Search results for "graphic"
showing 10 items of 7871 documents
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…
Sex specific differences recorded in the behavior of an amphipod: implications for behavioral toxicology
2020
Behaviour is a useful endpoint in ecotoxicological research; it links the biochemical effects of contamination with physiology of individuals, which can be applied to higher levels of organisation with relevance to ecology. Animals exhibit species-specific and sex specific behaviours. Previous experiments within ecotoxicology using amphipods as models have either not separated by sex or have on the assumption that they may create more variability in the results. Therefore, the objectives of this study were to investigate the effect of time (which controlled light conditions), sex, and the interaction of time and sex on the swimming velocity in males and females of the marine amphipod Echino…
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.
Epifaunal and infaunal responses to submarine mine tailings in a Norwegian fjord.
2019
Abstract Disposal of mine tailings in marine shallow water ecosystems represents an environmental challenge, and the present paper reports results from a field study in Fraenfjorden, Norway, which is subject to such disposal. Structural and functional responses of benthic infauna and epifauna were investigated along a gradient from heavy tailings deposition to reference conditions. The tailings clearly impacted the faunal composition, with lowered species number close to the outfall. Total abundance of infauna increased in the most impacted area due to dominance of opportunistic species, whereas the epifauna was reduced and represented by a few scattered specimens only. In the most impacted…
Iodine emissions from the sea ice of the Weddell Sea
2012
Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I<sub>2</sub> mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH<sub>3</sub>I, C<sub>2</sub>H<sub>5</sub>I, CH&l…
Primary production calculations for sea ice from bio-optical observations in the Baltic Sea
2016
Abstract Bio-optics is a powerful approach for estimating photosynthesis rates, but has seldom been applied to sea ice, where measuring photosynthesis is a challenge. We measured absorption coefficients of chromophoric dissolved organic matter (CDOM), algae, and non-algal particles along with solar radiation, albedo and transmittance at four sea-ice stations in the Gulf of Finland, Baltic Sea. This unique compilation of optical and biological data for Baltic Sea ice was used to build a radiative transfer model describing the light field and the light absorption by algae in 1-cm increments. The maximum quantum yields and photoadaptation of photosynthesis were determined from 14C-incorporatio…
An integrated analysis of micro- and macro-habitat features as a tool to detect weather-driven constraints: A case study with cavity nesters.
2017
The effects of climate change on animal populations may be shaped by habitat characteristics at both micro- and macro-habitat level, however, empirical studies integrating these two scales of observation are lacking. As analyses of the effects of climate change commonly rely on data from a much larger scale than the microhabitat level organisms are affected at, this mismatch risks hampering progress in developing understanding of the details of the ecological and evolutionary responses of organisms and, ultimately, effective actions to preserve their populations. Cavity nesters, often with a conservation status of concern, are an ideal model because the cavity is a microenvironment potentia…