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Arndt Hampe - One of the best experts on this subject based on the ideXlab platform.
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The role of fruit diet within a temperate breeding bird community in southern Spain
Bird Study, 2020Co-Authors: Arndt HampeAbstract:In southern temperate regions many fleshy-fruited plant species ripen their fruits during the breeding or early post-breeding season and these are consumed by resident birds. I studied the frugivore community of the summerfruiting tree Frangula alnus ssp. baetica in southern Spain and the significance of fruit in the diet of adult and recently fledged birds. Twelve species consumed F. alnus fruits. Almost 97% of the foraging visits were carried out by the four most abundant species, Robin Erithacus rubecula, Blackcap Sylvia atricapilla, Blackbird Turdus merula and Blue Tit Parus caeruleus. During the ripening season Robins and Blackcaps concentrated at fruit-rich sites. Entire families of Blackcap and Blackbird regularly entered fruiting trees together. In contrast, adult Robins always foraged solitarily, and accounted for only 4% of the tree visits, while 96% were realized by recently fledged birds of the first brood. In all species, young birds foraged as efficiently as adults. F. alnus fruits are not part of the regular nestling diet, but they are a significant part of the diet for recently fledged Robins during their postnatal dispersal. Conversely, these are the most important and effective seed dispersers while adult Robins scarcely take part in the dispersal of F. alnus seeds.
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Foraging and flocking behaviour of migrating and resident frugivorous songbirds
Journal of Ornithology, 2020Co-Authors: Arndt Hampe, Franz BairleinAbstract:Migrating birds that arrive at unknown stopover sites have to satisfy greater nutritive demands in restricted time and simultanously run a higher predation risk than residents which are familiar with the area. Foraging behaviour of resident and migrant frugivores feeding on fruits of Alder Buckthorn (Frangula alnus) was studied in Germany and Spain. German trees ripen their fruits during the autumn migration period, Spanish ones during the breeding and early postbreeding season. In both areas fruits were mainly eaten bySylvia warblers, Robin (Erithacus rubecula) and thrushes (Turdus sp.). At the stopover site birds spent less time in the tree, consumed more fruits per visit and therefore foraged more efficiently. In both areas birds clearly synchronized foraging bouts and formed intra- and interspecific assemblages, which were more frequent in migrants than in residents on the interspecific level. The influence of nutritive demands and predator avoidance upon the foraging behaviour and its consequences for seed dispersal are discussed.
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isolation and characterization of 16 polymorphic microsatellite loci for Frangula alnus rhamnaceae
Molecular Ecology Resources, 2009Co-Authors: Cristina Rigueiro, Arndt Hampe, Juan Arroyo, Regino Zamora Rodriguez, Pedro JordanoAbstract:We report the first 16 polymorphic nuclear microsatellite markers developed for Frangula alnus (Rhamnaceae). Markers were tested on all three subspecies as well as on three local populations, including analyses of both leaf and seed endocarps. A total of 87 alleles were found (mean number of alleles per locus was 5.44) for 72 individuals genotyped. Observed and expected heterozygosities ranged from 0.097 to 0.792 and from 0.093 to 0.794, respectively. The levels of polymorphism and exclusionary power of the developed markers render them applicable for parentage analyses and measurements of seed dispersal through direct comparison of endocarps and adult tree genotypes.
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Modified dispersal‐related traits in disjunct populations of bird‐dispersed Frangula alnus (Rhamnaceae): a result of its Quaternary distribution shifts?
