Ideal Point Method Applied in Forest Harvest Regulation

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Leaf resorption efficiency and proficiency in a Quercus robur population following forest harvest

Nutrient resorption is an important mechanism for nutrient preservation in plants. Variations in nutrient availability can interfere with resorption-regulating mechanisms. Disturbances (such as forest harvest) leading to a loss of organic matter and nutrients in the soil could therefore determine important changes in resorption rates. This paper examines the effect of pine forest harvest on N and P resorption in young common oaks (Quercus robur) living under pine cover over a 4-year study period. The results obtained show a decrease in N-NH₄⁺ concentration in the soil in the 2 years following the forest harvest process. Forest harvest did not affect the edaphic concentration of NO₃⁻ and PO₄³⁻, which presented relatively low values in both areas. Foliar concentration of N was significantly lower in the areas affected by forest harvest, whereas the differences in the foliar concentration of P varied each year. The mean foliar N/P ratio was greater in the non-harvested areas, but showed possible limitation by P in both harvested and non-harvested sites.     

卫星遥感数据在森林采伐监测中的应用

分别采用SPOT5、TM5影像前后两期多光谱遥感影像的波谱特征变化,检测森林资源变化信息,确定变化类型,以计算机自动识别对森林资源变化(减少)的区域(伐区)进行信息提取,并在此基础上进行室内人工预判读;结合采伐证、伐区作业设计、二类调查材料,进行补充判读,得出森林采伐图斑。古丈TM5(30 m分辨率)的面积正判率为96.3%;古丈SPOT5(10 m分辨率)的面积正判率为96.9%。实证分析表明,使用中、高分辨率卫星遥感数据能对森林采伐进行监测,结合辅助材料后能显著提高森林采伐监测精度。     

Nutrient export and harvest residue decomposition patterns of a Eucalyptus dunnii Maiden plantation in temperate climate of Uruguay

The potential export of nutrients from Eucalyptus plantations harvested for pulp production may be high. However, depending on the harvest method, the nutrients from the residue can be recycled. The aims of this study were (i) to quantify the content and distribution of nutrients in different residue components at harvest for a Eucalyptus dunnii Maiden plantation; and (ii) to quantify the decomposition rates of the harvest residues, and the return of nutrients to the soil in the temperate climate conditions of Uruguay. Six trees of a 9-year-old E. dunnii plantation with average diameter at breast-height (DBH) were harvested, and the biomass produced and the N, P, K, Ca and Mg contents in commercial and non-commercial logs, leaves, branches, bark and litter were estimated. Decomposition of the remains of leaves, branches, non-commercial logs, bark and litter was studied in the field for 2 years. Although commercial logs accounted for 61% of the biomass produced, only 27% of the N, 35% of the P, 18% of the K, 16% of the Ca and 41% of the Mg present in the forest were exported with the product. When logs are exported without de-barking in the site, the nutrient export would increase to 41%, 55%, 46%, 68% and 66% of the total extraction of N, P, K, Ca and Mg, respectively. Residue decomposition showed that the leaves lost the highest proportion of biomass (half life 0.86 years), and bark was most resistant to decomposition in the field (half life 5.36 years). As regards the nutrients, K was lost most rapidly and Ca showed the slowest loss, while N, P and Mg losses were generally more gradual, and proportional to the decomposition rate.     

Effects of clear-cutting on decomposition processes in leaf litter and the nitrogen and lignin dynamics in a temperate secondary forest

The effects of clear-cutting on the decomposition rate of leaf litter and on nitrogen (N) and lignin dynamics were investigated in a temperate secondary forest. Decomposition processes were examined over an 18-month period by the litterbag method and compared between a clear-cut site and an adjacent uncut control site using leaf litter from five dominant tree species (Clethra barvinervis, Quercus serrata, Camellia japonica, Ilex pedunculosa and Pinus densiflora). The decomposition rate for litter from C. barvinervis, Q. serrata and I. pedunculosa was significantly greater in the clear-cut plot than in the control plot, and there was no significant difference between plots for C. japonica and P. densiflora. Water content of litter was consistently lower in the clear-cut plot than in the control plot. Nitrogen mass increased after 6 months in the control plot, whereas no net increase of N was observed in the clear-cut plot. Nitrogen concentration increased with respect to accumulated mass loss of litter and was consistently lower in the clear-cut plot for all five species. The mass of lignin remaining in decomposing litter was generally lower in the clear-cut plot, but lignin concentration in decomposing litter was not significantly different between the clear-cut and control plots.     

