scholarly journals Floral resource-landscapes and pollinator-mediated interactions in plant communities

2015 ◽  
Author(s):  
Henning Nottebrock ◽  
Baptiste Schmid ◽  
Katharina Mayer ◽  
Céline Devaux ◽  
Karen J. Esler ◽  
...  
Keyword(s):  
Plant Species ◽  
Plant Communities ◽  
Species Coexistence ◽  
Seed Set ◽  
Floral Resources ◽  
Allee Effects ◽  
Common Currency ◽  
Visitation Rates ◽  
Nectar Sugar ◽  
Floral Resource

Plant communities provide floral resource-landscapes for pollinators. Yet, it is insufficiently understood how these landscapes shape pollinator-mediated interactions among multiple plant species. Here, we study how pollinators and the seed set of plants respond to the distribution of a floral resource (nectar sugar) in space and across plant species, inflorescences and flowering phenologies. In a global biodiversity hotspot, we quantified floral resource-landscapes on 27 sites of 4 ha comprising 127,993 shrubs of 19 species. Visitation rates of key bird pollinators strongly depended on the phenology of site-scale resource amounts. Seed set of focal plants increased with resources of conspecific neighbours and with site-scale resources, notably with heterospecific resources of lower quality (less sugar per inflorescence). Floral resources are thus a common currency determining how multiple plant species interact via pollinators. These interactions may alter conditions for species coexistence in plant communities and cause community-level Allee effects that promote extinction cascades.

scholarly journals Salvage of floral resources through re-absorption before flower abscission

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Graham H. Pyke ◽  
Zong-Xin Ren ◽  
Judith Trunschke ◽  
Klaus Lunau ◽  
Hong Wang
Keyword(s):  
Floral Resources ◽  
Floral Nectar ◽  
Nectar Volume ◽  
Flower Colours ◽  
Nectar Concentration ◽  
Nectar Sugar ◽  
Biochemical Mechanisms ◽  
Floral Resource ◽  
Almost All

Abstract Plants invest floral resources, including nectar and pigment, with likely consequent reproductive costs. We hypothesized that plants, whose flowers abscise with age, reabsorb nectar and pigment before abscission. This was tested with flowers of Rhododendron decorum, which has large, conspicuous white flowers that increasingly abscise corollas as flowers age. As this species is pollinated by bees, we also hypothesized that nectar concentration would be relatively high (i.e., > 30% wt/vol) and petals would contain UV-absorbing pigment. Floral nectar volume and concentration were sampled on successive days until abscission (up to ten days old, peak at five days) and for sub-sample of four-day-old flowers. Flowers just abscised were similarly sampled. Flower colours were measured using a modified camera, with recordings of spectral reflectance for abscised and open non-abscised flowers. Pigment content was summed values of red, green, blue channels of false color photos. As expected, flowers reabsorbed almost all nectar before abscission, separately reabsorbing nectar-sugar and nectar-water, and petals contained UV-absorbing pigment. However, flowers did not reabsorb pigment and nectar-concentration was < 30% wt/vol. That flowers reabsorb nectar, not pigment, remains unexplained, though possibly pigment reabsorption is uneconomical. Understanding floral resource reabsorption therefore requires determination of biochemical mechanisms, plus costs/benefits for individual plants.

scholarly journals Floral UV Features of Plant Species From a Neotropical Savanna

2021 ◽  
Vol 12 ◽  
Author(s):  
Priscila Tunes ◽  
Maria Gabriela Gutierrez Camargo ◽  
Elza Guimarães
Keyword(s):  
Plant Species ◽  
Floral Resources ◽  
Neotropical Savanna ◽  
Ecological Processes ◽  
Reproductive Structures ◽  
Shared Ancestry ◽  
Resource Type ◽  
Colour Patterns ◽  
Floral Resource ◽  
Pollination Systems