Ecography, 2008Co-Authors: Arndt Hampe, Franz BairleinAbstract:Many European tree species survived Pleistocene glaciations in Mediterranean refugia and rapidly recolonized temperate Europe afterwards. Inter- and postglacial migration processes are assumed to have catalized evolutionary optimizations of dispersal-related traits, but up to now empirical evidence is lacking in vertebrate-dispersed plants. We investigated if south Iberian glacial relict and central European qcolonizerq populations of the bird-dispersed tree Frangula alnus have experienced differentiations of dispersal-related traits which increase the mobility of northern populations. A comparison of lifetime reproductive strategy, disperser guilds, ripening phenology, and fruit design revealed considerable differences. Compared to south Iberian conspecifics, central European plants were considerably smaller and experienced a highly accelerated generation turnover, In south Iberian populations seed dispersal was carried out almost completely by resident birds which occurred in constant abundances throughout the ripening season. In contrast, central European seeds were dispersed by migrants whose abundances changed considerably during the ripening season. Several bird species were involved in both study areas but rendered different importance for seed dispersal. The fruit ripening pattern was highly asynchronous throughout the ripening season in south Iberia, while central European trees showed a complex ripening sequence which resulted in a significant correlation between fruit abundance and changing disperser availability. Central European fruits were smaller and showed a considerably smaller seed load than south Iberian fruits, thus presumably being more attractive for their small-sized main dispersers (Sylvia warblers). Chemical analyses revealed significant differences in contents of water, glucose, fructose, proteins, ash, and phenolic compounds. The extensive differentiation of dispersal-related traits in F. alnus suggests that even weak selective pressures by frugivores may induce evolutionary adjustments of dispersal traits over large time scales. We suggest that the differences we observe today evolved during the species' distribution shifts in the Quaternary.
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anatomical notes on turkish Frangula alnus mill rhamnaceae
Plant Biosystems, 2007Co-Authors: B Serdar, K Coskuncelebi, S Terzioglu, Arndt HampeAbstract:In this study, the Turkish representatives of Frangula alnus were investigated in terms of wood, leaf and petiole anatomy. Some important differences were observed between the two native subspecies F. alnus subsp. alnus and F. alnus subsp. pontica. These include the grouping and frequency of vessels, the size of vessel fibres and rays, and the presence of cubic and solitary crystals in square ray cells. Significant differences in the distributions of secretory cavities and crystals in the leaves and petioles were also observed. The described features provide a useful complementary key for the distinction of the two subspecies native to Turkey that is applicable both to fresh material and macrofossil remains.
Secundino Lopez - One of the best experts on this subject based on the ideXlab platform.
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effects of rhubarb rheum spp and Frangula Frangula alnus on intake digestibility and ruminal fermentation of different diets and feedstuffs by sheep
Animal Feed Science and Technology, 2012Co-Authors: R Garciagonzalez, F.j. Giráldez, A.r. Mantecón, Jesus Salvador Gonzalez, Secundino LopezAbstract:Abstract Previous in vitro work suggests that rhubarb ( Rheum spp.) and Frangula ( Frangula alnus ) potentially modify rumen fermentation, but no in vivo research has confirmed these findings or examined the suitability of these plants in the diet of ruminants. Our objective was to examine effects of these plants on feed intake, digestibility and ruminal fermentation in vivo . Effects on intake were determined in 20 sheep individually housed and fed a TMR ad libitum . Sheep were distributed into 4 experimental groups, which were supplemented with rhubarb (30 g/d), Frangula (30 g/d), monensin (30 mg/kg DM) or nothing (control), respectively. The digestibility of the TMR was determined by placing 4 of the sheep of each group into metabolic cages. The impact of these plants on ruminal fermentation was also examined using rumen cannulated grazing sheep. Fifteen sheep were distributed into 3 groups: control, rhubarb (30 g/d) and Frangula (30 g/d); plant material was supplied daily directly into the rumen, and measurements started after 3 wks of supplementation., which consisted in rumen fluid analyses and in vitro and in situ incubations (12 and 24 h) of several feedstuffs. In the intake experiment, both rhubarb and Frangula groups had an intake comparable to control, while the monensin group had a lower (P in vitro , the cultures yielded less gas and CH 4 , and the gas production curves revealed an overall lower production, but fractional rates similar to control sheep. In situ degradability of several feedstuffs was similar in rhubarb and control sheep. In Frangula supplemented sheep there were small effects on some of the parameters described above for the in vitro incubations. Rhubarb changed the fermentation in the rumen of sheep without affecting intake or digestibility of the diet, suggesting a promising role of rhubarb, or its metabolites, as rumen modifiers for ruminants, and suggest more research to elucidate their impacts on productive performance.