Forest carbon sequestration changes in response to timber harvest

Forest succession contributes to the global terrestrial carbon (C) sink, but changes in C sequestration in response to varied harvest intensities have been debated. The forests of the Central Appalachian region have been aggrading over the past 100 years following widespread clear-cutting that occurred in the early 1900s and these forests are now valuable timberlands. This study compared the history of ecosystem C storage in four watersheds that have been harvested at different frequencies and intensities since 1958. We compared NPP, NEP, and component ecosystem C fluxes (g C m⁻² year⁻¹) in response to the four different harvest histories (no harvest, clear-cutting, single tree selection cutting, and 43 cm diameter-limit cutting). Clear-cutting had short-term negative effects on NEP but harvest did not significantly impact long-term average annual C sequestration rates. Average plant C (g C m⁻²) since 1950 was about 33% lower in response to a clear-cut event than plant C in an un-harvested forest, suggesting that the C sequestration associated with clear-cutting practices would decline over time and result in lower C storage than diameter-limit cut, selective cut, or un-harvested forests. Total C stored over a 55-year period was stimulated ∼37% with diameter-limit cutting and selective cutting relative to un-harvested forests.     

Carbon balance of a forest ecosystem after stump harvest

Abstract

Stump harvest in forests can cause both reductions of CO₂ emissions through a decrease of decomposable substrate (direct effect) and emission increases as a consequence of deep and extensive soil disturbance (indirect effect). Here, the effects of stump harvest on net ecosystem CO₂ exchange (NEE) in a former Norway spruce stand in mid Sweden are presented. CO₂ exchange was continuously followed by eddy-covariance measurements during the first years after harvest. Differences in NEE from stump harvested and mounded (reference) plots were determined by soil-surface respiration measurements. Respiration from decaying stumps was estimated by a decomposition model. Fluxes indicated a direct effect (decreased efflux) during the first year after harvest that corresponded to the absence of decomposing stumps. During the following years, this emission reduction was increasingly counteracted by an indirect effect (increased efflux) of similar magnitude. This means that the expected emissions caused by extra soil disturbance occur with a certain delay and seem to increase with time. By these emissions, the substitution efficiency of stumps as bioenergy resource is reduced. Furthermore, at a time scale of centuries, instant combustion of stumps leads to a larger contribution to global warming than slow decomposition, because the stump carbon is available earlier in form of greenhouse gas. This is estimated by the time integral of emissions. Thus, despite the surprisingly low initial emissions, the overall substitution efficiency and climate benefits of stump harvest are likely to be small. The long-term consequences of stump harvest for the carbon budget are, however, still uncertain.     

Bat response to shelterwood harvests and forest structure in oak-hickory forests

Forest management practices, such as shelterwood harvesting, can greatly impact bat habitat relationships. Such practices can alter the amount of structural volume within a forest, which can influence bat foraging patterns. We determined the effects of shelterwood harvests of different retention levels (50% and 70% of full stocking) on bat activity patterns in oak-hickory forests located in southern Ohio. We used the Anabat system to monitor activity during May-September 2006. Our objectives were to quantify the effects of harvesting on structural volume and use the results to explain variations in bat activity. Because harvesting alters vertical structure as well as the total amount of volume within a forest, we also determined the height within the vertical profile where changes in structural volume begin to influence overall and species-specific activity. Overall bat activity did not differ significantly between shelterwood harvest levels, but was significantly different between harvested and control sites, with more passes detected within the harvested sites. Lasiurus borealis (red bat), Eptesicus fuscus (big brown bat), and Lasionycteris noctivagans (silver-haired bat) activity was significantly greater in harvested versus control sites, but did not differ between shelterwood harvest levels. Myotis spp. (Myotis lucifugus (little brown bat) and Myotis septentrionalis (northern Myotis)) and Perimyotis subflavus (tri-colored bat) activity did not vary between shelterwood harvest levels or between harvested and control sites. The greatest reductions in structural volume occurred in the understory to mid-canopy of the shelterwood harvests. Overall activity was most influenced by the amount of volume within 3-6 m above the forest floor, and declined as volume within that height strata increased. Mean bat passes declined by 50% when volume within 3-6 m exceeded 17 m³/ha. Estimated use by L. borealis decreased by 50% at volumes exceeding 1750 m³/ha in the understory to mid-canopy (0-12 m), while E. fuscus and L. noctivagans estimated use was the highest when volumes within 3-6 m were less than 63 m³/ha. Our results suggest that forest management practices that reduce the amount of structural volume in the understory to mid-canopy provide suitable habitat for foraging bats. Quantifying the amount of structural volume at various heights within the vertical profile of the forest can lend valuable insights into overall and species-specific bat activity patterns.     

