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Southeast Asia is home to a large number of active and well-studied volcanoes, the majority of which are located in Indonesia and the Philippines. Northern Southeast Asia (Myanmar, Cambodia, Laos, Thailand and Vietnam) also hosts volcanoes that for several reasons (post-World War II conflicts, poor accessibility due to dense vegetation, no known historical activity) have been poorly studied. Systematic assessments of the threat these volcanoes pose to resident populations do not exist, despite evidence of numerous eruptions through the late Pleistocene and likely even during the Holocene. A recent study inferred the location of the Australasian meteorite impact to be beneath the Bolaven Volcanic Field in southern Laos; this study provided a wealth of data for the field: in particular, mapping of vents and flows, and their relative or absolute ages. The Bolaven Volcanic Field (16 Ma—< 40 ka) has a surface area of about 5000 km 2 , contains nearly 100 scoria cones and more than 100 individual lava flows. Some lava flow systems are as long as 50 km, with thickness ranging from a few meters at the flow edges, up to > 50 m in some locations. Building upon this foundation, we used the Bolaven Volcanic Field as a case study for assessing the potential exposure of populations and infrastructure to lava flows during future effusive eruptions. Our study uses remote sensing to map past flows and vents (i.e. scoria cones), lava-flow simulations from new simulated vents, and open-access exposure data, to assess hazards and exposure. Our results show that future vents are most likely to occur in a N-S band atop the Bolaven plateau, with some flows channelling into canyons and spilling down the plateau flanks onto lower plains that support more populated areas such as the provincial centre, Pakse. Our exposure assessment suggests that around 300,000 people could experience socio-economic impacts from future lava flow inundations. The largest impacts would be on two of the main economic sectors in the region, agriculture and hydropower. The potential also exists for life-threatening explosions from interactions between magma and surface waters, which are abundant in the region. We estimate an average recurrence interval of approximately 10,400 years, based on information from lava flows and scoria cones.

For 76 annual, biennial, and perennial species common in the grasslands of central Minnesota, USA, we determined the patterns of correlations among seven organ-level traits (specific leaf area, leaf thickness, leaf tissue density, leaf angle, specific root length, average fine root diameter, and fine root tissue density) and their relationships with two traits relating to growth form (whether species existed for part of the growing season in basal, non-caulescent form and whether species were rhizomatous or not). The first correlation of traits showed that grasses had thin, dense leaves and thin roots while forbs had thick, low-density leaves and thick roots without any significant differences in growth form or life history. The second correlation of traits showed a gradient of species from those with high-density roots and high-density erect leaves to species with low-density roots and low-density leaves that were held parallel to the ground. High tissue density species were more likely to exist as a basal rosette for part of the season, were less likely to be rhizomatous, and less likely to be annuals. We examined the relationships between the two axes that represent the correlations of traits and previously collected data on the relative abundance of species across gradients of nitrogen addition and disturbance. Grasses were generally more abundant than forbs and the relative abundance of grasses and forbs did not change with increasing nitrogen addition or soil disturbance. High tissue density species became less common as fertility and disturbance increased.

Aim: Large trees (d.b.h. ≥70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore which intrinsic (species trait) and extrinsic (environment) variables are associated with the density of large trees and forest biomass at continental and pan-tropical scales. Location: Pan-tropical. Methods: Aboveground biomass (AGB) was calculated for 120 intact lowland moist forest locations. Linear regression was used to calculate variation in AGB explained by the density of large trees. Akaike information criterion weights (AICcwi) were used to calculate averaged correlation coefficients for all possible multiple regression models between AGB/density of large trees and environmental and species trait variables correcting for spatial autocorrelation. Results: Density of large trees explained c. 70% of the variation in pan-tropical AGB and was also responsible for significantly lower AGB in Neotropical [287.8 (mean) ± 105.0 (SD) Mg ha⁻¹] versus Palaeotropical forests (Africa 418.3 ± 91.8 Mg ha⁻¹; Asia 393.3 ± 109.3 Mg ha⁻¹). Pan-tropical variation in density of large trees and AGB was associated with soil coarseness (negative), soil fertility (positive), community wood density (positive) and dominance of wind dispersed species (positive), temperature in the coldest month (negative), temperature in the warmest month (negative) and rainfall in the wettest month (positive), but results were not always consistent among continents. Main conclusions: Density of large trees and AGB were significantly associated with climatic variables, indicating that climate change will affect tropical forest biomass storage. Species trait composition will interact with these future biomass changes as they are also affected by a warmer climate. Given the importance of large trees for variation in AGB across the tropics, and their sensitivity to climate change, we emphasize the need for in-depth analyses of the community dynamics of large trees.

Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an effective predator of pests of tomato crops and a promising biocontrol agent of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in the Mediterranean area. The aim of this study was to determine the numerical response of N. tenuis to different levels of abundance of T. absoluta and its potential for controlling it when infesting tomato crops. The effects of infesting plants with either 0.2 or 2 larvae of T. absoluta and releasing either 2 or 0 adults of N. tenuis per plant were assayed in a complete factorial randomised-block design with 3 repeats in 12 greenhouse compartments in southern Spain. The population dynamics of the moth was similar in all compartments, with and without N. tenuis, but T. absoluta reached a lower absolute peak density in compartments with N. tenuis (29.1 +/- 8.2 larvae per leaf) than in those without them (44.5 +/- 19.4 larvae per leaf). The peak numbers of larvae of T. absoluta did not differ on the plants initially infested with 0.2 or 2 larvae. Nesidiocoris tenuis reached a maximum of 1.9 +/- 0.43 and 3.0 +/- 0.4 individuals per leaf in compartments in which low and high numbers of T. absoluta were initially introduced, respectively. The yield of tomatoes was higher in the treatments with N. tenuis than in those without, but the percentage of damaged fruit (more than 50%) was similar. The slow numerical response of N. tenuis might have been due, among other things, to the poor establishment of this mirid due to the scarcity of prey. N. tenuis densities of about 0.2 individuals per leaf during the linear population growth phase of T. absoluta (0.5 to 3 larvae per leaf) did not prevent outbreaks.

The study was conducted to evaluate the effect of Zn and Mn source (inorganic vs. organic) in the diet for hens on laying performance, eggshell and bones quality. The experiment was carried out on 84 Hy Line Brown hens, from 25 to 70 weeks of age, allocated to seven experimental groups, each containing 12 hens individually caged on wire-mesh floor. All layers were fed the same basal diet with 52 mg Zn/kg and 30 mg Mn/kg. Experimental diets were supplemented with 30 mg Zn/kg and 50 mg Mn/kg and inorganic forms of Zn (ZnO) and Mn (MnO) were gradually replaced (in 0, 50 or 100%) with their organic sources (amino acid complexes). Egg production, egg weight, feed intake and feed efficiency were not affected by dietary treatments. Substitution of Zn and Mn oxides with amino acid complexes of microelements had no effect on physical and geometrical characteristics of tibia, ash content in tibia and in toes, eggshell percent, eggshell thickness and eggshell density, but improved (P less than 0.05) the eggshell breaking strength in the late phase of the laying cycle (at 62 and 70 weeks of age). Our results indicate that feeding Zn and Mn organic complexes could alleviate the negative effect of hen age on eggshell breaking strength.

Interactions among predators can a have substantial effect on the total impact of the predator complex. We investigated the interaction between foliar-foraging (Coccinella septempunctata) and ground-foraging (Harpalus pennsylvanicus) predators of the pea aphid (Acyrthosiphon pisum) in a series of laboratory and field experiments. The intensity and direction of the interaction were determined by comparing the combined and individual impacts of both predators. In a laboratory mesocosm, the combined predation rate of both predators was nearly double the sum of their individual predation rates. The mechanism for the interaction was the aphid \"dropping\" behavior elicited by C. septempunctata, which rendered the aphids susceptible to predation by H. pennsylvanicus on the ground. The strength of the synergistic interaction increased with increasing prey density. The interaction between the predators was also demonstrated in both open and closed field cages where the combined impact of the two predators on aphid population growth was significantly greater than the sum of their individual impacts. These results indicate that the importance of ground-foraging predators in agroecosystems may need to be reevaluated and that positive interactions between predators must be considered in models predicting the impact of multiple predator complexes.