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decrease of ruminal methane production in rusitec fermenters through the addition of plant material from rhubarb rheum spp and alder buckthorn Frangula alnus
Journal of Dairy Science, 2010Co-Authors: R Garciagonzalez, Jesus Salvador Gonzalez, Secundino LopezAbstract:Roots of rhubarb (Rheum spp.) and bark of alder buckthorn (Frangula alnus) were tested as feed additives for decreasing ruminal methane production released from anaerobic fermentation of a forage-based diet in a rumen-simulating fermenter (Rusitec). Sixteen fermentation units (vessels) were set up for the experiment lasting 19 d. Treated vessels were supplied with 1 g/d of rhubarb or alder buckthorn (4 vessels per plant species); another 4 vessels received 12 μM sodium monensin (positive control), and the remaining 4 vessels were controls (no additive). Upon termination of the experimental period, batch cultures were inoculated with the liquid contents of the vessels for examining in vitro fermentation kinetics of cellulose, starch, barley straw, and the same substrate used in the Rusitec cultures. Monensin induced changes in fermentation in agreement with those reported in the literature, and inocula from those cultures decreased the fermentation rate and total gas produced in the gas kinetics study. Rhubarb decreased methane production, associated with limited changes in the profile of volatile fatty acids throughout the duration of the study, whereas digestibility and total volatile fatty acids production were not affected. Rhubarb inocula did not affect gas production kinetics except for cellulose. Alder buckthorn decreased only methane concentration in fermentation gas, and this effect was not always significant. The use of rhubarb (milled rhizomes of Rheum spp.) in the diets of ruminants may effectively modulate ruminal fermentation by abating methane production, thus potentially involving productive and environmental benefits.
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Screening the activity of plants and spices for decreasing ruminal methane production in vitro
Animal Feed Science and Technology, 2008Co-Authors: R. García-gonzález, M Fernandez, Secundino Lopez, Raúl Bodas, Jesus Salvador GonzalezAbstract:Abstract Different plants, herbs and spices (158 samples) were tested in a screening trial to assess their potential to modify ruminal fermentation in vitro , in particular their effectiveness for decreasing methane production. In vitro incubations were carried in buffered rumen fluid at 39 °C and after 24 h of fermentation, gas production and pH were recorded, and gas and volatile fatty acids (VFA) were analysed. Residual matter was determined by filtration. Most of the plants tested did not cause any noticeable effect on the fermentation parameters studied. However, rhizomes and roots of Rheum officinale (rhubarb), bark of Frangula alnus (Frangula or alder buckthorn) and bulbs of Allium sativum (garlic) decreased methane production and acetate to propionate ratio. Changes in ruminal fermentation observed in response to the addition of these plants were confirmed in subsequent in vitro assays. This is the first report to identify that rhubarb and Frangula may contain active secondary compounds targeting ruminal methanogenic microorganisms.
Olivier Honnay - One of the best experts on this subject based on the ideXlab platform.