Regeneration of Populus nine years after variable retention harvest in boreal mixedwood forests

Aspen and balsam poplar regeneration from root suckers were assessed in boreal mixedwood forests nine years after logging in a variable retention experiment (EMEND Project—Ecosystem Management Emulating Natural Disturbance) located north of Peace River, Alberta, Canada. Five levels of retention of mature trees (2%, 10%, 20%, 50% or 75% of the original basal area) were applied in stands dominated by aspen, white spruce or mixtures of the two species. Basal area of aspen (or that of aspen plus balsam poplar combined) prior to logging strongly influenced sucker density of aspen (or aspen + balsam poplar combined) and in some cases their growth. Nine years after harvest there was a decline in sucker density and volume ha⁻¹ with increasing retention levels of aspen (or both poplars combined); sucker density declined by 50% when only 20% of the original basal area was left in the stand. Retaining mature spruce trees in the stand had little influence on the number of suckers but did affect their total volume ha⁻¹. Thus, we suggest that by knowing stand aspen and balsam poplar density prior to logging and varying levels of retention of aspen and balsam poplar or conifers at harvest, the density of Populus regeneration can be predicted by managers, thereby allowing them to create a range of mixedwood conditions.     

Planning timber harvest of residual forest stands without compromising bird and small mammal communities in boreal landscapes

Numerous efforts have been invested in designing and configuring residual forest stands in Canadian boreal forest to preserve their overall biodiversity. Now that several landscapes have been partially logged, the next issue in forest management involves the planning of residual forest stand harvesting without compromising wildlife populations. Residual stands can be cut when adjacent regeneration reaches 3 m in height according to current regulations in several Canadian provinces (e.g., Québec, Ontario, Alberta, and British-Columbia). However, little is known on whether such regenerating habitat (RE-3m) can maintain wildlife communities similar to those found in unharvested mature forest (CO). We estimated the relative abundance of small mammals and forest birds in RE-3m and CO habitats and characterized landscape and stand structures. These variables were then compared between the two contrasting successional stages and were used to build habitat use models (HUMs) for 21 species. CO and RE-3m differed with regard to several landscape characteristics and stand structure variables as a result of logging. Snowshoe Hare, Northern Flicker, Alder Flycatcher, Ruby-crowned Kinglet, White-throated Sparrow and Magnolia Warbler were more abundant in RE-3m than CO, while Red-backed Vole, Brown Creeper and Golden-crowned Kinglet exhibited lower abundances in RE-3m. No significant differences in abundance were observed for the 12 other species. Species HUMs were highly significant and explained between 64.3 and 99.1% of the total variability in abundance. Following variance partitioning, stand structure variables accounted for most of the explained variability (54.2%) while landscape characteristics accounted for only 28.7%. No difference in species richness was observed but community evenness was greater in CO than RE-3m. Our results suggest that current regulations may threaten the maintenance of 3 out of 21 censused species for which abundances were significantly lower in regenerating 3 m tall stands. As stand structure explained a large amount of variability in abundance, it should be considered during timber harvest planning in both mature and regenerating stands. Until we know more on whether the current regulations are suitable for maintaining overall biodiversity, our results suggest that some mature forest stands should be maintained within managed landscapes for a complete logging rotation period.     

Inclusion of forest harvest legacies, forest type, and regeneration spatial patterns in updated forest maps: A comparison of mapping results

In Maine and other heavily forested states, existing land cover maps quickly become dated due to forest harvesting and land use conversion; therefore, these maps may not adequately reflect landscape properties and patterns relevant to current resource management and ecosystem studies. By updating an older land cover product (the 1993 Maine GAP map) using Landsat imagery and established forest change detection techniques, we demonstrate a practical and accurate means of providing contemporary, spatially explicit forest cover data needed to quantify landscape change. For a 1.8 million hectares study area in northern Maine, we quantify the accuracy of forest harvest classes and compare mapped harvest and regeneration area between the 2004 GAP update product and the 2004 Maine Landcover Dataset (MeLCD), a map recently developed in coordination with the 2001 National Land-Cover Database (NLCD). For the period 1995–2004, the overall harvest/non-harvest accuracy of the GAP update map is 87.5%, compared to 62.1% for the MeLCD. Producer and user accuracy for harvest detection is 92.4% and 89.7%, respectively for the GAP update, and 48.8% and 92.5% for the MeLCD. Mapped harvest area differs considerably, reflecting a systematic under-representation of recent harvest activity on the part of the MeLCD. By integrating older land cover data, the GAP update retains the forest disturbance legacies of the late 1970s through the early 1990s while simultaneously depicting 2004 forest composition for harvested and regenerating stands. In contrast, the MeLCD (and 2001 NLCD) over-represents the area and connectivity of older forest (undisturbed since the late 1970s), and provides no forest composition information for mapped forest regeneration. Systematic misclassification of forest age classes and harvest history has serious implications for studies focused on wildlife habitat modeling, forest inventory, and biomass or carbon stock estimation. We recommend the integration of older land cover data and time-series forest change detection for retention of harvest or disturbance classes when creating new forest and land cover maps.     

