human activities. Ninety percent of these streams had roads in the riparian areas. In natural streams, large-pool frequencies increased or remained the same in 96% of the streams (88% for deep pools). In commodity streams, large- and deep-pool frequencies decreased in 52% and 54% of the streams, respectively. Despite differences in stream size and the level of human activities, the magnitude and direction of these changes were consistent. Land ownership did not influence trends; pools decreased significantly on both private and public lands. Only where entire watersheds or headwaters were designated as wilderness or roadless areas did pools consistently remain unchanged or increase. Pool frequencies decreased in all ecoregions except the North Cascades ecoregion. We developed regional histories of human activities for the Columbia River Basin. Human activity histories were typically of low spatial resolution and available for broad geographic areas only; we rarely were able to obtain information at the scale of individual watersheds. Consequently, we were unable to test the relationship between temporal and spatial patterns in human activities and their influence on site-specific trends in pools. Despite our inability to isolate causal mechanisms, management emphasis and human activities clearly influenced trends in pools. We conclude that the persistent effects of human activities have simplified stream channels and reduced large- and deep-pool frequencies in watersheds outside of designated wilderness and roadless areas in the Columbia River Basin.

Preemptive Habitat Destruction under the Endangered Species Act

This paper examines the extent to which landowners have preemptively destroyed habitat for the endangered red‐cockaded woodpeckers (RCWs) in the forests of North Carolina in order to avoid potential land‐use regulations prescribed under the Endangered Species Act (ESA). Under the ESA, it is illegal to kill an endangered species and it is also illegal to damage its habitat. By preventing the establishment of an old‐growth pine stand, landowners can ensure that RCWs do not inhabit their land and avoid ESA regulations that limit or prohibit timber harvest activity. Data from 1984–90 on over 1,000 individual forest plots are used to test predictions about the probability of harvest and the age of timber when it is harvested. We find that increases in the proximity of a plot to RCWs increases the probability that the plot will be harvested and decreases the age at which the forest is harvested.

Riparian Zone Management in the Pacific Northwest: Who's Cutting What?

sp.), regional governments now restrict timber harvest in riparian forests. I summarize and assess the riparian zone management guidelines of the states of California, Oregon, and Washington (USA) and the province of British Columbia (Canada). Only Oregon and British Columbia protect fish-bearing streams with “no-harvest” zones, and only the wider (20–50 m) no-harvest zones for larger fish-bearing streams in British Columbia are likely to maintain near-natural linkages between riparian and stream ecosystems. All four jurisdictions protect most streams with “management zones” of variable width, in which timber harvest activities are restricted. All the management zone guidelines permit the harvest of the largest conifers from riparian forests and will, if applied over a series of timber harvest rotations (60–80 years), result in the continued removal of potential sources of large woody debris from the region's watersheds. All four jurisdictions require additional protection for streams and watersheds that are severely degraded or (in the United States) contain threatened or endangered species. The governments of the PNW have taken a “manage until degraded, then protect” approach to riparian forest management that is unlikely to maintain or restore the full suite of riparian-stream linkages necessary for lotic ecosystems to function naturally at the stream, watershed, basin, or regional scale.

Winter distribution of woodland caribou in relation to clear-cut logging in west-central Alberta

The responses of a herd of migratory woodland caribou (Rangifer tarandus caribou) to timber harvesting that fragmented about 11% of their winter range in west-central Alberta were examined in this study. From 1981 to 1996, 45 caribou were radio-collared and monitored during the initiation and completion of first-pass timber harvest (50% removal). Variables examined were home-range size, daily movement rates, and distance to the nearest cut block for radio-collared individuals. Daily movement rates and individual winter range sizes decreased as timber harvesting progressed. Caribou avoided using recently fragmented areas by an average of 1.2 km. If fragmentation of the winter range continues through timber harvesting and other industrial activities, the "spacing out" antipredator strategy used by caribou may be compromised. Based on these findings, timber-harvesting strategies are recommended that (i) ensure an adequate area of usable habitat to support the current population, (ii) minimize the amount of fragmented area, and (iii) in the short term avoid presently defined core use areas.

