Sedgwick Reserve

18 Aug, 01 PM - 27 Aug, 01 PM

1. TEST FOR LOCALIZED GENETIC ADAPTATION IN QUERCUS LOBATA Sork et al. (PNAS 113(29):8064-8071)) reviewed the indirect support (i.e., many molecular subpopulations within the species) for the hypothesis that valley oaks may be very locally adapted to their native, local environments because of their life history traits of sessility, high reproductive output, and long dispersal distances. We (Pearse et al., Ecol. Entom. 40:525-531) found such locally-adaptive differences in herbivore (leaf-miners) resistance in 15-year old valley oak trees that were planted in a common-garden (Provenance) plot at Sedgwick Reserve. I will do a pilot study of possible genetic and environmental affects on the shapes of valley oaks (Quercus lobata) leaves using 2 resources at the Sedgwick Reserve (the Provenance Plot of approximately 440 trees from 4 different localities that were planted in 1997, and a collection of pressed herbarium specimens from many of the mother trees of these provenance trees). I will be looking to see if there are differences in leaf traits of trees from 2 localities: (1) the Sedgwick (native) and the Los Angeles (foreign) populations. Geographical differences can be partitioned from local environment by comparing variance of within-family and between-locality plants. The Provenance trees allow for such a study because these trees have been grown in a common garden, where they all have experienced the same growing conditions. Samples of leaves of provenance trees, from 3 families of Sedgwick trees and their mother trees and a similar set of samples for 3 families of Los Angeles trees, will be collected, pressed, and scanned at high resolution. These digital images will form the materials for shape analysis. Various leaf traits (e.g., petiole length, lamina length, number of lobes, lobe width, and sinus width) will be examined for the amount of variance explained by family versus locality status. Significant amounts of associated variance for shape traits within family groups would an interesting discovery. But, significant amounts of associated variance for Los Angeles versus Sedgwick trees would support the contention of Sork et al. (2016) that local adaptation is frequent. Another way that such regional, adaptive evolution might be shown is to look for signs of shape pathologies in the leaves of the Los Angeles trees (foreign) in comparison to the Sedgwick (native) trees. If foreign genomes are not so well adapted to the climate and soil regimes at Sedgwick then the development of the leaves might be altered by the Sedgwick environment. Such developmental instability might produce an increase in the asymmetry between the paired-sides of a leaf (e.g., different numbers of lobes, greater variation in the amount of sinus width on opposite sides of the midrib, greater variability in the degree of ribbing or number of lobes on opposite sides of the leaf vein. Measures of the degree of asymmetry in leaf shape between local (Sedgwick) and foreign (Los Angeles) plants will be done to test for developmental alterations in the Los Angeles trees. In 1997, when I was collecting the acorns that were later planted out in the Provenance Plot, I also collected one or two branches from many of these mother trees. These were pressed and saved as herbarium sheets. Many of the sheets are in the collection at the Reserve, and the remainders of them are in my possession. During August to September I will re-collect samples of leaves from the mother trees of the 6 selected plot families and do a similar type of study of shape traits in the 1997 and 2016 leaves. One aim of this study is to test whether the inter-year, within-tree similarities are greater than random. This would support a large genetic component to leaf traits in this species, especially with a 20-year interval separating the first and second samples. A second test will be of the amount of within-locality (Los Angeles versus Sedgwick) variance exists in leaf shape. Such a difference would be consistent with local genetic adaptation. And if a significant association is shown in leaf traits between the mother trees and their within-family plot trees, that would be strong support for genetic adaptation. The strongest test here would be in the comparison of the Sedgwick (native) trees, because the possible alteration in leaf shape of Los Angeles plot-trees due to developmental alterations would be expected to reduce or destroy any genetic tendencies. 2. STARTING A UCNRS DATA SET: GPS DATA ON MARKED SEDGWICK OAKS: During my years of work on the Sedgwick oaks (1996-1999) I marked approximately 180 trees of 3 species (Q. lobata, Q. douglasii, and Q. agrifolia) with aluminum tree-tags. As time allows during my August-to-October visits, I will take GPS readings for these tagged trees. This information would be essential for re-locating trees for which other kinds of information (e.g., circumference measurements, herbarium sheets, and the Sedgwick mother trees of some of the Provenance Plot trees. The information will be entered into a database (Exel file) that I will start developing for these trees that could be entered into the UCNRS database. This file will be built up from an already existing, R. D. Sage Field Catalog file. I dont have the computer skills to actually create a proper UCNRS data set, but will be agreeable to providing the Exel file to someone who could curate it into the proper format for the NRS program. 3. STARTING A UCNRS DATA SET: GROWTH (CIRCUMFERANCE) INFORMATION ON MARKED SEDGWICK OAKS: During my years of work on the Sedgwick oaks (1996-1999) I measured the circumference (DBH) of many of these tagged trees. As time permits during my August-to-October visits, I will re-measure as many of these trees as I can. These measurements may be useful for long-term studies of the growth and performance of these trees. This information will be added to the GPS data in the file mentioned in Project 2.

Visit #47277 @Sedgwick Reserve

Approved

Under Project # 6938 | Research

Ecological studies of the Valley Oak (Quercus lobata)

professional - University of California, Berkeley

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R Sage Aug 18 - 27, 2016 (10 days)

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Bed in Ranch House Shared Bedrooms 1 Aug 20 - 31, 2016