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Transatlantic invasion routes and adaptive potential in North American populations of the invasive glossy buckthorn, Frangula alnus
Annals of Botany, 2016Co-Authors: Hanne De Kort, Hans Jacquemyn, Joachim Mergeay, Olivier HonnayAbstract:Many invasive species severely threaten native biodiversity and ecosystem functioning. One of the most prominent questions in invasion genetics is how invasive populations can overcome genetic founder effects to establish stable populations after colonization of new habitats. High native genetic diversity and multiple introductions are expected to increase genetic diversity and adaptive potential in the invasive range. Our aim was to identify the European source populations of Frangula alnus (glossy buckthorn), an ornamental and highly invasive woody species that was deliberately introduced into North America at the end of the 18th century. A second aim of this study was to assess the adaptive potential as an explanation for the invasion success of this species. Using a set of annotated single-nucleotide polymorphisms (SNPs) that were assigned a putative function based on sequence comparison with model species, a total of 38 native European and 21 invasive North American populations were subjected to distance-based structure and assignment analyses combined with population genomic tools. Genetic diversity at SNPs with ecologically relevant functions was considered as a proxy for adaptive potential. Patterns of invasion coincided with early modern transatlantic trading routes. Multiple introductions through transatlantic trade from a limited number of European port regions to American urban areas led to the establishment of bridgehead populations with high allelic richness and expected heterozygosity, allowing continuous secondary migration to natural areas. Targeted eradication of the urban populations, where the highest genetic diversity and adaptive potential were observed, offers a promising strategy to arrest further invasion of native American prairies and forests. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Transatlantic invasion routes and adaptive potential in North American populations of the invasive glossy buckthorn, Frangula alnus
Annals of Botany, 2016Co-Authors: Hanne De Kort, Hans Jacquemyn, Joachim Mergeay, Olivier HonnayAbstract:© The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. Background and Aims Many invasive species severely threaten native biodiversity and ecosystem functioning. One of the most prominent questions in invasion genetics is how invasive populations can overcome genetic founder effects to establish stable populations after colonization of new habitats. High native genetic diversity and multiple introductions are expected to increase genetic diversity and adaptive potential in the invasive range. Our aim was to identify the European source populations of Frangula alnus (glossy buckthorn), an ornamental and highly invasive woody species that was deliberately introduced into North America at the end of the 18th century. A second aim of this study was to assess the adaptive potential as an explanation for the invasion success of this species. Methods Using a set of annotated single-nucleotide polymorphisms (SNPs) that were assigned a putative function based on sequence comparison with model species, a total of 38 native European and 21 invasive North American populations were subjected to distance-based structure and assignment analyses combined with population genomic tools. Genetic diversity at SNPs with ecologically relevant functions was considered as a proxy for adaptive potential. Key Results Patterns of invasion coincided with early modern transatlantic trading routes. Multiple introductions through transatlantic trade from a limited number of European port regions to American urban areas led to the establishment of bridgehead populations with high allelic richness and expected heterozygosity, allowing continuous secondary migration to natural areas. Conclusions Targeted eradication of the urban populations, where the highest genetic diversity and adaptive potential were observed, offers a promising strategy to arrest further invasion of native American prairies and forests.
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The population genomic signature of environmental selection in the widespread insect-pollinated tree species Frangula alnus at different geographical scales
Heredity, 2015Co-Authors: Hanne De Kort, Joachim Mergeay, K Vandepitte, K V Mijnsbrugge, Olivier HonnayAbstract:The evaluation of the molecular signatures of selection in species lacking an available closely related reference genome remains challenging, yet it may provide valuable fundamental insights into the capacity of populations to respond to environmental cues. We screened 25 native populations of the tree species Frangula alnus subsp. alnus (Rhamnaceae), covering three different geographical scales, for 183 annotated single-nucleotide polymorphisms (SNPs). Standard population genomic outlier screens were combined with individual-based and multivariate landscape genomic approaches to examine the strength of selection relative to neutral processes in shaping genomic variation, and to identify the main environmental agents driving selection. Our results demonstrate a more distinct signature of selection with increasing geographical distance, as indicated by the proportion of SNPs (i) showing exceptional patterns of genetic diversity and differentiation (outliers) and (ii) associated with climate. Both temperature and precipitation have an important role as selective agents in shaping adaptive genomic differentiation in F. alnus subsp. alnus , although their relative importance differed among spatial scales. At the ‘intermediate’ and ‘regional’ scales, where limited genetic clustering and high population diversity were observed, some indications of natural selection may suggest a major role for gene flow in safeguarding adaptability. High genetic diversity at loci under selection in particular, indicated considerable adaptive potential, which may nevertheless be compromised by the combined effects of climate change and habitat fragmentation.