Winter distribution of woodland caribou in relation to clear-cut logging in west-central Alberta

The responses of a herd of migratory woodland caribou (Rangifer tarandus caribou) to timber harvesting that fragmented about 11% of their winter range in west-central Alberta were examined in this study. From 1981 to 1996, 45 caribou were radio-collared and monitored during the initiation and completion of first-pass timber harvest (50% removal). Variables examined were home-range size, daily movement rates, and distance to the nearest cut block for radio-collared individuals. Daily movement rates and individual winter range sizes decreased as timber harvesting progressed. Caribou avoided using recently fragmented areas by an average of 1.2 km. If fragmentation of the winter range continues through timber harvesting and other industrial activities, the "spacing out" antipredator strategy used by caribou may be compromised. Based on these findings, timber-harvesting strategies are recommended that (i) ensure an adequate area of usable habitat to support the current population, ( ii) minimize the amount of fragmented area, and (iii) in the short term avoid presently defined core use areas.

Preemptive Habitat Destruction Under the Endangered Species Act

This paper examines the extent to which landowners have preemptively destroyed endangered species' habitats in order to avoid potential landuse regulations prescribed under the Endangered Species Act (ESA). Under the ESA it is not only illegal to take (kill) an endangered species, but it is also illegal to damage their habitat. Our application is to red-cockaded woodpeckers (RCWs) in the forests of North Carolina. RCWs are an endangered species that live in old growth pine forests throughout the Southeast. Our primary hypothesis is that the closer a landowner is to known populations of RCWs, the more likely the landowner will take action to destroy the habitat for RCWs, primarily by prematurely cutting their pine forest. By preventing the establishment of an old growth pine stand, the landowner can insure that RCWs do not inhabit their land and avoid ESA regulations that limit or prohibit timber harvest activity. Two empirical questions are addressed: How does the potential for ESA regulation affect the harvest probability of a particular forest plot? How does the potential for ESA regulation affect the age at which a forest will be harvested? Data on over 1,000 individual forest plots from the U.S. Forest Service's Forest Inventory and Analysis (FIA) and a 1997-98 North Carolina State University (NCSU) survey of over 400 landowners are used to test predictions about the probability of harvest and the age of timber when it is harvested. The location of RCW populations is used to construct various measures of the probability that a forest plot will become inhabited by RCWs and thus subject to ESA restrictions on land use. Probit regressions estimate the probability that a plot is harvested and OLS regressions - corrected for harvest selection bias - estimate the age at which a plot is harvested. In all our estimates we find that increases in the proximity of a plot to RCWs increases the probability that the plot will be harvested and decreases the age at which the forest is harvested. These findings indicate that the ESA, at least for RCWs in North Carolina, actually reduces the amount of endangered species habitat.

Simulating Spatial and Temporal Context of Forest Management Using Hypothetical Landscapes

/ Spatially explicit models that combine remote sensing with geographic information systems (GIS) offer great promise to land managers because they consider the arrangement of landscape elements in time and space. Their visual and geographic nature facilitate the comparison of alternative landscape designs. Among various activities associated with forest management, none cause greater concern than the impacts of timber harvesting on the composition, structure, and function of landscape ecosystems. A timber harvest allocation model (HARVEST) was used to simulate different intensities of timber harvest on 23,592-ha hypothetical landscapes with varying sizes of timber production areas and different initial stand age distributions. Our objectives were to: (1) determine the relative effects of the size of timber production areas, harvest intensity, method used to extract timber, and past timber harvest activity on the production of forest interior and edge; and (2) evaluate how past management (in the form of different initial stand age distributions) constrains future timber production options. Our simulations indicated that the total area of forest interior and the amount of forest edge were primarily influenced by the intensity of timber harvest and the size of openings created by harvest. The size of the largest block of interior forest was influenced most by the size of timber harvests, but the intensity of harvest was also significant, and the size of nontimber production areas was important when harvests were numerous and widely dispersed within timber management areas, as is often the case in managed forests. Stand age-class distributions produced by past harvest activity limited the amount of timber production primarily when group selection was used, but also limited clear-cutting when recent harvest levels were high.KEY WORDS: Simulation modeling; Timber harvest; Historical context; Spatial context; Landscape pattern; Forest interior; Forest edge

