00412nas a2200145   4500008004500000020002200045245001200067210001200079260004300091300001100134100002500145700002900170700002300199856004400222       2011                        Engldsh    a978-3-642-21249-900aQuercus0 aQuercus  bSpringer Berlin Heidelbergc2011/01/01  a89-1291 aAldrich, Preston, R.1 aCavender-Bares, Jeannine1 aKole, Chittaranjan  uhttps://quercus.myspecies.info/node/13303959nas a2200277   4500008004100000245014000041210006900181490000700250520301000257653002003267653003003287653002003317653002303337653002003360653001903380653002803399653003103427653004403458653001403502100002903516700003203545700002103577700001803598700002103616856004403637       2011                        eng d00aPhylogeography and climatic niche evolution in live oaks (<i>Quercus </i>series <i>Virentes</i>) from the tropics to the temperate zone0 aPhylogeography and climatic niche evolution in live oaks iQuercu0 v383 aAim: We investigated the phylogeography, geographic variation in leaf morphology, freezingtolerance and climatic niches of two widespread evergreen sister oak species (Quercus) in theseries Virentes to gain insight into 1) the historical biogeographic explanations for populationgenetic structure and leaf morphological variation, and 2) the influence of genetically-basedvariation in freezing tolerance within and between species on climatic range limits and geneflow, and 3) to examine the evidence for contrasting impacts of Pleistocene glacial cycles ongenetic structure and diversity in tropical and temperate regions.Location: Southeastern U.S., Mexico and Central AmericaMethods: Nuclear microsatellites, non-recombining nuclear sequences within ITS and NIA-i3and chloroplast DNA sequences were obtained from samples collected throughout the range oftwo sister lineages of live oaks, represented by Quercus virginiana in the temperate zone andQuercus oleoides in the tropics. Divergence times were estimated for the two major geographicand genetic breaks. Differentiation in leaf morphology, analyzed from field specimens, wascompared to the molecular data. Freezing sensitivities of Q. virginiana and Q. oleoidespopulations were assessed in a common garden under controlled tropical and temperate climatesand compared to minimum temperature climatic niches for each species.Results: The geographic break between Q. virginiana and Q. oleoides was associated withstrong genetic differentiation of possible Miocene origin and with differentiation in freezingsensitivity, climatic envelopes and leaf morphology. A second important geographic and geneticbreak within Q. oleoides between Costa Rica and the rest of Central America showed aPleistocene divergence time and no differentiation in leaf morphology. Population geneticdifferentiation was greater but genetic diversity was lower within temperate Q. virginianacompared to tropical Q. oleoides, and genetic breaks largely corresponded to breaks in leafmorphology.Main Conclusions: Two major breaks, one between Mexico and the U.S. at the speciesboundary, and a more recent one within Q. oleoides between Honduras and Costa Rica implicateclimatic changes as potential causes. The latter break may be associated with formation of theCordillera Guanacaste followed by seasonal changes in precipitation. In the former case, an “outof the tropics” scenario is hypothesized, in which acquisition of freezing tolerance in Q.virginiana permitted colonization of and expansion in the temperate zone while differences inclimatic tolerances between the species limited secondary contact. More pronounced Pleistocenechanges in climate and sea level in the southeastern U.S. relative to Central America may explainthe greater population differentiation within temperate Q. virginiana and greater genetic diversityin tropical Q. oleoides. These patterns are predicted to hold for other taxa that span temperateand tropical zones of North and Middle America10aCentral America10achloroplast DNA sequences10aclimatic niches10afreezing tolerance10aleaf morphology10aNIA-i3 and ITS10anuclear microsatellites10aPleistocene glacial cycles10arise, unglaciated eastern North America10asea level1 aCavender-Bares, Jeannine1 aGonzalez-Rodriguez, Antonio1 aPahlich, Annette1 aKoehler, Kari1 aDeacon, Nicholas  uhttps://quercus.myspecies.info/node/13502231nas a2200229   4500008004100000020001400041245014400055210007100199260002900270300001000299520145500309653002301764653001601787653001401803653002801817653001401845653003201859100001801891700001901909700002901928856004401957       2011                        eng d  a1469-813700aEvidence for a freezing tolerance–growth rate trade-off in the live oaks (Quercus series Virentes) across the tropical–temperate divide0 aEvidence for a freezing tolerance–growth rate tradeoff in the li  bBlackwell Publishing Ltd  ano-no3 a* •It has long been hypothesized that species are limited to the north by minimum temperature and to the south by competition, resulting in a trade-off between freezing tolerance and growth rate. We investigated the extent to which the climatic origins of populations from four live oak species (Quercus series Virentes) were associated with freezing tolerance and growth rate, and whether species fitted a model of locally adapted populations, each with narrow climatic tolerances, or of broadly adapted populations with wide climatic tolerances. * •Acorns from populations of four species across a tropical–temperate gradient were grown under common tropical and temperate conditions. Growth rate, seed mass, and leaf and stem freezing traits were compared with source minimum temperatures. * •Maximum growth rates under tropical conditions were negatively correlated with freezing tolerance under temperate conditions. The minimum source temperature predicted the freezing tolerance of populations under temperate conditions. The tropical species Q. oleoides was differentiated from the three temperate species, and variation among species was greater than among populations. * •The trade-off between freezing tolerance and growth rate supports the range limit hypothesis. Limited variation within species indicates that the distributions of species may be driven more strongly by broad climatic factors than by highly local conditions.10afreezing tolerance10agrowth rate10alive oaks10aQuercus series Virentes10atrade-off10atropical–temperate divide1 aKoehler, Kari1 aCenter, Alyson1 aCavender-Bares, Jeannine  uhttps://quercus.myspecies.info/node/137