@article {88,
	title = {Biogeographical Distribution of Chloroplast Diversity in Northern Red Oak (Quercus rubra L.)},
	journal = {The American Midland Naturalist},
	volume = {161},
	year = {2009},
	month = {2009},
	pages = {134-145},
	abstract = {We mapped the biogeographical distribution of chloroplast haplotypes in northern red oak (Quercus rubra L.) to test the hypotheses that the founder effects during postglacial migration will result in a latitudinal gradient of haplotype diversity with exhaustion of haplotype richness at the extreme northern edge of the range. PCR-RFLP markers for 23 populations of Q. rubra in old growth and minimally disturbed forests across 13,000 km2 of the contemporary range revealed only four of the five haplotypes detected previously at 12 sites in Indiana. The four northernmost populations were fixed for either haplotype I or haplotype II, the two most common haplotypes. Haplotype richness declined poleward, but the biogeographical pattern of 829 haplotypes across the 35 sites did not clearly indicate postglacial migration routes along latitudinal gradients from the southern edges of the study area. Although Q. rubra and the European white oak Q. robur L. are both early successional species that recolonized vast areas as the glaciers retreated, the data indicate that Q. rubra has lower chloroplast haplotype richness, suggesting that the population dynamics of Q. rubra prior to or during Pleistocene climate fluctuations may have differed from the population dynamics of the European white oak taxa.},
	url = {http://www.bioone.org/doi/abs/10.1674/0003-0031-161.1.134},
	author = {BIRCHENKO, I. and FENG, Y. and ROMERO-SEVERSON, J.}
}
@article {126,
	title = {Elucidating the role of genetic drift and natural selection in cork oak differentiation regarding drought tolerance},
	journal = {Molecular Ecology},
	volume = {18},
	year = {2009},
	month = {2009},
	pages = {3803-3815},
	abstract = {Drought is the main selection agent in Mediterranean ecosystems and it has been suggested as an important evolutionary force responsible for population diversification in these types of environments. However, population divergence in quantitative traits can be driven by either natural selection, genetic drift or both. To investigate the roles of these forces on among-population divergence in ecophysiological traits related to drought tolerance (carbon isotope discrimination, specific leaf area, leaf size and leaf nitrogen content), we compared molecular and quantitative genetic differentiation in a common garden experiment including thirteen cork oak (Quercus suber L.) populations across a gradient of rainfall and temperature. Population differentiation for height, specific leaf area, leaf size and nitrogen leaf content measured during a dry year far exceeded the molecular differentiation measured by six nuclear microsatellites. Populations from dry-cool sites showed the lowest nitrogen leaf content and the smallest and thickest leaves contrasting with those from humid-warm sites. These results suggest (i) these traits are subjected to divergence selection and (ii) the genetic differences among populations are partly due to climate adaptation. By contrast, the low among-population divergence found in basal diameter, annual growth and carbon isotopic discrimination (a surrogate for water use efficiency) suggests low or no divergence selection for these traits. Among-population differentiation for neutral markers was not a good predictor for differentiation regarding the quantitative traits studied here, except for leaf size. The correlation observed between the genetic differentiation for leaf size and that for molecular markers was exclusively due to the association between leaf size and the microsatellite QpZAG46, which suggests a possible linkage between QpZAG46 and genes encoding for leaf size.},
	url = {http://dx.doi.org/10.1111/j.1365-294X.2009.04317.x},
	author = {RAM and LORENZO, Z. and SOTO, A. and VALLADARES, F. and Gil, L. and ARANDA, I.}
}
@article {125,
	title = {Extreme host plant conservatism during at least 20 million years of host plant pursuit by oak gallwasps},
	journal = {Evolution},
	volume = {63},
	year = {2009},
	month = {2009},
	pages = {854-869},