ASSESSING STREAM CHANNEL STABILITY THRESHOLDS USING FLOW COMPETENCE ESTIMATES AT BANKFULL STAGE1

ABSTRACT: Stream channel stability is affected by peak flows rather than average annual water yield. Timber harvesting and other land management activities that contribute to soil compaction, vegetation removal, or increased drainage density can increase peak discharges and decrease the recurrence interval of bankfull discharges. Increased peak discharges can cause more frequent movement of large streambed materials, leading to more rapid stream channel change or instability. This study proposes a relationship between increased discharge and channel stability, and presents a methodology that can be used to evaluate stream channel stability thresholds on a stream reach basis. Detailed surveys of the channel cross section, water surface slope, streambed particle size distribution, and field identification of bankfull stage are used to estimate existing bankfull flow conditions. These site specific stream channel characteristics are used in bed load movement formulae to predict critical flow conditions for entrainment of coarse bed material (D84 size fraction). The “relative bed stability” index, defined as the ratio of critical flow condition to the existing condition at bankfull discharge, can predict whether increased peak discharges will exceed stream channel thresholds.

Multiobjective grid packing model: An application in forest management

In this paper, we formulate and solve a 0/1 multiobjective integer programming model that addresses the management of two conflicting forest resources: wildlife habitat and timber harvesting activities, subject to certain spatial restrictions. The tradeoff between these two conflicting resource uses is addressed in the context of a regular grid of parcels for a single time period problem. Timber harvest adjacency constraints were developed and incorporated into the model which prevented harvests from occurring next to one another, as well as next to habitat areas. The model performed exceptionally well computationally with hypothetical data. The majority of runs were solved exactly in their relaxed form in less than 60 s using the multiobjective weighting method, with the remaining cases requiring only a few branch and bound nodes to solve to completion.

Guidelines for managing wildlife habitats in southwestern ponderosa pine forests of the United States

Forest management practices, particularly timber harvesting activities, affect the habitats of a large number of wildlife species found in southwestern ponderosa pine forests of the United States. Timber harvesting activities and other vegetative treatments often change the relative abundances of food and cover. Wildlife habitats for some wildlife species are benefited, while the habitats for other wildlife species are detrimentally impacted. The guidelines presented in this paper should be helpful to foresters, wildlife managers, and other interested in maintaining or increasing wildlife habitat qualities in the forest ecosystems investigated. While the wildlife species considered are indigenous to the southwestern ponderosa pine forests, many of the wildlife management principles implied in the guidelines are likely to have applications in other ecosystems throughout the world.

Limnological Effects of 19th Century Canal Construction and Other Disturbances on the Trophic State History of Upper Rideau Lake, Ontario

ABSTRACT Upper Rideau Lake is a major lake in the Rideau Canal system; a waterway constructed in 1832 to link Kingston with Ottawa. The lake is currently borderline eutrophic, and local residents are concerned about its water quality. Long-term water chemistry data, however, are not available, and so we used diatom-based paleolimnological techniques to reconstruct the lake's development over the last two centuries. Our data indicate that Upper Rideau Lake was moderately productive even before European settlers began to affect this part of Ontario. The construction of the Rideau Canal, the first major anthropogenic disturbance in this system, greatly affected water quality. During the construction of the canal, the water level in Upper Rideau Lake was raised 1.5 m, resulting in increased nutrient and sediment loading, and an enlarged littoral zone. Deforestation associated with timber harvesting and agricultural activities maintained higher nutrient levels between ca. 1830 and the 1940s. Nutrient levels in...

Designing surveys for microchiropteran bats in complex forest landscapes—a pilot study from south-east Australia

