Pollination Using Florivores: From Brood Site Mutualism to Active Pollination

2011 ◽  
Author(s):  
Pat Willmer
Keyword(s):  
Pollination Syndrome ◽  
Plant Fitness ◽  
Costs And Benefits ◽  
Pollen Transfer ◽  
Pollination Success ◽  
The Third ◽  
Nursery Pollination ◽  
Lepidopteran Larvae ◽  
Seed Eating ◽  
Pollination Systems

This chapter examines brood site mutualisms, where the pollinators are florivores. In brood site mutualisms, the pollinators are sometimes referred to as nursery pollinators. Here pollination success affects not only plant fitness but also pollinator fitness, and the balance between costs and benefits may be highly variable from place to place and across seasons. There are at least thirteen known nursery pollination systems, and this phenomenon can be divided into three categories. Two of these are relatively unspecialized, where beetle or lepidopteran larvae develop in decomposing flower heads, or where thrips feed in flowers as pollen parasites. The third category is termed “active pollination,” also known as “seed-eating pollination syndrome.” The chapter first considers nursery pollination and thrips as pollen parasites before discussing active pollination, where active pollen transfer occurs and a clear mutualism results.

scholarly journals Bumblebee Preadators Reduce Pollinator Density and Plant Fitness

2004 ◽  
Vol 28 ◽  
pp. 94-97
Author(s):  
Reuven Dukas
Keyword(s):  
Food Reward ◽  
Fruit Set ◽  
Field Work ◽  
Pollination Biology ◽  
Food Sources ◽  
Plant Fitness ◽  
Predatory Activity ◽  
Selective Agents ◽  
Flower Visiting ◽  
Pollination Systems

Research in pollination biology has focused on the interactions between animals and the flowers they visit for food reward. However, other selective agents, including predators, seed feeders and herbivores, may affect pollination systems. Because flowers are predictable food sources for a variety of species, flowers are also reliable sites at which predators can locate flower-visiting animals. Prominent among pollinators' predators are beewolves (Philanthus spp), common sphecid wasps (Sphecidae) that prey almost exclusively on bees. My field work over three years indicates, first, that an area of approximately 50 square km surrounding a single bumblebee wolf (Philanthus bicinctus) aggregation had a low bumblebee (Bombus spp) density caused by intense predation by the wasps, and, second, that fruit set of the bumblebee pollinated western monkshood (Aconitum columbianum) was significantly lower at locations and times of bumblebee wolf activity than at control locations and times with no such predatory activity. These results indicate that predation can sometimes alter plant­pollinator interactions.

scholarly journals Evolution of pollination syndromes and corolla symmetry in Balsaminaceae reconstructed using phylogenetic comparative analyses

2020 ◽  
Author(s):  
Saroj Ruchisansakun ◽  
Arne Mertens ◽  
Steven B Janssens ◽  
Erik F Smets ◽  
Timotheüs van der Niet
Keyword(s):  
Phylogenetic Trees ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Plastid Dna ◽  
Pollination Syndrome ◽  
Pollination Syndromes ◽  
Bee Pollination ◽  
Floral Symmetry ◽  
Considerable Uncertainty ◽  
Pollination Systems

Abstract Background and Aims Floral diversity as a result of plant–pollinator interactions can evolve by two distinct processes: shifts between pollination systems or divergent use of the same pollinator. Although both are pollinator driven, the mode, relative importance and interdependence of these different processes are rarely studied simultaneously. Here we apply a phylogenetic approach using the Balsaminaceae (including the species-rich genus Impatiens) to simultaneously quantify shifts in pollination syndromes (as inferred from the shape and colour of the perianth), as well as divergent use of the same pollinator (inferred from corolla symmetry). Methods For 282 species we coded pollination syndromes based on associations between floral traits and known pollination systems, and assessed corolla symmetry. The evolution of these traits was reconstructed using parsimony- and model-based approaches, using phylogenetic trees derived from phylogenetic analyses of nuclear ribosomal and plastid DNA sequence data. Key Results A total of 71 % of studied species have a bee pollination syndrome, 22 % a bimodal syndrome (Lepidoptera and bees), 3 % a bird pollination syndrome and 5 % a syndrome of autogamy, while 19 % of species have an asymmetrical corolla. Although floral symmetry and pollination syndromes are both evolutionarily labile, the latter shifts more frequently. Shifts in floral symmetry occurred mainly in the direction towards asymmetry, but there was considerable uncertainty in the pattern of shift direction for pollination syndrome. Shifts towards asymmetrical flowers were associated with a bee pollination syndrome. Conclusion Floral evolution in Impatiens has occurred through both pollination syndrome shifts and divergent use of the same pollinator. Although the former appears more frequent, the latter is likely to be underestimated. Shifts in floral symmetry and pollination syndromes depend on each other but also partly on the region in which these shifts take place, suggesting that the occurrence of pollinator-driven evolution may be determined by the availability of pollinator species at large geographical scales.