	abstract = {Diversification of insect herbivores is often associated with coevolution between plant toxins and insect countermeasures, resulting in a specificity that restricts host plant shifts. Gall inducers, however, bypass plant toxins and the factors influencing host plant associations in these specialized herbivores remain unclear. We reconstructed the evolution of host plant associations in Western Palaearctic oak gallwasps (Cynipidae: Cynipini), a species-rich lineage of specialist herbivores on oak (Quercus). (1) Bayesian analyses of sequence data for three genes revealed extreme host plant conservatism, with inferred shifts between major oak lineages (sections Cerris and Quercus) closely matching the minimum required to explain observed diversity. It thus appears that the coevolutionary demands of gall induction constrain host plant shifts, both in cases of mutualism (e.g., fig wasps, yucca moths) and parasitism (oak gallwasps). (2) Shifts between oak sections occurred independently in sexual and asexual generations of the gallwasp lifecycle, implying that these can evolve independently. (3) Western Palaearctic gallwasps associated with sections Cerris and Quercus diverged at least 20 million years ago (mya), prior to the arrival of oaks in the Western Palaearctic from Asia 520137 mya. This implies an Asian origin for Western Palaearctic gallwasps, with independent westwards range expansion by multiple lineages.},
	url = {http://dx.doi.org/10.1111/j.1558-5646.2008.00604.x},
	author = {Stone, G.N. and Hernandez-Lopez, A.}
}
@article {103,
	title = {Latitudinal decrease in acorn size in bur oak (Quercus macrocarpa) is due to environmental constraints, not avian dispersal},
	journal = {Botany},
	volume = {87},
	year = {2009},
	month = {2009},
	pages = {349-356},
	abstract = {The size of acorns produced by several species of eastern North American oaks decreases with latitude. We investigated three hypotheses for this pattern in the bur oak (Quercus macrocarpa Michx.) using samples collected over 2 years throughout the species},
	author = {Koenig, W.D. and Knops, J.M.H. and Dickinson, J.L. and Zuckerberg, B.}
}
@article {79,
	title = {Molecular, morphological, and ecological niche differentiation of sympatric sister oak species, Quercus virginiana and Q. geminata (Fagaceae)},
	journal = {American Journal of Botany},
	volume = {96},
	year = {2009},
	month = {2009},
	pages = {1690-1702},
	abstract = {The genus Quercus (the oaks) is notorious for interspecific hybrization, generating questions about the mechanisms that permit coexistence of closely related species. Two sister oak species, Quercus virginiana and Q. geminata, occur in sympatry in Florida and throughout the southeastern United States. In 11 sites from northern and southeastern regions of Florida, we used a leaf-based morphological index to identify individuals to species. Eleven nuclear microsatellite markers significantly differentiated between the species with a high correspondence between molecular and morphological typing of specimens. Nevertheless, Bayesian clustering analysis indicates interspecific gene flow, and six of 109 individuals had mixed ancestry. The identity of several individuals also was mismatched using molecular markers and morphological characters. In a common environment, the two species performed differently in terms of photosynthetic performance and growth, corresponding to their divergent ecological niches with respect to soil moisture and other edaphic properties. Our data support earlier hypotheses that divergence in flowering time causes assortative mating, allowing these ecologically distinct sister species to occur in sympatry. Limited gene flow that permits ecological differentiation helps to explain the overdispersion of oak species in local communities.},
	url = {http://www.amjbot.org/cgi/content/abstract/96/9/1690},
	author = {Cavender-Bares, J. and Pahlich, A.}
}
@article {77,
	title = {Patterns of seed dispersal and pollen flow in Quercus garryana (Fagaceae) following post-glacial climatic changes},
	journal = {Journal of Biogeography},
	volume = {36},
	year = {2009},
	month = {2009},
	pages = {929-941},
