Logged Sites Research Articles

Scalable causal message logging for wide‐area environments

AbstractWide‐area systems are gaining in popularity as an infrastructure for running scientific applications. From a fault tolerance perspective, these environments are challenging because of their scale and their variability. Causal message logging protocols have attractive properties that make them suitable for these environments. They spread fault tolerance information around in the system providing high availability. This information can also be used to replicate objects that are otherwise inaccessible because of network partitions.However, current causal message logging protocols do not scale to thousands or millions of processes. We describe the Hierarchical Causal Message Logging Protocol (HCML) that uses a hierarchy of shared logging sites, or proxies, to significantly reduce the space requirements as compared with existing protocols. These proxies also act as caches for fault tolerance information and reduce the overall message overhead by as much as 50%. HCML also leverages differences in bandwidth between processes that reduces overall message latency by as much as 97%. Copyright © 2003 John Wiley & Sons, Ltd.

EVALUATING BUFFER STRIPS ALONG BOREAL STREAMS USING BRYOPHYTES AS INDICATORS

Buffer strips have recently become the main management practice for re- ducing logging impact on stream habitats in boreal and temperate regions. The habitat value of buffer strips, however, has not received much attention, although riparian forests belong to the systems with the highest biodiversity in these regions. We used plants as indicators of the ability of buffer strips to maintain an environment similar to intact riparian forests in a boreal forest landscape in northern Sweden. We measured the growth of three common bryophyte species (Hylocomiastrum umbratum , Calypogeia integristipula, and Tritomaria quinquedentata) transplanted to riparian habitat close to a stream in clear-cut logged sites, 10-15 m wide buffer strips on each side of the stream, and intact (reference) sites. Each of the three site categories included six wet and six moist-mesic sites and the experiment was followed over three months in 1999. The species remained vital in the reference sites and grew substantially during the 3- mo-long experiment, but in the logged sites almost no growth was registered, and many shoots died (except for T. quinquedentata). The pattern was consistent irrespective of the ground moisture class. The performance of bryophytes in the moist-mesic buffer strips was almost as bad as in the logged sites, whereas in the wet buffer strips it was either intermediate between that in logged and reference sites (H. umbratum) or very similar to that in reference sites (C. integristipula and T. quinquedentata). The edge effect has pre- viously been shown to vary depending on edge orientation, edge physiognomy, and weather conditions. We found that ground moisture can be of major importance as well. Although many buffer strips function better than no strips, 20-30 m wide strips (with a stream in the middle) through a logged area consist entirely of edge habitat. Increasing the buffer width and avoiding clear-cut logging on both sides of a watercourse would be the first steps to take for improving biodiversity conservation in riparian habitats. Our results also show that bryophytes are good indicators of habitat quality and efficient tools for assessing the ecological function of buffer strips.

Growth of black spruce seedlings planted in burned, logged, and undisturbed boreal mixedwood stands of southeastern Manitoba

Growth of black spruce seedling planted in burned, harvested, and undisturbed boreal mixedwood stands was studied in southeastern Manitoba. Although seedlings on each site were subjected to similar light competition (measured by % of full sunlight received at the middle crown of each crop seedling in 1998), mean annual growth of height, root collar diameter and aboveground biomass was different among the three sites, with burned > logged > undisturbed. During each of last seven years (1992 to 1998 except 1997), the burned site had greater annual height growth than the logged and undisturbed sites. Similarly, the logged site had greater height growth than the undisturbed site except 1997 and 1998. Relative competition intensity (calculated based on annual height growth from 1992 to 1998) fluctuated between 0.70 to 0.76 on the undisturbed site, increased from 0.48 to 0.73 on the logged site, and increased from 0.23 to 0.74 on the burned site. Relative competition intensity remained similar in the most recent three years (1996–1998) despite larger differences found in earlier years (1992–1995) between sites. A significant relationship was found between the relative competition intensity and % full sunlight on each site. Results from this case study suggested that, by affecting the development of competing vegetation, the type/intensity of past disturbances created different competition dynamics for black spruce seedlings planted on the burned, logged and undisturbed sites. Key words: interspecific competition, vegetation management, competition dynamics, plantation