Wild boar population size in the Iberian Peninsula was estimated using hunting bag statistics from Spain and Portugal. Density was estimated assigning the wild boar population size to the “potential resources” or suitable habitats categorized by their importance to provide food and/or shelter to wild boars. Land uses were selected from CORINE, the EU database for land cover, using scientific literature and statistical significance for wild boar presence from published data. The hunting bag was 176245 and 15167 in Spain and Portugal, respectively. The average density was 0.373/km2 (min 0.014-max 2.22) in Spain and 0.13/km2 (min 0.00048-max 1.99) in Portugal, being 0.31/km2 (0.00048-2.22) over the entire Peninsula. Statistical analysis showed that wild boar presence was significantly (p < 0.05) associated to thirteen of the seventeen CORINE land uses selected. Agro-forestry, moors and heathland land use were not statistically significant but were included in the model due to their biological importance. Suitable habitats and distribution of wild boar were mapped for the Iberian Peninsula. This approach is a preliminary step intended to be useful in environmental management and animal health.

Root length and diameter distribution are important characteristics to be considered when describing and comparing root systems. Root length and root-diameter distribution may be obtained in two ways: by microscopical measurements, which are laborious, or by computerised analysis, which is fast but sensitive to the scanning protocol. Although scanning protocols vary widely between laboratories, papers rarely report the details. Using two commercially available root analysis software packages (Delta-T Scan and WinRHIZO), we performed a sensitivity analysis of scanning protocols for estimating root length and diameter distribution. The results are shown graphically, rather than numerically, because the interactions between different parameters in the overall scanning protocol are most clearly illustrated by the shape of the curves. The present analysis clearly demonstrated the sensitivity of the two scanning methods with regard to staining period, maximum root density, scanning resolution and transformation threshold. For example, estimating the root-diameter distribution versus measuring root length, puts opposite constraints on the transformation threshold settings. We suggest the following settings for the most sensitive parameters: a staining period of 24 h, a root density of less than 0.5 mm root per mm 2 surface, a resolution of 400 dpi and the automatic threshold for WinRHIZO and a brightness of 200 for Delta-T Scan. According to this protocol, comparison of computerised analyses with microscopic measurements showed good total root length and diameter distribution agreement for three contrasting root systems. We suggest to always start with the present protocol when studying other species. If validation indicates that the proposed scanning protocol needs to be modified for other species, the present sensitivity analysis may be used as a guideline for changing the most critical parameters. Similarly, the use of another stain than neutral red may also require modifications of the scanning protocol. In general, a long staining period (e.g., 24 h) is recommended for all stains, as small differences in staining period have the least effect when the root tissue is saturated. To enhance comparability of results in the literature, the staining period, stain, (maximum) root density, scanner resolution and threshold should always be listed when root data obtained by scanning are presented.

Despite the innumerable ecological problems and large economic costs associated with biological invasions, the proximate causes of invasion success are often poorly understood. Here, evidence is provided that reduced intraspecific aggression and the concomitant abandonment of territorial behavior unique to introduced populations of the Argentine ant contribute to the elevated population densities directly responsible for its widespread success as an invader. In the laboratory, nonaggressive pairs of colonies experienced lower mortality and greater foraging activity relative to aggressive pairs. These differences translated into higher rates of resource retrieval, greater brood production, and larger worker populations

This study examined the effects of density and layer structure on the mechanical properties and dimensional stability of strandboard manufactured from moso bamboo (Phyllostachys pubescens). The strandboard was fabricated in a laboratory at five densities and three different structures including a randomly oriented homogenous board, a unidirectionally oriented homogenous board, and a three-layered board with a cross-oriented core layer (BOSB). Bamboo strand alignment distribution could be predicted using the von Mises distribution function. Bending properties increased with increasing density and were affected by layer structure. The modulus of rupture (MOR) of the threelayered board in the parallel direction increased remarkably compared with the random board MOR; in the perpendicular direction, it exhibited less strength reduction. Elastic properties of the three-layered board could be predicted using elastic constants of the unidirectional board. Internal bond strength (IB) was greatly affected by density, but the layer structure effect did not appear in IB. Linear expansion per unit moisture change ranged from 0.017 to 0.022 for random and three-layered boards; these values are comparable with or lower than values for commercial board.