- PE&RC (4)
- WIAS (2)
- Alterra - Environmental risk assessment (1)
- Aquaculture and Fisheries (1)
- Aquatic Ecology and Water Quality Management (1)
- Behavioral Ecology (1)
- Behavioural Ecology (1)
- Biometris (WU MAT) (1)
- Chair Soil Biology and Biological Soil Quality (1)
- EPS (1)
- Environmental Risk Assessment (1)
- Farming Systems Ecology (1)
- IMARES Onderzoeksformatie (1)
- Laboratory of Plant Physiology (1)
- Mathematical and Statistical Methods - Biometris (1)
- Nature Conservation and Plant Ecology (1)
- Onderzoeksformatie (1)
- Plant Ecology and Nature Conservation (1)
- Resource Ecology (1)
- Soil Biology (1)
- Soil Biology and Biological Soil Quality (1)
- WIMEK (1)
- Han A.B. Wösten (1)
- L.M. Aplin (1)
- Jacqueline Augusiak (1)
- F.J.J.A. Bianchi (1)
- Azra Blythe-Mallett (1)
- Anupol Chareesri (1)
- R.A. Crates (1)
- Antica Culina (1)
- S.A. Cunningham (1)
- Armanda D.S. Bastos (1)
- Jan Dijksterhuis (1)
- Hans Dyck van (1)
- Alison E. Bennett (1)
- Courtney E. Cox (1)
- Marcia E. Roy (1)
- Dewald F. Keet (1)
- Richard F. Preziosi (1)
- D.R. Farine (1)
- J.A. Firth (1)
- Martha H. Davis (1)
- L. Hemerik (1)
- C.A. Hinde (1)
- Pim Hooft van (1)
- Catherine J. Booker (1)
- Stephen J. Box (1)
- Paul J. Brink van den (1)
- Colin J. Garroway (1)
- Ayco J.M. Tack (1)
- Diana K. Brebner (1)
- Nathan K. Truelove (1)
- Mona K. Webber (1)
- Andreas Kelager (1)
- Kimani Kitson-Walters (1)
- Erik M. Boman (1)
- Sarah M. Griffiths (1)
- Dirk Maes (1)
- Joachim Mergeay (1)
- Roy Neilson (1)
- J.G.B. Oostermeijer (1)
- Ricardo Pérez Enríquez (1)
- David R. Nash (1)
- Wieke R. Teertstra (1)
- Andy S. Kough (1)
- N.A. Schellhorn (1)
- Iris Segura-García (1)
- Tamsen T. Byfield (1)
- Martin Tegelaar (1)
- Pil U. Rasmussen (1)
- An Vanden Broeck (1)
- Allan W. Stoner (1)
- Michiel Wallis de Vries (1)
- B.J. Walters (1)
- Irma Wynhoff (1)
The impact of dispersal, plant genotype and nematodes on arbuscular mycorrhizal fungal colonization
Rasmussen, Pil U. ; Chareesri, Anupol ; Neilson, Roy ; Bennett, Alison E. ; Tack, Ayco J.M. - \ 2019
Soil Biology and Biochemistry 132 (2019). - ISSN 0038-0717 - p. 28 - 35.
Arbuscular mycorrhizal fungi - Colonization ability - Dispersal - Genotype - Nematodes - Plantago lanceolata
While the majority of parasitic and mutualistic microbes have the potential for long-range dispersal, the high turnover in community composition among nearby hosts has often been interpreted to reflect dispersal constraints. To resolve this apparent contradiction, we need further insights into the relative importance of dispersal limitation, host genotype and the biotic environment on the colonization process. We focused on the important root symbionts, the arbuscular mycorrhizal (AM) fungi. We studied AM fungal colonization ability in a controlled mesocosm setting, where we placed Plantago lanceolata plants belonging to four different genotypes in sterile soil at 10, 30 and 70 cm from a central AM fungal inoculated P. lanceolata plant. In part of the mesocosms, we also inoculated the source plants with nematodes. AM fungi colonized receiver plants <1 m away over the course of ten weeks, with a strong effect of distance from source plant on AM fungal colonization. Plant genotype influenced AM fungal colonization during the early stages of colonization, while nematode inoculation had no effect on AM fungal colonization. Overall, the effect of both dispersal limitation and plant genetic variation may underlie the small-scale heterogeneity found in natural AM fungal communities.
