@article {112,
	title = {Ecology of mast-fruiting in three species of North American deciduous oaks},
	journal = {Ecology},
	volume = {74},
	year = {1993},
	note = {199395129424ArticleEnglish},
	month = {1993},
	pages = {528-541},
	abstract = {We conducted an 8-yr study of flower and acorn production in three species of oak in east-central Missouri (USA): white oak (Quercus alba), red oak (Q. rubra), and black oak (Q. velutina). The goal was to evaluate whether mast -fruiting, the synchronous production of large seed crops followed by small seed crops, is simply a response to weather conditions or is actually an evolved reproductivity strategy. In this paper, we address four specific questions: (1) Are annual fluctuations in acron crop size the result of synchronous production of acorns by individuals? (2) Are large acorn crops the result of large flower crops and/or high survival of those flowers to mature fruit? (3) To what extent do weather variables account for variation in acorn production among years? (4) Does acorn crop size correlate negatively with prior acorn production? Red oak and white oak showed a greater degree of mast -fruiting than did black oak. Within a species, individuals tended to produce large acorn crops in the same years, but each species differed in which years they produced large crops. The size of a given acorn crop was determined by both flower abundance and survival of flowers to fruit. Principal components and multiple-regression analyses were used to describe the relationship between weather variables and acorn production. The first principal component explained the largest amount of the variation in black oak (R-2 = 0.55) and red oak (R-2 = 0.89). In white oak, two principal components combined to explain 77\% of the variation in acorn production. The weather variables that were associated with these principal components included spring temperature (positive effect) and summer drought (negative effect). Past acorn production had a major impact on the size of the current acorn crop, with each species showing a different pattern. In black oak, the current acorn crop was negatively correlated with the crop 3 yr prior but positively correlated with the crop 2 yr prior. In red oak, acorn crop size 1, 2, and 3 yr prior had negative correlations with current acorn crop, while acorn crop size 4 yr prior was positively correlated. In white oak, there were negative correlations between acorn crop size and crop size 1, 2, and 4 yr prior but a positive correlation with the acorn crop size 3 yr prior. These data are consistent with the hypothesis that mast-fruiting species must store resources during some years in order to produce a mast crop. We discuss the possibility that these three species may have inherent cycles of reproduction that are modified by the impact of weather conditions, black oak with 2-yr cycles, white oak with 3-yr cycles, and red oak with 4-yr cycles. We conclude that the patterns of acorn production for black oak, red oak, and white oak are not simply responses to weather events but are also a function of prior reproductive events. This suggests that masting is an evolved reproductive strategy.},
	keywords = {(Fagaceae-), [26070-] Fagaceae-, ACORN-CROP-SIZE, Angiospermae-, Climatology-: Environmental-Sciences, Dicots-, Dicotyledones-, DROUGHT-, Ecology-: Environmental-Sciences, Fagaceae-: Angiosperms-, FLOWER-ABUNDANCE, Missouri-: USA-, Nearctic-region, North-America, Physiology-, Plantae-, Plants-, Quercus-alba (Fagaceae-), Quercus-rubra (Fagaceae-), Quercus-velutina, Reproduction-, REPRODUCTIVE-STRATEGY, Spermatophyta-, Spermatophytes-, TEMPERATURE-, USA-: North-America, Vascular-Plants, WEATHER-},
	author = {Sork, V.-L. and Bramble, J. and Sexton, O.}
}
@article {65,
	title = {Pollen movement in declining populations of California Valley oak, Quercus lobata: Where have all the fathers gone?},
	journal = {Molecular Ecology},
	volume = {11},
	year = {2002},
	note = {200200321338ArticleEnglish},
	month = {2002},
	pages = {1657-1668},
	abstract = {The fragmented populations and reduced population densities that result from human disturbance are issues of growing importance in evolutionary and conservation biology. A key issue is whether remnant individuals become reproductively isolated. California Valley oak (Quercus lobata) is a widely distributed, endemic species in California, increasingly jeopardized by anthropogenic changes in biota and land use. We studied pollen movement in a savannah population of Valley oak at Sedgwick Reserve, Santa Barbara County, to estimate effective number of pollen donors (Nep) and average distance of effective pollen movement (delta). Using TWOGENER, our recently developed hybrid model of paternity and genetic structure treatments that analyses maternal and progeny multilocus genotypes, we found that current Nep = 3.68 individuals. Based on an average adult density of d = 1.19 stems/ha, we assumed a bivariate normal distribution to model current average pollen dispersal distance (delta) and estimated delta = 64.8 m. We then deployed our parameter estimates in spatially explicit models of the Sedgwick population to evaluate the extent to which Nep may have changed, as a consequence of progressive stand thinning between 1944 and 1999. Assuming that pollen dispersal distance has not changed, we estimate Nep was 4.57 individuals in 1944, when stand density was 1.48. Both estimates indicate fewer effective fathers than one might expect for wind-pollinated species and fewer than observed elsewhere. The results presented here provide a basis for further refinements on modelling pollen movement. If the trends continue, then ongoing demographic attrition could further reduce neighbourhood size in Valley oak resulting in increased risk of reproductive failure and genetic isolation.},
	keywords = {[26070-] Fagaceae-, adult-density, Angiospermae-, declining-populations, Dicots-, Dicotyledones-, Fagaceae-: Angiosperms-, genetic-isolation, human-disturbance, Nearctic-region, North-America, Plantae-, Plants-, pollen-movement, Population-Genetics: Population-Studies, Quercus-lobata (Fagaceae-): California-Valley-oak, reproductive-failure, Santa-Barbara-County: California-, Sedgwick-Reserve, Spermatophyta-, Spermatophytes-, TWOGENER-model, USA-, Vascular-Plants},
	author = {Sork, V.-L. and Davis, F.-W. and Smouse, P.-E. and Apsit, V.-J. and Dyer, R.-J. and Fernandez-M, J.-F. and Kuhn, B.}
}