木質材料 針葉樹バークを原料としたブロック状成形物の製造と材質評価

A composite made from bark, named bark-block, was developed to promote utilization of the bark residue. Airdried bark of Japanese conifers (sugi and hinoki) was used as furnish. The bark-block with dimensions of 400mm by 400mm by 55mm was fabricated using urethane resin as a binder. Steam was injected during pressing through holes on the press platen. Target density of this composite was 0.4g/cm3. A small-scale production machine that can be installed in a local sawmill or a logging site was designed for this purpose. The effect of manufacturing parameters on the properties of the bark-block was investigated to obtain the optimum conditions. The experimental results showed that bending properties (MOR and MOE), compressive stiffness, and IB strength increased with increasing resin content. Mechanical properties were proved to be controlled by the amount of the resin applied. It was found that the preferable steam injecting time for resin curing was 3 minutes. Thickness swelling was from 5 to 10 percent after water immersion treatment, while the water absorption was more than 80 percent. The bark-block produced have started to be used as a paving material in a park or in an exposition.

The Effect of Logging on the Ground-Foraging Ant Community in Eastern Amazonia

In order to determine the suitability of ants as indicator organisms for habitat disruption in tropical forests, we studied the effects of both high and low impact logging on ant communities in northeastern Pará State, in the Brazilian Amazon. We collected ants from logged forests and unlogged forest sites with Winkler bags throughout the 1998 rainy season (January and April) and the following dry season (July and September). Both methods of timber harvesting showed impacts on ant community composition when compared with unlogged forest, although these impacts did not include modifications in total species richness or the relative contribution of each ant subfamily to the total number of species. Instead, logging induced alterations took place at the level of species and genera. A 2-fold reduction in the dominance of ants of the highly diverse genus Pheidole was associated with forest alterations in high-impact logging sites. Thus, logging in Amazonia can be seen to promote species shifts in ant communities, without, however, altering species richness. Ants of the genus Pheidole are potentially useful indicators for forest disturbances resulting from timber extraction.

Strontium isotopes reveal distant sources of architectural timber in Chaco Canyon, New Mexico.

Between A.D. 900 and 1150, more than 200,000 conifer trees were used to build the prehistoric great houses of Chaco Canyon, New Mexico, in what is now a treeless landscape. More than one-fifth of these timbers were spruce (Picea) or fir (Abies) that were hand-carried from isolated mountaintops 75-100 km away. Because strontium from local dust, water, and underlying bedrock is incorporated by trees, specific logging sites can be identified by comparing (87)Sr/(86)Sr ratios in construction beams from different ruins and building periods to ratios in living trees from the surrounding mountains. (87)Sr/(86)Sr ratios show that the beams came from both the Chuska and San Mateo (Mount Taylor) mountains, but not from the San Pedro Mountains, which are equally close. Incorporation of logs from two sources in the same room, great house, and year suggest stockpiling and intercommunity collaboration at Chaco Canyon. The use of trees from both the Chuska and San Mateo mountains, but not from the San Pedro Mountains, as early as A.D. 974 suggests that selection of timber sources was driven more by regional socioeconomic ties than by a simple model of resource depletion with distance and time.

Breeding birds in the tropical rain forests of Kibale National Park, Uganda

AbstractA combination of trapping and foot surveys was used to assess the breeding status of birds in unlogged and logged sites in the tropical rain forest of Kibale National Park, Uganda. Breeding of forest edge and gap species was greatly enhanced by logging, whereas crevice and hole nesting specialist breeders were adversely affected. Egg‐laying periods corresponded to higher rainfall regimes at the nearby field station. The relevance of these findings to bird conservation is discussed.

Seasonal and annual changes of forest soil hardness at a logging site.

Seasonal and annual changes of forest soil hardness at a logging site.

