01385nas a2200145   4500008004100000245006200041210006200103260000900165300001200174490000700186520097100193100001701164700001801181856004001199       1998                        eng d00aTesting for Spatial Autocorrelation in Ecological Studies0 aTesting for Spatial Autocorrelation in Ecological Studies  c1998  a423-4290 v213 aWe describe a statistical method appropriate for the analysis of spatial autocorrelation in data varying in time as well as space. In particular, the technique was developed to address the issue of geographic synchrony in ecological variables that may change markedly from year to year such as population density of animals or seed production of trees. The method yields "modified correlograms" that test for significant autocorrelation between sites located within any given range of distances apart. This technique facilitates detecting and understanding spatial processes in a variety of ecological phenomena, including testing the plausibility of causational hypotheses using cross-correlational analyses. Several examples are discussed, including population densities of squirrels in Finland, winter densities of two hawk species in California, and acorn production and radial growth by individual blue oak Quercus douglasii trees in central coastal California.1 aKoenig, W.D.1 aKnops, J.M.H.  uhttp://www.jstor.org/stable/368317701878nas a2200157   4500008004100000245012900041210006900170260000900239300001400248490000700262520134300269100001601612700001701628700001701645856005801662       2002                        eng d00aLimited hybridization between Quercus lobata and Quercus douglasii (Fagaceae) in a mixed stand in central coastal California0 aLimited hybridization between Quercus lobata and Quercus douglas  c2002  a1792-17980 v893 aMany oak species are interfertile, and morphological and genetic evidence for hybridization is widespread. Here we use DNA microsatellite markers to characterize hybridization between two closely related oak species in a mixed stand in central coastal California, Quercus lobata (valley oak) and Q. douglasii (blue oak) (Fagaceae). Genotypes from four microsatellite loci indicate that many alleles are shared between the two species. However, each species harbors unique alleles, and allele frequencies differ significantly. A Bayesian analysis of genetic structure in the stand identified two highly differentiated genetic clusters, essentially corresponding to species assignment based on morphology. Data from the four loci were sufficient to assign all 135 trees to one of the two species. In addition, five putative hybrid individuals having intermediate morphologies could be assigned genetically to one or the other species, and all but one had low probability of hybrid ancestry. Overally, only six (4.6%) trees showed >0.05 probability of hybrid ancestry, in all cases their probabilities for nonhybrid ancestry were substantially higher. We conclude that adult hybrids of Q. douglasii x Q. lobata are rare at this site and plasticity in morphological characters may lead to overestimates of hybridization among Quercus species.1 aCraft, K.J.1 aAshley, M.V.1 aKoenig, W.D.  uhttp://www.amjbot.org/cgi/content/abstract/89/11/179200812nas a2200169   4500008004100000245012800041210006900169260000900238300001200247490000700259520026000266100001700526700001800543700002000561700001900581856004200600       2009                        eng d00aLatitudinal decrease in acorn size in bur oak (Quercus macrocarpa) is due to environmental constraints, not avian dispersal0 aLatitudinal decrease in acorn size in bur oak Quercus macrocarpa  c2009  a349-3560 v873 aThe 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 species1 aKoenig, W.D.1 aKnops, J.M.H.1 aDickinson, J.L.1 aZuckerberg, B.  uhttps://quercus.myspecies.info/node/6