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isolation characterization and genotyping of single nucleotide polymorphisms in the non model tree species Frangula alnus rhamnaceae
Conservation Genetics Resources, 2014Co-Authors: Hanne De Kort, Joachim Mergeay, Katrien Vandepitte, Olivier HonnayAbstract:The genomic content of the non-model plant Frangula alnus remains largely unexplored. However, because of its occurrence over a wide latitudinal range and its invasive nature in the US and Canada, F. alnus may serve as an excellent study species in tree conservation genomic research. We used pooled paired-end sequencing of Restriction-site Associated DNA to discover SNPs in the insect pollinated shrub F. alnus. We identified 7,383 SNPs from which the corresponding contig sequences were annotated to the available plant genomes. An enrichment analysis showed an excess of putatively adaptive and plastic gene ontology terms.
R Garciagonzalez - One of the best experts on this subject based on the ideXlab platform.
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effects of rhubarb rheum spp and Frangula Frangula alnus on intake digestibility and ruminal fermentation of different diets and feedstuffs by sheep
Animal Feed Science and Technology, 2012Co-Authors: R Garciagonzalez, F.j. Giráldez, A.r. Mantecón, Jesus Salvador Gonzalez, Secundino LopezAbstract:Abstract Previous in vitro work suggests that rhubarb ( Rheum spp.) and Frangula ( Frangula alnus ) potentially modify rumen fermentation, but no in vivo research has confirmed these findings or examined the suitability of these plants in the diet of ruminants. Our objective was to examine effects of these plants on feed intake, digestibility and ruminal fermentation in vivo . Effects on intake were determined in 20 sheep individually housed and fed a TMR ad libitum . Sheep were distributed into 4 experimental groups, which were supplemented with rhubarb (30 g/d), Frangula (30 g/d), monensin (30 mg/kg DM) or nothing (control), respectively. The digestibility of the TMR was determined by placing 4 of the sheep of each group into metabolic cages. The impact of these plants on ruminal fermentation was also examined using rumen cannulated grazing sheep. Fifteen sheep were distributed into 3 groups: control, rhubarb (30 g/d) and Frangula (30 g/d); plant material was supplied daily directly into the rumen, and measurements started after 3 wks of supplementation., which consisted in rumen fluid analyses and in vitro and in situ incubations (12 and 24 h) of several feedstuffs. In the intake experiment, both rhubarb and Frangula groups had an intake comparable to control, while the monensin group had a lower (P in vitro , the cultures yielded less gas and CH 4 , and the gas production curves revealed an overall lower production, but fractional rates similar to control sheep. In situ degradability of several feedstuffs was similar in rhubarb and control sheep. In Frangula supplemented sheep there were small effects on some of the parameters described above for the in vitro incubations. Rhubarb changed the fermentation in the rumen of sheep without affecting intake or digestibility of the diet, suggesting a promising role of rhubarb, or its metabolites, as rumen modifiers for ruminants, and suggest more research to elucidate their impacts on productive performance.
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decrease of ruminal methane production in rusitec fermenters through the addition of plant material from rhubarb rheum spp and alder buckthorn Frangula alnus
Journal of Dairy Science, 2010Co-Authors: R Garciagonzalez, Jesus Salvador Gonzalez, Secundino LopezAbstract:Roots of rhubarb (Rheum spp.) and bark of alder buckthorn (Frangula alnus) were tested as feed additives for decreasing ruminal methane production released from anaerobic fermentation of a forage-based diet in a rumen-simulating fermenter (Rusitec). Sixteen fermentation units (vessels) were set up for the experiment lasting 19 d. Treated vessels were supplied with 1 g/d of rhubarb or alder buckthorn (4 vessels per plant species); another 4 vessels received 12 μM sodium monensin (positive control), and the remaining 4 vessels were controls (no additive). Upon termination of the experimental period, batch cultures were inoculated with the liquid contents of the vessels for examining in vitro fermentation kinetics of cellulose, starch, barley straw, and the same substrate used in the Rusitec cultures. Monensin induced changes in fermentation in agreement with those reported in the literature, and inocula from those cultures decreased the fermentation rate and total gas produced in the gas kinetics study. Rhubarb decreased methane production, associated with limited changes in the profile of volatile fatty acids throughout the duration of the study, whereas digestibility and total volatile fatty acids production were not affected. Rhubarb inocula did not affect gas production kinetics except for cellulose. Alder buckthorn decreased only methane concentration in fermentation gas, and this effect was not always significant. The use of rhubarb (milled rhizomes of Rheum spp.) in the diets of ruminants may effectively modulate ruminal fermentation by abating methane production, thus potentially involving productive and environmental benefits.
