Search results for "feature"
showing 10 items of 4091 documents
A new hybrid in the genus <em>Anthyllis</em> (Loteae-Leguminosae) from the eastern Iberian Peninsula
2016
We describe a new nothotaxon for the genus Anthyllis (Loteae- Leguminosae), A. . currasii P.P. Ferrer, Roselló & Guara, as result of natural interbreeding between A. cytisoides (Lag.) Pau and A. lagascana Benedí. It has been located at Monte de La Cañada, in Paterna (Valencia, Spain). This new hybrid is compared morphologically with its parents and the rest of nothotaxa described hitherto for the genus in the Iberian Peninsula, analysing the main diagnostic characters. The existence of the nothotaxa A. . fortuita Guara & P.P. Ferrer and A. . currasii implies the creation of the new nothosubgenus Ternijovis P.P. Ferrer, Roselló & Guara. A map of the known and documented distribut…
Identity and relationships of Sempervivum tectorum (Crassulaceae) in the Rhine Gorge area
2018
Sempervivum tectorum (Crassulaceae), an orophyte widespread in the European high mountains, also grows in rocky habitats of the Rhine Gorge area (Upper Middle Rhine, Mosel and Ahr river valleys). On the background of its long history of cultivation, it is unclear whether S. tectorum is native or naturalized in the Rhine Gorge area. Using 52 accessions of S. tectorum from across its geographical range (except SE Europe) as well as 15 samples of S. calcareum and S. marmoreum in our final sample, we conducted a genotyping-by-sequencing analysis. The genetic data were used for the identification of genetic groups and for the reconstruction of phylogenetic relationships. We found that the materi…
Potential of a no‐take marine reserve to protect home ranges of anadromous brown trout (Salmo trutta)
2018
The extent to which no-take marine reserves can benefit anadromous species requires examination. Here, we used acoustic telemetry to investigate the spatial behavior of anadromous brown trout (sea trout, Salmo trutta) in relation to a small marine reserve (similar to 1.5 km(2)) located inside a fjord on the Norwegian Skagerrak coast. On average, sea trout spent 42.3 % (+/- 5.0% SE) of their time in the fjord within the reserve, a proportion similar to the area of the reserve relative to that of the fjord. On average, sea trout tagged inside the reserve received the most protection, although the level of protection decreased marginally with increasing home range size. Furthermore, individual…
Defoliation and patchy nutrient return drive grazing effects on plant and soil properties in a dairy cow pasture
2009
Large herbivores can influence plant and soil properties in grassland ecosystems, but especially for belowground biota and processes, the mechanisms that explain these effects are not fully understood. Here, we examine the capability of three grazing mechanisms-plant defoliation, dung and urine return, and physical presence of animals (causing trampling and excreta return in patches)-to explain grazing effects in Phleum pratense-Festuca pratensis dairy cow pasture in Finland. Comparison of control plots and plots grazed by cows showed that grazing maintained original plant-community structure, decreased shoot mass and root N and P concentrations, increased shoot N and P concentrations, and …
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 …
Drivers of plant richness patterns of Mediterranean riparian forests at local and regional scales have bottom-up and top-down effects
2019
Questions: It has been long recognized that community species richness depends on factors operating at different spatial scales. Most frequently, across-scale studies have focused on the impact of regional factors on local richness (top-down effects) while few have analyzed the importance of local factors on regional richness (bottom-up) and even fewer have tried to integrate effects on both directions. Our objectives were to reveal the key factors shaping plant species richness of Mediterranean riparian forests and to test whether empirical models based on top-down or bottom-up relationships are able to explain the spatial scaling of richness. Location: Southern half of Spain, SW Europe. M…
Hydroperiod length as key parameter controlling seed strategies in Mediterranean salt marshes: The case of Halopeplis amplexicaulis
2018
Abstract The comprehension of plant biology and the response to the environment is fundamental to achieve the optimal skills to manage and conserve the fine equilibrium between biotic and abiotic parameters regulating natural biodiversity in salt marshes. The behaviour of annuals living in these stressful conditions is poorly understood and constitutes a good model for a better understanding of this relationship. We thus identified the determinant environmental factors involved in population survival of Halopeplis amplexicaulis, a threatened annual species inhabiting salt marshes. To achieve this objective, maternal climatic parameters were analyzed in seeds collected in different years, an…
Body growth and its implications in population dynamics of Acanthodactylus erythrurus (Schinz, 1834) in the Eastern Iberian peninsula
2019
Abstract We calculated growth rate for the spiny-footed lizard (Acanthodactylus erythrurus) inhabiting coastal eastern Spain from long-term mark-recapture data. Growth curves differ between sexes, with males growing faster than females and achieving larger size maximums. In this population each sex reaches maturity at about 300 days of age, approximately 34% faster than males, and 28% faster than females studied in a population further south and west in Iberia. Our logarithmic growth model has an accuracy of 96.8% and high statistical significance ( for males and for females). Although both the exponential curve of “best fit” for growth estimated for males (), and the linear curve of “best …
The effects of drainage and restoration of pine mires on habitat structure, vegetation and ants
2016
Habitat loss and degradation are the main threats to biodiversity worldwide. For example, nearly 80% of peatlands in southern Finland have been drained. There is thus a need to safeguard the remaining pristine mires and to restore degraded ones. Ants play a pivotal role in many ecosystems and like many keystone plant species, shape ecosystem conditions for other biota. The effects of mire restoration and subsequent vegetation succession on ants, however, are poorly understood. We inventoried tree stands, vegetation, water-table level, and ants (with pitfall traps) in nine mires in southern Finland to explore differences in habitats, vegetation and ant assemblages among pristine, drained (30…
Exploration of the Oxynoticeratidae ornamental morphospace using the discrete cosine transform (DCT) to analyze rib patterns.
2006
The discrete cosine transform (DCT) is a Fourier-related transform widely used in signal processing and well suited to analyzing open outlines such as ammonite ribs. The method is applied here to depict and decipher the ribbing morphospace of a large group of Lower Jurassic ammonites composed of the Oxynoticeratidae and their close ancestors. Because they are clearly associated with buoyancy and/or swimming ability, the usually clearly involute, comparatively smooth and compressed shells of these ammonites may well be misleading taxonomic markers. In this context, quantitative analysis of the ribbing pattern using the DCT may significantly improve our perception of the ornamental patterns e…