Results 261 to 270 of about 2,221,299 (300)

Pollen limitation and seed set associated with year-to-year variation in flowering of Gmelina arborea in a natural tropical forest

Grana, 2019
The year-to-year variations in flowering, pollen and fruit production in ten Gmelina arborea individuals in a natural forest were observed over a period of five years, 2009−2013, and pollinator visits were observed closely over two years, 2011 and 2012 ...
V. P. Khanduri, Kewat Sanjay Kumar, C. M. Sharma, M. Riyal, K. Kar   +4 more
semanticscholar   +1 more source

Reproduction of Echinacea angustifolia in fragmented prairie is pollen‐limited but not pollinator‐limited

Ecology, 2010
Pollen limitation of plant reproduction occurs in many plant species, particularly those in fragmented habitat; however, causes of pollen limitation are often unknown. We investigated the relationship between pollen limitation and pollinator visitation in the purple coneflower, Echinacea angustifolia (Asteraceae), which grows in the extremely ...
Stuart, Wagenius, Stephanie Pimm, Lyon
openaire   +2 more sources

Pollen limitation meets resource allocation: towards a comprehensive methodology

New Phytologist, 2007
SummaryThe standard method of measuring pollen limitation is to add pollen to a number of flowers, preferably to a whole plant, and to compare fruit and seed set with that of naturally pollinated flowers on other plants. In 25 yr of research, this method has yielded valuable data, but it is difficult to use in large plants.
openaire   +2 more sources

Dating With Pollen: Methodology, Applications, Limitations

1984
Abstract Although the dating function of pollen has been largely superceded by radiocarbon, the former is still valuable particularly for dating beyond the range of 14C, in determining the chronology of recent and short-term events, and in sediments where 14C cannot be used. Pollen stratigraphies may be useful as checks on the accuracy of radiocarbon
openaire   +1 more source

Genetic rescue by distant trees mitigates qualitative pollen limitation imposed by fine‐scale spatial genetic structure

Molecular Ecology, 2019
Restricted seed dispersal frequently leads to fine‐scale spatial genetic structure (i.e., FSGS) within plant populations. Depending on its spatial extent and the mobility of pollinators, this inflated kinship at the immediate neighbourhood can critically
A. Castilla, P. J. Garrote, M. Żywiec, Gemma Calvo, Alberto Suárez-Esteban, M. Delibes, José A. Godoy, F. Xavier Picó, J. Fedriani   +8 more
semanticscholar   +1 more source

Allocation of Reproductive Effort in Perennial Plants Under Pollen Limitation

The American Naturalist, 1994
We find the evolutionarily stable allocation of reproductive effort in both hermaphroditic and dioecious perennial plants. The model focuses on the effect of pollen availability on the allocation of reproductive effort and on sex allocation. The model shows that the effect of pollen limitation depends on the detailed assumptions made about the delivery
Olivieri, Isabelle, Couvet, Denis, Slatkin, M.   +2 more
openaire   +4 more sources

Limited proteolysis of antigens E and K from ragweed pollen

Archives of Biochemistry and Biophysics, 1981
Abstract The two ragweed allergens, antigens E and K, are present in pollen as single-chain polypeptides of about 38,000 daltons. During isolation the single-chain precursor of antigen E, or that of antigen K, can undergo limited proteolysis to give other isoelectric forms containing two noncovalently held chains of about 12,000 and 26,000 daltons ...
T P, King, A, Alagón, L, Kochoumian, J, Kuan, A, Sobotka, L M, Lichtenstein   +5 more
openaire   +2 more sources

Pollinator-mediated facilitation alleviates pollen limitation in a plant–hummingbird network

Oecologia, 2022
P. Bergamo, Leandro Freitas, M. Sazima, M. Wolowski   +3 more
semanticscholar   +1 more source

Pollen season and climate: Is the timing of birch pollen release in the UK approaching its limit?

International Journal of Biometeorology, 2012
In light of heightened interest in the response of pollen phenology to temperature, we investigated recent changes to the onset of Betula (birch) pollen seasons in central and southern England, including a test of predicted advancement of the Betula pollen season for London.
Newnham, R.M., Sparks, T.H., Skjøth, C.A., Head, K., Adams-Groom, B., Smith, M.   +5 more
openaire   +3 more sources

Floral density, pollen limitation, and reproductive success in Trillium grandiflorum

Oecologia, 2003
Decreases in floral density can disrupt mutualistic interactions between plants and their pollinators, and decrease reproductive success. I addressed the relationship between floral density and plant reproductive success using two experimental approaches: a pollen supplementation experiment in 12 populations of Trillium grandiflorum that naturally ...
openaire   +2 more sources