Improved timber harvest techniques maintain biodiversity in tropical forests

Tropical forests are selectively logged at 20 times the rate at which they are cleared, and at least a fifth have already been disturbed in this way. In a recent pan-tropical assessment, Burivalova et al. demonstrate the importance of logging intensity as a driver of biodiversity decline in timber estates. Their analyses reveal that species richness of some taxa could decline by 50% at harvest intensities of 38 m3 ha-1. However, they did not consider the extraction techniques that lead to these intensities. Here, we conduct a complementary meta-analysis of assemblage responses to differing logging practices: conventional logging and reduced-impact logging. We show that biodiversity impacts are markedly less severe in forests that utilise reduced-impact logging, compared to those using conventional methods. While supporting the initial findings of Burivalova et al., we go on to demonstrate that best practice forestry techniques curtail the effects of timber extraction regardless of intensity. Therefore, harvest intensities are not always indicative of actual disturbance levels resulting from logging. Accordingly, forest managers and conservationists should advocate practices that offer reduced collateral damage through best practice extraction methods, such as those used in reduced-impact logging. Large-scale implementation of this approach would lead to improved conservation values in the 4 million km2 of tropical forests that are earmarked for timber extraction

Representing Structural Information of Helical Charge Distributions in Cylindrical Coordinates

Structural information in the local electric field produced by helical charge distributions, such as dissolved DNA, is revealed in a straightforward manner employing cylindrical coordinates. Comparison of structure factors derived in terms of cylindrical and helical coordinates is made. A simple coordinate transformation serves to relate the Green function in cylindrical and helical coordinates. We also compare the electric field on the central axis of a single helix as calculated in both systems.Comment: 11 pages in plain LaTex, no figures. Accepted for publication in PRE March, 199

Interpolating fields of carbon monoxide data using a hybrid statistical-physical model

Atmospheric Carbon Monoxide (CO) provides a window on the chemistry of the atmosphere since it is one of few chemical constituents that can be remotely sensed, and it can be used to determine budgets of other greenhouse gases such as ozone and OH radicals. Remote sensing platforms in geostationary Earth orbit will soon provide regional observations of CO at several vertical layers with high spatial and temporal resolution. However, cloudy locations cannot be observed and estimates of the complete CO concentration fields have to be estimated based on the cloud-free observations. The current state-of-the-art solution of this interpolation problem is to combine cloud-free observations with prior information, computed by a deterministic physical model, which might introduce uncertainties that do not derive from data. While sharing features with the physical model, this paper suggests a Bayesian hierarchical model to estimate the complete CO concentration fields. The paper also provides a direct comparison to state-of-the-art methods. To our knowledge, such a model and comparison have not been considered before.Comment: Published in at http://dx.doi.org/10.1214/08-AOAS168 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

High conservation value or high confusion value? Sustainable agriculture and biodiversity conservation in the tropics

Green labeling of products that have been produced sustainably is an emerging tool of the environmental movement. A prominent example is the Forest Stewardship Council, which certifies timber that is harvested to manage and maintain forests defined as having High Conservation Value (HCV). The criteria for HCV are now being applied to four rapidly expanding crops in the tropics: oil palm, soy, sugarcane, and cacao. However, these criteria do not provide adequate protection for biodiversity when applied to agriculture. The only criterion that provides blanket protection to forests is one that protects large expanses of habitat (≥20,000-500,000 ha, depending on the country). Absent of other HCVs, the collective clearing of forest patches below these thresholds could result in extensive deforestation that would be sanctioned with a green label. Yet such forest patches retain much biodiversity and provide connectivity within the agricultural matrix. An examination of forest fragments in biodiverse countries across the tropics shows that future agricultural demand can be met by clearing only forest patches below a 1,000 ha threshold. We recommend the development of a new HCV criterion that recognizes the conservation value of habitat patches within the agricultural matrix and that protects patches above 1,000 ha. © 2011 Wiley Periodicals, Inc

Preventing tropical mining disasters

Mining for fossil fuels and minerals is penetrating into many of the world's most remote and biologically important tropical forests. In the Amazon, there are some 53,000 active mining leases (1), and hundreds of billions of dollars in new mines are planned across the Congo basin (2). But are extractive industries in the tropics investing sufficiently to prevent environmental disasters

Review of best management practices for aquatic vegetation control in stormwater ponds, wetlands, and lakes