Factors Controlling Periphyton Accrual during Summer in Headwater Streams of Southwestern British Columbia, Canada

In headwater coastal streams of southwestern British Columbia, previous research suggested that light limited periphyton growth and abundance of grazing invertebrates. Logging along a reach of stream allowed us to further examine the importance of light, as well as other abiotic factors, in regulating stream periphyton and grazers. We placed unglazed ceramic tiles in three watershed, two of which served as controls. In the third watershed, we placed tiles in one reach that was newly harvested, as well as in an upstream, forested reach. Tiles were placed in streams in late June and removed weekly over a six-week period for determination of periphyton chlorophyll α and ash-free dry mass. We also measured discharge, dissolved nitrate and phosphate, and counted the number of invertebrate grazers on each removed tile weekly. Peak biomass, as chlorophyll α, was reached on day 29 with alga biomass at the logged site (19 μg m−2) seven to fourteen times higher than at the control sites. Stepwise, multiple linear regression suggested that light was the single best predictor explaining 64% of the variation in peak biomass of chlorophyll a Although periphyton biomass on tiles was much higher in the clearcut reach, so was fine sediment. Inorganic mass entrapped in the periphyton mat was two to four times higher in the clearcut stream than at other sites. Grazer abundance was not related to periphyton biomass, but was negatively related to sediment levels. Our results are consistent with the hypothesis that grazer abundance was determined by sediment levels rather than alga biomass.

Does Reduced-Impact Logging Help Preserve Biodiversity in Tropical Rainforests? A Case Study from Borneo using Dung Beetles (Coleoptera: Scarabaeoidea) as Indicators

The role of reduced-impact logging on the preservation of biodiversity in tropical lowland dipterocarp rainforest is examined by looking at differences in dung beetle community structure between two sites logged in 1993: one harvested using reduced-impact methods and one using conventional techniques. Collections were made using two flight intercept traps over 7 d, and samples were compared with previous collections made from primary forest (riverine and interior-forest) and older forest logged using conventional techniques (logged in 1981). Of the two 1993 sites, the higher diversity and species richness (S = 57, n = 969, alpha = 13.23, H′ = 3.24) was recorded in the forest logged using reduced-impact techniques: the conventionally logged site had both lower diversity and species richness (S = 48, n = 1968, alpha = 8.88, H′ = 1.89), and lacked some primary forest specialists present in the reduced-impact forest samples. The dung beetle community in the 1993 conventional logged site is similar to that of the conventional logging site harvested in 1981. Primary forest has a well-defined ecotone, from interior to riverine forest: both 1993 sites contain a mixture of interior-forest and riverine specialists that are usually spatially separated along this ecotone. Although the dung beetle assemblage in the forest harvested by reduced-impact logging is more similar to a primary interior-forest assemblage than the conventionally logged site, both 1993 sites have assemblages that are closer in similarity to assemblages from primary-riverine habitat than they are to ones from primary interior-forest. However, because the forest logged using reduced-impact logging techniques has a more equitable and diverse dung beetle assemblage and a greater number of interior-forest specialists than the conventionally logged site, this study suggests that reduced-impact logging has better preserved the primary forest assemblage than conventional logging techniques.

