We applied newly developed methods for modelling the distribution of invasive species to the invasive shrub Rhododendron ponticum-a foliar reservoir host for the Phytophthora oomycete plant pathogens, P. ramorum and P. kernoviae, that threaten woodland and heathland habitat in Scotland. We compiled eleven datasets of biological records for R. ponticum (1,691 points, 8,455 polygons) and developed Maximum Entropy (MaxEnt) models incorporating landscape, soil and climate predictors. Our models produced accurate predictions of current suitable R. ponticum habitat (training AUC = 0.838; test AUC = 0.838) that corresponded Selleckchem Androgen Receptor Antagonist well with population performance
(areal cover). Continuous broad-leaved woodland cover, low elevation (< 400 m a.s.l.) and intermediate levels of soil moisture (or Enhanced Vegetation Index) favoured presence of R. ponticum. The high coincidence of suitable habitat with both core native woodlands (54 % of woodlands) and plantations of another sporulation host, Larix kaempferi (64 % of plantations) suggests a high potential selleck for spread of Phytophthora infection to woodland mediated by R. ponticum. Incorporating non-equilibrium modelling methods did not improve habitat suitability predictions of this invasive host, possibly because, as a long-standing invader, R. ponticum has filled more of its available habitat at this national scale than previously suspected.”
physiological and behavioural responses of early life phases in
American Atlantic sturgeon (Acipenser oxyrinchus) towards sand and gravel substrate were examined during the first 15 days post-hatch. The free embryos were reared in circular tanks with approximately 30% of the bottom surface covered with either coarse gravel or sand. A group reared in tanks without additional substrate served as a control. Diurnal differences in activity patterns were observed. Substrate use by the free embryos revealed significant differences during the first 5 days post-hatch, being higher in the gravel group than in the sand group. The results in size of the free embryos revealed significant differences, with the gravel group showing the lowest total length and wet mass until the onset of exogenous feeding – although dry mass and energy contents were highest. In contrast, length and wet mass during yolk sac absorption were highest in the control Ilomastat group, but energy content at onset of exogenous feeding was 14% lower compared to the gravel group. The onset of exogenous feeding in the gravel group had a 1-day delay when compared to the two other treatments. On day 14, following the successful establishment of exogenous feed uptake, the specific growth rate in wet mass (SGR) for the gravel group (0.250 +/- 0.088) exceeded those of the two other treatments (sand 0.132 +/- 0.038 and control 0.095 +/- 0.020) significantly (Dunn’s n = 10 and n = 5, P < 0.05), indicating a compensational growth pattern.