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  • McLaughlin Hewitt posted an update 9 days ago

    Certain genotypes either contain active transposable elements or are more permissive of transposition and accumulate copies of particular transposable elements. Overall, it is important to quantify genotype-specific transposable element dynamics as well as population averages to understand the dynamics of transposable element accumulation over time. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.Bushmeat hunting has reduced population sizes of large frugivorous vertebrates throughout the tropics, thereby reducing the dispersal of seeds. This is believed to affect tree population dynamics, and therefore community composition, because the seed dispersal of large-seeded trees depends upon large-bodied vertebrates.We report on a long-running study of the effect of defaunation on a tropical tree community. In three censuses over 11 years, we compared sapling recruitment between a hunted and a nonhunted site, which are nearby and comparable to one another, to determine the extent to which species composition has changed through time following defaunation. We expected to find a reduced abundance of tree species that rely on large frugivores for dispersal at the hunted site and altered community structure as a consequence.Although community composition at the hunted site diverged from that at the nonhunted site, the changes were independent of dispersal syndrome, with no trend toward a decline in species that are dispersed by large, hunted vertebrates. Moreover, the loss of large-bodied dispersers did not generate the changes in tree community composition that we hypothesized. Some species presumed to rely on large-bodied frugivores for dispersal are effectively recruiting despite the absence of their dispersers.Synthesis The presumption that forests depleted of large-bodied dispersers will experience rapid, directional compositional change is not fully supported by our results. Altered species composition in the sapling layer at the hunted site, however, indicates that defaunation may be connected with changes to the tree community, but that the nature of these changes is not unidirectional as previously assumed. It remains difficult to predict how defaunation will affect tree community composition without a deeper understanding of the driving mechanisms at play. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.One of the key features in reproduction of polygynous species is seminal recovery after mating. However, it is poorly known how environmental factors affect the recuperation period of seminal material. This study aims to test plasticity in recovery of seminal reserves in response to distinct environmental conditions of the kelp crab Taliepus dentatus. Male crabs were maintained after depletion of seminal reserves in one of eight different treatments in a factorial design of temperature (12 and 16°C), food availability (with alimentation and food deprivation), and time period (15 and 30 days), simulating different environmental situations in the laboratory to which the crab might be exposed to along its distribution. Temperature and food availability modulated the seminal recovery period in T. dentatus. Complete replenishment was reached within 30 days in all treatments (i.e., 12 and 16°C each with alimentation and food deprivation), but the highest recovery index was found in crabs without food provision (16°C). In this condition, the recovery index was twice as high compared with males maintained at a similar temperature but with feeding. Prolonged starvation at 16°C may be extremely stressful conditions for male crabs, during which risk to die probably triggered a concentration of the reproductive effort in favor of immediate reproduction. This suggests that plasticity of energy allocation toward reproduction may be expressed during extremely suboptimal conditions, which might be a similar strategy as proposed by the terminal investment hypothesis. The generally relatively fast seminal recovery regardless of the temperature may explain the kelp crab’s continuous mating throughout the year. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.Mass loss and nutrient release during litter decomposition drive biogeochemical cycling in terrestrial ecosystems. However, the relationship between the litter decomposition process and the decomposition stage, precipitation, and litter quality has rarely been addressed, precluding our understanding of how litter decomposition regulates nutrient cycling in various ecosystems and their responses to climate change. In this study, we measured mass loss as well as carbon and nutrient releases during the decomposition of 16 types of leaf litter under three precipitation treatments over 12 months in a common garden experiment (i.e., using standardized soil and climatic conditions). Sixteen types of leaves were divided into three functional groups (evergreen, deciduous, and herbaceous). The objectives were to understand the effects of decomposition stages and precipitation regimes on litter decomposition and to examine the relationship between this effect and chemical properties. The mass loss and release of nitrogen and potassium were significantly higher in the 6- to 12-month stage of decomposition (high temperature and humidity) than in the 0- to 6-month stage. Phosphorus was relatively enriched in evergreen leaves after 6 months of decomposition. The rates of mass loss and nutrient release were significantly greater in herbaceous than in deciduous and evergreen leaves. Increasing precipitation from 400 to 800 mm accelerated mass loss and potassium release but decreased phosphorus release in the 0- to 6-month stage of decomposition. NVP-BGT226 These results highlighted the contribution to and complexity of litter chemical properties in litter decomposition. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.The Coral Triangle (CT), a region spanning across Indonesia and Philippines, is home to about 4,350 marine fish species and is among the world’s most emblematic regions in terms of conservation. Threatened by overfishing and oceans warming, the CT fisheries have faced drastic declines over the last decades. Usually monitored through a biomass-based approach, fisheries trends have rarely been characterized at the species level due to the high number of taxa involved and the difficulty to accurately and routinely identify individuals to the species level. Biomass, however, is a poor proxy of species richness, and automated methods of species identification are required to move beyond biomass-based approaches. Recent meta-analyses have demonstrated that species richness peaks at intermediary levels of biomass. Consequently, preserving biomass is not equal to preserving biodiversity. We present the results of a survey to estimate the shore fish diversity retailed at the harbor of Ambon Island, an island located at the center of the CT that display exceptionally high biomass despite high levels of threat, while building a DNA barcode reference library of CT shore fishes targeted by artisanal fisheries.

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