Search results for "SCA"

Fine-Scale Population Differences in Atlantic Cod Reproductive Success: A Potential Mechanism for Ecological Speciation in a Marine Fish

2018

Abstract Successful resource‐management and conservation outcomes ideally depend on matching the spatial scales of population demography, local adaptation, and threat mitigation. For marine fish with high dispersal capabilities, this remains a fundamental challenge. Based on daily parentage assignments of more than 4,000 offspring, we document fine‐scaled temporal differences in individual reproductive success for two spatially adjacent (<10 km) populations of a broadcast‐spawning marine fish. Distinguished by differences in genetics and life history, Atlantic cod (Gadus morhua) from inner‐ and outer‐fjord populations were allowed to compete for mating and reproductive opportunities. After …

Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?

2016

Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana) on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recentl…

Landowner preferences and conservation prioritization: response to Nielsen et al.

2017

Eco-geomorphological connectivity and coupling interactions at hillslope scale in drylands: Concepts and critical examples

2020

The diagnosis of land degradation requires a deep understanding of ecosystem functioning and evolution. In dryland systems, in particular, research efforts must address the redistribution of scarce resources for vegetation, in a context of high spatial heterogeneity and non-linear response. This fact explains the prevalence of eco-hydrological perspectives interested in runoff processes and, the more recent, focused on connectivity as an indicator of system resource optimisation. From a geomorphological perspective and reviewing the concepts of eco-hydro-geomorphological interactions operating in ecosystems, this paper explores the effects of erosion on vegetation configuration through two …

An early Ca2+ influx is a prerequisite to thaxtomin A-induced cell death in Arabidopsis thaliana cells

2008

International audience; The pathogenicity of various Streptomyces scabies isolates involved in potato scab disease was correlated with the production of thaxtomin A. Since calcium is known as an essential second messenger associated with pathogen-induced plant responses and cell death, it was investigated whether thaxtomin A could induce a Ca 2+ influx related to cell death and to other putative plant responses using Arabidopsis thaliana suspension cells, which is a convenient model to study plant–microbe interactions. A. thaliana cells were treated with micromolar concentrations of thaxto-min A. Cell death was quantified and ion flux variations were analysed from electrophysiological measu…

Towards understanding isotope variability in elephant ivory to establish isotopic profiling and source-area determination

2016

Abstract We present here new isotopic data (δ 13 C, δ 15 N, δ 18 O, δ 2 H, and δ 34 S) from pulverised ivory powder, measured by continuous flow isotope ratio mass spectrometry from an unprecedented large dataset of 507 ivory samples, derived from twenty-eight African and six Asian elephant range states. The aim of this study is to assess the accuracy of isotopic fingerprinting and to evaluate its forensic potential and limitations to predict the provenance of ivory of unknown origin. We constructed a nominal assignment framework for the African reference samples, consisting of 208 different sites and applied the weighted k -Nearest Neighbor Classifier with reference site as classifier and …

Occurrence of ‘blue’ and ‘frost’ rings reveal frost sensitivity of eastern Baltic provenances of Scots pine

2020

Abstract Assisted gene flow is advised as one of the most effective means to sustain the productivity of forests under warming climate via application of the provenances (genotypes) capable to utilize longer vegetation season. Nevertheless in the temperate and boreal zones, the extension of vegetation period also subjects trees to effects of frosts, which can have severe economic impact under warming climate. In this study, wood anatomical anomalies related to late frosts in spring (‘frost’ rings) and early frosts in late summer (‘blue’ rings) for the eastern Baltic provenances of Scots pine (Pinus sylvestris L.) with a contrasting field performance were analysed retrospectively. Three tria…

Sclerochronology - a highly versatile tool for mariculture and reconstruction of life history traits of the queen conch, Strombus gigas (Gastropoda)

2009

International audience; The queen conch, Strombus gigas, is an important fisheries resource in the Western Tropical Atlantic. In order to maintain harvesting success, improve fisheries management and contribute to mariculture pursuits, a detailed understanding of the life history traits of this species is required. Traditionally, this has been achieved by tedious and time-consuming long-term field observations. This study presents a highly versatile and rapid technique to estimate the timing and rate of shell growth based on sclerochronology. The Belizean S. gigas specimens (N = 2) from the offshore atoll, Glovers Reef, reached their final shell size (maximum shell height: 22.7 and 23.5 cm,…

Positive impacts of important bird and biodiversity areas on wintering waterbirds under changing temperatures throughout Europe and North Africa

2020

Clausen, Preben/0000-0001-8986-294X WOS: 000536149100018 Migratory waterbirds require an effectively conserved cohesive network of wetland areas throughout their range and life-cycle. Under rapid climate change, protected area (PA) networks need to be able to accommodate climate-driven range shifts in wildlife if they are to continue to be effective in the future. Thus, we investigated geographical variation in the relationship between local temperature anomaly and the abundance of 61 waterbird species during the wintering season across Europe and North Africa during 1990-2015. We also compared the spatio-temporal effects on abundance of sites designated as PAs, Important Bird and Biodivers…

Winter movement patterns of a globally endangered avian scavenger in south-western Europe

2020

AbstractPartial migration, whereby some individuals migrate and some do not, is relatively common and widespread among animals. Switching between migration tactics (from migratory to resident or vice versa) occurs at individual and population levels. Here, we describe for the first time the movement ecology of the largest wintering population of Egyptian Vultures (Neophron percnopterus) in south-west Europe. We combined field surveys and GPS tracking data from December to February during four wintering seasons (2014–2018). The wintering population consisted on average of 85 individuals (range 58–121; 76% adults and 24% subadults). Individuals were counted at five different roosting sites lo…