First report of Ectinogonia buquetti (Spin.) (Coleoptera: Buprestidae) in bioenergy plantations of Eucalyptus camaldulensis (Dehnh.) in Chile

Ectinogonia buquetti (Spin.) (Coleoptera, Buprestidae) was identified as the agent causing damage on a Eucalyptus camaldulensis (Dehnh.) bioenergy plantation. Damage affected the principal apex and upper lateral branches and loss of lateral branches on E. camaldulensis due to complete ring-barking. E. buquetti is a coleopteron native to Chile, it preferably feeds on the wood of native species. A total of 205 individuals, all adults were found; 45% of the plants presented some type of damage.     

Effect of stocking on juvenile wood stiffness for three <Emphasis Type="Italic">Eucalyptus</Emphasis> species

The effects of stocking on wood stiffness (MoE) for three Eucalyptus species are quantified using a 6-year-old trial established in New South Wales, Australia. An acoustic time-of-flight tool measured the velocity between two probes in the outerwood, from which the stiffness was estimated. Four stocking levels (714, 1,250, 1,667 and 3,333 sph) were examined. Stiffness varied significantly between all species, with E. cloeziana showing the highest stiffness (14.2–15.7 GPa), followed by E. pilularis (12.2–13.5 GPa) and E. dunnii (10.7–12.6 GPa). There was a stiffness increase (around 11%) between 714 and 1,250 stems/ha for all species but thereafter differences between stockings were not always significant. Trees were also assessed for basic density, dbh, total height, crown area, green crown height and stem slenderness (height/dbh). Only stem slenderness had a significant association (0.41 ± 0.17) with stiffness. These findings suggest that, where stiffness is a priority, forest managers could reduce establishment costs with low stockings (around 1,250 stems/ha).

Nutritional status and genetic variation in the response to nutrient availability in Pinus pinaster. A multisite field study in Northwest Spain

The low nutrient availability of the acidic and sandy soils of Galicia (Northwest Spain) is probably the main environmental factor limiting forest primary productivity in the area. These particular edaphic conditions could have imposed selective pressures on maritime pine populations leading to specific local adaptations.We first assessed the nutritional status of 22 young contemporary Pinus pinaster plantations in Northwest Spain, and then analysed the response to fertilization in three family × fertilization trials, and how this response varied across sites and genotypes.Growth of P. pinaster in Northwest Spain appeared to be largely limited by nutrient availability, where most of the plantations showed severe nutrient deficiencies, especially in P and Mg. According to these deficiencies, a strong positive response to nutrient additions was observed in the three trials, with height increments of up to 30% compared with the unfertilized control. However, the response to fertilizers was very variable from site to site, and in some cases did not agree with the foliar nutritional diagnosis. The response to fertilization was also significantly affected by pine genotype, suggesting that the plastic response to nutrient additions within each environment was under genetic control. However, the family response to nutrient availability was not consistent across sites, and no significant differences among families were observed for the RDPI plasticity index – a single index that summarizes the phenotypic change in multiple environments – when analysed across environments.The strong environmental component modulating phenotypic responses to fertilization could impose an important obstacle to evolve specific adaptations to the local edaphic conditions, as well as to artificially select genotypes adapted to different environments and silviculture regimes.     

Succession and management of tropical dry forests in the Americas: Review and new perspectives

Understanding tropical forest succession is critical for the development of tropical forest conservation strategies worldwide, given that tropical secondary forests can be considered the forests of the future. Tropical dry forests (TDF) are among the most threatened tropical ecosystems, there are more secondary forests and forest restoration efforts that require a better understanding of successional processes. The main goal of this synthesis for this special issue on the ecology and management of tropical dry forests in the Americas is to present a summarized review of the current knowledge of the ecology and management implications associated to TDF succession. We explore specific issues associated to tropical dry forest succession with emphasis on the use of chronosequences, plant diversity and composition, plant phenology and remote sensing, pollination, and animal–plant interactions; all under the integrating umbrella of ecosystem succession. We also emphasize the need to conduct socio-ecological research to understand changes in land-use history and its effects on succession and forest regeneration of TDF. We close this paper with some thoughts and ideas associated with the strong need for an integrating dimension not considered until today: the role of cyberinfrastructure and eco-informatics as a tool to support sound conservation, management and understanding of TDF in the Americas.     

Chemical constituents of Roldana lineolata

The new eremophilanolide 1, the known eremophilane derivatives 2 and 3, already described as part of mixtures, the known compounds hyperin, 2'-acetylhyperin and two calenduladiol esters were isolated from Roldana lineolata. Their structures were determined by spectroscopic methods. Compounds 1 and 2 as well as their acetylated and oxidized derivatives were tested against several fungi strains. Eremophilanolide 1 showed a mild activity against Trichophyton mentagrophytes.     