Bottomland hardwood forest recovery following tornado disturbance and salvage logging

Catastrophic wind events, including tornado, hurricane, and linear winds, are significant disturbances in temperate forested wetlands. Information is lacking on how post-disturbance salvage logging may impact short and long-term objectives in conservation areas where natural stands are typically managed passively. Woody regeneration and herbaceous cover were assessed for three years in a bottomland hardwood forest across a gradient of damage from an F4 tornado, with and without subsequent salvage logging. Soil disturbance intensity and recovery associated with salvage logging within wind-disturbed sites were also assessed. Woody stem density and proportion of potential overstory species (species with the potential to occupy a position in the canopy) increased as a function of wind disturbance intensity. Stem density, proportion of overstory trees, or species diversity did not differ between wind + salvage and wind-disturbed-only plots. Significant dissimilarity occurred among soil disturbance classes within salvaged sites. By the third growing season, vegetation in soil disturbance classes in wind + salvage areas was converging toward undisturbed conditions and bottomland hardwood forest recovery was underway in all vegetation disturbance types and soil disturbance classes. Post-tornado salvage logging, applied judiciously, may contribute to microsite and vegetation diversity.     

An interactive multiobjective approach to harvest decisions in forest planning

A hierarchical approach to forest planning is formulated, where harvest schedules are first determined, followed by a decision about harvest methods (harvest regime). Choice of harvest methods is particularly important because of concerns about harvest‐related site disturbance. In the decision model developed in this article, determination of a harvest regime is expressed as a multiple‐objective decision incorporating maximization of net present value and minimization of cumulative site disturbance for different site classes, subject to maintaining high levels of production, an even flow of timber, and avoiding adjacency violations. The search for preferred harvest regimes is performed interactively over a set of non‐dominated harvest schedules with alternative aspiration levels identified for the various objectives to reflect values of different stakeholders.     

Simulating restoration strategies for a southern boreal forest landscape with complex land ownership patterns

Restoring altered forest landscapes toward their ranges of natural variability (RNV) may enhance ecosystem sustainability and resiliency, but such efforts can be hampered by complex land ownership and management patterns. We evaluated restoration potential for southern-boreal forests in the ∼2.1 million ha Border Lakes Region of northern Minnesota (U.S.A.) and Ontario (Canada), where spatially distinct timber harvest and fire suppression histories have differentially altered forest conditions (composition, age–class distribution, and landscape structure) among major management areas, effectively resulting in forest landscape “bifurcation.” We used a forest landscape simulation model to evaluate potential for four hypothetical management and two natural disturbance scenarios to restore forest conditions and reduce bifurcation, including: (1) a current management scenario that simulated timber harvest and fire suppression practices among major landowners; (2) three restoration scenarios that simulated combinations of wildland fire use and cross-boundary timber harvest designed to emulate natural disturbance patterns; (3) a historical natural disturbance scenario that simulated pre-EuroAmerican settlement fire regimes and windthrow; and (4) a contemporary fire regime that simulated fire suppression, but no timber harvest. Forest composition and landscape structure for a 200-year model period were compared among scenarios, among major land management regions within scenarios, and to six RNV benchmarks. The current management scenario met only one RNV benchmark and did not move forest composition, age–class distribution, or landscape structures toward the RNV, and it increased forest landscape bifurcation between primarily timber-managed and wilderness areas. The historical natural disturbance scenario met five RNV benchmarks and the restoration scenarios as many as five, by generally restoring forest composition, age–class distributions, and landscape structures, and reducing bifurcation of forest conditions. The contemporary natural disturbance scenario met only one benchmark and generally created a forest landscape dominated by large patches of late-successional, fire-prone forests. Some forest types (e.g., white and red pine) declined in all scenarios, despite simulated restoration strategies. It may not be possible to achieve all objectives under a single management scenario, and complications, such as fire-risk, may limit strategies. However, our model suggests that timber harvest and fire regimes that emulate natural disturbance patterns can move forest landscapes toward the RNV.     

