Data for: Life history variation in eelgrass

Hypotheses: Allocation to shoot size, branching, and flowering differs across five populations of eelgrass (Zostera marina) in Willapa Bay, Washington, and reflects estuarine environmental variation. Methods: From May 2019 to Oct 2020, shoots were measured for multiple traits: length, biomass, branching, density, leaf emergence rate, internode length, above-per-below ground ratio, and flowering. Results: Across sites, shoot size traded off with branching, and flowering occurred along an orthogonal axis in multivariate space. Two populations were annual (germinating and flowering over summer months), and three populations were perennial (lower rates of flowering, shoots that survived overwinter). Flowering at annual sites lagged perennial sites by two months. At perennial sites, relative growth rate peaked with daylength, but flowering was initiated before, size lagged, and branching occurred in two peaks on either side of the longest days. Annual populations occurred at higher tidal elevation. Shoot length declined at more thermally-variable sites. Data: Density_Archive.xls contains eelgrass shoot counts from field quadrats. Sites_Archive.xls contains site meta-data. Growth_Archive.xls contains measurements on individual shoots, including many that were marked for growth in the field and collected about two weeks later. R2019transplantTsummer.csv, R2019transplantTwinter.csv, and R2020transplantTsummer.csv contain temperatures measured with continuous autonomous sensors at each site.