scholarly journals Severely pollen-limited fruit set in a pear (Pyrus communis) orchard revealed by yield assessments and DNA-based paternity assignment of seedlings

2007 ◽  
Vol 13 (3) ◽  
Author(s):  
H. Mattison ◽  
J. Sehic ◽  
H. Nybom
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Rapd Analysis ◽  
Total Yield ◽  
Fruit Tree ◽  
Pollen Transfer ◽  
Pear Cultivar ◽  
Pollination Success ◽  
Viable Seeds ◽  
High Yields

In commercial fruit tree orchards, consistently high yields are necessary for a durable economy. The Swedish pear cultivar 'Carola' has been noted for low setting in some orchards, possibly due to insufficient pollination. In this study, fruit set was evaluated in a research orchard where `Carola' had been planted together with four potential pollinators. Total yield and number of fruits was noted during three and four years, respectively. In 2003, seeds were germinated from the harvested `Carola' fruits, and the paternity of three seedlings from 50 trees was determined with RAPD analysis. 'Clapp's Favourite' had sired 39.6% of the seedlings, closely followed by `Seigneur d'Esperen' (30.7%) and 'Clara Frijs' (26.7%) whereas 'Skanskt sockerparon' only sired 1.1% of the seedlings. The remaining 2.3% appeared to have been derived by selfing. Pollen-limited seed set was indicated at surprisingly short distances; accumulated number of fruits on the `Carola' trees was significantly higher when separated by only 2 m from one of the two most efficient pollinators, 'Clapp's Favourite' or 'Seigneur d'Esperen‘, compared to trees 4—l0 in away in the same row. Number of viable seeds per fruit was also higher in fruits from trees immediately adjacent to the pollinators, suggesting an effect of improved pollination success. The importance of very short inter-cultivar distances for efficient pollen transfer became even more clear when comparisons involved the true pollination distances as determined by RAPD; the accumulated yields decreased linearly from 55 kg at a 2 in distance to only 17 kg at 13 m.

scholarly journals Electrostatic Processes Underlying Natural and Mechanized Transfer of Pollen

1998 ◽  
Author(s):  
Edward Law ◽  
Samuel Gan-Mor ◽  
Hazel Wetzstein ◽  
Dan Eisikowitch
Keyword(s):  
Electric Fields ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Basic Knowledge ◽  
Pollen Deposition ◽  
Average Charge ◽  
Pollen Transfer ◽  
Transfer Vectors ◽  
Pollination Systems ◽  
Relaxation Characteristics

The project objective was to more fully understand how the motion of pollen grains may be controlled by electrostatic forces, and to develop a reliable mechanized pollination system based upon sound electrostatic and aerodynamic principles. Theoretical and experimental analyses and computer simulation methods which investigated electrostatic aspects of natural pollen transfer by insects found that: a) actively flying honeybees accumulate ~ 23 pC average charge (93 pC max.) which elevates their bodies to ~ 47 V likely by triboelectrification, inducing ~ 10 fC of opposite charge onto nearby pollen grains, and overcoming their typically 0.3-3.9 nN detachment force resulting in non-contact electrostatic pollen transfer across a 5 mm or greater air gap from anther-to-bee, thus providing a theoretical basis for earlier experimental observations and "buzz pollination" events; b) charge-relaxation characteristics measured for flower structural components (viz., 3 ns and 25 ns time constants, respectively, for the stigma-style vs. waxy petal surfaces) ensure them to be electrically appropriate targets for electrodeposition of charged pollen grains but not differing sufficiently to facilitate electrodynamic focusing onto the stigma; c) conventional electrostatic focusing beneficially concentrates pollen-deposition electric fields onto the pistill tip by 3-fold as compared to that onto underlying flower structures; and d) pollen viability is adequately maintained following exposure to particulate charging/management fields exceeding 2 MV/m. Laboratory- and field-scale processes/prototype machines for electrostatic application of pollen were successfully developed to dispense pollen in both a dry-powder phase and in a liquid-carried phase utilizing corona, triboelectric, and induction particulate-charging methods; pollen-charge levels attained (~ 1-10 mC/kg) provide pollen-deposition forces 10-, 77-, and 100-fold greater than gravity, respectively, for such charged pollen grains subjected to a 1 kV/cm electric field. Lab and field evaluations have documented charged vs. ukncharged pollen deposition to be significantly (a = 0.01-0.05) increased by 3.9-5.6 times. Orchard trials showed initial fruit set on branches individually treated with electrostatically applied pollen to typically increase up to ~ 2-fold vs. uncharged pollen applications; however, whole-tree applications have not significantly shown similar levels of benefit and corrective measures continue. Project results thus contribute important basic knowledge and applied electrostatics technology which will provide agriculture with alternative/supplemental mechanized pollination systems as tranditional pollen-transfer vectors are further endangered by natural and man-fade factors.