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dose response effects of rheum officinale root and Frangula alnus bark on ruminal methane production in vitro
Animal Feed Science and Technology, 2008Co-Authors: R Garciagonzalez, S. López, M Fernandez, Jesus Salvador GonzalezAbstract:Abstract A previous screening assay showed that, when used as additives in batch cultures of mixed ruminal microorganisms, both Rheum officinale root (RH) and Frangula alnus bark (FR) decreased methane production and caused changes in several fermentation parameters. The work reported here aimed to identify optimum dose levels of these plants to decrease methane production without causing adverse changes in ruminal fermentation. Increasing doses of both RH and FR, used as a dried powder, were tested in batch cultures in vitro . Amounts added of these plants replaced 48, 91, 135 and 178 mg/g of the substrate incubated (520 mg in the control), respectively, corresponding to 0.50, 0.95, 1.40 and 1.85 g/l in the medium of 50 ml, respectively. Substrate incubated was a mixture of alfalfa hay (500 g/kg), grass hay (200 g/kg) and barley grain (300 g/kg). Both plants caused similar changes in rumen fermentation pattern, resulting in a dose-dependent linear decrease in methane production and in the acetate to propionate ratio. These changes were similar to those observed with monensin, included in the assay as a positive control. At the higher doses ( i.e. , 1.40 and 1.85 g/l), the plant additives seemed to have an adverse effect on rumen fermentation, causing a decrease in extent of substrate degradation accompanied by lower production of total volatile fatty acids (VFA). However, this inhibition did not occur with the lower doses of addition ( i.e. , 0.50 and 0.95 g/l). Based on effects of these plants on butyrate and branched-chain VFA produced, and on the diminished calculated hydrogen recovery, our suggestion is that these plants may have a direct effect on methanogens. In this in vitro system, doses up to 1 g/l of either RH or FR caused a decrease in methane production accompanied by changes in the VFA molar proportions, whereas other fermentation parameters were not affected, suggesting that this would be the optimum rate of addition of these plant additives when the goal is to decrease methane emissions from ruminal fermentation.
Franz Bairlein - One of the best experts on this subject based on the ideXlab platform.
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Foraging and flocking behaviour of migrating and resident frugivorous songbirds
Journal of Ornithology, 2020Co-Authors: Arndt Hampe, Franz BairleinAbstract:Migrating birds that arrive at unknown stopover sites have to satisfy greater nutritive demands in restricted time and simultanously run a higher predation risk than residents which are familiar with the area. Foraging behaviour of resident and migrant frugivores feeding on fruits of Alder Buckthorn (Frangula alnus) was studied in Germany and Spain. German trees ripen their fruits during the autumn migration period, Spanish ones during the breeding and early postbreeding season. In both areas fruits were mainly eaten bySylvia warblers, Robin (Erithacus rubecula) and thrushes (Turdus sp.). At the stopover site birds spent less time in the tree, consumed more fruits per visit and therefore foraged more efficiently. In both areas birds clearly synchronized foraging bouts and formed intra- and interspecific assemblages, which were more frequent in migrants than in residents on the interspecific level. The influence of nutritive demands and predator avoidance upon the foraging behaviour and its consequences for seed dispersal are discussed.
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Modified dispersal‐related traits in disjunct populations of bird‐dispersed Frangula alnus (Rhamnaceae): a result of its Quaternary distribution shifts?