Genetic insights into dispersal distance and disperser fitness of African lions (Panthera leo) from the latitudinal extremes of the Kruger National Park, South Africa
Hooft, Pim van; Keet, Dewald F. ; Brebner, Diana K. ; Bastos, Armanda D.S. - \ 2018
BMC Genetics 19 (2018)1. - ISSN 1471-2156
Disease spread - Dispersal - Gene flow - Kruger National Park - Lion - Management - Microsatellite - Mitochondrial DNA - Panthera leo - RS-3
Background: Female lions generally do not disperse far beyond their natal range, while males can disperse distances of over 200 km. However, in bush-like ecosystems dispersal distances less than 25 km are reported. Here, we investigate dispersal in lions sampled from the northern and southern extremes of Kruger National Park, a bush-like ecosystem in South Africa where bovine tuberculosis prevalence ranges from low to high across a north-south gradient. Results: A total of 109 individuals sampled from 1998 to 2004 were typed using 11 microsatellite markers, and mitochondrial RS-3 gene sequences were generated for 28 of these individuals. Considerable north-south genetic differentiation was observed in both datasets. Dispersal was male-biased and generally further than 25 km, with long-distance male gene flow (75-200 km, detected for two individuals) confirming that male lions can travel large distances, even in bush-like ecosystems. In contrast, females generally did not disperse further than 20 km, with two distinctive RS-3 gene clusters for northern and southern females indicating no or rare long-distance female dispersal. However, dispersal rate for the predominantly non-territorial females from southern Kruger (fraction dispersers ≥0.68) was higher than previously reported. Of relevance was the below-average body condition of dispersers and their low presence in prides, suggesting low fitness. Conclusions: Large genetic differences between the two sampling localities, and low relatedness among males and high dispersal rates among females in the south, suggestive of unstable territory structure and high pride turnover, have potential implications for spread of diseases and the management of the Kruger lion population.
Isolation by oceanic distance and spatial genetic structure in an overharvested international fishery
Truelove, Nathan K. ; Box, Stephen J. ; Aiken, Karl A. ; Blythe-Mallett, Azra ; Boman, Erik M. ; Booker, Catherine J. ; Byfield, Tamsen T. ; Cox, Courtney E. ; Davis, Martha H. ; Delgado, Gabriel A. ; Glazer, Bob A. ; Griffiths, Sarah M. ; Kitson-Walters, Kimani ; Kough, Andy S. ; Pérez Enríquez, Ricardo ; Preziosi, Richard F. ; Roy, Marcia E. ; Segura-García, Iris ; Webber, Mona K. ; Stoner, Allan W. - \ 2017
Diversity and Distributions 23 (2017)11. - ISSN 1366-9516 - p. 1292 - 1300.
Connectivity - Conservation - Dispersal - Fisheries - Genetics - Spatial
Aim: A detailed understanding of spatial genetic structure (SGS) and the factors driving contemporary patterns of gene flow and genetic diversity are fundamental for developing conservation and management plans for marine fisheries. We performed a detailed study of SGS and genetic diversity throughout the overharvested queen conch (Lobatus gigas) fishery. Caribbean countries were presented as major populations to examine transboundary patterns of population differentiation. Location: Nineteen locations in the greater Caribbean from Anguilla, the Bahamas, Belize, Caribbean Netherlands, Honduras, Jamaica, Mexico, Turks and Caicos, and the USA. Methods: We genotyped 643 individuals with nine microsatellites. Population genetic and multivariate analyses characterized SGS. We tested the alternate hypotheses: (1) SGS is randomly distributed in space or (2) pairwise genetic structure among sites is correlated with oceanic distance (IBOD). Results: Our study found that L. gigas does not form a single panmictic population in the greater Caribbean. Significant levels of genetic differentiation were identified between Caribbean countries (FCT = 0.011; p = .0001), within Caribbean countries (FSC = 0.003; p = .001), and among sites irrespective of geographic location (FST = 0.013; p = .0001). Gene flow across the greater Caribbean was constrained by oceanic distance (p = .0009; Mantel r = .40), which acted to isolate local populations. Main conclusions: Gene flow over the spatial scale of the entire Caribbean basin is constrained by oceanic distance, which may impede the natural recovery of overfished L. gigas populations. Our results suggest a careful blend of local and international management will be required to ensure long-term sustainability for the species.
