DOI: 10.5061/dryad.6djh9w10v
title: Temporal variation in selection influences microgeographic local adaptation

description: Ecological heterogeneity can lead to local adaptation when populations
 exhibit fitness trade-offs among habitats. However, the degree to which
 local adaptation is affected by the spatial and temporal scale of
 environmental variation is poorly understood. A multi-year reciprocal
 transplant experiment was performed with populations of the annual plant
 Leptosiphon parviflorus living on adjacent serpentine and non-serpentine
 soil. Local adaptation over this small geographic scale was observed, but
 there were differences in the temporal variability of selection across
 habitats. On serpentine soil, the local population had a consistently
 large survival advantage, presumably due to the temporal stability in
 selection imposed by soil cation content. In contrast, a fecundity
 advantage was observed for the sandstone population on its native soil
 type, but only in the two years of study with the highest rainfall. A
 manipulative greenhouse experiment demonstrated that the fitness advantage
 of the sandstone population in its native soil type depends critically on
 water availability. The temporal variability in local adaptation driven by
 variation in precipitation suggests that continued drought conditions have
 the potential to erode local adaptation in these populations. These
 results show how different selective factors can influence spatial and
 temporal patterns of variation in fitness trade-offs.
description: <strong>ReciprocalTransplant.csv</strong>:
 Reciprocal transplant experiments were conducted at Jasper Ridge
 Biological Preserve (JRBP) in San Mateo County California during four
 spring growing seasons between 2012-2015 with populations of Leptosiphon
 parviflorus. These populations grow on serpentine soil and sandstone soil
 in close proximity (~100 m.) at JRBP. Plants were
 transplanted at the seedling stage. Source seeds were collected from
 maternal plants grown in common greenhouse conditions that descended from
 plants collected from both populations at the study locations. After
 germination, seedlings were first transplanted into plug trays containing
 either serpentine or sandstone soil collected from the study site, and
 then transplanted into the field. During the first 1-2 weeks of growth,
 all plants were watered, after which supplemental watering ceased. Any
 seedlings that died before establishment (defined as 10 days after field
 transplant) were excluded from the dataset. Study
 plants were censused periodically to count the number of flowers and
 fruits produced and whenever possible fruits were collected to count the
 number of seeds per fruit.
 <strong>SeedPlots.csv</strong>:
 Seeds from each population were collected from maternal plants
 grown in a common greenhouse environment, and in mid-December, roughly the
 time period that plants naturally germinate in the field, five seeds from
 each source population were placed in 100 cells in randomized order across
 an 11 x 24 grid. The remaining cells were kept empty to ensure that
 natural germinants were not being counted. In March,
 (approximately 3 months after sowing), plants in each grid position were
 thinned to leave only one focal seedling to follow for remaining fitness
 estimates.
 <strong>Greenhouse.csv</strong>:
 Greenhouse experiments were performed at Michigan State
 University using soil collected from JRBP at both field locations. Seeds
 were germinated using the same methods as described for the field
 experiment, except after two weeks in an incubator, seedlings were
 transplanted to containers filled with a mixture of sieved field soil
 (serpentine or sandstone) and perlite in a 4:1 ratio. Seedlings were top
 watered for 3 days after transplanting, and then exclusively bottom
 watered. After one month of growth, plants were randomly assigned to one
 of two treatments: an unlimited water treatment where plants were
 continuously bottom watered throughout the duration of the experiment, or
 a drought treatment, where watering was ceased when the first plant began
 flowering, which occurred approximately one month after
 transplanting.
 <strong>Hydroponic.csv</strong>:
 Hydroponic experiments were performed at Michigan State
 University. Seeds from each parental population were sown in randomized
 order directly into rockwool sheets of 1” x 1” cubes (©Grodan) saturated
 with deionized water. These were placed in the dark at 4°C for ten days
 while periodically spraying with nutrient solution. They were then
 transferred to a growth chamber set at 22°C, 12-hour days and the rockwool
 was kept moist using 1⁄2 strength Hoagland’s solution and supplemental
 spraying of deionized water. After five days in the growth chamber,
 seedling germination and survival were censused. Seedlings were allowed to
 grow in half-strength Hoagland’s solution for an additional five days
 before being randomly assigned to one of four treatments with two
 replicate blocks per treatment. Block location in the growth chamber was
 randomized twice per week.  The nutrient solution
 (1⁄2-strength Hoagland’s) was provided by the MSU growth chamber facility
 and contained calcium nitrate (3.6 mmole l-1), potassium nitrate (2.5 mmol
 l-1), potassium phosphate (400 μM l-1), boric acid (24 μM l-1), manganous
 sulphate (5 μM l-1), zinc sulphate (700 nmol l-1), copper sulphate (263
 nmol l-1), and sequestrene iron chelate (38 mg l-1) dissolved in
 deionized water. The control solution (also used in the initial growth
 stages of all plants) contained 1 mmol l-1 MgSO4. The treatments consisted
 of a control treatment (half-strength Hoagland’s containing 1 mmol l-1
 MgSO4), and three treatments with increasing amounts of magnesium sulfate
 (50 mM, 100 mM, 150 mM) added to the nutrient solution.
 Solutions were replaced two times per week, which allowed the
 rock wool to stay moist throughout the experiment. Plants were censused
 twice a week for flowering and survival and at the end of the experiment,
 the total lifetime production of flowers was counted for each individual.
 A leak in one of the flats caused plants in one of the control blocks to
 dry and senesce prematurely, therefore these plants were excluded from
 analyses of fecundity and total fitness.
 <strong>JRPrecipitationData.csv</strong>:
 Data collected from weather station at Jasper Ridge Biological
 Preserve. Data also available from Woodside Fire Station from NOAA (used
 to fill in gaps when precipitation data were missing from JRBP). Data were
 formatted to make machine-readable (see Precipitation_analyes.R)
 <strong>Local_Adaptation.zip</strong>:
 Code used for ASTER analyses (cloned from: https://github.com/EDitt/Local_Adaptation on 4/26/23). Includes data files to recreate results.
description: Scripts require R