Competitive success of southern populations of Betula pendula and Sorbus aucuparia under simulated southern climate experiment in the subarctic

Global warming has been commonly accepted to facilitate species' range shifts across latitudes. Cross-latitudinal transplantations support this; many tree species can well adapt to new geographical areas. However, these studies fail to capture species' adaptations to new light environment because the experiments were not designed to explicitly separate species' responses to light and temperature. Here we tested reaction norms of tree seedlings in reciprocal transplantations 1,000km apart from each other at two latitudes (60 degrees N and 69 degrees N). In contrast to past studies, we exposed our experimental plants to same temperature in both sites (temperature of 60 degrees N growing site is recorded to adjust temperature of 69 degrees N site in real time via Internet connection) while light environment (photoperiod, light quality) remained ambient. Shoot elongation and autumn coloration were studied in seedlings of two deciduous trees (Betula pendula and Sorbus aucuparia), which were expected to respond differently to day length. Sorbus as a member of Rosaceae family was assumed to be indifferent to photoperiod, while Betula responds strongly to day length. We hypothesized that (1) southern and northern populations of both species perform differently; (2) southern populations perform better in both sites; (3) autumn phenology of southern populations may delay in the northern site; (4) and Sorbus aucuparia is less dependent on light environment. According to the hypotheses, shoot elongation of northern population was inherently low in both species. An evolutionary consequence of this may be a competitive success of southern populations under warming climate. Southern population of B.pendula was delayed in autumn coloration, but not in growth cessation. Sorbus aucuparia was less responsive to light environment. The results suggest that light provides selection pressure in range shifts, but the response is species dependent

Concentrations of potentially toxic elements and soil environmental quality evaluation of a typical Prosecco vineyard of the Veneto region (NE Italy)

Purpose The aim of this work was to assess the concentrations of potentially toxic elements and to evaluate the soil quality of a typical Prosecco Denomination of Controlled and Guaranteed Origin vineyard of the Veneto region, NE Italy. Materials and methods Soil samples and leaves of Taraxacum officinale and Vitis vinifera were collected during spring–summer 2014. Element determination (Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb, V, and Zn) were performed with ICP-OES after microwave digestion of samples. Soil quality was assessed via the biological soil quality (BSQ-ar) index. Lipid peroxidation test was performed to evaluate the vegetation oxidative stress, based on malondialdehyde (MDA) content via spectrophotometer. Results and discussion High concentrations of Al,Mg, and P were identified in soil, while high contents of Al, Cu, Fe, and Zn were found in V. vinifera leaves. The high concentrations in soil are probably due to agricultural activities, whereas those in leaves are probably due to atmospheric deposition and repeated use of foliar sprays in viticulture. The bioconcentration factor showed an effective transport of Cu, P, and Zn, from soil to leaf. The BSQ-ar values registered were similar to those obtained in preserved soils; hence, the biological class (VI) of these soils is high. The MDA content in T. officinale and V. vinifera leaves was below the reference value for T. officinale (2.9 ± 0.2 μM), suggesting that the metal content did not stress the vegetation in the investigated site. Conclusions The MDA value for V. vinifera (1.1 ± 0.7 μM) could be adopted as another control value for soil quality, which in our case is of Bgood quality.^ Moreover, our results suggest that high concentrations of elements detected in the analyzed samples do not influence negatively the quality of soil, but a better agronomic management could improve soil quality in the studied area