skip to main content


Search for: All records

Creators/Authors contains: "Williams, Susan L."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Abstract

    Environmental change is multidimensional, with local anthropogenic stressors and global climate change interacting to differentially impact populations throughout a species’ geographic range. Within species, the spatial distribution of phenotypic variation and its causes (i.e., local adaptation or plasticity) will determine species’ adaptive capacity to respond to a changing environment. However, comparatively less is known about the spatial scale of adaptive differentiation among populations and how patterns of local adaptation might drive vulnerability to global change stressors. To test whether fine‐scale (2–12 km) mosaics of environmental stress can cause adaptive differentiation in a marine foundation species, eelgrass (Zostera marina), we conducted a three‐way reciprocal transplant experiment spanning the length of Tomales Bay, CA. Our results revealed strong home‐site advantage in growth and survival for all three populations. In subsequent common garden experiments and feeding assays, we showed that countergradients in temperature, light availability, and grazing pressure from an introduced herbivore contribute to differential performance among populations consistent with local adaptation. Our findings highlight how local‐scale mosaics in environmental stressors can increase phenotypic variation among neighboring populations, potentially increasing species resilience to future global change. More specifically, we identified a range‐center eelgrass population that is pre‐adapted to extremely warm temperatures similar to those experienced by low‐latitude range‐edge populations of eelgrass, demonstrating how reservoirs of heat‐tolerant phenotypes may already exist throughout a species range. Future work on predicting species resilience to global change should incorporate potential buffering effects of local‐scale population differentiation and promote a phenotypic management approach to species conservation.

     
    more » « less
  2. Abstract

    Understanding the diffusion of innovative ideas, behaviors, and technologies could reduce disconnects between conservation science and management, such as the science‐practice gap between biodiversity research and restoration practice. To assess knowledge uptake as an indicator of diffusion of innovation in restoration practice, we conducted an online survey of two organizations focused on coastal habitat restoration: Coastal and Estuarine Research Federation (CERF) and International Coral Reef Society (ICRS). We evaluated experience restoring particular habitats, along with perceptions of the purpose of restoration, the metrics used to evaluate restoration success, and the challenges to successful restoration. We then examined the perceived importance of genetic diversity for restoration success as an indicator of knowledge‐practice transfer in conservation strategy. The practice of coastal habitat restoration diverged by organization and habitat: a higher percentage of CERF members had restored oysters, marshes, and seagrasses compared to ICRS, whereas the reverse was true for corals. Views of the purpose of restoration, the site selection process, and the challenges to successful restoration were similar. Despite similarities in perceptions of the restoration process, the two organizations had variable indications of knowledge‐practice transfer: ICRS respondents ranked the importance of genetic diversity as a restoration strategy higher than did CERF respondents. The perceived importance of genetic diversity also differed by habitat, with both CERF and ICRS respondents ranking diversity as more important for corals. The more successful transfer of knowledge to practice in the coral community indicates that the disconnect between genetic diversity research and restoration practice is surmountable. In addition, it serves as a potential strategy for promoting the spread of innovative restoration practices to achieve long‐term recovery of ecosystems.

     
    more » « less
  3. Abstract

    Mortality and shifts in species distributions are among the most obvious consequences of extreme climatic events. However, the sublethal effects of an extreme event can have persistent impacts throughout an individual’s lifetime and into future generations via within‐generation and transgenerational phenotypic plasticity. These changes can either confer resilience or increase susceptibility to subsequent stressful events, with impacts on population, community, and potentially ecosystem processes. Here, we show how a simulated extreme warming event causes persistent changes in the morphology and growth of a foundation species (eelgrass,Zostera marina) across multiple clonal generations and multiple years. The effect of previous parental exposure to warming increased aboveground biomass, shoot length, and aboveground–belowground biomass ratios while also greatly decreasing leaf growth rates. Long‐term increases in aboveground–belowground biomass ratios could indicate an adaptive clonal transgenerational response to warmer climates that reduces the burden of increased respiration in belowground biomass. These transgenerational responses were likely decoupled from clonal parent provisioning as rhizome size of clonal offspring was standardized at planting and rhizome starch reserves were not impacted by warming treatments. Future investigations into potential epigenetic mechanisms underpinning such clonal transgenerational plasticity will be necessary to understand the resilience of asexual foundation species to repeated extreme climatic events.

     
    more » « less