Biodiversity,dynamics, and impact of chakras on the Ecuadorian Amazon

Aims Deforestation and biodiversity loss are two alarming, closely related problems, and the main factors triggering changes in land use. Indigenous agricultural practices in the western Amazon Basin are known as chakras, and their structure and dynamics are seemingly optimal for forest management. However, the variability in tree species and the degree of forest recovery after abandonment is poorly documented in this agroforestry system (AFS). The goals of this study were: (i) to investigate whether the different AFSs (chakras) preserve similar levels of forest diversity, (ii) to determine the effect of transformation of mature forests (MF) to chakras, in particular, forest alpha and beta diversity levels, and (iii) to investigate whether native tree species recovery leads to the original forest structure following chakra abandonment.     

Pockmarks enhance deep‐sea benthic biodiversity: a case study in the western Mediterranean Sea

Aim Pockmarks are craters on the sea floor formed by sub‐sea‐floor fluid expulsions, which occur world‐wide at all ocean depths. These habitats potentially host a highly specialized fauna that can exploit the hydrocarbons released. Pockmarks at relatively shallow depths can be easily destroyed by human activities, such as bottom trawling. In the present study, we investigated the combined effects of sea‐floor heterogeneity, rate of fluid emission and trophic conditions of different pockmarks on the biodiversity of the deep‐sea assemblages. Location Continental slope of the Gulf of Lions, western Mediterranean Sea, at water depths from 265 to 434 m. Methods We investigated the biodiversity associated with sea‐floor pockmarks that are both inactive and that have active gas emissions. Control sites were selected on the sea floor outside the influence of the gas seepage, both within and outside the pockmark fields. We examined the combined effects of: (i) sea‐floor heterogeneity; (ii) variable levels of fluid (gas) emissions; and (iii) trophic characteristics of the meiofaunal assemblage structure and nematode diversity. Results Sediments within the pockmark fields had lower meiofaunal abundance and biomass when compared with the surrounding sediments that were not influenced by the gas seepage. Although several higher taxa were absent in the pockmarks (e.g. Turbellaria, Tardigrada, Cumacea, Isopoda, Tanaidacea, Nemertina and Priapulida, which were present in the control areas), the richness of the nematode species within all of these pockmarks was very high. About 25% of the total species encountered in the deep‐sea sediments of the investigated areas was exclusively associated with these pockmarks. Main conclusions We conclude that both active and inactive pockmarks provide significant contributions to the regional (gamma) diversity of the continental slope in the western Mediterranean Sea, and thus the protection of these special and fragile habitats is highly relevant to the conservation of deep‐sea biodiversity.     

Piecing together our woodlands – Interview with Suzanne Prober

Over nearly three decades, Suzanne Prober has played a pivotal role in shifting research in Australian agricultural landscapes to include a focus on native woodlands, and to examine ways woodland conservation can co‐exist with production, contributing to new models for conservation within multi‐use landscapes.     

The latitudinal position of peak marine diversity in living and fossil biotas

Aim Peak marine taxonomic diversity has only rarely occurred at or near the equator during the Phanerozoic Eon, in contrast to the present‐day pattern. This fundamental difference is difficult to reconcile because the latitude at which peak diversity occurs for living marine taxa has not yet been explicitly determined at a broad taxonomic and spatial scale. Here, we attempt to determine this value in order to compare the contemporary and fossil patterns directly. Location Our data are global in coverage. Methods We used a literature compilation of 149 present‐day marine latitudinal diversity gradients. We summed the number of marine taxa that exhibited peak diversity within 10° latitudinal bins. In addition, we recorded locality data, general habitat (benthic/pelagic), and the taxonomic level of the study organisms. Results We found that peak diversity for most sampled marine taxa currently occurs between 10° and 20° N, even after correcting for a Northern Hemisphere sampling bias. Moreover, this peak position is a global phenomenon: it is found across habitats and higher taxa, within all sampled ocean basins, and on both sides of the Atlantic and Pacific oceans. Benthic taxa, which dominate our data, exhibit one peak at 10°–20° N, while pelagic taxa exhibit a peak at 10°–20° N and an additional peak at 10°–20° S, producing a distinct trough at the equator. Main conclusions Our data indicate that peak marine diversity for many taxa is currently within 10°–20° N rather than at the equator, and that this is not likely to result from either undersampling at lower latitudes or the pattern being dominated by a particular taxon. Possible explanations may include a coincidence with the intertropical convergence zone, a mid‐domain effect, abundant shallow marine habitat, or high ocean temperatures at latitudes nearest the equator. Regardless of its exact cause, the position of peak diversity should be considered a fundamental feature of the latitudinal diversity gradient that must be accounted for within attempts to explain the latter’s existence.     

