Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Program Information
• Funding

Daily growth rates of 8 populations of Chaetoceros simplex grown at 31C and control population at 25C, in regular L1 medium (884 μm NO3−) or nitrogen‐reduced L1 medium (5 μm NO3−).

Chaetoceros simplex cultures, were obtained from population strain CCMP 200 (National Center for Marine Algae and Microbiota, NCMA).

Evolution experiment:
Eight populations were grown at 31 °C, and one was maintained as a control at 25 °C in regular L1 medium (884 μm NO3−).

At 31 °C, four populations remained in regular L1 medium (884 μm NO3−), while the other four received nitrogen‐reduced L1 medium (5 μm NO3−);

Populations were maintained in 50 mL polycarbonate culture flasks, at 100 μmol quanta m−2 s−1 cool white fluorescent light on a 14/10 h day/night cycle. We gently inverted and randomly repositioned flasks daily. Every three days c. 10^6 cells (never < 6 × 10^5 cells) from each population were transferred to fresh media. We monitored populations by measuring in vivo optical density daily (436 nm wavelength absorbance) using a Shimadzu UV‐2401PC spectrophotometer before and after each transfer

Growth rate calculations:
When more than two biomass observations (optical density or fluorescence, depending on the experiment) within the exponential growth phase were available, we calculated population growth rates (day−1), as the slope of the linear regression of ln(biomass) vs. time (days). Alternatively, when biomass measurements were made every 2–3 days, we calculated growth rate as

(lnB2-LnB1)/(t2-t1)

where B is biomass and t is time (days) and the number of generations within a particular time range, Δt, as

(u/ln2)^Δt

where u is growth rate. 

Calculations were made with R, and scripts can be downloaded from: https://github.com/MariaArangurenGassis/PhytoEvolutionPaper2019.
More details in Aranguren-Gassis et al. 2019, Ecology Letters.

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- reduced precision of Growth_rates from 9 to 1 decimal places.

NSF Award Abstract:
Photosynthetic marine microbes, phytoplankton, contribute half of global primary production, form the base of most aquatic food webs and are major players in global biogeochemical cycles. Understanding their community composition is important because it affects higher trophic levels, the cycling of energy and elements and is sensitive to global environmental change. This project will investigate how phytoplankton communities respond to two major global change stressors in aquatic systems: warming and changes in nutrient availability. The researchers will work in two marine systems with a long history of environmental monitoring, the temperate Narragansett Bay estuary in Rhode Island and a subtropical North Atlantic site near Bermuda. They will use field sampling and laboratory experiments with multiple species and varieties of phytoplankton to assess the diversity in their responses to different temperatures under high and low nutrient concentrations. If the diversity of responses is high within species, then that species may have a better chance to adapt to rising temperatures and persist in the future. Some species may already be able to grow at high temperatures; consequently, they may become more abundant as the ocean warms. The researchers will incorporate this response information in mathematical models to predict how phytoplankton assemblages would reorganize under future climate scenarios. Graduate students and postdoctoral associates will be trained in diverse scientific approaches and techniques such as shipboard sampling, laboratory experiments, genomic analyses and mathematical modeling. The results of the project will be incorporated into K-12 teaching, including an advanced placement environmental science class for underrepresented minorities in Los Angeles, data exercises for rural schools in Michigan and disseminated to the public through an environmental journalism institute based in Rhode Island.

Predicting how ecological communities will respond to a changing environment requires knowledge of genetic, phylogenetic and functional diversity within and across species. This project will investigate how the interaction of phylogenetic, genetic and functional diversity in thermal traits within and across a broad range of species determines the responses of marine phytoplankton communities to rising temperature and changing nutrient regimes. High genetic and functional diversity within a species may allow evolutionary adaptation of that species to warming. If the phylogenetic and functional diversity is higher across species, species sorting and ecological community reorganization is likely. Different marine sites may have a different balance of genetic and functional diversity within and across species and, thus, different contribution of evolutionary and ecological responses to changing climate. The research will be conducted at two long-term time series sites in the Atlantic Ocean, the Narragansett Bay Long-Term Plankton Time Series and the Bermuda Atlantic Time Series (BATS) station. The goal is to assess intra- and inter-specific genetic and functional diversity in thermal responses at contrasting nutrient concentrations for a representative range of species in communities at the two sites in different seasons, and use this information to parameterize eco-evolutionary models embedded into biogeochemical ocean models to predict responses of phytoplankton communities to projected rising temperatures under realistic nutrient conditions. Model predictions will be informed by and tested with field data, including the long-term data series available for both sites and in community temperature manipulation experiments. This project will provide novel information on existing intraspecific genetic and functional thermal diversity for many ecologically and biogeochemically important phytoplankton species, estimate generation of new genetic and functional diversity in evolution experiments, and develop and parameterize novel eco-evolutionary models interfaced with ocean biogeochemical models to predict future phytoplankton community structure. The project will also characterize the interaction of two major global change stressors, warming and changing nutrient concentrations, as they affect phytoplankton diversity at functional, genetic, and phylogenetic levels. In addition, the project will develop novel modeling methodology that will be broadly applicable to understanding how other types of complex ecological communities may adapt to a rapidly warming world.

(adapted from the NSF Synopsis of Program)
Dimensions of Biodiversity is a program solicitation from the NSF Directorate for Biological Sciences. FY 2010 was year one of the program.  [MORE from NSF]

The NSF Dimensions of Biodiversity program seeks to characterize biodiversity on Earth by using integrative, innovative approaches to fill rapidly the most substantial gaps in our understanding. The program will take a broad view of biodiversity, and in its initial phase will focus on the integration of genetic, taxonomic, and functional dimensions of biodiversity. Project investigators are encouraged to integrate these three dimensions to understand the interactions and feedbacks among them. While this focus complements several core NSF programs, it differs by requiring that multiple dimensions of biodiversity be addressed simultaneously, to understand the roles of biodiversity in critical ecological and evolutionary processes.