EXPERIMENTAL TESTS OF THE SPATIOTEMPORAL SCALE OF SEED PREDATION IN MAST-FRUITING DIPTEROCARPACEAE

Mast-fruiting Dipterocarpaceae exhibit highly synchronous, interspecific seedfall at irregular, multiyear intervals. To investigate how the temporal pattern of seedfall affects dipterocarp seed and seedling survival, in both a logged and a primary lowland tropical forest, we planted Shorea stenoptera Burck seeds in the last three weeks of a 12-wk synchronous dipterocarp seedfall during a major community mast-fruiting event in West Kalimantan, Indonesia. As a result of commercial timber harvest of dipterocarp individuals eight years before, total dipterocarp seed production in the logged site was only 23% of that in the primary forest. At both sites, an average of 35 kg of seed was sown across a large area (≥1 km2) to examine the spatial pattern of seed destruction. During the period in which “natural” community mast seed was available to predators, 92% and 99% of experimentally sown seed escaped predators in logged and in primary forest, respectively. After regional seed resources were exhausted, nomadic vertebrates (primarily the bearded pig, Sus barbatus) were observed in both forest areas, and all ungerminated seed was destroyed. Seed predators arrived earlier in the logged area, before most experimentally sown seed had germinated, and the logged site experienced greater seed loss to vertebrates than did the primary forest. Because nomadic seed predators were absent during peak fruit fall of naturally occurring communities at both study sites, there was no evidence of local predator satiation. Rather, experimentally sown seed escaped predation because of rapid germination before predator arrival, as opposed to being ignored by satiated predators. Seed escape was more dependent on the late arrival of pigs than on the amount of local seed production. There was no significant spatial autocorrelation of seed predation. All remaining seed at the scale of the experiment (>1 km2) was destroyed by predators. These findings suggest that satiation of nomadic predators occurs at the landscape scale. Postdispersal seed predators caused significantly greater seed destruction in the experimentally sown seed populations than in naturally dispersed, mast-fruiting communities at both sites. In both logged and primary forests, there was significantly greater loss of experimentally sown seed to predation than was found in the entire natural mast-fruiting Shorea community combined (21 spp.). Moreover, a naturally occurring, but late-fruiting, Shorea species also exhibited greater seed losses to predation than did all other species within each mast-fruiting community, and these proportional losses were similar to those observed in the experimentally sown seeds. Seeds that escaped predation and vertebrate herbivory on post-establishment seedlings displayed high survival, indicating that the availability of suitable microsites did not limit recruitment. In the primary forest, 65% of the germinated experimental seed that survived early causes of mortality was alive 40 mo post-planting, which coincided with the next mast-fruiting event. The spatial distribution of these seedlings was modified primarily by the foraging behavior of vertebrate seed predators in the first two weeks post-planting. The influence of vertebrate predation on seed and seedling survival suggests that foraging behavior by terrestrial vertebrate seed predators may cause directional and/or stabilizing selection for synchronous, interspecific supra-annual dipterocarp seed production across forest regions in Kalimantan.

Better utilisation of the skidder winch can decrease the overrun on the logging site

SYNOPSIS A study of seven articulated wheel skidders was conducted at five different locations, where the winch line was pulled out for a distance of up to 60 metres from the skid trail. The further the winch line is pulled porn a skid trail to hitch a load, the further apart the skid trail spacing can be, with the resultant decrease in the negative effects of the skidder on the logging site. Winching skidder pay loads from beyond the usual 10 metres will involve a productivity and a cost penalty. The effect of a long winching distance on the productivity and cost of logging and its effect on the logging site is discussed.

The diet of the long‐footed potoroo (Potorous longipes)

The diet of the long‐footed potoroo Potorous longipes was studied at logged and unlogged sites in East Gippsland and northeastern Victoria. Most data were for two sites in East Gippsland, with the logged site (Bellbird) having the most samples. Faecal material collected between 1993 and 1995 at Bellbird comprised 91.2 ?? 4.4% fungal remains, with no significant seasonal variation, in contrast to all other dietary studies of Australian mycophagous mammals. There were, however, significant differences in the composition of the fungi consumed seasonally and between years. One genus of fungus, Mesophellia, constituted on average 40% of all spores found in scats at Bellbird and was the most seasonally variable. Mesophellia spores were least common in scats in winter 1993 and autumn/winter 1994 but most common in winter 1995. The high occurrence of Mesophellia in scats at Bellbird reflected the disturbed nature of the site. Fungal species requiring deep, friable soils and a deep litter layer were more commonly represented at comparatively undisturbed sites.

Wood-decomposing fungi and seed-tree cutting: A 40-year perspective

The effects of logging on wood-decomposing Basidiomycetes were studied in the boreal forests in northern Finland. The study area consisted of pine forest sites felled 3, 18 and 42 years before our study. The species composition of fungi in cut plots was compared to that of uncut old-growth forest sites. Altogether, 47 species were recorded on 570 logs. The species compositions reflected the amount and quality of coarse woody debris (CWD) available in the stands. In the old-growth stands, the species diversity was high, but the distribution of fungi was strongly affected by the patchy occurrence of CWD. Pioneer white-rot fungi predominated in the 3-year old logging sites. In the 40-year old logging sites, the number of species on the logging waste was 50–60% lower than in the old-growth forests, but the residual CWD from the pre-logging time still hosted a large portion of the species of the virgin forests. The species regarded as old-growth forest indicators showed different ecological tolerance to the effects of logging: the majority was confined only to naturally produced CWD, while some species were able to invade logging waste. The results showed that some polypores known to prefer old-growth forest habitats can survive for decades in managed forests. However, the species diversity of lignicolous fungi after logging greatly depended on the availability and diversity of decaying wood created before the management.

