03254nas a2200493   4500008004100000245012000041210006900161260000900230300001400239490000700253520179700260653002302057653001802080653001802098653002602116653001202142653001902154653002802173653002202201653002202223653002002245653001802265653001302283653001202296653002002308653004402328653005402372653002502426653003802451653002102489653001902510653002002529653001902549653000902568653002002577100001602597700001702613700001802630700001702648700001602665700002302681700001302704856004302717       2002                        eng d00aPollen movement in declining populations of California Valley oak, Quercus lobata: Where have all the fathers gone?0 aPollen movement in declining populations of California Valley oa  c2002  a1657-16680 v113 aThe 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.10a[26070-] Fagaceae-10aadult-density10aAngiospermae-10adeclining-populations10aDicots-10aDicotyledones-10aFagaceae-: Angiosperms-10agenetic-isolation10ahuman-disturbance10aNearctic-region10aNorth-America10aPlantae-10aPlants-10apollen-movement10aPopulation-Genetics: Population-Studies10aQuercus-lobata (Fagaceae-): California-Valley-oak10areproductive-failure10aSanta-Barbara-County: California-10aSedgwick-Reserve10aSpermatophyta-10aSpermatophytes-10aTWOGENER-model10aUSA-10aVascular-Plants1 aSork, V.-L.1 aDavis, F.-W.1 aSmouse, P.-E.1 aApsit, V.-J.1 aDyer, R.-J.1 aFernandez-M, J.-F.1 aKuhn, B.  uhttps://quercus.myspecies.info/node/5602293nas a2200133   4500008004100000245014100041210006900182260000900251300001200260520181300272100001602085700001502101856004302116       2002                        eng d00aGenetic differentiation of two california red oak species, Quercus parvula var. shreveii and Q. wislizeni, based on AFLP genetic markers0 aGenetic differentiation of two california red oak species Quercu  c2002  a417-4263 aOaks are renowned for posing problems in defining species boundaries. One example is the case of the interior live oak complex that is usually taken to include two varieties of Quercus wislizeni from the Coast Ranges of California and the Sierra Nevada, and Q. parvula var. shreveii from the central coast of California. The latter taxon was separated from Q. wislizeni, and was recognized in The Jepson Manual, but still is not fully accepted, since its morphological separation is ambiguous. In an attempt to test differentiation of these two taxa, molecular genetic analysis was carried out using Amplified Fragment Length Polymorphism (AFLP) markers. A total of 202 individuals from 19 populations including Q. parvula var. shreveii, Quercus wislizeni, Q. kelloggii and Q. agrifolia were analyzed. Four primer sets generated 311 polymorphic band classes. Although species-specific markers were observed between Q. kelloggii and other members of the red oak group in California, fixed genetic differences were not apparent among Q. agrifolia, Q. parvula var. shreveii and Q. wislizeni. Cluster analysis and principal coordinate analysis revealed low levels of genetic differentiation among coast live oak, interior live oak and shreve oak. Cluster analysis also suggested that Q. agrifolia populations are more similar to populations of Q. parvula var. shreveii than to coastal populations of Q. wislizeni. This may reflect the relatively short time since divergence of these species. On the other hand, repetitive hybridization and introgression may have acted as a homogenizing factor for these genetic markers. The relatively high genetic similarity between Q. agrifolia and Q. parvula var. shreveii may have implications for the management of Sudden Oak Death in the limited range of the latter taxon.1 aKashani, N.1 aDodd, R.S.  uhttps://quercus.myspecies.info/node/50