Ecography, 2008Co-Authors: Arndt Hampe, Franz BairleinAbstract:Many European tree species survived Pleistocene glaciations in Mediterranean refugia and rapidly recolonized temperate Europe afterwards. Inter- and postglacial migration processes are assumed to have catalized evolutionary optimizations of dispersal-related traits, but up to now empirical evidence is lacking in vertebrate-dispersed plants. We investigated if south Iberian glacial relict and central European qcolonizerq populations of the bird-dispersed tree Frangula alnus have experienced differentiations of dispersal-related traits which increase the mobility of northern populations. A comparison of lifetime reproductive strategy, disperser guilds, ripening phenology, and fruit design revealed considerable differences. Compared to south Iberian conspecifics, central European plants were considerably smaller and experienced a highly accelerated generation turnover, In south Iberian populations seed dispersal was carried out almost completely by resident birds which occurred in constant abundances throughout the ripening season. In contrast, central European seeds were dispersed by migrants whose abundances changed considerably during the ripening season. Several bird species were involved in both study areas but rendered different importance for seed dispersal. The fruit ripening pattern was highly asynchronous throughout the ripening season in south Iberia, while central European trees showed a complex ripening sequence which resulted in a significant correlation between fruit abundance and changing disperser availability. Central European fruits were smaller and showed a considerably smaller seed load than south Iberian fruits, thus presumably being more attractive for their small-sized main dispersers (Sylvia warblers). Chemical analyses revealed significant differences in contents of water, glucose, fructose, proteins, ash, and phenolic compounds. The extensive differentiation of dispersal-related traits in F. alnus suggests that even weak selective pressures by frugivores may induce evolutionary adjustments of dispersal traits over large time scales. We suggest that the differences we observe today evolved during the species' distribution shifts in the Quaternary.
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modified dispersal related traits in disjunct populations of bird dispersed Frangula alnus rhamnaceae a result of its quaternary distribution shifts
Ecography, 2000Co-Authors: Arndt Hampe, Franz BairleinAbstract:Many European tree species survived Pleistocene glaciations in Mediterranean refugia and rapidly recolonized temperate Europe afterwards. Inter- and postglacial migration processes are assumed to have catalized evolutionary optimizations of dispersal-related traits, but up to now empirical evidence is lacking in vertebrate-dispersed plants. We investigated if south Iberian glacial relict and central European qcolonizerq populations of the bird-dispersed tree Frangula alnus have experienced differentiations of dispersal-related traits which increase the mobility of northern populations. A comparison of lifetime reproductive strategy, disperser guilds, ripening phenology, and fruit design revealed considerable differences. Compared to south Iberian conspecifics, central European plants were considerably smaller and experienced a highly accelerated generation turnover, In south Iberian populations seed dispersal was carried out almost completely by resident birds which occurred in constant abundances throughout the ripening season. In contrast, central European seeds were dispersed by migrants whose abundances changed considerably during the ripening season. Several bird species were involved in both study areas but rendered different importance for seed dispersal. The fruit ripening pattern was highly asynchronous throughout the ripening season in south Iberia, while central European trees showed a complex ripening sequence which resulted in a significant correlation between fruit abundance and changing disperser availability. Central European fruits were smaller and showed a considerably smaller seed load than south Iberian fruits, thus presumably being more attractive for their small-sized main dispersers (Sylvia warblers). Chemical analyses revealed significant differences in contents of water, glucose, fructose, proteins, ash, and phenolic compounds. The extensive differentiation of dispersal-related traits in F. alnus suggests that even weak selective pressures by frugivores may induce evolutionary adjustments of dispersal traits over large time scales. We suggest that the differences we observe today evolved during the species' distribution shifts in the Quaternary.