Forest floor temperature and relative humidity following timber harvesting in southern New England,USA

Forest amphibians, especially salamanders, prefer forests with shaded, cool, and moist forest floors. Timber harvesting opens the forest canopy and exposes the forest floor to direct sunlight, which can increase forest floor temperatures and reduce soil moisture. These microclimatic changes can potentially degrade the harvested stand for amphibian habitat or affect other biotic resources or ecological processes at the forest floor and in the understory. The degree of forest floor disturbance is directly related to the intensity of harvesting, however, the duration of this effect is unknown. We conducted a study of forest floor temperature and relative humidity over a 12-year chronosequence (1993–2004) of timber harvests. We compared simultaneous, paired measurements of temperature and relative humidity at three positions (soil, forest floor, air) in harvested and control sites over three seasonal survey sessions. Vegetation composition and structure were measured at each survey location. Ambient weather conditions were recorded at three open-field locations across the study area.     

The relation of harvesting intensity to changes in soil, soil water, and stream chemistry in a northern hardwood forest, Catskill Mountains, USA

Previous studies have shown that clearcutting of northern hardwood forests mobilizes base cations, inorganic monomeric aluminum (Al_im), and nitrate (NO₃⁻-N) from soils to surface waters, but the effects of partial harvests on NO₃⁻-N have been less frequently studied. In this study we describe the effects of a series of partial harvests of varying proportions of basal area removal (22%, 28% and 68%) on Al_im, calcium (Ca²⁺), and NO₃⁻-N concentrations in soil extracts, soil water, and surface water in the Catskill Mountains of New York, USA. Increases in NO₃⁻-N concentrations relative to pre-harvest values were observed within a few months after harvest in soils, soil water, and stream water for all three harvests. Increases in Al_im and Ca²⁺ concentrations were also evident in soil water and stream water over the same time period for all three harvests. The increases in Al_im, Ca²⁺, and NO₃⁻-N concentrations in the 68% harvest were statistically significant as measured by comparing the 18-month pre-harvest period with the 18-month post-harvest period, with fewer significant responses in the two harvests of lowest intensity. All three solutes returned to pre-harvest concentrations in soil water and stream water in the two lowest intensity harvests in 2-3 years compared to a full 3 years in the 68% harvest. When the results of this study were combined with those of a previous nearby clearcut and 40% harvest, the post-harvest increases in NO₃⁻-N concentrations in stream water and soil water suggest a harvesting level above which the relation between concentration and harvest intensity changes; there was a greater change in concentration per unit change in harvest intensity when basal area removal was greater than 40%. These results indicate that the deleterious effects on aquatic ecosystems previously demonstrated for intensive harvests in northern hardwood forests of northeastern North America that receive high levels of atmospheric N deposition can be greatly diminished as harvesting intensity decreases below 40-68%. These results await confirmation through additional incremental forest harvest studies at other locations throughout the world that receive high levels of atmospheric N deposition.     

Leakage of forest harvest changes in a small open economy: case Norway

The effect of changes in roundwood harvests in Norway on the harvests in rest of the world is examined using a global forest sector model. About 60–100% of the harvest change in Norway is offset by an opposite change in the rest of the world. Such leakage rates vary over time, wood category, background scenario, and the size of the harvest change. Asymmetries between the effects of increasing and decreasing the harvests also exist. Hence, the magnitude of leakage rate is case specific, though considerable. Under tightening wood supply there is less need/room to respond to harvest increase/decrease in Norway with incremental/reduced harvests elsewhere. When the use of global forest resources intensifies with increasing wood demand in the future, leakage rates can be smaller than today. It is important to account for harvest leakage in order to avoid overestimating the climate benefits of policies that decrease or increase roundwood harvests. For instance, for full carbon sequestration benefits of increasing harvests for harvested wood products, creating fresh additional demand for these products should be prioritized. Else the origin of raw material and the place of production for these products may change instead of their stock.     