Expression patterns of the creatine metabolism‐related molecules AGAT,GAMT and CT1 in adult zebrafish Danio rerio

AGAT, GAMT and CT1, three creatine synthesis and transport‐related molecules, have been widely studied in mammals. To explore their homologous genes in adult zebrafish Danio rerio, the gene expression patterns of these three genes in D. rerio were investigated. The results reveal that AGAT, GAMT and CT1 are expressed widely in diverse tissues of D. rerio where the homologous genes in mammals are also expressed.     

Effect of Soybean Monoculture on the Bacterial Communities Associated with Cysts of Heterodera glycines

The soybean cyst nematode (SCN), Heterodera glycines, can cause significant reductions in soybean yield and quality in many parts of the world. Natural biological control may play an important role in regulating SCN population. In this study the bacterial communities associated with SCN cysts obtained from fields under different lengths of soybean monoculture were explored. Soil samples were collected in 2010 and 2011 from six fields that had been used for soybean monoculture for 2 to 41 yr. SCN population densities were determined and bacterial communities from SCN cysts were investigated by Biolog and PCR-DGGE methods. SCN population densities initially increased in the first 5 yr of soybean monoculture but then declined steeply as years of soybean monoculture increased. Catabolic diversity of bacterial communities associated with cysts tended to decline as number of years of monoculture increased. Some specific PCR-DGGE bands, mainly representing Streptomyces and Rhizobium, were obtained from the cysts collected from the long-term monoculture fields. Principal component analysis of Biolog and PCR-DGGE data revealed that bacterial communities associated with cysts could be divided into two groups: those from cysts obtained from shorter (< 8 yr) vs. longer (> 8 yr) monoculture. This research demonstrates that the composition of the bacterial communities obtained from SCN cysts changes with length of soybean monoculture; the suppressive impact of these bacterial communities to SCN is yet to be determined.     

Pollen morphology of Solanurn L. section Solanum

J. M. EDMONDS, 1984. Pollen morphology of Solanum L. section Solnnum . The pollen morphology of both dried and fresh, fixed material was examined using SEM. The work confirmed thc spheroidal to sub-prolate shape, the tricolporate nature and the granular surface sculpturing, typical of Solanurn pollen, but failed to demonstrate the occurrence of exine patterns which could bc of practical taxonomic use is differentiating the species belonging to the section Solanurn . Quantification of the exine sculpturing, by means of granule density counts, indicated a possible relationship between this feature and the morpho-genetic diversity of certain species.     

Assessing the biodiversity benefits of plantations: The Plantation Biodiversity Benefits Score

Summary   All forests, including commercial plantations, provide a range of habitats for conserving and enhancing elements of native biodiversity. However, the biodiversity values of commercial plantations will depend on the management practices adopted on site, as well as the landscape context of the plantation. The present study describes a generic, quantitative method for assessing the potential biodiversity benefits that might be derived from a plantation, depending on the management practices adopted. This method is based on existing ecological design and management principles. The Plantation Biodiversity Benefits Score (PBBS) was designed to be repeatable and practical to apply. The method can be used either as a stand-alone tool or as part of an integrated framework to assess and compare the commercial and environmental benefits that can be derived from different layouts, management practices and locations of plantations anywhere in Australia.