| 1 | The role of the pollination niche in community assembly of Erica species in a biodiversity hotspot显示文摘Aims Closely related species frequently co-occur in plant communities.The role of niche partitioning for allowing their coexistence has been called into question,but most studies on community ecol-ogy neglect pollination as a niche component,and thus poten-tially underestimate niche partitioning.Here,we investigate the importance of the pollination niche for determining coexistence in a biodiversity hotspot.We specifically test whether co-flowering insect-pollinated species of Erica,the most species-rich plant genus of the South African Cape Floristic Region,are characterized by dif-ferent functional floral traits and different specialized pollination systems.Methods Communities of co-flowering Erica species were studied at three sites in the fynbos biome in the Western Cape of South Africa.We focused on five species with flowers that conform to an insect pol-lination syndrome.We assessed whether floral traits important for pollinator attraction and mechanical fit overlap by comparison of scent(gas chromatography coupled with mass spectrometry),col-our(spectrophotometry and models of bee vision),nectar volume and concentration and corolla morphology.Pollinator partitioning was quantified by comparison of floral visitor profiles and pollinator importance,calculated as the product of visitation rate,number of flowers probed per visit and pollen load for each functional visitor group among species within communities.Potential effects of com-petition were assessed by comparing visitation rates both directly and using anther ring disturbance as a proxy for lifetime visitation.Important Findings Floral phenotypes differed among species within communities in all functional traits.Visitor assemblages were diverse,including ants,beetles,flies,honeybees,moths and solitary bees.However,the Cape honeybee,Apis mellifera capensis,was the main pollinator of all but one Erica species.Insect visitation rates were significantly lower for E.imbricata and E.calycina relative to congeners,but high rates of anther ring disturbance,which differed significantly in only two out of seven comparisons,suggest that long-term visitation rates are mostly similar among species that share pollinators.This study shows that coexistence of co-flowering insect-pollinated Erica species is not determined by specialization for different pollination systems.Pollinator sharing might rather lead to facilitation among co-flowering species,and floral constancy mediated by extensive interspecific floral trait variation might mitigate its potentially nega-tive effects. | Roderick W.Bouman Sandy-Lynn Steenhuisen Timotheüs van der Niet | 2017 | Journal of Plant Ecology2017，10，4： | 0 |
| 2 | Weda,a new genus with two new species of Euphorbiaceae-Crotonoideae from Halmahera(North Maluku,Indonesia)and phylogenetic relationships of the Australasian tribe Ricinocarpeae显示文摘During the environmental impact study for a proposed nickel mine near Weda Bay on Halmahera in North Moluccas(Maluku Utara Province),Indonesia,two unknown Euphorbiaceae were discovered.Morphological comparisons and molecular phylogenetic analyses using four markers(plastid trnL-F and rbcL,and nuclear ribosomal internal transcribed spacer and external transcribed spacer)indicated that they should be recognized as constituting a new,distinct genus of two species,which are described and illustrated here as Weda fragarioides and Weda lutea.The new taxa are members of the Australasian tribe Ricinocarpeae in subfamily Crotonoideae,and they are most closely related to Alphandia.In contrast with the otherwise mostly sclerophyllous Ricinocarpeae,Weda possesses stellate to dendritic hairs,large,long-petiolate,glandular leaves,and inflorescences with a pair of large,leafy,subopposite bracts.The two narrowly distributed species are distinguished from each other by vegetative and floral features,molecular data,and elevational preferences.Leaf elemental analysis of Weda indicated manganese,but not nickel,accumulation.Newly resolved generic relationships and potential morphological synapomorphies within Crotonoideae are discussed,and the circumscription of Ricinocarpeae is expanded from 7 to 11 genera. | Peter Cvan Welzen Susana Arias Guerrero Deby Arifiani Tjut J.F.Bangun Roderick W.Bouman Marcel C.M.Eurlings Iska Gushilman Peter B.Phillipson Iris Tabak Esmee Winkel Kenneth J.Wurdack | 2021 | Journal of Systematics and Evolution2021，59，5： | 0 |
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