Search results for "Dispersal"
showing 10 items of 465 documents
The mechanistic basis of changes in community assembly in relation to anthropogenic disturbance and productivity
2016
Anthropogenic disturbance often causes changes in communities. However, the mechanistic basis of these changes remains elusive. As all patterns in community ecology can be understood as a result of four processes (speciation, selection, drift, and dispersal), the effect of disturbance should depend on how disturbance disrupt these processes. We studied the effects of disturbance and productivity on species richness, community composition, and community dispersion (i.e., variation in community composition) in the vegetation of 120 boreal peatlands using null-model approach to determine whether community assembly processes differ between pristine and disturbed sites. Sites represented three p…
Spatial and Temporal Diversity During the Neolithic Spread in the Western Mediterranean: The First Pottery Productions
2017
Actual research into the neolithization process and the development of farming communities in the Western Mediterranean reveals a diverse and complex cultural landscape. Dispersal routes and rhythm of diffusion of the agro-pastoral economy, Mesolithic inheritance, regional interactions between communities, and functional adaptations all have to be explored to trace how Mediterranean societies were reshaped during this period. The different pottery traditions that accompany the Neolithic spread and its economic development are of course interconnected (the “impressed ware”), but they also show some degree of polymorphism. This variability has been variously interpreted, but rarely quantified…
Contrasting Effects of Chronic Anthropogenic Disturbance on Activity and Species Richness of Insectivorous Bats in Neotropical Dry Forest
2022
For prioritizing conservation actions, it is vital to understand how ecologically diverse species respond to environmental change caused by human activity. This is particularly necessary considering that chronic human disturbance is a threat to biodiversity worldwide. Depending on how species tolerate and adapt to such disturbance, ecological integrity and ecosystem services will be more or less affected. Bats are a species-rich and functionally diverse group, with important roles in ecosystems, and are therefore recognized as a good model group for assessing the impact of environmental change. Their populations have decreased in several regions, especially in the tropics, and are threatene…
Ten principles for conservation translocations of threatened wood-inhabiting fungi
2020
Abstract Unlike for many other organism groups, conservation translocations of fungi are still rare. Encouraged by recent successful translocations, there is a growing interest in applying this conservation tool to threatened wood-inhabiting fungi. When combined with other conservation or restoration measures, translocation can be an effective measure for preventing further population decline in the short term, and species extinctions in the long term. Translocations can be appropriate for rare and specialist fungal species that occur as small local populations in isolated patches across fragmented landscapes, where there is a low likelihood of successful dispersal between distant host tree…
TAXONOMY AND AFFINITIES OF AFRICAN CENOZOIC METATHERIANS
2021
The record of extinct African metatherians (Mammalia, Theria) is scanty, restricted in time (Eocene–Miocene), and its taxonomy is still subject of debate. A review of all African metatherians, or alleged metatherians, known up to now, led us to the recognition of only three taxa referable to this group: (1) Kasserinotherium tunisiense (Peradectoidea?), from the early Eocene of Tunisia; (2) Peratherium africanum (Herpetotheriidae), from the early Oligocene of Egypt and Oman, and (3) an indeterminate Herpetotheriidae? from the early Miocene of Uganda. Herpetotheriids probably reached Afro-Arabia from Europe in one or more dispersal waves since the early Oligocene. Kasserinotherium , on t…
Pheromones and Chemical Ecology of Dispersal and Foraging in Termites
2010
Pheromones play a crucial role in the ecology of dispersal and foraging in termites. Sex-pairing pheromones possess a double role of long-range attraction to unite sexual partners and a short-range or contact attraction to maintain the pair during the tandem behaviour. Sex-pairing pheromones most often comprise a single compound capable of eliciting both behavioural effects. They appear very conservative in their evolution, and their role in the reproductive isolation of sympatric species greatly varies according to species. Species-specific sex-pairing pheromones consist of different major compounds or of a common major compound with species-specific minor components. Foraging is a collect…
Towards a Unified Functional Trait Framework for Parasites
2019
Trait-based research holds high potential to unveil ecological and evolutionary processes. Functional traits are fitness-related characteristics of individuals, which are measured at individual level and defined without using information external to the individual. Despite the usefulness of the functional approach to understand the performance of individuals in ecosystems, and parasitism being the most common life-history strategy on Earth, studies based on functional traits of parasites are still scarce. Since the choice of functional traits is a critical step for any study, we propose a core list of seven functional traits of metazoan parasites, related to three universal challenges faced…
Detection of steering direction using EEG recordings based on sample entropy and time-frequency analysis.
2016
Monitoring driver's intentions beforehand is an ambitious aim, which will bring a huge impact on the society by preventing traffic accidents. Hence, in this preliminary study we recorded high resolution electroencephalography (EEG) from 5 subjects while driving a car under real conditions along with an accelerometer which detects the onset of steering. Two sensor-level analyses, sample entropy and time-frequency analysis, have been implemented to observe the dynamics before the onset of steering. Thus, in order to classify the steering direction we applied a machine learning algorithm consisting of: dimensionality reduction and classification using principal-component-analysis (PCA) and sup…
Disturbance-induced emigration: an overlooked mechanism that reduces metapopulation extinction risk.
2021
Emigration propensity (i.e., the tendency to leave undisturbed patches) is a key life-history trait of organisms in metapopulations with local extinctions and colonizations. Metapopulation models of dispersal evolution typically assume that patch disturbance kills all individuals within the patch, thus causing local extinction. However, individuals may instead be able to leave a patch when it is disturbed, either by fleeing before being killed or simply because the disturbance destroys the patch without causing mortality. This scenario may pertain to a wide range of organisms from horizontally transmitted symbionts, to aquatic insects inhabiting temporary ponds, to vertebrates living in fra…
Dynamics of Ostracoda (Crustacea) assemblages in a Mediterranean pond system (Racó de l'Olla, Albufera Nat. Park) with focus on the exotic speciesCan…
2013
Coastal pond systems can account for a rich aquatic faunal diversity and complex functioning due to interplay between freshwater wetlands and marine influences. Within the large Albufera wetland Natural Park, Raco de l'Olla is constituted by a set of permanent and temporary ponds with strict protection level for migrating bird conservation. Its terrestrial faunal diversity and dynamics has been partially characterized in previous studies, but nothing was known about its ostracod communities. Benthic samples collected monthly for 1 year in 11 points through the pond system, together with limnological information, allowed establishing a sound knowledge on its ostracod community and population…