Most of Australia's forest-dwelling microchiropteran bats are reliant on hollows in trees for shelter and breeding. These bats typically comprise a significant proportion (at times over 40%) of the mammalian fauna of a forest region. Because of past and current impacts of timber harvesting and other human activities on native forest ecosystems, insectivorous bats may be threatened by the loss of habitat, hollow-bearing trees and food sources that provide essential life requirements. Unfortunately, reliable assessment of the conservation status of most species remains problematic because of a lack of basic data on distribution, abundance and autecology. Here, we outline an approach for designing regional surveys of microchiropteran bats based on the use of sophisticated, geographic information system techniques. The forests of south-east New South Wales are used as a case study. We also assess the duration of trapping on the detection of bats and compare the efficacy of harp traps and ultrasonic detectors in censusing forest bats. A gradsect or gradient-oriented transect approach was employed in the design of the regional survey. We characterised regional variation in climate, forest vegetation, and terrain as a basis for sampling. The assessment of bat sampling methods was restricted to three areas (South Brooman/Shallow Creek, Quart Pot/Buckenbowra, and Badja State Forest) with specific climate attributes within unlogged portions of one of the common forest types (Dry Forest dominant over Moist Forest) in the region. A total of 13 species of insectivorous, forest-dwelling bats was detected with the use of harp traps. Three of these species, the Golden-tipped Bat ( Kerivoula papuensis), Eastern False Pipistrelle ( Falsistrellus tasmaniensis) and the Eastern Little Freetail-bat ( Mormopterus norfolkensis) are listed as vulnerable and rare on Schedule 12 of the N.S.W. National Parks and Wildlife Act 1974. One further species, the White-striped Mastiff bat ( Tadarida australis) was detected only by the use of ultrasonic equipment. Our data indicate that two to three nights trapping per area may be adequate to estimate species presence but this must be qualified with regard to weather. Variation in the trapping of bats between sites within an area indicated that improved sampling may be achieved by using more traps per night rather than extending the duration of trapping.

Monitoring Timber Harvest Impacts on Stream Sedimentation: Instream vs. Upslope Methods

Abstract There is increasing pressure on forest managers and natural resource professionals to measure, monitor, and evaluate stream sediment production from timber harvest activities. However, the great expense of instream sediment monitoring severely limits the number of monitoring projects which can be undertaken and has hindered the development of regulations to maintain water quality. The purpose of this study was to compare instream vs. upslope monitoring on three experimental clearcuts in northeast Washington State. The up slope monitoring approach tested in this study appeared to circumvent most problems associated with instream monitoring and provided a clear physical linkage between measurements and on-site processes. However, on-site observations indicated that important sedimentation event were unaccounted for by both instream and upslope monitoring. It was concluded that qualitative observations can also be important tools for monitoring the effects of forest management activities on sediment production and delivery. West. J. Appl. For. 11(1):25-32.

A shortest path model for the optimal timing of forest harvest decisions

The management of National Forests is a complex problem in which resources are scarce and multiple uses often conflict. A key aspect of forest policy is the determination of how to manage the timber resources of the forest, as many of the nontimber resources are conditioned by timber levels and harvest activities. In this paper, we present a 0–1 integer programming model which is used to determine an optimal timber harvesting sequence for a single stand, or group of stands, over a particular planning horizon. The harvesting model is developed around the classic shortest path network-flow model and, as such, exhibits the unique solution characteristics of the shortest path problem. The integer programming model performs extremely well computationally, always solving exactly in all 0–1 variables in its relaxed linear programming form.

Emphasis Areas as an Alternative to Buffer Zones and Reserved Areas in the Conservation of Biodiversity and Ecosystem Processes

Historically, buffer zones or reserved areas have been used to restrict the array of management actions within unique habitats or sensitive-species areas. This action, although necessary as an immediate protection measure, can create administrative fragmentation of the forest and associated problems over time. Rarely is the dynamic nature of the reserved or buffered area considered and the disturbance events that created and maintained these sites are not conserved. Sizes of buffer zones and reserved areas generally reflect concern for a single management action, such as local timber harvest activities, and do not reflect adequate concern for other disturbances such as fire, livestock grazing, insect hazard, or flooding that involve much larger landscape scales. Boundaries are usually hard in the sense that few management activities are allowed. However, management may be required to maintain the unique habitat and adjacent landscapes in dynamic forest ecosystems of eastern Oregon and Washington. We suggest a variable-source emphasis area that has multiple but softer boundaries that vary according to the spatial scale of the potential disturbance. Disturbances are evaluated at relative scales for their impact on the featured species or habitat and on sustainability of the associated landscape. Unique habitats or sensitive species are emphasized in management goals but required disturbance events are encouraged for long-term sustainability of the sensitive species, unique habitats, and associated landscapes.