Effects of landscape patterns on species density and abundance of trees in a tropical subdeciduous forest of the Yucatan Peninsula

Most studies of the effects of fragmentation and landscape patterns on plant communities focus on particular patches and on local species richness (α-diversity), while few studies examine different patch-types at the whole landscape level and address effects on abundance and composition of species or functional groups. The present study aims to identify and characterize relationships between patch-type metrics and species density and abundance of trees using four tropical subdeciduous forest landscapes in the Yucatan Peninsula considering the entire landscape as the unit of study. Species density and abundance of different groups of tree species resulting from hierarchical clustering were related to landscape patterns of patch-types (area, edge, shape, similarity and contrast) using regression analysis and Akaike Information Criterion (AIC). The abundance of tree species in the oldest stages of succession was associated with percentage of land of a patch-type. Total area may favor the establishment of shade-tolerant tree species in the study area because as the area of forest patches increases, the area of forest interior conditions also increases. Conversely, the abundance of species at early and intermediate stages was related to total edge contrast and edge density, respectively. Fragmentation increases the proportion of edge zones of a patch-type, creating contrasting microclimate conditions that could promote the establishment of pioneer and light-demanding species. Thus, the combined effect of total area and edge length of a patch-type may enhance total tree species richness in the study area by favoring species with different life-history strategies. The appearance of area, shape, edge and contrast in most of the regression models suggests that some generalization can be made about the effects of spatial geometry of patch-types on species composition and abundance of tropical trees. Understanding associations between landscape metrics and species density and abundance of objectively derived groups or guilds of species can provide important insights on the effects of fragmentation and landscape pattern on these guilds and on overall α-diversity, as well as guidelines for their conservation and management.     

Antioxidant Compounds Recovery from Juçara Residue by Thermal Assisted Extraction

This study aimed to recover bioactive compounds by solid-liquid extraction from the agro-industrial residue obtained during juçara fruits processing into pulp. A preliminary study using different solvents (methanol, ethanol and water) indicated ethanol in aqueous solution as the best solvent for antioxidants recovery. Then, a Box-Behnken design was applied considering as independent variables the solvent composition (30–70% ethanol in water), temperature (30–70 °C) and time (30–60 min), in order to evaluate the effects of these factors on antioxidant activity in juçara extract. Results showed that the extracts with higher antioxidant activity were obtained using 30% ethanol at 70 °C for 60 min; measurements included ABTS and DPPH assays, determination of total phenolic content and total monomeric anthocyanins. Furthermore, the effect of pH in antioxidants recovery was evaluated. For this purpose, the 30% ethanol solution was acidified to pH 1 and 2 with HCl. Principal component analysis showed the formation of three distinct groups: one characterized by high bioactive compounds content (pH 1.0), another with superior antioxidant activity (pH 5.75, non-acidified), and finally the group at pH 2 presenting the worst concentrations in the evaluated responses. HPLC analysis showed the presence of cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside in the extracts. Therefore, the conventional solid-liquid extraction using renewable solvent can be successfully applied to recover bioactive compounds from juçara residue, which can be used by different food industries.     

Vegetative propagation of the underutilized oilseed crop sacha inchi (<Emphasis Type="Italic">Plukenetia volubilis</Emphasis> L.)

Underutilized crop species have the potential to aid in alleviating some of the challenges faced by the world today; reduced food security and malnutrition, land degradation, and climate change. The incorporation of little-known crops into sustainable agricultural systems provides new developmental opportunities and can increase the resilience of food production systems. However, measures need to be taken to address issues of variation in product quality and access to propagation material. Plukenetia volubilis L. (Euphorbiaceae) is an oleaginous liana native to the Amazon basin. It is of growing economic importance in the food, pharmaceutic, cosmetic and horticultural industries, however, commercial cultivars are lacking and the genetic variation within the species is very high. Furthermore, the majority of landraces of P. volubilis are susceptible to nematodes. In order to attain plants with a consistent quality and yield, vegetative propagation schemes are beneficial. Grafting is an especially favourable technique which enables the selection of pest and disease resistant rootstocks in combination with high-yielding or ornamentally valuable scions. Three different grafting techniques combined with three different systems of protection were tested on P. volubilis and evaluated according to the growth of the scions following grafting. The experiment was carried out under nursery conditions in the San Martín region of Peru, where P. volubilis is commonly cultivated. Regardless of the grafting technique, a 100% survival rate was found for plants covered with a plastic bag following grafting. This result may aid in the further domestication of P. volubilis by providing farmers with access to plant material of consistent quality and allowing the selection of pest resistant rootstocks in combination with high-yielding scions.     

Snapshots Analyses for Turbidity Measurements in Water

Turbidity has been used as an effective indicator of water quality and it is regulated by national control agencies as a water potability parameter. This work proposes a simple, low-cost, and easily reproducible method based on digitally processed snapshots of electromagnetic radiation beam through a scattering medium in order to measure turbidity. The formazin polymer was used as the standard reference in the experiments to prepare samples from 0.1 to 100 NTU for high turbidity range and from 0.02 to 10 FNU for low turbidity range. The device design is comprised of a webcam and an LED/laser as a light sensor and a radiation source, respectively. The captured scattered light snapshot can be decomposed digitally in color components values and correlated with the turbidity parameter. It is possible to obtain differently device performances changing the light sensor device configuration. The linear regression analyses have shown a distinct relationship among red, green, blue, and grayscale components and the turbidity. At high range, the green component present the best LOD and LOQ values 0.64 and 2.10, respectively, operating with an ordinary webcam and white LED. Nevertheless, the best device performances were obtained with dedicated Raspberry Pi camera modules and white LED for low range turbidity reaching LOD=0.027 and LOQ=0.087 FNU. The figures of merit show recovery between (97.50?101.95%), repeatability (2.11%), within-laboratory reproducibility (2.25%), and limits of quantification (0.087 FNU). The achieved performance device shows the effectiveness of digitally processed snapshots obtained with digital cameras for turbidity measurements.