Log in

Editor's Picks

quercus_x_vilmoriniana_proce_nantes_0159.jpg
An intercontinental artifical hybrid raised at Arboretum...
Roderick Cameron | Apr 12, 2020
q._sp1_-_copy.jpg
David More shares some of his magnificent illustrations of...
David More | Apr 08, 2020
cork_oak_seedlings.jpg
A project aims to recover and restore habitats in Serra de...
Justin Roborg-Söndergaard | Apr 07, 2020

Plant Focus

cyclobalanopsis_hypophaea_2.jpg
First described by the Japanese botanist Bunzō Hayata in 1913, Quercus hypophaea is a medium to large evergreen oak restricted to the...

Landscape and Conservation Genetics of the Island Oak, Quercus tomentella

PDF icon Log in or register to access the full text.

Mary V. Ashley, Janet R. Backs, and Saji T. Abraham

Published May 2016 International Oaks No. 27: 83–90

Abstract

The island oak, Quercus tomentella Englem., is a rare island endemic, found only on five California Channel Islands and Guadalupe Island, Mexico. Quercus tomentella is a member of Section Protobalanus that until recently had uncertain evolutionary origins and affinities. The most widespread species of Protobalanus, Q. chrysolepis Liebmann, is found on the mainland but also on some of the islands and may hybridize with Q. tomentella. Here we present the first population genetic survey of Q. tomentella using DNA microsatellites analysis. A total of 378 trees were sampled from several sites on each of the islands where Q. tomentella occurs to assess levels of genetic diversity and to determine how that diversity is partitioned within and among islands. Genotypes were also used to quantify the extent of clonal versus sexual reproduction in Q. tomentella. Cryptic clonal growth was extensive at some sites. We found that Q. tomentella maintains moderate levels of genetic diversity despite having small, isolated populations. Populations on each island are genetically distinct, and significant population differentiation also occurs within islands. Such strong local population structure is in contrast to other studies of oaks, where high gene flow through pollen generally keeps populations homogeneous over large areas.

Keywords

microsatellites, California Islands, conservation genetics, clonal reproduction, island endemic, population structure, Protobalanus

References

Abraham, S.T., D.N. Zaya, W.D. Koenig, and M.V. Ashley. 2011. Interspecific and intraspecific pollination patterns of valley oak, Quercus lobata, in a mixed stand in coastal central California. International Journal of Plant Sciences 172: 691-699.

Arnold, J.E. 1992. Complex Hunter-Gatherer-Fishers of Prehistoric California: Chiefs, Specialists, and Maritime Adaptations of the Channel Islands. American Antiquity 57: 60-84.

Ashley, M.V. 2010. Plant parentage, pollination, and dispersal: how DNA microsatellites have altered the landscape. Critical Reviews in Plant Sciences 29: 148-161.

Ashley, M.V., S. Abraham, L.C. Kindsvater, D.A. Knapp, and K. Craft. 2010. Population structure and genetic variation of island oak, Quercus tomentella Engelmann on Santa Catalina Island. In Oak ecosystem restoration on Santa Catalina Island, California: Proceedings of an on-island workshop, February 2-7, 2007  edited by D.A. Knapp. Avalon, CA: Catalina Island Conservancy.

Atwater, T. M. 1998. Plate tectonic history of southern California with emphasis on the western Transverse Ranges and northern Channel Islands, 1-8. In Contributions to the geology of the Northern Channel Islands, Southern California. American Association of Petroleum Geologists, Pacific Section.

Beltran, R.S., N. Kreidler, D.H. Van Vuren, S.A. Morrison, E.S. Zavaleta, K. Newton, B.R. Tershy, and D.A. Croll. 2014. Passive recovery of vegetation after herbivore eradication on Santa Cruz Island, California. Restoration Ecology 22: 790-797.

Buschbom, J., Y. Yanbaev, and B. Degen. 2011. Efficient Long-Distance Gene Flow into an Isolated Relict Oak Stand. Journal of Heredity 102: 464-472.

Craft, K.J. and M.V. Ashley. 2010. Pollen-mediated gene flow in isolated and continuous stands of bur oak, Quercus macrocarpa (Fagaceae). American Journal of Botany 97: 1999-2006.

Fauvelle, M. 2013. Evaluating cross-channel Exchange in the Santa Barbara region: Experimental data on acorn processing and transport. American Antiquity 78: 790-798.

Guillot, G., F. Mortier, and A. Estoup. 2005. GENELAND: a computer package for landscape genetics. Molecular Ecology Resourcess 5: 712-715.

Hipp, A.L., D.A. Eaton, J. Cavender-Bares, E. Fitzek, R. Nipper, and P.S. Manos. 2014. A framework phylogeny of the American oak clade based on sequenced RAD data. PloS one 9:e93975.

Hubisz, M. J., D. Falush, M. Stephens, and J. K. Pritchard. 2009. Inferring weak population structure with the assistance of sample group information. Molecular Ecology Resources 9: 1322-1332.

Junger, A., and D. L. Johnson. 1980. Was there a Quaternary land bridge to the northern Channel Islands?, 33-39. In The California Islands: Proceedings of a multidisciplinary symposium. Santa Barbara Museum of Natural History.

Knowlton, J.L., C. Josh Donlan, G.W. Roemer, A. Samaniego-Herrera, B.S. Keitt, B. Wood, A. Aguirre-Muñoz, K.R. Faulkner, and B.R. Tershy. 2007. Eradication of non-native mammals and the status of insular mammals on the California Channel Islands, USA, and Pacific Baja California Peninsula Islands, Mexico. The Southwestern Naturalist 52: 528-540.

Pritchard, J.K., M. Stephens, and P. Donnelly. 2000. Inference of population structure using multilocus genotype data. Genetics 155: 945-959.

Rick, T.C., T.S. Sillett, C.K. Ghalambor, C.A. Hofman, K. Ralls, R.S. Anderson, C.L. Boser, T.J. Braje, D.R. Cayan, and R.T. Chesser. 2014. Ecological Change on California's Channel Islands from the Pleistocene to the Anthropocene. BioScience 64: 680-692.

Schumann, R.R., S.A. Minor, D R. Muhs, L.T. Groves, and J.P. McGeehin. 2012. Tectonic influences on the preservation of marine terraces: Old and new evidence from Santa Catalina Island, California. Geomorphology 179: 208-224.

Vedder, J.G. and D.G. Howell. 1980. Topographic evolution of the southern California borderland during late Cenozoic time, 7-32. In The California Islands: Proceedings of a multidisciplinary symposium. Santa Barbara, California: Santa Barbara Museum of Natural History.

Westman, W.E. 1983. Island Biogeography: Studies on the xeric shrublands of the Inner Channel Islands, California. Journal of Biogeography 10: 97-118.