11 December, 2012

Facilitation or competition for pollination between invasive and native plant species?

by Valérie Cawoy et al.

The invasive Giant Balsam (Impatiens glandulifera) - Photo: A. Vervoort
Plant species that invaded regions where they did not occur before can have deleterious effects on the native flora. They are often ‘supergeneralists’ that attract large numbers of insects with high amounts of nectar and pollen. This may lure pollinators away from co-flowering native species in the surroundings. Consequently, these native species receive less visits and less pollen is transferred, which could lead to reduced fruit and seed production. On the other hand, so-called facilitation effects have been also observed, where the invaders attract pollinators to a patch of flowering plants and may thus increase flower visits to native species.

Read the whole summary: in English or in French
Read the scientific publication in JPE

The Importance of bee pollination for commercial sour cherry production in Denmark

by Lise Hansted et al.

Low fruit set, despite normally-developed flowers in Spring, is often a significant contributor to poor yield in the self-fertile sour cherry (Prunus cerasus) cultivar ‘Stevnsbaer’ in Denmark. This study set out to investigate the effect of insect, and particularly, bee pollination on the fruit set of this cultivar, to provide information for beekeepers and cherry growers concerning the potential benefits of placing bees in the orchards.
A flowering sour cherry branch caged with wire mesh and tulle net, allowing wind through whilst keeping insects out

Read the whole summary: in English or in Danish.
Read the scientific publication in JPE.

04 November, 2012

Reproductive Biology of Pointleaf Manzanita and the Pollinator-Nectar Robber Spectrum

by Leif L. Richardson And Judith L. Bronstein

A female mason bee (Osmia species) foraging at manzanita flowers that have been previously nectar robbed. Photo by Dorit Eliyahu
Mutualism is a biological phenomenon in which two species interact to their mutual benefit. A classic example is pollination, in which plants exchange a food reward (usually pollen or nectar) for pollen transport between flowers. Mutualisms are ubiquitous in nature, but so is their exploitation by organisms (often individuals of the mutualist species pair) that benefit from the exchange while not reciprocating with either partner. Despite their prevalence, theoretical models predict that these ‘cheaters’ should drive mutualisms to extinction because deriving a benefit without paying a cost should spread. How do mutualisms persist in the face of this pervasive exploitation?

Read the whole summary: pdf
Read the scientific publication in JPE.


31 October, 2012

Estimating pollination success with artificial flowers

By James D. Thomson, Jane E. Ogilvie, Takashi T. Makino, Angela Arisz, Sneha Raju, Vanessa Rojas-Luengas, Marcus Tan

An artificial flower
Investigators of the interactions between plants and pollinating animals have frequently resorted to artificial flowers to clarify aspects of pollinator preferences and choice-making.  Such experiments typically present animals with arrays of multiple phenotypes of “flowers” constructed to vary in particular characters; animals’ responses are measured as the visitation rates to the different floral phenotypes.

Read the whole summary: pdf
Read the scientific publication in JPE .