Monogamy in the bark beetle Ips latidens: ecological correlates of an unusual mating system

Abstract. 1. The diversity of mating systems in bark beetles (Coleoptera: Scolytidae) is poorly understood. Ips latidens (LeConte) is a small‐bodied species of a harem polygynous genus whose mating system in nature had not been established previously. This study examines the breeding biology of I. latidens breeding in recently dead ponderosa pine (Pinus ponderosa) in California. It was expected that both the heterogeneous habitat quality inherent in dead trees and small body size would favour polygyny.2. Contrary to expectations, I. latidens was found to be monogamous on the basis of excavations of 131 galleries conducted throughout the oviposition period at two wind‐felled trees and at four sites composed of freshly‐cut logs. Males left the galleries much sooner than females (50% gone by 24 and 36 days, respectively).3. Individual females made up to four egg gallery arms extending from the male nuptial chamber, with the number of arms and the length of individual arms increasing with the age of the gallery. The relationship between total gallery length and gallery age was consistent among the trees and log sites, and did not depend on the presence of the male.4. Ips latidens bred in a wide range of tree diameters (10–24 cm), and occurred in both pure aggregations and in aggregations with two other bark beetle species, Dendroctonus brevicomis and I. paraconfusus. The presence of the other species did not appear to influence negatively the density of I. latidens.5. Monogamy in I. latidens may be due to lower male mortality during dispersal associated with a greater range of suitable breeding habitat than occurs for other Ips species, resulting in an even sex ratio at breeding sites.

Preliminary estimates of the population density of the Sokoke scops owl Otus ireneae Ripley in the East Usambara lowlands, Tanzania

Preliminary population density estimates are presented for a recently discovered population of the Sokoke scops owl Otus ireneae in the lowlands of the East Usambara mountains, Tanzania. Calling birds were mapped at two sites totalling 6·3 km2. Approximate densities were 3–4 territories/km2 in Kwamgumi Forest Reserve and <1·5 territories/km2 in Manga Forest Reserve, a much more heavily logged site. Densities in prime habitat in Arabuko‐Sokoke forest, Kenya, the only other locality for the species, exceed seven territories/km2. The total population in the East Usambaras cannot be calculated, but it is probably markedly smaller than in Arabuko‐Sokoke. Suggestions for more precise surveys are made.

Monitoring carbon sequestration benefits associated with a Reduced-Impact Logging Project in Malaysia

The Reduced-Impact Logging Project, a pilot carbon offset project, was initiated in 1992 when a power company provided funds to a timber concessionaire to implement timber-harvesting guidelines in dipterocarp forest. The rationale for the offset is that when logging damage is reduced, more, carbon is retained in living trees, and, because soil damage is minimized, forest productivity remains high. To estimate the carbon benefit associated with implementation of harvesting guidelines, a monitoring program was developed based on 1) field studies for measuring carbon stocks and flows; 2) a computer model of forest carbon dynamics for simulating various combinations of harvesting intensity and damage; and, 3) a projection model for calculating carbon balance over the project lifespan. Seventy-five percent of the carbon stored in this forest is in biomass, and of this, 59% is in large, trees (≧6- cm, diameter); consequently, reliable estimates of variables related to large trees are critical to the estimate of carbon benefits. Allometric methods for estimating belowground biomass are recommended over pit-sampling methods because of low cost-effectiveness of obtaining precise estimates of woody root biomass. Sensitivity analyses of variables used in the simulation model suggest that maintenance of ecosystem productivity has a large influence on long-term carbon storage in the forest. Projections of differences in carbon stores between the reduced-impact and conventional logging sites rely on assumptions about tree mortality, growth, and recruitment; published, data for comparable sites in Malaysia are probably appropriate for estimating forest recovery from conventional but not reduced-impact logging. Continuing field work is expected to provide the data needed to evaluate assumptions of the models.