	abstract = {Aim�We examined the genetic structure of Quercus garryana to infer post-glacial patterns of seed dispersal and pollen flow to test the hypotheses that (1) peripheral populations are genetically distinct from core populations and from one another; (2) genetic diversity declines towards the poleward edge of the species{\textquoteright} range; and (3) genetic diversity in the chloroplast genome, a direct measure of seed dispersal patterns, declines more sharply with increasing latitude than diversity in the nuclear genome. We address our findings in the context of known historical oak distribution from pollen core data derived from previously published research.Location� Oak2013savanna ecosystems from southern Oregon, USA (core populations/non-glaciated range) northward to Vancouver Island, British Columbia, Canada (peripheral populations/glaciated range).Methods� We genotyped 378 trees from 22 sites with five chloroplast and seven nuclear microsatellite loci. For both sets of markers, we estimated genetic diversity and differentiation using an analysis of molecular variance and generated Mantel correlograms to detect genetic and geographical distance correlations. For the nuclear markers, we also used a Bayesian approach to infer population substructure.Results� There was a large degree of population differentiation revealed by six chloroplast haplotypes, with little (2264�3) or no haplotype diversity within sites. Peripheral island locations shared the same, maternally inherited chloroplast haplotype, whereas locations in mainland Washington had greater haplotype diversity. In contrast, genetic diversity of the nuclear markers was high at all locations sampled. Populations clustered into two groups and were significantly positively correlated over large spatial scales (2264�200�km), although allele richness decreased significantly with latitude. Population substructure was observed between core and peripheral populations because rare alleles were absent in peripheral localities and common allele frequencies differed.Main conclusions� The observed pattern of chloroplast haplotype loss at the northern periphery suggests restricted seed dispersal events from mainland sites to peripheral islands. This pattern was unexpected, however, as refugial oak populations remained near the current post-glacial range even during the Last Glacial Maximum. Using nuclear markers, we found high within-population diversity and population differentiation only over large spatial scales, suggesting that pollen flow is relatively high among populations.},
	url = {http://dx.doi.org/10.1111/j.1365-2699.2008.02049.x},
	author = {Marsico, T.D. and Hellmann, J.J.}
}
@article {133,
	title = {Phylogenetic and trait similarity to a native species predict herbivory on non-native oaks},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {106},
	year = {2009},
	month = {2009},
	pages = {18097-18102},
	abstract = {Introduced plants tend to experience less herbivory than natives, although herbivore loads vary widely. Herbivores may switch hosts onto an introduced plant for at least two reasons. They may recognize the novel plant as a potential host based on similarity of the plant{\textquoteright}s traits to the traits of one of its native hosts, a similarity that may or may not exhibit phylogenetic signal. Alternatively, herbivores may feed optimally, assessing which introduced plants provide the best nutrition irrespective of similarity to native species. Here, we created a phylogeny of 57 oak (Quercus) taxa, which were grown outside of their ranges in a common botanical garden that contained one abundant native oak (Quercus lobata). We used the phylogeny to estimate the phylogenetic conservatism of herbivory by two feeding guilds of insects (leaf chewers and leaf miners) and 11 plant traits expected to affect herbivore performance. We found high phylogenetic signal in chewing damage but not mining damage and all traits except for leaf maturation time. Introduced oaks that are more closely related to the native oak received more chewing and mining damage than distantly related oaks, and introduced oaks that had greater overall similarity in leaf traits also received higher chewing damage but not mining damage. These results demonstrate that interactions between introduced plants and their herbivores are driven independently by traits that track plant phylogeny and leaf traits that likely affect herbivore performance.},
	author = {Pearse, I.S. and Hipp, A.L.}
}
@article {80,
	title = {Relative contribution of contemporary pollen and seed dispersal to the effective parental size of seedling population of California valley oak (Quercus lobata N)},
	journal = {Molecular Ecology},
	volume = {18},
	year = {2009},
	month = {2009},
	pages = {3967-3979},
