Search results for "Biotic component"
showing 10 items of 127 documents
Invasion biology in non‐free‐living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in …
2013
In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entoc…
The Ecology of Ostracoda Across Levels of Biological Organisation from Individual to Ecosystem
2012
Abstract Palaeoenvironmental and palaeoclimatic applications of fossil ostracods rely on a uniformitarian approach underpinned by knowledge of the biology and ecology of living species. This review reveals that in recent decades, major advances have been made in the understanding of species’ abiotic niches in relation to their preferences for different water chemistries and temperatures. However, the underlying ecophysiological mechanisms for such preferences are still largely unknown. Only a few works analyse in detail aspects of population growth or species interactions (competition, predation) in the framework of classical ecological theories. Similarly, the role of Ostracoda in the asse…
Environmentally driven changes in Baltic salmon oxidative status during marine migration.
2020
The fitness and recruitment of fish stocks can be markedly affected by environmental disturbances including global warming, eutrophication and contamination. Understanding the effects of environmental stressors on salmon physiology during marine residence is of a global concern as marine survival has decreased. We present a unique combination of physiological responses - antioxidant defence and oxidative damage biomarkers, stable isotopes and contaminant exposure biomarkers - measured from adult Atlantic salmon (Salmo salar) collected at the Baltic Sea and studied in relation to environmental variables and fitness estimates. The results demonstrate that feeding populations of salmon display…
Low-altitude outbreaks of human fascioliasis related with summer rainfall in Gilan province, Iran
2011
Following human fascioliasis outbreaks in 1988 and 1999 in Gilan province, northern Iran, efforts are now made to shed light on the seasonal pattern of fascioliasis transmission in this endemic area, taking into account snail host populations, climatic conditions and human cases. Populations of the intermediate host snail (Lymnaea spp.) peak in May and November, while there is a fourfold increase in the rate of human fascioliasis in February compared to that of September. Transmission is likely to occur mainly in late autumn and sporadically in late spring. Rainfall, seasonally analysed in periods of 3 years, indicates that accumulated summer rainfall may be related with the 1988 and 1999 h…
Aquatic pollution may favor the success of the invasive species A. franciscana
2015
The genus Artemia consists of several bisexual and parthenogenetic sibling species. One of them, A. franciscana, originally restricted to the New World, becomes invasive when introduced into ecosystems out of its natural range of distribution. Invasiveness is anthropically favored by the use of cryptobiotic eggs in the aquaculture and pet trade. The mechanisms of out-competition of the autochthonous Artemia by the invader are still poorly understood. Ecological fitness may play a pivotal role, but other underlying biotic and abiotic factors may contribute. Since the presence of toxicants in hypersaline aquatic ecosystems has been documented, our aim here is to study the potential role of an…
Factors Affecting Polyphenol Biosynthesis in Wild and Field Grown St. John’s Wort (Hypericum perforatum L. Hypericaceae/Guttiferae)
2009
The increasing diffusion of herbal products is posing new questions: why are products so often different in their composition and efficacy? Which approach is more suitable to increase the biochemical productivity of medicinal plants with large-scale, low-cost solutions? Can the phytochemical profile of a medicinal plant be modulated in order to increase the accumulation of its most valuable constituents? Will polyphenol-rich medicinal crops ever be traded as commodities? Providing a proactive answer to such questions is an extremely hard task, due to the large number of variables involved: intraspecific chemodiversity, plant breeding, ontogenetic stage, post-harvest handling, biotic and abi…
Macrolepidoptera (Insecta: Lepidoptera) Indicator of Climate Changes
2011
Lately, it has become increasingly clear that global warming has a significant impact on a broad range of organisms, regardless of their ecological and geographical spread. Temperature is one of the most important abiotic factors that determine the spatiotemporal dynamics of structural and functional parameters of populations of Lepidoptera and influencing production and survival of these species of insects in nature. Climate warming has the potential to affect some processes related to the ecology and life cycle of the butterfly, especially directly controlled temperature, such as: gathering the required temperature for a species to reach reproductive maturity, growth initiation and cessat…
Interfacial photochemistry of biogenic surfactants: a major source of abiotic volatile organic compounds
2017
Films of biogenic compounds exposed to the atmosphere are ubiquitously found on the surfaces of cloud droplets, aerosol particles, buildings, plants, soils and the ocean. These air/water interfaces host countless amphiphilic compounds concentrated there with respect to in bulk water, leading to a unique chemical environment. Here, photochemical processes at the air/water interface of biofilm-containing solutions were studied, demonstrating abiotic VOC production from authentic biogenic surfactants under ambient conditions. Using a combination of online-APCI-HRMS and PTR-ToF-MS, unsaturated and functionalized VOCs were identified and quantified, giving emission fluxes comparable to previous …
Environmental stress affects the expression of a carotenoid-based sexual trait in male zebra finches.
2007
SUMMARY Abiotic factors including thermal stress are suggested to exert constrains on sexual ornaments through trade-offs between sexual displays and physiological functions related to self-maintenance. Given the health properties of carotenoid pigments, carotenoid-based ornaments offer a relevant context in which to investigate the effect of environmental stress, such as ambient temperature, on the production and maintenance of secondary sexual traits and, also, to explore the proximate mechanisms shaping their expression. In this study, we exposed male zebra finches (Taeniopygia guttata) to environmental stress by exposing them to two temperature regimes (6 and 26°C) over a 4 week period.…
Parasites as Indicators of Water Quality and the Potential Use of Helminth Transmission in Marine Pollution Studies
1995
Publisher Summary This chapter focuses on parasites as indicators of water quality and the potential use of helminth transmission in marine pollution studies. There are good reasons for focusing on parasitic organisms in general and helminth parasites in particular, in the search for highly sensitive indicators. First, there are more parasitic than free-living species. Second, helminth parasites have complex life cycles and the different developmental stages have widely differing requirements, therefore, each stage must be assessed separately for sensitivity to environmental change, thereby widening the choice of potential indicators. Many biotic and abiotic factors affect the numbers and d…