Despite the wide interest in flower colours, only after the end of the nineteenth-century studies started to comprise floral UV reflection, which is invisible to humans but visible to the major groups of pollinators. Many flowers and inflorescences display colour patterns, an important signal for pollinators, promoted by the presence of at least two different colours within flowers or inflorescences, including colours in the UV waveband. For Neotropical savanna plant species, we characterised floral UV features using UV-photography and reflectance measurements. We tested (i) whether floral UV features were constrained by their shared ancestry, (ii) whether floral UV features were associated with pollinators, and (iii) whether floral UV features were associated with floral traits mediating these interactions, including floral resource, type of attraction unit and presence/absence of non-UV colour patterns. Of 80 plant species, ca. 70% were UV-patternless, most of them UV-absorbing. Approximately 30% presented one of three types of UV-patterns: bullseye, contrasting corolla markings oriented toward floral resources or contrasting reproductive structures, which were all considered as floral guides. Floral UV features were phylogenetically constrained and were associated with pollinators, floral resources and attraction unit, but not with non-UV colour patterns. UV-patternless flowers were associated with most of the pollination systems, while UV-patterned flowers were mainly associated with bee-pollination. UV-absorbing flowers comprised the only category with hawkmoth- and butterfly-pollinated flowers, and a high percentage of hummingbird-pollinated species. Nocturnal pollinated species were also commonly UV-absorbing, except for one UV-reflecting bat-pollinated species and one beetle-pollinated species with UV-reflecting stigmas. All types of floral UV features were associated with nectar; however, flowers with contrasting reproductive structures were mainly associated with pollen. There was an association between UV-absorbing species and the presence of inflorescences and intermediate attraction units. Our results evince that phylogenetic relatedness can constraint floral UV features’ diversification, but combinations of evolutionary and ecological processes may be expected in this scenario.

scholarly journals Reduced visitation to the buzz-pollinated Cyanella hyacinthoides in the presence of other pollen sources in the hyperdiverse Cape Floristic Region

2021 ◽  
Author(s):  
Jurene E Kemp ◽  
Francismeire J Telles ◽  
Mario Vallejo-Marin
Keyword(s):  
Plant Species ◽  
Flower Colour ◽  
Cape Floristic Region ◽  
Floral Resources ◽  
Visitation Rates ◽  
Competitive Disadvantage ◽  
Pollen Sources ◽  
Floral Visitors ◽  
Time And Energy ◽  
Poricidal Anthers

Many plant species have floral morphologies that restrict access to floral resources, such as pollen or nectar, and only a subset of floral visitors can perform the complex handling behaviours required to extract restricted resources. Due to the time and energy required to extract resources from morphologically complex flowers, these plant species potentially compete for pollinators with co-flowering plants that have more easily accessible resources. A widespread floral mechanism restricting access to pollen is the presence of tubular anthers that open through small pores or slits (poricidal anthers). Some bees have evolved the capacity to remove pollen from poricidal anthers using vibrations, giving rise to the phenomenon of buzz-pollination. These bee vibrations that are produced for pollen extraction are presumably energetically costly, and to date, few studies have investigated whether buzz-pollinated flowers may be at a disadvantage when competing for pollinators' attention with plant species that present unrestricted pollen resources. Here, we studied Cyanella hyacinthoides (Tecophilaeaceae), a geophyte with poricidal anthers in the hyperdiverse Cape Floristic Region of South Africa, to assess how the composition and relative abundance of flowers with easily accessible pollen affect bee visitation to a buzz-pollinated plant. We found that the number of pollinator species was not influenced by community composition. However, visitation rates to C. hyacinthoides were negatively related to the abundance of flowers with more accessible resources. Visitation rates were strongly associated with petal colour, showing that flower colour is important in mediating these interactions. We conclude that buzz-pollinated plants might be at a competitive disadvantage when many easily accessible pollen sources are available, particularly when competitor species share its floral signals.

scholarly journals Foraging activity of africanized honeybees (Apis mellifera L.): A study of nectar and pollen resources on a temporal scale

2019 ◽  
Vol 12 (1) ◽  
pp. 11-18
Author(s):  
Leandro Pereira Polatto ◽  
Valter Vieira Alves Junior ◽  
João Cloves Stanzani Dutra ◽  
José Chaud-Netto
Keyword(s):  
Apis Mellifera ◽  
Plant Species ◽  
Secondary Growth ◽  
Food Resources ◽  
Floral Resources ◽  
Natural Food ◽  
Foraging Activity ◽  
Forest Fragment ◽  
Floral Resource ◽  
Africanized Honeybees