scholarly journals Generalist birds outperform specialist sunbirds as pollinators of an African Aloe

2019 ◽  
Vol 15 (7) ◽  
pp. 20190349 ◽  
Author(s):  
Carolina Diller ◽  
Miguel Castañeda-Zárate ◽  
Steven D. Johnson
Keyword(s):  
Seed Production ◽  
Pollen Grains ◽  
Pollen Transfer ◽  
Bird Pollination ◽  
Single Visit ◽  
Highly Effective ◽  
Aloe Ferox ◽  
Pollination Systems ◽  
Effective Pollinators

Bird pollination systems are dominated by specialist nectarivores, such as hummingbirds in the Americas and sunbirds in Africa. Opportunistic (generalist) avian nectarivores such as orioles, weavers and bulbuls have also been implicated as plant pollinators, but their effectiveness as agents of pollen transfer is poorly known. Here, we compare the single-visit effectiveness of specialist and opportunistic avian nectarivores as pollinators of Aloe ferox, a plant that relies almost exclusively on birds for seed production. We found that the number of pollen grains on stigmas of flowers receiving single visits by opportunistic avian nectarivores was approximately threefold greater than on those receiving single visits by specialist sunbirds and about twofold greater than on those that received single visits by honeybees. The number of pollen grains on stigmas of flowers visited by sunbirds was similar to that on stigmas of unvisited flowers. These results show that opportunistic birds are highly effective pollinators of A. ferox , supporting the idea that some plants are specialized for pollination by opportunistic birds.

A Model of Costs and Benefits of Training in the Police Service of Northern Ireland

2003 ◽  
Vol 76 (1) ◽  
pp. 30-44 ◽  
Author(s):  
Tim Meaklim
Keyword(s):  
Northern Ireland ◽  
Limited Resources ◽  
Costs And Benefits ◽  
Police Service ◽  
Training Interventions ◽  
The Third ◽  
Crucial Problem ◽  
Planning Decision ◽  
And Control ◽  
Awareness System

This article is concerned with research carried out in the Police Service of Northern Ireland to develop a model of costs and benefits of training. It provides a blueprint for use by those who practise planning, decision making and management every day in the police organisation in order that they can solve the most crucial problem in training: how to decide on good quality and relevant training interventions within limited resources. The model has three systems: an Awareness System that sets out the culture and understanding of the organisation; the Operational System which includes identification of the needs, achieving the training outputs, delivering quality products, evaluating the products to test its value and worth and costing all of these issues under a standard costing process; and the third system is the Monitor and Control System which maintains the overall system.

scholarly journals Increased variation in sex organ positions can increase reciprocity and pollination success in heterostylous plant populations

2020 ◽  
Author(s):  
Shatarupa Ganguly ◽  
P.M. Shreenidhi ◽  
Deepak Barua
Keyword(s):  
Reproductive Success ◽  
Natural Populations ◽  
Population Variation ◽  
Success For All ◽  
Pollen Transfer ◽  
Plant Populations ◽  
Pollination Success ◽  
Naturally Occurring ◽  
Transfer Success ◽  
The Relationship