	abstract = {For plant populations, gene movement through pollen and seed dispersal governs the size of local genetic neighbourhoods and shapes the opportunities for natural selection and genetic drift. A critical question is how together these two processes influence the evolutionary dynamics of local populations. To assess the respective contributions of pollen and seed flow, we propose a novel indirect assessment of the separate male and female gametic contributions to total effective parental size (Ne), based on parental correlations estimated via kinship coefficients, that can be applied to data sets that include unambiguous genotypes for male and female gametic contributions. Using the endemic Californian valley oak (Quercus lobata) as our study species, we apply this method to a set of microsatellite genotypes for two distinct ecological sets of naturally recruiting seedlings with acorns attached. We found that the effective numbers of contributing male parents (Nep) exceed effective numbers of female parents (Nem) for seedlings established beneath adult trees (Nep},
	url = {http://dx.doi.org/10.1111/j.1365-294X.2009.04326.x},
	author = {GRIVET, D. and Robledo-Arnuncio, J.J. and Smouse, P.E. and Sork, V.L.}
}
@article {106,
	title = {A review of the taxonomic status of Quercus ellipsoidalis and Quercus coccinea in the Eastern United States},
	journal = {International Oak Journal},
	volume = {20},
	year = {2009},
	month = {2009},
	pages = {65-84},
	author = {Shepard, D.A.}
}
@article {117,
	title = {Species relative abundance and direction of introgression in oaks},
	journal = {Molecular Ecology},
	volume = {18},
	year = {2009},
	month = {2009},
	pages = {2228-2242},
	abstract = {Successful hybridisation and subsequent introgression lead to the transfer of genetic material across species boundaries. In this process, species relative abundance can play a significant role. If one species is less abundant than the other, its females will receive many heterospecific gametes, increasing mate-recognition errors and thus hybridisation rate. Moreover, first-generation hybrids will also more likely mate with the more abundant species, leading to asymmetric introgression. These predictions have important fundamental consequences, especially during biological invasions or when a rare species threatened by extinction is surrounded by individuals from a related species. However, experimental tests in nature of the importance of the relative abundance of each species on hybridisation dynamics remain scarce. We assess here the impact of species relative abundance on hybridisation dynamics among four species from the European white oak species complex. A total of 2107 oak trees were genotyped at 10 microsatellite markers and Bayesian clustering methods were used to identify reference trees of each species. We then used these reference trees to simulate purebred and hybrid genotypes to determine optimal threshold for genetic assignment. With this approach, we found widespread evidence of hybridisation between all studied oak species, with high occurrence of hybrids, varying from 11\% to 31\% according to stand and sampling strategies. This finding suggests that hybridisation is a common phenomenon that plays a significant role in evolution of this oak species complex. In addition, we demonstrate a strong impact of species abundance on both hybridisation rate and introgression directionality.},
	keywords = {Quercus},
	url = {http://dx.doi.org/10.1111/j.1365-294X.2009.04137.x},
	author = {Lepais, O. and Petit, R.J. and Guichoux, E. and Lavabre, J.E. and Alberto, F. and Kremer, A. and Gerber, S.}
}
@article {102,
	title = {Age Structure and Genetic Diversity of Four Quercus macrocarpa (Michx.) Populations in Fragmented Oak Savanna along the Central Minnesota River Valley},
	journal = {The American Midland Naturalist},
	volume = {161},
	year = {2009},
	month = {2009},
	pages = {301-312},
	abstract = {Only 0.02\% of historic oak savanna exists today. To provide management recommendations, we characterized age-class structure, measured cover of competing tree species and estimated genetic variation within and among four Quercus macrocarpa Michx (bur oak) populations in the Minnesota River Valley. At each site, few middle-aged bur oaks existed, most were 90},
	url = {http://www.bioone.org/doi/abs/10.1674/0003-0031-161.2.301},
	author = {Kittelson, P.M. and Pinahs, C. and Dwyer, J. and Ingersoll, A. and Mans, E. and Rieke, J. and Rutman, B. and Volenec, M.}
}