Landscape-scale mass-action of spiders explains early-season immigration rates in crops
Bianchi, F.J.J.A. ; Walters, B.J. ; Cunningham, S.A. ; Hemerik, L. ; Schellhorn, N.A. - \ 2017
Landscape Ecology 32 (2017)6. - ISSN 0921-2973 - p. 1257 - 1267.
Agroecosystem - Ballooning - Dispersal - Landscape ecology - Spatial ecology
Context: Early-season immigration into arable fields by natural enemies is key for effective biocontrol, but little is known about the mechanisms underlying immigration processes. Objectives: Here we test the mass action hypothesis for ballooning spiders, stating that local immigration rates are positively related to the amount of spiders in the surrounding landscape. Methods: Immigration rates of spiders were assessed by sticky traps in remnant vegetation, in arable land 25–125 m from remnant vegetation, and in arable land further than 400 m from remnant vegetation. The experiment was conducted at 18 locations across two landscapes and repeated three times in a 2-week period in 2007 and 2008. Spider densities in crop and non-crop habitats were assessed by beat sheet sampling and used to calculate spider loads in landscape sectors around the experimental locations at five spatial scales. Results: Regression analysis indicated that immigration rates were influenced by meteorological variables and landscape context at 2 km and possibly beyond. Regression models that included spider load at relevant spatial scales received more statistical support from the data than models with the proportion of remnant vegetation and crops. Regression analysis further indicated that wheat and—to a lesser extent—remnant vegetation are important habitats for the recruitment of ballooning spiders. Conclusions: Our study provides support for the mass action hypothesis by showing that a combination of land-use variables with habitat specific spider densities allows the generation of functional cover types with greatly improved explanatory power.
Gene flow and effective population sizes of the butterfly Maculinea alcon in a highly fragmented, anthropogenic landscape
Vanden Broeck, An ; Maes, Dirk ; Kelager, Andreas ; Wynhoff, Irma ; Wallis de Vries, Michiel ; Nash, David R. ; Oostermeijer, J.G.B. ; Dyck, Hans van; Mergeay, Joachim - \ 2017
Biological Conservation 209 (2017). - ISSN 0006-3207 - p. 89 - 97.
Butterfly conservation - Dispersal - Effective population size - Gene flow - Sedentary species
Understanding connectivity among populations in fragmented landscapes is of paramount importance in species conservation because it determines their long-term viability and helps to identify and prioritize populations to conserve. Rare and sedentary species are particularly vulnerable to habitat fragmentation as they occupy narrow niches or restricted habitat ranges. Here, we assess contemporary interpopulation connectedness of the threatened, myrmecophilous butterfly, Maculinea alcon, in a highly fragmented landscape. We inferred dispersal, effective population sizes, genetic diversity and structure based on 14 locations of M. alcon in Belgium and the Netherlands using data from 12 microsatellite loci. Despite the reported sedentary behaviour of M. alcon, we observed moderate levels of contemporary dispersal between patches, but only in landscapes where populations were located within a distance of 3 km from neighbouring populations. Estimates of effective population sizes (Ne) were very low (ranging from 1.6 to 17.6) and bottleneck events occurred in most of the studied populations. We discuss the functional conservation units delineated based on a former mark-release-recapture study, and formulate appropriate conservation strategies to maintain viable (meta)populations in highly fragmented, anthropogenic landscapes.
Maturation of conidia on conidiophores of Aspergillus niger
Teertstra, Wieke R. ; Tegelaar, Martin ; Dijksterhuis, Jan ; Golovina, Elena A. ; Ohm, Robin A. ; Wösten, Han A.B. - \ 2017
Fungal Genetics and Biology 98 (2017). - ISSN 1087-1845 - p. 61 - 70.