Auckland Council (AC) is responsible for the development and operation of a stormwater network across the region to avert risks to citizens and the environment. Within this stormwater network, aquatic vegetation (including plants, unicellular and filamentous algae) can have both a positive and negative role in stormwater management and water quality treatment. The situations where management is needed to control aquatic vegetation are not always clear, and an inability to identify effective, feasible and economical control options may constrain management initiatives. AC (Infrastructure and Technical Services, Stormwater) commissioned this technical report to provide information for decision- making on aquatic vegetation management with in stormwater systems that are likely to experience vegetation-related issues. Information was collated from a comprehensive literature review, augmented by knowledge held by the authors. This review identified a wide range of management practices that could be potentially employed. It also demonstrated complexities and uncertainties relating to these options that makes the identification of a best management practice difficult. Hence, the focus of this report was to enable users to screen for potential options, and use reference material provided on each option to confirm the best practice to employ for each situation. The report identifies factors to define whether there is an aquatic vegetation problem (Section 3.0), and emphasises the need for agreed management goals for control (e.g. reduction, mitigation, containment, eradication). Resources to screen which management option(s) to employ are provided (Section 4.0), relating to the target aquatic vegetation, likely applicability of options to the system being managed, indicative cost, and ease of implementation. Initial screening allows users to shortlist potential control options for further reference (Section 5.0). Thirty-five control options are described (Section 5.0) in sufficient detail to consider applicability to individual sites and species. These options are grouped under categories of biological, chemical or physical control. Biological control options involve the use of organisms to predate, infect or control vegetation growth (e.g. classical biological control) or manipulate conditions to control algal growth (e.g. pest fish removal, microbial products). Chemical control options involve the use of pesticides and chemicals (e.g. glyphosate, diquat), or the use of flocculants and nutrient inactivation products that are used to reduce nutrient loading, thereby decreasing algal growth. Physical control options involve removing vegetation or algal biomass (e.g. mechanical or manual harvesting), or setting up barriers to their growth (e.g. shading, bottom lining, sediment capping). Preventative management options are usually the most cost effective, and these are also briefly described (Section 6.0). For example, the use of hygiene or quarantine protocols can reduce weed introductions or spread. Catchment- based practices to reduce sediment and nutrient sources to stormwater are likely to assist in the avoidance of algal and possibly aquatic plant problems. Nutrient removal may be a co-benefit where harvesting of submerged weed biomass is undertaken in stormwater systems. It should also be considered that removal of substantial amounts of submerged vegetation may result in a sudden and difficult-to-reverse s witch to a turbid, phytoplankton dominated state. Another possible solution is the conversion of systems that experience aquatic vegetation issues, to systems that are less likely to experience issues. The focus of this report is on systems that receive significant stormwater inputs, i.e. constructed bodies, including ponds, amenity lakes, wetlands, and highly-modified receiving bodies. However, some information will have application to other natural water bodies

Analysis of United Kingdom Off-Highway Construction Machinery Market and Its Consumers Using New-Sales Data

The off-highway construction machinery market and its consumers have attracted minimal previous research. This study addresses that void by analyzing annual United Kingdom (UK) (volume/portfolio) new-sales data for the 10 most popular products within that market, 1990–2010 inclusive. Graphical, descriptive statistical, Pearson-correlational, autocorrelational, and elementary modeling are employed to identify contrasts in sales regarding (1) high- and low-volume items; (2) growth trends and significant recessionary effects on volumes; (3) a demand change point circa 1997, since when annual product portfolio has changed little; and (4) product associations in consumer demand. Significant association is demonstrated between demand and construction output, especially with the value of new housing. Subsequently, consumption of wheeled loaders is modeled using construction volume, and demand for mini and crawler excavators is modeled using new-housing data. Time series trends for these machinery types are presented and forecast through 2015. The primary contribution of this study is a deeper understanding of the UK new-machinery market and the predilections of its consumers over the last two decades (to present)

Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts

Attempts to use coarse-grained molecular theories to calculate corrections to the random-phase approximation (RPA) for correlations in polymer mixtures have been plagued by an unwanted sensitivity to the value of an arbitrary cutoff length, {\it i.e.}, by an ultraviolet (UV) divergence. We analyze the UV divergence of the inverse structure factor $S^{-1}(k)$ predicted by a `one-loop' approximation similar to that used in several previous studies. We consider both miscible homopolymer blends and disordered diblock copolymer melts. We show, in both cases, that all UV divergent contributions can be absorbed into a renormalization of the values of the phenomenological parameters of a generalized self-consistent field theory (SCFT). This observation allows the construction of a UV convergent theory of corrections to SCFT phenomenology. The UV-divergent one-loop contribution to $S^{-1}(k)$ are shown to be the sum of: (i) a $k$-independent contribution that arises from a renormalization of the effective $\chi$ parameter, (ii) a $k$-dependent contribution that arises from a renormalization of monomer statistical segment lengths, (iii) a contribution proportional to $k^{2}$ that arises from a square-gradient contribution to the one-loop fluctuation free energy, and (iv) a $k$-dependent contribution that is inversely proportional to the degree of polymerization, which arises from local perturbations in fluid structure near chain ends and near junctions between blocks in block copolymers.Comment: 35 pages, 2 figure