Abstract. The spatial and temporal distribution of food resources, as well as the type, quantity, and quality of the foods stocked in the hive are the principal regulatory factors of the choice and intensity of floral resource harvesting by bees. We evaluated the annual foraging activity of Africanized honeybees Apis mellifera L. (Apidae) on the most abundant natural food resources available. Nineteen abundant plant species susceptible to foraging by bee communities in the interior of a secondary growth forest fragment with a transition physiognomy between Atlantic Forest and Cerradão vegetation were accompanied to estimate the intensity of floral resource collection by Africanized honeybees A. mellifera during the year. We determined the productivity of the flowers (the quality and quantity of nectar and/or pollen made available) and floral abundance (the quantities of flowers produced and the duration of flowering) of the 19 plant species selected. Africanized honeybees A. mellifera collected floral resources from 11 species. The intensities of visits per flower and per area of floral exposition were greater among plant species visited by Africanized honeybees when bee collecting behavior resulted in pollen transfer to the floral stigmas. It is estimated that 70.5% of all visits by Africanized honeybees A. mellifera individuals during the year in the study area occurred on Senegalia polyphylla (DC.) Britton & Rose (Fabaceae), Grazielia cf. dimorpholepis (Baker) R.M.King & H.Rob (Asteraceae), and Gouania cf. latifolia Reissek (Rhaminaceae); those visits demonstrated seasonal patterns, with peaks of activity between January and April. Weak foraging activity was observed in June and between June and November.Atividade de forrageio de abelhas africanizadas (Apis mellifera L.): um estudo das fontes de néctar e pólen em uma escala temporalResumo. A distribuição espacial e temporal dos recursos alimentares, bem como o tipo, quantidade e qualidade do alimento estocado na colmeia são os principais fatores reguladores na escolha e intensidade da coleta dos recursos florais pelas abelhas. O objetivo desse trabalho foi avaliar a atividade anual de forrageio de abelhas africanizadas Apis mellifera L. (Apidae) nas fontes alimentares naturais mais abundantes. A coleta de dados foi realizada em 19 espécies vegetais abundantes e suscetíveis ao forrageio pela comunidade de abelhas no interior de um fragmento de floresta secundária com fisionomia em transição entre Mata Atlântica e Cerradão, durante um ano. Para estimar a intensidade de coleta de recursos florais pelas abelhas africanizadas A. mellifera, foi determinada a produtividade das flores (qualidade e quantidade do néctar e/ou pólen alocada nas flores) e a abundância (quantidade de flores e duração do florescimento) das 19 espécies vegetais selecionadas. As abelhas africanizadas A. mellifera coletaram recursos florais em 11 espécies vegetais. As intensidades de visitas por flor e áreas de exposição floral foram superior nas espécies de plantas que foram visitadas pelas abelhas africanizadas A. mellifera cujos comportamentos de coleta resultavam em transferência de pólen aos estigmas das flores. Estima-se que 70,5% de todas as visitas promovidas por A. mellifera africanizada no decorrer do ano na região de estudo ocorreram em Senegalia polyphylla (DC.) Britton & Rose (Fabaceae), Grazielia cf. dimorpholepis (Baker) R.M.King & H.Rob (Asteraceae), e Gouania cf. latifolia Reissek (Rhaminaceae), demonstrando, dessa forma, um padrão sazonal, com picos de atividade em janeiro, abril e agosto, respectivamente. Por outro lado, houve fraca atividade de forrageio em junho e entre setembro e novembro.

scholarly journals Honeybee Floral Resources in Southwestern Nigeria

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Abel Adebayo Ayansola ◽  
Banjo Adedoyin Davies
Keyword(s):  
Apis Mellifera ◽  
Plant Species ◽  
Food Plants ◽  
Floral Resources ◽  
Flowering Period ◽  
Southwestern Nigeria ◽  
Medicinal Uses ◽  
Visitation Rates

Every beekeeper is expected to be familiar with the bee floral resources near/ or around his/her apiary for successful beekeeping operation. Understanding the major nectar and pollen producing plants and their flowering period is of great advantage to maximise the efficiency of the bees. Regrettably however, there is dearth of information on floral resources of honeybees in southwestern Nigeria. This study investigated the food-plants of honeybees (Apis mellifera andasonii) in the rainforest and derived savannah zones of southwestern Nigeria between April 2009 and March 2011. Forty nine species of melliferous plants belonging to different families were recorded. The flowering period of each plant species differs from one another. However, there was no month in the year that a plant was not in flower. Differences in bee visitation rates to each plant species were observed. Bee flowering calendar was prepared with the intensity of bee visitation rates. The ethno-medicinal uses of the bee-plants were also documented.