Asexual reproduction - Aspergillus - Conidia - Development - Dispersal - Fungus
Conidia of Aspergillus niger are produced on conidiophores. Here, maturation of conidia on these asexual reproductive structures was studied. Pigmented conidia that had developed on conidiophores for 2, 5, and 8 days were similarly resistant to heat and were metabolically active as shown by CO2 release and conversion of the metabolic probe Tempone. A total number of 645–2421 genes showed a ⩾2-fold change in expression when 2-day-old conidia were compared to 5- and 8-day-old spores. Melanin was extracted more easily from the cell wall of 2-day-old conidia when compared to the older spores. In addition, mannitol content and germination rate of the 2-day-old conidia were higher. Dispersal efficiency by water was lower in the case of the 8-day-old conidia but no differences were observed in dispersal by wind and a hydrophobic moving object. These data and the fact that only a minor fraction of the conidia on a conidiophore were dispersed in the assays imply that a single colony of A. niger releases a heterogeneous population of conidia. This heterogeneity would provide a selective advantage in environments with rapidly changing conditions such as availability of water.
The influence of insecticide exposure and environmental stimuli on the movement behaviour and dispersal of a freshwater isopod
Augusiak, Jacqueline ; Brink, Paul J. van den - \ 2016
Ecotoxicology 25 (2016)7. - ISSN 0963-9292 - p. 1338 - 1352.
Aquatic macroinvertebrates - Automated video tracking - Dispersal - Locomotion
Behaviour links physiological function with ecological processes and can be very sensitive towards environmental stimuli and chemical exposure. As such, behavioural indicators of toxicity are well suited for assessing impacts of pesticides at sublethal concentrations found in the environment. Recent developments in video-tracking technologies offer the possibility of quantifying behavioural patterns, particularly locomotion, which in general has not been studied and understood very well for aquatic macroinvertebrates to date. In this study, we aim to determine the potential effects of exposure to two neurotoxic pesticides with different modes of action at different concentrations (chlorpyrifos and imidacloprid) on the locomotion behaviour of the water louse Asellus aquaticus. We compare the effects of the different exposure regimes on the behaviour of Asellus with the effects that the presence of food and shelter exhibit to estimate the ecological relevance of behavioural changes. We found that sublethal pesticide exposure reduced dispersal distances compared to controls, whereby exposure to chlorpyrifos affected not only animal activity but also step lengths while imidacloprid only slightly affected step lengths. The presence of natural cues such as food or shelter induced only minor changes in behaviour, which hardly translated to changes in dispersal potential. These findings illustrate that behaviour can serve as a sensitive endpoint in toxicity assessments. However, under natural conditions, depending on the exposure concentration, the actual impacts might be outweighed by environmental conditions that an organism is subjected to. It is, therefore, of importance that the assessment of toxicity on behaviour is done under relevant environmental conditions.
The role of social and ecological processes in structuring animal populations : A case study from automated tracking of wild birds
Farine, D.R. ; Firth, J.A. ; Aplin, L.M. ; Crates, R.A. ; Culina, Antica ; Garroway, Colin J. ; Hinde, C.A. - \ 2015
Royal Society Open Science 2 (2015)4. - ISSN 2054-5703
Dispersal - Great tit - Group living - Immigration - Paridae - Social organization
Both social and ecological factors influence population process and structure, with resultant consequences for phenotypic selection on individuals. Understanding the scale and relative contribution of these two factors is thus a central aim in evolutionary ecology. In this study, we develop a framework using null models to identify the social and spatial patterns that contribute to phenotypic structure in a wild population of songbirds. We used automated technologies to track 1053 individuals that formed 73 737 groups from which we inferred a social network. Our framework identified that both social and spatial drivers contributed to assortment in the network. In particular, groups had a more even sex ratio than expectedand exhibited a consistent age structure that suggested local association preferences, such as preferential attachment or avoidance. By contrast, recent immigrants were spatially partitioned from locally born individuals, suggesting differential dispersal strategies by phenotype. Our results highlight how different scales of social decision-making, ranging from post-natal dispersal settlement to fission–fusion dynamics, can interact to drive phenotypic structure in animal populations.