CHARACTERISTICS OF SMALL RODENT COMMUNITY IN DIFFERENT AGED CUT-OVER AREAS IN DAILING MOUNTAIN

STUDYAREAThefieldinvestigationofsmallrodentcommunitywasconductedinLiangshuiReservefromJunel0t0Julyl8,l992.LiangshuiReserve(El28o53'2OH,N47oI0,50H)locatedinDailingDistrict,YichunCity.Sixforestcut-overareaswithdifferentages(lyear,5years,l0years,l5years,2Oyearsand28years)wereselected.Inthecentreofeacharea,a2.5hm2sam-plesitewasmarkedout.Thetrappingdaymethodwasused.Fourtytrapswereplacedineachsampleareafortwo24-hourcyclesandwereexaminedonetimein24hours.Thebaitwasfreshpineseeds.Theseclear…     

Do ungulates preferentially feed in forest gaps in European temperate forest?

Ungulate populations across Europe have been strongly increasing over the past decades. Simultaneously with this increase, concerns about the impact of ungulates on forest systems, and forestry specifically, are increasing. In this study we discuss how the common forestry practice of creating clear cuts in relatively homogenous, managed forests may increase the potential impact of ungulates. Growth of trees in full light conditions is generally higher, but due to higher photosynthetic activity they tend to have higher C:N ratio in their leaves thus decreasing food quality. Next to that, biomass of herbaceous vegetation is enhanced in clear cuts. These changes likely affect foraging decisions of ungulates and it has been suggested that ungulates forage in forest gaps rather than in closed forest. We tested this hypothesis by using an experimental approach. The experiment was conducted in the Białowieża Primeval Forest in Poland, where a full assemblage of native large herbivores occurs. Six plots (6 m × 6 m) inside small clear cuts were compared to six control plots in adjacent closed forest. To exclude the effect of differences in number and species composition of available tree saplings, equal numbers of trees saplings of five species were planted at each plot. Ungulate visitation frequency and visitation time were measured by means of three methods: track plots, camera- and video trapping, and pellet counts. Visitation frequency of all ungulates combined (European bison, red deer, roe deer, moose and wild boar) was almost twice as high inside forest gaps compared to closed forest. Also cumulative visitation time by all ungulates tended to be higher inside forest gaps. Red deer showed the strongest preference for gaps, and duration of single visits was almost seven times longer for forest gaps than in closed forest. The observed preferential foraging of ungulates in forest gaps leads to an uneven distribution of their browsing behaviour. Hence, the creation of forest gaps by clear cutting followed by reforestation provides attractive foraging patches for ungulates potentially leading to high damage. In this way, forestry practices may enhance damage of ungulates to plantations especially when due to management the surrounding forest has a low carrying capacity for ungulates. We suggest that there is much to gain if management approaches would focus at influencing foraging behaviour of ungulates and reduce their concentration in forest gaps, rather than purely focusing on population control.     

Assessing the relations between aquatic habitat indicators and forest harvesting at watershed scale in the interior of British Columbia

Selection of appropriate aquatic habitat indicators is important for supporting sustainable forest and watershed management. To date, many identified watershed indicators have not been well tested. To address this issue, we sampled 28 stream reaches in the central and south interior of British Columbia, Canada. The selected reaches were similar with respect to gradient, watershed and topographic characteristics but with various levels of forest harvesting. Aquatic habitat indicators were derived based on a field survey, involving substrates, channel dimensions, pools, and large woody debris (LWD), together with some ratios and derivatives generated from them. Timber harvest disturbance at the watershed scale was quantified by calculating historical forest clear-cut area based on the BC vegetation resources inventory database. To account for the subsequent forest recovery, equivalent clear-cut area (ECA) was calculated based on the dominant species of each stream watershed and its regrowth since being logged. Pearson correlation coefficients showed that percent ECA and percent historical clear-cut area could effectively quantify the cumulative logging disturbance by limiting the effect of factors not related to logging activity (i.e., watershed area and elevations). These two variables were then related to the aquatic habitat indicators. Pearson correlation analyses found that relative width (ratio of D to bankfull width) (D is the b axis diameter of the largest substrate particle found in the reach), relative roughness (ratio of D to bankfull depth), pool frequency and per piece LWD volume are sensitive to percent ECA, i.e., significant (p < 0.01) while independent of influence from non-forest logging activity related factors and spatial clustering of samples. This relationship also holds true for the last two indicators when related to percent historical clear-cut area, though with a reduced degree of correlation. In addition, mean LWD diameter also showed significant relationship with percent historical clear-cut area, but not with percent ECA. Overall, per piece LWD volume was considered as the best aquatic habitat indicator. The performance of mean LWD diameter was comparable to per piece LWD volume if percent historical clear-cut area was used to quantify forest disturbance. Implications of these findings for forest management strategies are discussed.