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Nahrungssuche und Vergesellschaftung frugivorer Zug- und Brutvögel
Journal für Ornithologie, 2000Co-Authors: Arndt Hampe, Franz BairleinAbstract:Migrating birds that arrive at unknown stopover sites have to satisfy greater nutritive demands in restricted time and simultanously run a higher predation risk than residents which are familiar with the area. Foraging behaviour of resident and migrant frugivores feeding on fruits of Alder Buckthorn ( Frangula alnus ) was studied in Germany and Spain. German trees ripen their fruits during the autumn migration period, Spanish ones during the breeding and early postbreeding season. In both areas fruits were mainly eaten by Sylvia warblers, Robin ( Erithacus rubecula ) and thrushes ( Turdus sp.). At the stopover site birds spent less time in the tree, consumed more fruits per visit and therefore foraged more efficiently. In both areas birds clearly synchronized foraging bouts and formed intra- and interspecific assemblages, which were more frequent in migrants than in residents on the interspecific level. The influence of nutritive demands and predator avoidance upon the foraging behaviour and its consequences for seed dispersal are discussed. Zugvögel, die sich in unbekannten Rastgebieten aufhalten, müssen ihren erhöhten Nahrungsbedarf in begrenzter Zeit befriedigen und sind gleichzeitig einem höheren Prädationsrisiko ausgesetzt als residente Vögel, die das Gebiet kennen. Resultierende Unterschiede im Nahrungssuchverhalten von ziehenden und residenten fruchtfressenden Vögeln wurden anhand systematischer Beobachtungen an fruchtenden Faulbäumen ( Frangula alnus ) in Deutschland und Spanien untersucht. Deutsche Faulbäume fruchten während des Herbstzuges, spanische bereits während und kurz nach der Brutsaison. In beiden Gebieten wurden die Früchte vor allem von Grasmücken ( Sylvia sp.), Rotkehlchen ( Erithacus rubecula ) und Drosseln ( Turdus sp.) verzehrt. Im Durchzugsgebiet hielten sich Vögel zum Teil kürzer im Baum auf, verzehrten mehr Früchte pro Besuch und gingen damit effizienter vor. In beiden Gebieten bestand eine starke Tendenz zur Synchronisation von Baumbesuchen und zur intra- und interspezifischen Vergesellschaftung während der Nahrungssuche, die auf interspezifischem Niveau im Durchzugsgebiet noch ausgeprägter war als im Brutgebiet. Der Einfluß von Nahrungsbedarf und Prädationsvermeidung auf das Nahrungssuchverhalten sowie dessen Auswirkungen auf die Samenausbreitung der Pflanze werden diskutiert.
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Nahrungssuche und Vergesellschaftung frugivorer Zug- und Brutvögel
Journal of Ornithology, 2000Co-Authors: Arndt Hampe, Franz BairleinAbstract:Zugvogel, die sich in unbekannten Rastgebieten aufhalten, mussen ihren erhohten Nahrungsbedarf in begrenzter Zeit befriedigen und sind gleichzeitig einem hoheren Pradationsrisiko ausgesetzt als residente Vogel, die das Gebiet kennen. Resultierende Unterschiede im Nahrungssuchverhalten von ziehenden und residenten fruchtfressenden Vogeln wurden anhand systematischer Beobachtungen an fruchtenden Faulbaumen (Frangula alnus) in Deutschland und Spanien untersucht. Deutsche Faulbaume fruchten wahrend des Herbstzuges, spanische bereits wahrend und kurz nach der Brutsaison. In beiden Gebieten wurden die Fruchte vor allem von Grasmucken (Sylvia sp.), Rotkehlchen (Erithacus rubecula) und Drosseln (Turdus sp.) verzehrt. Im Durchzugsgebiet hielten sich Vogel zum Teil kurzer im Baum auf, verzehrten mehr Fruchte pro Besuch und gingen damit effizienter vor. In beiden Gebieten bestand eine starke Tendenz zur Synchronisation von Baumbesuchen und zur intra- und interspezifischen Vergesellschaftung wahrend der Nahrungssuche, die auf interspezifischem Niveau im Durchzugsgebiet noch ausgepragter war als im Brutgebiet. Der Einflus von Nahrungsbedarf und Pradationsvermeidung auf das Nahrungssuchverhalten sowie dessen Auswirkungen auf die Samenausbreitung der Pflanze werden diskutiert.
