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Pollination Treatments (pollination + treatment)
Selected AbstractsNoncorrelated effects of seed predation and pollination on the perennial herb Ruellia nudiflora remain spatially consistentBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2009LUIS ABDALA-ROBERTS By simultaneously manipulating both seed predator and pollinator effects on the perennial herb Ruellia nudiflora at two sites in Yucatan (Mexico), the present study evaluated (1) whether a correlation (interaction) existed between seed predator and pollinator effects on R. nudiflora seed production and (2) whether such an interaction varied geographically. We used three populations per site, and a total of 20 plants per population (N = 120). Groups of five plants were randomly chosen at each population to simultaneously receive one of two seed predator and pollinator exclosure levels (present or excluded in each case). These two factors were fully crossed, resulting in each group being subjected to one of four possible combinations: pollinators excluded/herbivores present; herbivores excluded/pollinators present; herbivores excluded/pollinators excluded; or control (neither excluded). Response variables were the number of seeds produced per plant and the proportion of attacked fruits by seed predators per plant. Seed predators had a large impact on R. nudiflora seed production but did not show any preference for fruits from plants not excluded from pollinators. In addition, the pollination treatment was not significant, indicating no effect of pollinators on reproductive success. These findings resulted in a nonsignificant herbivory × pollination interaction, which was consistent across sites, indicating lack of correlated selection of these two guilds on R. nudiflora seed production. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 800,807. [source] Disruption of an exotic mutualism can improve management of an invasive plant: varroa mite, honeybees and biological control of Scotch broom Cytisus scoparius in New ZealandJOURNAL OF APPLIED ECOLOGY, Issue 2 2010Quentin Paynter Summary 1.,A seed-feeding biocontrol agent Bruchidius villosus was released in New Zealand (NZ) to control the invasive European shrub, broom Cytisus scoparius, in 1988 but it was subsequently considered unable to destroy sufficient seed to suppress broom populations. We hypothesized that an invasive mite Varroa destructor, which has caused honeybee decline in NZ, may cause pollinator limitation, so that the additional impact of B. villosus might now reach thresholds for population suppression. 2.,We performed manipulative pollination treatments and broad-scale surveys of pollination, seed rain and seed destruction by B. villosus to investigate how pollinator limitation and biocontrol interact throughout the NZ range of broom. 3.,The effect of reduced pollination in combination with seed-destruction was explored using a population model parameterized for NZ populations. 4.,Broom seed rain ranged from 59 to 21 416 seeds m,2 from 2004 to 2008, and was closely correlated with visitation frequency of honeybees and bumblebees. Infestation of broom seeds by B. villosus is expected to eventually reach 73% (the average rate observed at the localities adjacent to early release sites). 5.,The model demonstrated that 73% seed destruction, combined with an absence of honeybee pollination, could cause broom extinction at many sites and, where broom persists, reduce the intensity of treatment required to control broom by conventional means. 6.,Nevertheless, seed rain was predicted to be sufficient to maintain broom invasions over many sites in NZ, even in the presence of the varroa mite and B. villosus, largely due to the continued presence of commercial beehives that are treated for varroa mite infestation. 7.,Synthesis and applications. Reduced pollination through absence of honeybees can reduce broom seed set to levels at which biocontrol can be more effective. To capitalize on the impact of the varroa mite on feral honeybees, improved management of commercial beehives (for example, withdrawal of licences for beekeepers to locate hives on Department of Conservation land) could be used as part of a successful integrated broom management programme at many sites in NZ. [source] Reproductive biology and pollination ecology of the rare Yellowstone Park endemic Abronia ammophila (Nyctaginaceae)PLANT SPECIES BIOLOGY, Issue 2 2006N. ELIZABETH SAUNDERS Abstract We examined the breeding system, reproductive output and pollination ecology of Abronia ammophila Greene, a rare and highly restricted endemic of Yellowstone National Park, Wyoming, USA. Floral morphology permits the automatic deposition of self-pollen on the stigma of individual flowers, and male and female reproductive functions temporally overlap. In controlled hand-pollination treatments, we found no significant difference among pollination treatments (unmanipulated, self-pollinated or cross-pollination). The species maintains a long reproductive season with high reproductive output (natural seed set ranged from 59 to 84%). Our results, along with pollinator observations, suggest that A. ammophila exhibits a mixed-mating system: the species can produce seed without pollinators (via either autogamy or agamospermy), but is also visited by an array of pollinating insects that included moths, butterflies and bumblebees. However, noctuid moths were the most abundant pollinators. In contrast, other Abronia species are obligate outcrossers. The mixed-mating system of A. ammophila may have evolved as a consequence of ecological pressures such as scarcity of mates or pollinators. [source] Contribution of small insects to pollination of common buckwheat, a distylous cropANNALS OF APPLIED BIOLOGY, Issue 1 2009Hisatomo Taki Abstract Crop pollination by animals is an essential ecosystem service. Among animal-pollinated crops, distylous plants strongly depend on animal pollination. In distylous pollination systems, pollinator species are usually limited, although flowers of some distylous plants are visited by diverse animals. We studied the pollination biology of common buckwheat (Fagopyrum esculentum), a distylous crop mainly pollinated by honeybees and visited by many insect species, to evaluate the effects of non-honeybee species on pollination services. We focused on insects smaller than honeybees to determine their contribution to pollination. We applied pollination treatments with bags of coarse mesh to exclude flower visits by honeybees and larger insects and compared the seed set of bagged plants with that of untreated plants for pin and thrum flower morphs. We found a great reduction of seed set only in bagged pin flowers. We also confirmed that small insects, including ants, bees, wasps and flies, carried pin-morph pollen. These small insects transfer pollen from the short anthers of pin flowers to the short styles of thrum flowers, leading to sufficient seed set in thrum flowers. Consequently, small, non-honeybee insects have the potential to maintain at least half of the yield of this honeybee-dependent distylous crop. [source] | ||||||||||