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  • 1
    Electronic Resource
    Electronic Resource
    [s.l.] : Macmillan Magazines Ltd.
    Nature 391 (1998), S. 685-687 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Despite the recognized importance of maintaining viable populations of keystone plant resources in tropical wildlife parks and forested preserves, the critical question of what constitutes effective breeding units of these species has not been directly addressed. Here we use paternity analysis ...
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 48 (1994), S. 201-215 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Intertidal sediments of Königshafen (Island of Sylt, North Sea) were sieved for mesofauna (〉0.25 mm) and macrofauna (〉1 mm) in spring and autumn 1990. Although sediments are coarser than in other parts of the Wadden Sea, the macrobenthic fauna was very similar but with a tendency towards higher species density, abundance and biomass. Taking into account the areal size of sandy flats, seagrass beds, mud flats and mussel beds, the average biomass is calculated to be 65 g ash-free dry weight m−2 The lugwormArenicola marina dominates the biomass (28%), followed by the bivalvesMytilus edulis (21%),Mya areanaria (16%),Cerastoderma edule (10%) and the mudsnailHydrobia ulvae (9%). While spring and autumn biomass are almost alike, abundance is highly variable and entirely dominated byH. ulvae. Mesofauna is mainly composed of oligochaetes, small and juvenile polychaetes. Abundance is similar to that of macrofauna, while biomass is only about 1 g m−2. Macrophyte biomass amounted to 9% of that macrofauna. In the course of the centurym mussel beds expanded while muddy areas declined. The concomitant effects on biomass presumably compensated each other.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 45 (1989), S. 637-647 
    ISSN: 1420-9071
    Keywords: Ficus ; figs ; fig pollinating wasps ; pollination mutualisms ; coevolution ; sex allocation ; plant breeding systems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1) Figs (Ficus) and fig-pollination wasps (Agaonidae) are highly coevolved mutualists that depend completely on each other for continued reproduction. However, their reproductive interests are not identical. 2) The natural history of their interaction often permits the direct measurement of total lifetime reproductive success of the wasp and of major components of reproductive success for the fig. 3) Data from 12 monoecious species of New World figs (subgenusUrostigma) and their wasp pollinators (Pegoscapus spp.) indicate that fig fruit size (number of flowers per fruit), wasp size, and the number of foundresses that pollinate and lay eggs in any given fruit interact in complex but systematic ways to affect the reproductive success of both the wasps and the figs. 4) Different aspects of the interaction may work against the reproductive interests of either the wasp or the fig, or often, both. For example, in some species an ‘average’ foundress may only realize 25% of its reproductive potential due to the high average number of foundresses. However, that same crowding slects for more male-biased sex ratios in the wasps that reduce potential fitness gains through pollen dispersal for the fig. Nonetheless, the natural distributions of numbers of foundresses per fruit more clearly reflect the reproductive interests of the figs than of the wasps. 5) Generally, it appears that most of the fig species studied can be arranged along a continuum from those with physically small fruits that produce a relatively low proportion of viable seed butt are very efficient at the production of female wasps to physically large, relatively seed-rich fruits that are relatively inefficient at producing female wasps. The implications of these findings for the coevolution of figs and their wasps are discussed.
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  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 370 (1994), S. 604-604 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR - Moore in a News and Views article1 compared how yuccas and figs control seed consumption by their pollinators. We would like to point out that several recent studies show that there is little or no empirical support for many of the mechanisms that have commonly been proposed to allow figs to ...
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 41 (1985), S. 1265-1276 
    ISSN: 1420-9071
    Keywords: Sex allocation ; sex ratio ; sex change ; hermaphrodites ; gonochores ; natural selection ; trait-group selection ; individual selection ; selection within populations ; selection between species ; outlaw genes ; fig wasps ; bluehead wrasses ; Thalassoma bifasciatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1939
    Keywords: Ficus fruit ; Wasp lethal temperatures Energy budgets ; Coevolution ; Mutualism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Figs are completely dependent for pollen dispersal on species-specific fig-pollinating wasps that develop within developing fig fruits. These wasps are very sensitive to heat and die at temperatures only a few degrees above ambient. Such temperatures are expected and observed in objects exposed to full sunlight, as fig fruits frequently are. In detailed field and experimental studies of 11 species of Panamanian figs with fruit ranging in size from 5 mm to 50 mm in diameter, we found that both the relative and absolute contribution of transpiration to maintaining non-lethal fruit temperatures increased with fruit size. Small and large fruits reached temperatures of 3 and 8°C, respectively, above air temperature in full sunlight when transpiration was prevented by grease. The temperature reached by large, nontranspiring fruits was sufficient to kill their pollinators. Control fruits which transpired reached temperatures of 2–3°C above air temperature in sunlight, regardless of size. An analysis of the solar energy budget of fruit revealed that large fruits must transpire to maintain tolerable temperatures for the wasps because heat diffusion from fruit to air was too low to balance net radiation in sunlight. By contrast, small fruits do not need to transpire to maintain tolerable temperatures for the pollinators.
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  • 7
    ISSN: 1432-1939
    Keywords: Key words  Ficus ; Frugivory ; Fruit removal ; Seed dispersal ; Bats ; Birds ; Coadaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We describe fruiting characteristics for 12 species in a community of strangler figs (Moraceae: Urostigma) studied in Panama. We quantify diurnal and nocturnal removal rates and proportions of fruits removed, and relate them to the activities of the main dispersers of the figs: bats and birds. These results combined with previous studies show that there are clear differences between fig species with fruit that ripen red and those with fruit that remain green(ish). In the red-fruited species, the fruit are small, ripen asynchronously over relatively long periods, produce little scent, and are mainly taken during the day by birds. In contrast, in the green(ish)-fruited species, the fruits are larger, span a range of sizes, ripen relatively synchronously, produce very distinctive aromas, and are mainly taken at night by bats. This dichotomy in fruiting characteristics suggests coadaptive links between groups of dispersers and different species within the genus Ficus. All fig species produce a range of fruit crop sizes (10–155 fuits/m2 canopy area) of which a high proportion were removed by seed dispersers (〉80%). Removal rates (fruit removed per day) were positively correlated with crop size, suggesting that trees with large crop size attract more frugivores. Removal rates of green-fruited figs were significantly lower and persistence and abortion of ripe fruit were significant higher around full moon, apparently due to the reduced activity of bats. We further estimate the number of bats that are sustained by a tree fruit crop and account for the observed fruit removal. We then discuss the evidence for coadaptation between different groups of figs and their seed dispersers, Finally, we consider the conservation implications for figs as keystone resources in tropical forests.
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  • 8
    ISSN: 1573-8477
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 9
  • 10
    Publication Date: 2005-05-03
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
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