Arthropod availability in relation to ruffed grouse brood habitat in the southern Appalachians

Arthropod availability to ruffed grouse (Bonasa umbellus) chicks was studied by sweep netting on 6 habitats considered to be brood range in the Cherokee National Forest, Tennessee. The objectives of the study were: (1) determine the abundance, biomass, and taxa of arthropods collected in these habitats, and (2) determine which forest management practices are most beneficial to ruffed grouse chicks in terms of arthropod production and vegetative structure. Arthropod abundance was highest on managed logging roads and in mature hardwood with herbaceous ground cover, while arthropod biomass was highest on managed logging roads. Managed logging roads were sowed and maintained in clover and/or orchard grass. Young clearcuts (\u3c 3 years old) were least productive of arthropods. Arthropods representing taxa preferred by chicks were most abundant on managed logging roads and in mature hardwood with herbaceous ground cover. No significant differences were determined in arthropod abundance or biomass between unmanaged logging roads traversing mature hardwood and unmanaged logging roads passing through clearcuts. Managed logging roads planted to clover were more productive than those planted to orchard grass in terms of arthropod abundance and biomass. Arthropods from the taxa preferred by chicks were more abundant on roads where clover was the principal vegetative component. Maintenance of ruffed grouse chicks should be highest where optimal cover (areas of high woody stem density) is located near habitat productive for arthropods

The impact of logging roads on dung beetle assemblages in a tropical rainforest reserve

The demand for timber products is facilitating the degradation and opening up of large areas of intact habitats rich in biodiversity. Logging creates an extensive network of access roads within the forest, yet these are commonly ignored or excluded when assessing impacts of logging on forest biodiversity. Here we determine the impact of these roads on the overall condition of selectively logged forests in Borneo, Southeast Asia. Focusing on dung beetles along > 40 km logging roads we determine: (i) the magnitude and extent of edge effects alongside logging roads; (ii) whether vegetation characteristics can explain patterns in dung beetle communities, and; (iii) how the inclusion of road edge forest impacts dung beetle assemblages within the overall logged landscape. We found that while vegetation structure was significantly affected up to 34 m from the road edge, impacts on dung beetle communities penetrated much further and were discernible up to 170 m into the forest interior. We found larger species and particularly tunnelling species responded more than other functional groups which were also influenced by micro-habitat variation. We provide important new insights into the long-term ecological impacts of tropical logging. We also support calls for improved logging road design both during and after timber extraction to conserve more effectively biodiversity in production forests, for instance, by considering the minimum volume of timber, per unit length of logging road needed to justify road construction. In particular, we suggest that governments and certification bodies need to highlight more clearly the biodiversity and environmental impacts of logging roads

How persistent are the impacts of logging roads on Central African forest vegetation?

Logging roads can trigger tropical forest degradation by reducing the integrity of the ecosystem and providing access for encroachment. Therefore, road management is crucial in reconciling selective logging and biodiversity conservation. Most logging roads are abandoned after timber harvesting; however, little is known about their long-term impacts on forest vegetation and accessibility, especially in Central Africa. In 11 logging concessions in the Congo Basin, we field-sampled a chronosequence of roads that, judging from satellite images, had been abandoned between 1985 and 2015. We assessed recovery of timber resources, tree diversity and above-ground biomass in three zones: the road track, the road edge (where forest had been cleared during road construction) and the adjacent logged forest. The density of commercial timber species <15 cm d.b.h. was almost three times higher in the road track (321 individuals ha−1) and edge (267) than in the logged adjacent forest (97). Over time, tree species diversity converged to a comparable level between roads and adjacent forests, along with an increase in canopy closure. The average width of forest clearing for road construction was 20 m, covering a total 0·76% of the forest area inside concessions. After 15 years following abandonment, road tracks had recovered 24 Mg ha−1 of above-ground woody biomass, which was 6% of that in the adjacent forest, while road edges had accumulated 167 Mg ha−1 (42%). Ten years after abandonment, roads were no longer penetrable by poachers on motorcycles. An exotic herb species was fully replaced by dominant Marantaceae that have even higher abundance in the adjacent forest. • Synthesis and applications. Our evidence of vegetation recovery suggests that logging roads are mostly transient elements in the forest landscapes. However, given the slow recovery of biomass on abandoned road tracks, we advocate both reducing the width of forest clearing for road construction and reopening old logging roads for future harvests, rather than building new roads in intact forests. Road edges seem suitable for post-logging silviculture which needs to be assisted by removing dominant herbs during the early years after abandonment while the road track is still accessible. (Résumé d'auteur

Legacy of logging roads in the Congo Basin: how persistent are the scars in forest cover?