AbstractAimsThe reciprocal position of sexual organs in complementary floral morphs is central to our understanding of heterostyly. Reciprocity indices are used to quantify the spatial match between complementary sex organs, but previous indices fail to appropriately account for variation in sex organ positions among individuals in a population. The objective of this study was to examine how reciprocity and consequently reproductive success change with an increase in intra-population variation in sex organ heights. To this end, we formulated a reciprocity index that incorporates variation in sex organ positions among individuals in a population and asked if estimates of reciprocity can predict reproductive success in naturally occurring heterostylous populations.MethodsWe developed a reciprocity index that assumed pollen transfer success equalled one for a perfectly matched stigma-anther pair, and decreased to zero with increasing mismatch. Reciprocity was quantified as the average pollen transfer success for all pair-wise combinations of complementary sex organs in the population. We examined the relationship between intra-population variation and reciprocity using simulated populations that varied in the distribution of sex organ positions, and with empirical data from natural populations. We compared previously proposed indices using the simulated and natural populations, and for a subset of natural populations we tested the ability of the indices to predict reproductive success.Important FindingsIn both simulated and natural populations we observed that when differences between mean anther and stigma heights of complementary morphs are small, increasing intra-population variation in heights resulted in a monotonous decrease in reciprocity. However, when differences between mean complementary anther and stigma heights are larger, reciprocity increased, reached a peak, and then decreased with increasing variation. Previous indices failed to capture this behaviour and were largely insensitive to variation or differences in mean complementary sex organ heights. Seed set was consistently positively related to reciprocity for our index, and for two of the four previous indices. These results highlight the importance of incorporating intra-population variation in sex organ dimensions in quantifying reciprocity, and challenge the current understanding that increasing variation will always decrease reciprocity in heterostylous populations. These results may help explain why heterostylous systems exhibit, and tolerate high amounts of intra-population variation in sex organ heights.

scholarly journals Spatiotemporal shifts in the role of floral traits in shaping tropical plant-pollinator interactions

2020 ◽  
Author(s):  
Yannick Klomberg ◽  
Robert Tropek ◽  
Jan E.J. Mertens ◽  
Ishmeal N. Kobe ◽  
Jiří Hodeček ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Elevational Gradient ◽  
Floral Traits ◽  
Pollination Syndrome ◽  
Floral Trait ◽  
Mount Cameroon ◽  
Tropical Plant ◽  
Random Forest Models ◽  
Pollination Systems ◽  
Plant Pollinator

AbstractThe pollination syndrome hypothesis predicts that plants pollinated by the same pollinator group bear convergent combinations of specific floral traits. Nevertheless, some studies have shown relatively low predictive power for these floral trait combinations. This discrepancy may be caused by changes in the importance of specific floral traits for shaping interactions under different environmental conditions and for different pollinator groups. To test this, we studied pollination systems and floral traits along an elevational gradient on Mount Cameroon during wet and dry seasons. Using Random Forest models, allowing the ranking of traits by significance, we demonstrated that some floral traits are more important than others in shaping interactions and that these traits predict pollinators relatively well. However, the distribution and importance of traits varies under different environmental conditions. Our results imply the need to improve our trait-based understanding of plant-pollinator interactions to better inform the debate surrounding pollination syndrome hypothesis.

scholarly journals Pollinator effectiveness in the mixed-pollination system of a Neotropical Proteaceae, Oreocallis grandiflora

2021 ◽  
Vol 26 ◽  
Author(s):  
Santiago Cárdenas-Calle ◽  
Juan D Cardenas ◽  
Boris O Landázuri ◽  
Gabriela Mogrovejo ◽  
Antonio M Crespo ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Control Group ◽  
Pollinator Effectiveness ◽  
Pollination Success ◽  
Naturally Occurring ◽  
Diverse Community ◽  
Floral Visitors ◽  
Qualitative Component ◽  
Pollination Systems ◽  
Nocturnal Mammals

In pollination systems with a diverse community of floral visitors, qualitative and quantitative variations in pollination effectiveness can lead to a system in which higher effectiveness results from the synergetic contribution of multiple pollinators. By employing a series of field and laboratory experiments in the south Andes of Ecuador, we compared the effectiveness of hummingbirds and nocturnal mammals visiting Oreocallis grandiflora, an Andean member of the Proteaceae. Pollinator effectiveness was measured with a quantitative component that assessed visitation rates to inflorescences and number of contacted stigmas per visit, and with a qualitative component that counted the number of deposited pollen grains in stigmas. Effectiveness estimates were complemented with controlled pollination experiments that contrasted fruit and viable seed set among flowers exposed to either diurnal or nocturnal pollination, self-pollinated flowers, and a control group with flowers exposed to naturally occurring pollination. Four species of hummingbirds and two species of nocturnal mammals visited the flowers of O. grandiflora. Hummingbirds outperformed nocturnal mammals in the quantitative components of pollination, while mammals were more effective than hummingbirds in the qualitative component. Pollination success was higher for the control group than for the other treatments, while hummingbirds and mammals performed similarly. Our findings suggest a case of functional complementarity in pollination: hummingbirds’ quantitative effectiveness complements nocturnal mammals’ qualitative effectiveness. Furthermore, our study demonstrates that pollination success in plants can be greater when flowers are visited by the whole diversity of pollinators. 

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