Project Baseline: a seed bank to study evolution

Heather Schneider, PhD Santa Barbara Botanic Garden Outline

• Background information • Scientific questions • Methods • Applications What is a Seed Bank?

• A collection of viable seeds that have not germinated yet – Natural: soil seed bank, seedling banks – Human-mediated: collections of seed specially prepared for long-term storage

Mimulus guttatus Helianthus annuus Yucca brevifolia Silene latifolia Why Do We Need Seed Banks?

• Food security – Maintain genetic diversity of agricultural crops • Conservation • Restoration • Research

Svalbard Global Seed Vault – Norway

Why Create a Research Seed Bank? • To test scientific hypotheses • To predict responses to environmental change • To inform conservation and restoration planning Project Baseline

A long-term, national project to create a seed bank that can be used to study evolution in wild plant populations in response to environmental change Environmental Change: Climate Change Environmental Change: Climate Change Environmental Change: Land-use Change & Anthropogenic Effects

• Urbanization • Grazing • Agriculture • Pollution Environmental Change: Habitat Fragmentation Creates genetically isolated populations

© 2008 3D Nature Environmental Change: Invasive Species • Compete with native plants • Alter soil nutrients • Increase fire risk • Decrease forage and habitat quality for animals • Alter local hydrology

Brassica nigra (black mustard) Erodium cicutarium (red stem filaree) Environmental Change: Invasive Species

California spends >$80 million/year on invasive plants Environmental Change: Invasive Species Competition with invasives creates selective pressure Before

After

Sahara Mustard Brassica tournefortii How will native plants respond to so much environmental change?

Project Baseline was designed to create a resource for future biologists to understand how wild plants evolve over time

What kinds of questions can Project Baseline collections answer?

1. Can plants adapt to the changing environment? 2. Which source populations should be used for restoration? 3. Should we facilitate gene flow between existing populations or introduce genotypes pre-adapted to changed conditions? 4. Will ecosystem functions become disrupted if keystone species disappear in the future? Can organisms adapt? Rapid evolution in plants has already been observed YES! BUT, if we can only rarely observe evolution in action, how can we answer the question?

Resurrection Ecology • Uses natural soil seed banks: direct comparison of resurrected ancestors and contemporary descendants Potential problems with the resurrection approach 1. Conditions that preserve seed viability are rare

2. Dormant seeds that survive under natural conditions have experienced selection

3. Few populations available from the geographic range

4. No sampling among maternal plants for estimating genetic variation within populations

5. No precise data on biotic and abiotic conditions that may drive evolutionary patterns Resurrection Ecology with Seed Collection

Seeds collected before (1997) and after (2004) drought from wet and dry sites

Brassica rapa field mustard

Franks et al. 2007 Resurrection Ecology in Brassica rapa: Rapid evolution of earlier flowering

Post-droughtBB 04 HybridsBB H Dry site Pre-droughtBB 97

Arb 04

PostPopulation -drought HybridsArb H Wet site Pre-droughtArb 97

30 40 50 60 70 80 Days to first flowering Flowering time significantly earlier in both sites after drought

Franks et al .,2007 PNAS 104: 1278-1282 Resurrection ecology via seed collection is the foundation of Project Baseline Project Baseline: three collection regions

Julie Etterson Ruth Shaw Steve Franks Susan Mazer U of Minnesota Fordham UC Santa Barbara University Project Baseline & the Resurrection Approach

• Populations collected across the geographic range of each species • including central and peripheral populations • across gradients in climate and elevation

• Maternal families collected to examine changes in population genetic diversity

• Best practices used for seed preservation

Project Baseline: Sampling Field mustard (Brassica rapa) Seed Storage: National Center for Genetic Resources Preservation, USDA, Fort Collins, CO

-18C, 20% RH

Field Work

• Reconnaissance

• Collect field data and herbarium specimens

• Phenological monitoring

• Collect seeds Sedgwick Reserve Santa Ynez Valley, CA Reconnaissance

• Obtain permits

• Locate collection populations

• Collect field data and herbarium specimens

• Record associated species Using herbarium records to locate populations and estimate phenology Phenology is the science of the seasons Phenology is the study of recurring plant and animal life cycle stages (phenophases)

Migration Fall Foliage Color Change

Spring Wildflowers Phenological Observations: Phenophases Flowers

Flower buds Juvenile

Ripe Fruits

Unripe Fruits Collecting herbarium specimens • Collect two samples from each population to be stored at: • Cheadle Center for Biodiversity and Ecological Restoration (CCBER) at UCSB • The Bell Museum of Natural History at the University of Minnesota, Duluth Collecting the Seeds

Seed Collecting Western Region species list – native species • Apocynum californica androsaemifolium • Helianthus annuus • Apocynum • Helianthus petiolaris cannabinum • Larrea tridentata • Clarkia exilis • Lupinus nanus • Clarkia purpurea • Mimulus guttatus • Clarkia unguiculata • Stipa pulchra • Dactylis glomerata • Yucca brevifolia • Eschscholzia

Western Region species list – exotic invasive species • Brassica nigra • Melilotus officinalis • Brassica rapa • Raphanus sativus • Bromus diandrus • Rumex crispus • Bromus inermis • Bromus tectorum • Dactylis glomerata • Hypericum perforatum

Nationwide Project Baseline Collections • 3 field seasons: 2013, 2014, 2015 • 36 states • > 65 species • 638 populations • > 3 million seeds Western Region Collections

• 7 states • 26 species • 344 populations • Approx.1 million seeds Joshua Tree National park Yucca brevifolia (Joshua tree) Hastings Natural History Reservation, California Tejon Ranch, California San Juan National Forest, Colorado Ochoco National Forest, Oregon Applications

• Test predictions in evolutionary biology

• Understand how environmental gradients (i.e. latitude, longitude, elevation) affect species responses to climate change

• Obtain insight into how species will continue to evolve in the future Addressing Evolutionary Questions with Project Baseline

• Do mating system, life history, and dispersal traits evolve in response to short-term environmental change?

• How do reproductive, physiological, or phenological traits evolve in response to environmental changes that affect the growing season?

• What factors are most strongly associated with declines in population performance, abundance, and fitness? Forecasting Evolutionary Trajectories in Clarkia

Clarkia unguiculata Clarkia exilis

Lives in relatively hot, dry places Lives in relatively cool, moist places Flowers early Flowers late Has small flowers Has largeflowers Has fast life cycle Has slow life cycle Self pollinates Relies on insect pollinators What might a hotter, drier future look like?

Hotter & Drier Cooler & moister

Climate change prediction for California We looked for genetic linkages between floral and life history traits

Days to germination Date of first flower Herkogamy

If traits are genetically linked, and natural selection favors drought-adapted traits under climate change  could we see the evolution of self-fertilization in response to climate change? Predictions (direction of evolution in response to climate change)  If: geographic differences among populations or species in life history and floral traits is the result of differences in climate

 If: Low elevations in California approximate future hotter, drier conditions (relative to higher elevations)

 Then: As the climate becomes hotter and drier, many populations may evolve to become more similar to low-elevation phenotypes

Acknowledgments http://www.baselineseedbank.org/

Steve Franks & Jenn Weber: Fordham University Julie Etterson, Nicole Soper-Gorden, Katie Winkler, Matt Jahnke: U Minnesota, Duluth Susan Mazer & Chris True: UC Santa Barbara Ruth Shaw: U Minnesota, Twin Cities Art Weis: U Toronto Christina Walters: USDA NCGRP Chris Richards: USDA NCGRP