scholarly journals Impacts of Land-Use Changes on Vegetation and Ecosystem Functioning: Old-Field Secondary Succession

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 990
Author(s):  
Javier Pérez-Hernández ◽  
Rosario G. Gavilán
Keyword(s):  
Plant Communities ◽  
Ecosystem Functioning ◽  
Secondary Succession ◽  
Species Coexistence ◽  
Human Impacts ◽  
Soil Seed Bank ◽  
Land Use Changes ◽  
Dispersal Limitation ◽  
Point Of View ◽  
Old Field

The study of ecological succession to determine how plant communities re-assemble after a natural or anthropogenic disturbance has always been an important topic in ecology. The understanding of these processes forms part of the new theories of community assembly and species coexistence, and is attracting attention in a context of expanding human impacts. Specifically, new successional studies provide answers to different mechanisms of community assemblage, and aim to define the importance of deterministic or stochastic processes in the succession dynamic. Biotic limits, which depend directly on biodiversity (i.e., species competition), and abiotic filtering, which depends on the environment, become particularly important when they are exceeded, making the succession process more complicated to reach the previous disturbance stage. Plant functional traits (PFTs) are used in secondary succession studies to establish differences between abandonment stages or to compare types of vegetation or flora, and are more closely related to the functioning of plant communities. Dispersal limitation is a PFT considered an important process from a stochastic point of view because it is related to the establishing of plants. Related to it the soil seed bank plays an important role in secondary succession because it is essential for ecosystem functioning. Soil compounds and microbial community are important variables to take into account when studying any succession stage. Chronosequence is the best way to study the whole process at different time scales. Finally, our objective in this review is to show how past studies and new insights are being incorporated into the basis of classic succession. To further explore this subject we have chosen old-field recovery as an example of how a number of different plant communities, including annual and perennial grasslands and shrublands, play an important role in secondary succession.

scholarly journals A matter of time: Recovery of plant species diversity in wild plant communities at declining nitrogen deposition

2021 ◽  
Author(s):  
Frank Berendse ◽  
Rob H. E. M. Geerts ◽  
Wim Th. Elberse ◽  
Thiemo Martijn Bezemer ◽  
Paul W. Goedhart ◽  
...  
Keyword(s):  
Species Diversity ◽  
Nitrogen Deposition ◽  
Plant Species ◽  
Plant Communities ◽  
Plant Species Diversity ◽  
Wild Plant

INFLUENCE OF HERACLEUM SOSNOWSKYI MANDEN. ON BIODIVERSITY OF VASCULAR PLANTS OF THE PROTECTED AREA «LIPOVAYA GORA» (PERM)

2020 ◽  
pp. 272-279
Author(s):  
D. N. Tiunov ◽  
◽  
E. G. Efimik ◽  
Keyword(s):  
Plant Species ◽  
Plant Communities ◽  
Protected Area ◽  
Vascular Plants ◽  
Rapid Development ◽  
Projective Cover ◽  
Seed Productivity ◽  
Heracleum Sosnowskyi ◽  
Rapid Spread

The problem of invasion of Sosnowsky hogweed (Heracleum sosnowskyi Manden.) In the Lipovaya Gora SPNA in Perm is considered. A map of distribution of hogweed cenopopulations in the protected area is presented. The results of the influence of the invasion of Sosnovsky hogweed on the biodiversity of vascu-lar plants of some plant communities are presented. It was revealed that the invasion of hogweed into phytocenoses of the Lipovaya Gora protected area leads to a decrease in the biodiversity of vascular plants by about 26.4% (up to 12 plant species). The ways of introduction of cow parsnip into the communities of the protected area are considered. High seed productivity, high projective cover, reaching in some cases 100%, high phytomass, the presence of dormant seeds, rapid development in spring, and high anthropo-genic load on the territory determine the rapid spread of H. sosnowskyi.

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