Logging roads in the Congo Basin are often associated with forest degradation through fragmentation and access for other land uses. However, in concessions managed for timber production, secondary roads are usually closed after exploitation and are expected to disappear subsequently. Little is known about the effectiveness of this prescription and the factors affecting vegetation recovery rate on abandoned logging roads. In a novel approach we assessed logging roads as temporary elements in the forest landscape that vary in persistence depending on environmental conditions. We analyzed road persistence during the period 1986–2013 in adjacent parts of Cameroon, Central African Republic and Republic of Congo. Three successive phases of road recovery were identified on LANDSAT images: open roads with bare soil, roads in the process of revegetation after abandonment and disappeared roads no longer distinguishable from the surrounding forest. Field based inventories confirmed significant differences between all three categories in density and richness of woody species and cover of dominant herbs. We used dead-end road segments, built for timber exploitation, as sampling units. Only 6% of them were identified as being re-opened. Survival analyses showed median persistence of four years for open roads before changing to the revegetating state and 20 years for revegetating roads before disappearance. Persistence of revegetating roads was 25% longer on geologically poor substrates which might result from slower forest recovery in areas with lower levels of soil nutrient content. We highlight the contrast amongst forests growing on different types of substrate in their potential for ecosystem recovery over time after roads have been abandoned. Forest management plans need to take these constraints into account. Logging activities should be concentrated on the existing road network and sites of low soil resource levels should be spared from business-as-usual exploitation. (Résumé d'auteur

Decker v. Northwest Environmental Defense Center

In Decker v. Northwest Environmental Defense Center(“Decker”), the United States Supreme Court considered whether the Clean Water Act (“CWA”) and its implementing regulations require states and industry to obtain permits for stormwater runoff from ditches and culverts built as part of logging roads. The Court determined that the Rule exempts discharges of “channeled stormwater” from logging roads under the CWA

Logging roads in tropical forests:Synthesis of literature written in French and English highlights environmental impact reduction through improved engineering

Logging roads are considered to be a major cause of forest degradation because of their direct and indirect impacts on ecosystem functioning and biodiversity. Given the prevalence of logging in tropical forests around the world, effective road management is of crucial importance to reduce both logging- related environmental impacts and the costs of logging operations. Through a review of the literature, our study analysed how logging roads have been addressed in scientific articles to date. We compared studies published over the past 65 years in the Bois et Forêts des Tropiques journal (BFT), mostly written in French, with a range of more recent articles from the Scopus and Web of Knowledge databases. Half of the articles in BFT were published before 1972, while the more generalist databases show a steady increase in publications on the subject since then, up to the current peak number. From the entire body of literature, we selected 126 articles dealing with impacts and management of logging roads in tropical forests around the world for critical appraisal. The BFT articles were characterized by a strong focus on practical issues in forest road engineering, while the focus of many publications written in English was on the identification of road impacts on forest ecosystems. Road-related environmental impacts stem from the loss of forest cover during construction, the increase in edge effects, soil erosion and interference with wildlife, as well as from the resulting easier access to the forest for hunting and agricultural colonization. Based on this review, we present a list of recommended measures to reduce these impacts. We conclude that, despite the continuing attention given to the subject of logging roads, little is known about how they evolve in the forest landscape over the long term. (Résumé d'auteur

Natural regeneration of trees in selectively logged forest in western Amazonia.

We evaluated the impacts of selective logging on tree regeneration one, four, and eight years after harvests in Antimary State Forest in the State of Acre, Brazil. We inventoried tree seedlings, saplings, and poles (>50 cm tall to <10 cm DBH) on secondary roads, log landing, and skid trails, as well as in the bole and crown zones of canopy gaps created by felling; for comparison we also sampled areas not affected directly by logging. We compared these habitats on the basis soil (physical) characteristics, canopy cover, and floristic composition. For areas one and four years after logging, we supplemented the ground-based information with aerial LiDAR data. By eight years post-logging the size class distributions of tree regeneration in all habitat types resembled those in unlogged areas, and densities were only lower in crown gaps. Eight years after logging, relative densities of pioneer trees were highest on secondary roads and log landings; no among habitat differences were observed in the relative densities of non-pioneer species at any time along the chronosequence. Tree species diversity (Fisher's alpha) converged on unlogged values on skid trails, bole gaps, and crown gaps at 8-years post-logging, but values remained lower on secondary roads and log landings. Canopy openness was greatest one year after logging, especially in log landings (mean 45.4 ± SE 4.5%) whereas four and eight years post-logging it did not exceed 10% and no differences were found among habitats. Soil bulk density was elevated relative to un-logged areas only on log landings one and four years after logging, and this difference disappeared by eight years postlogging. The total area disturbed by logging varied from 7.0% to 8.6% with nearly half of the totals in felling gaps (3.0-3.7%)