Tree hollows as a resource for wildlife in remnant woodlands: spatial and temporal patterns across the northern plains of Victoria, Australia

Hollows in living or dead trees are an important resource for a range of animal species in Australia. They are used for diurnal and nocturnal shelter and as breeding sites, and the availability of hollows may be a limiting factor for some populations. This study examined patterns in the distribution of tree hollows at 185 sites, each of 1.0 ha, in remnant woodlands across the northern plains, Victoria, a rural region where little remains of the natural woodland cover. Spatial and temporal variation in the abundance of tree hollows is evident at several scales including that of the individual tree, the landscape and the region. For individual trees, the number of holes increased with tree diameter, and the slope of this relationship differed between tree species. The percentage of trees that are hollow-bearing also differs between species. Large trees have a higher proportion of holes with a large entrance diameter (&gt;10 cm) and a lower proportion of small holes (?2 cm diameter) than do small trees. At the landscape scale, hollow-bearing trees were not evenly distributed throughout remnant woodlands. Significant variables in a regression model of the abundance of hollow-bearing trees included: the number of large trees (&gt;70 cms diameter), woodland tree species composition and mean annual rainfall. At the regional scale, the availability of hollows is influenced by the patchy distribution of remnant woodlands. Large tracts are mainly associated with public land along river systems and contrast with extensive areas of farmland where woodlands are sparse or absent. The abundance of hollows at the landscape and regional scale is strongly influenced by the impact of land management on two key processes; the loss of existing hollow-bearing trees and the recruitment of new trees. On privately managed land, generally grazed by domestic stock, large trees with hollows are often present, but the scarcity of saplings and small trees raises concern over the recruitment of future hollow-bearing trees, and indeed the long-term persistence of woodland vegetation. Conversely, most sites in large blocks of public land have ample regeneration but relatively fewer hollow-bearing trees due to the loss of larger trees from timber harvesting activities. In both situations, the abundance of trees with hollows is the consequence of management practices, and their future availability is directly amenable to management action. Some implications of the patterns of distribution of hollows for wildlife are discussed.

Local Regulation of Timber Harvesting and Trucking in Georgia

Abstract By early 1992, 49 Georgia counties regulated timber harvesting or trucking activities in their jurisdictions by either a formal ordinance or an informal working policy. As recently as 1988, only 14 counties were known to have such ordinances. All new regulation since 1988 occurred in rural counties. The most common form of regulation requires that a logging permit be obtained or that county officials be notified of an intent to harvest timber. The posting of a surety bond is also a common requirement. Current local regulations in Georgia are summarized in an easily updated field guide, Field Handbook of Local Logging and Log Trucking Regulations in Georgia, that is now available. Regular revisions of the handbook are planned to keep foresters and logging contractors up to date on local regulations in the future. South. J. Appl. For. 17(4):200-206.

Drainage-Wide Effects of Timber Harvesting on the Structure of Stream Fish Assemblages in Southeastern Oklahoma

We examined associations between timber harvesting (clear-cutting and associated activities) and structure of assemblages of stream fishes across 89 localities in the Little River drainage, Oklahoma. Timber-harvesting activities were quantified as the percentage of the watershed (upstream from each locality) covered by clear-cuts in each of eight different age-classes. We found significant associations with one or more age-classes of clear-cut for three indices of species diversity, 14 of 29 common fish species, and three of five multivariate axes (principal components) of covariation among species abundances. Further analyses indicated a nonrandom association between life history strategy (r- or K-selection) and whether the abundance of individual species was related positively or negatively to clear-cuts of different ages. The results suggest that r-selected species (small, short-lived) may respond quickly to clear-cutting perturbations whereas K-selected species (large, long-lived) exhibit a delayed response. The results of this study, together with an earlier survey of faunal changes, suggest that the effects of clear-cutting in the Little River system are limited to temporary changes in local fish assemblage structure.

Hybrid Econometric/Input-Output Modeling of the Cumulative Economic Impact of National Forest Harvest Levels

Abstract Econometric and input-output methods are combined to assess the multiforest personal income impacts of timber harvesting activities on regional economies in Northern California. The importance of a combined assessment is demonstrated using data from the El Dorado and Shasta-Trinity national forests. Depending upon the timber harvest levels of other national forests in the area, projected changes in personal income resulting from a change in harvest level on either forest varied by as much as 27%. For. Sci. 36(4):863-877.