Issues associated with the retention of hollow-bearing trees within eucalypt forests managed for wood production

The conservation of hollow-dependent fauna is a major forest management problem in natural eucalypt forests managed for wood production. Eucalypt forests support a diverse fauna that utilise hollows in trees. Hollow-bearing trees are a component of forest structure often lost or substantially modified as a result of timber harvesting operations, especially those that are intensive (like clearfelling) and take place on a short rotation (< 120 years) One approach adopted to conserve populations of hollow-dependent fauna in eucalypt forests has been to retain suitable trees in logged areas. This paper reviews a wide range of issues associated with the retention of such trees ranging from: (1) the characteristics of trees which should be selected for retention; (2) the number and spatial arrangement of retained stems; (3) the need for recruitment of new hollow-bearing trees to ensure there is a perpetual supply of such resources; and (4) how best to protect those trees that are retained. We also consider factors such as the inter-relationships between tree retention strategies and silvicultural requirements, and on-site tree retention strategies and forest management at the landscape-scale. A major conclusion from our study is that the array of issues associated with the retention of trees with hollows in eucalypt forests is considerably more complex than reflected by current management practice. Indeed, it appears that most existing prescriptions for the retention of trees with hollows in logged sites may not ensure a perpetual supply of a range of types of hollow trees or provide the necessary habitat conditions to support viable populations of some species of hollow-dependent fauna. This is because current prescriptions typically do not take account of factors such as: the prolonged periods until hollows first begin to develop in Eucalyptus trees; mortality and collapse amongst retained stems; and the need to supply trees with suitable characteristics and in a suitable configuration to meet the requirements of the full range of vertebrate taxa that utilise this resource. Taking these factors into account, we conclude that only modified partial cutting systems would adequately provide for the needs of all cavity-using species across logged sites in eucalypt forests. A major problem confounding attempts to develop more informed prescriptions for the retention of trees in logged areas is a lack of data on key topics such as stem longevity and hollow ontogeny, mortality of retained trees on logged sites and cavity use by animals. There is scope for some of these data to be readily gathered in routine timber assessment and inventory, stand regeneration surveys and fauna and vegetation surveys. We recommend that forest and wildlife management agencies review their field survey methods and include some new measures among the range of data collected. There is also considerable merit in instigating new tree and forest modelling projects to simulate long-term stand conditions in wood production eucalypt forests. Such studies would guide forest and wildlife managers in the development of tree retention strategies needed to create and maintain stand characteristics suitable to support populations of hollow-dependent wildlife over not one, but many rotations. Given the uncertainty associated with the effects of these operations on hollow-dependent fauna, and continued timber harvesting operations in these forests, we recommend a strategy which maintains a variety of approaches to management. Such a strategy is akin to ‘risk spreading’ and would involve implementing a range of tree retention strategies within cutting areas as well as the adoption of a number of strategies at the landscape level (e.g. wildlife corridors).

The effects of road design and harvest intensity on forest damage caused by selective logging: empirical results and a simulation model from the Bosque Chimanes, Bolivia

Selective harvesting in tropical forests has been shown to cause considerable damage to residual trees in stands that have relatively high densities of commercial trees. To complement existing studies, we measured forest damage caused by the selective harvesting of mahogany ( Swietenia macrophylla), a very low density species in the Bosque Chimanes, Bolivia. Secondary damage along main roads and skid trails accounted for most of the damage measured in the study site. Total damage was low (4.39% of the study area), but results from our simulation model suggested that damage could be decreased by up to 25% by requiring main roads and skid trails to be linear. We used our simulation model to investigate the relationship between harvest intensity and forest damage. At low harvest intensities, most forest damage occurs from the construction of main roads. As harvest intensity increases, secondary damage from skid trails and tree felling comes to dominate forest damage. Overall, less damage will result to the forest for a given harvest volume if the harvest area is reduced and harvest intensity increased. Additional benefits to increasing harvest intensity are that re-entry into the logged site can be delayed, allowing the forest more time to recover, and regeneration of light-demanding species such as mahogany can be enhanced. The main impediment to increasing the harvest intensity in selective harvesting operations in Latin America is the lack of international markets for lesser known species, although there is some local and national demand.

A state of afairs on logging site by feller buncher and grapple skidder (III) : Natural regeneration after one year of logging

A state of afairs on logging site by feller buncher and grapple skidder (III) : Natural regeneration after one year of logging