Search results for "540"
showing 10 items of 720 documents
50,000 years of ice and seals: Impacts of the Last Glacial Maximum on Antarctic fur seals
2021
Abstract Ice is one of the most important drivers of population dynamics in polar organisms, influencing the locations, sizes, and connectivity of populations. Antarctic fur seals, Arctocephalus gazella, are particularly interesting in this regard, as they are concomitantly reliant on both ice‐associated prey and ice‐free coastal breeding areas. We reconstructed the history of this species through the Last Glacial Maximum (LGM) using genomic sequence data from seals across their range. Population size trends and divergence events were investigated using continuous‐time size estimation analysis and divergence time estimation models. The combined results indicated that a panmictic population …
Responses of a native plant species from invaded and uninvaded areas to allelopathic effects of an invader
2019
Invaders exert new selection pressures on the resident species, for example, through competition for resources or by using novel weapons. It has been shown that novel weapons aid invasion but it is unclear whether native species co‐occurring with in‐ vaders have adapted to tolerate these novel weapons. Those resident species which are able to adapt to new selective agents can co‐occur with an invader while others face a risk of local extinction. We ran a factorial common garden experiment to study whether a native plant species, Anthriscus sylvestris, has been able to evolve a greater tolerance to the allelochemicals exerted by the invader, Lupinus polyphyllus. Lupinus polyphyllus produces …
Phylogeny of the ant genus Aphaenogaster (Hymenoptera: Formicidae) in the Iberian Peninsula, with the description of a new species
2018
A phylogenetic tree of the Iberian Aphaenogaster species - except for A. splendida (Roger) - and a key to the worker caste of all Iberian Aphaenogaster species are proposed. The position of A. striativentris Forel and A. cardenai Espadaler is discussed, stating the possibility that this second species may belong to a new, undescribed genus. Aphaenogaster ulibeli n. sp. is described from the Iberian Peninsula. Its closest relatives are A. gibbosa (Latreille) and A. striativentris. Its habitat seems to be restricted to caducifolia forests in the Western Central Massif.
Will legal international rhino horn trade save wild rhino populations?
2020
Wild vertebrate populations all over the globe are in decline, with poaching being the second-most-important cause. The high poaching rate of rhinoceros may drive these species into extinction within the coming decades. Some stakeholders argue to lift the ban on international rhino horn trade to potentially benefit rhino conservation, as current interventions appear to be insufficient. We reviewed scientific and grey literature to scrutinize the validity of reasoning behind the potential benefit of legal horn trade for wild rhino populations. We identified four mechanisms through which legal trade would impact wild rhino populations, of which only the increased revenue for rhino farmers cou…
Trade-offs between ecosystem service provision and the predisposition to disturbances: a NFI-based scenario analysis
2020
Abstract Background Scenario analyses that evaluate management effects on the long-term provision and sustainability of forest ecosystem services and biodiversity (ESB) also need to account for disturbances. The objectives of this study were to reveal potential trade-offs and synergies between ESB provision and disturbance predisposition at the scale of a whole country. Methods The empirical scenario model MASSIMO was used to simulate forest development and management from years 2016 to 2106 on 5086 sample plots of the Swiss National Forest Inventory (NFI). We included a business-as-usual (BAU) scenario and four scenarios of increased timber harvesting. Model output was evaluated with indic…
Evolution of sexually dimorphic pheromone profiles coincides with increased number of male‐specific chemosensory organs in Drosophila prolongata
2019
Abstract Binary communication systems that involve sex‐specific signaling and sex‐specific signal perception play a key role in sexual selection and in the evolution of sexually dimorphic traits. The driving forces and genetic changes underlying such traits can be investigated in systems where sex‐specific signaling and perception have emerged recently and show evidence of potential coevolution. A promising model is found in Drosophila prolongata, which exhibits a species‐specific increase in the number of male chemosensory bristles. We show that this transition coincides with recent evolutionary changes in cuticular hydrocarbon (CHC) profiles. Long‐chain CHCs that are sexually monomorphic …
Factors controlling plankton community production, export flux, and particulate matter stoichiometry in the coastal upwelling system off Peru
2020
Eastern boundary upwelling systems (EBUS) are among the most productive marine ecosystems on Earth. The production of organic material is fueled by upwelling of nutrient-rich deep waters and high incident light at the sea surface. However, biotic and abiotic factors can modify surface production and related biogeochemical processes. Determining these factors is important because EBUS are considered hotspots of climate change, and reliable predictions of their future functioning requires understanding of the mechanisms driving the biogeochemical cycles therein. In this field experiment, we used in situ mesocosms as tools to improve our mechanistic understanding of processes controlling organ…
Sex ratio at mating does not modulate age fitness effects in Drosophila melanogaster
2019
Abstract Understanding the effects of male and female age on reproductive success is vital to explain the evolution of life history traits and sex‐specific aging. A general prediction is that pre‐/postmeiotic aging processes will lead to a decline in the pre‐ and postcopulatory abilities of both males and females. However, in as much the sexes have different strategies to optimize their fitness, the decline of reproductive success late in life can be modulated by social context, such as sex ratio, in a sex‐specific manner. In this study, we used Drosophila melanogaster to investigate whether sex ratio at mating modulates age effects on male and female reproductive success. As expected, male…
sPlotOpen – An environmentally balanced, open‐access, global dataset of vegetation plots
2021
Datos disponibles en https://github.com/fmsabatini/sPlotOpen_Code
Biotope Determinants of EPT Assamblages Structure – Târnava Watershed (Transylvania, Romania) Case Study
2015
Abstract This study aims to analyze the biotopic factors affecting the EPT assemblage diversity in the rivers of the Târnava Watershed. Our research revealed that the high diversity of the Plecoptera communities is associated with river reaches with boulder and cobble lithological substrate, accentuated slope and natural bank dynamics, and also it is directly correlated with dissolved oxygen and inversely correlated with chemical and biochemical oxygen demand, total hardness, nitrates and total nitrogen in the water. The high diversity of the Trichoptera communities is associated with water which presents moderate quantities of nutrients (total phosphorus, phosphates) and with river reaches…