Guiding seed transfer with species occurrence data

Troy Wood,1 Brad Butterfield2

1USGS, Flagstaff2Northern Arizona University

News Flash: Plants are locally adapted

Multiple reviews, e.g.:

Leimu and Fischer, 2008; Sexton 2014Hereford 2009–local = 45% > fitness and magnitude predicted by environmental difference

….and others

CG Data on Priority Species

ACHY: 2 – 1 defines zonesBOGR2: 14ELEL2: 5KOMA: 8POSE: 5 (1 linked to B. tectorum competition)SPCR: 2

Forbs: 0 (1 study–multiple genetic groups)

Bouteloua gracilis (blue grama)

• C4 warm-season grass– Grazing tolerant and good forage– Market survey: highest demand (southern CP)

• Broad distribution + diverse morphologies– Genetic?– Environmental?

Source Populations

• Seeds collected from broad range of environmental conditions– 43 populations (3 improved)– 686 individuals– 2x + 4x individuals

• Planted in common garden near Flagstaff

Measurements

Survival[Flowering Time]Functional Traits (37,185)

• Specific leaf area• Leaf dry matter content• Leaf area

Environmental Variables• Mean Annual Temp• Temp Seasonality• Temp of Wettest Qrtr• Mean Annual Precip• Precip Seasonality• Precip of Hottest Qrtr

Genetic Variation in Leaf Area and SLA

SLA Decreases with Increasing MAT

• “Expensive” leaves in high MAT– Reduced transpiration,

greater longevity• Cheap leaves in low MAT

– High photosynthetic rate, low initial investment

• Tradeoff between photosynthetic capacity and water use efficiency

Area Increases with MAT, Precip Warm Qtr

• Larger/longer in hot, wet summer env.

Climatic Predictors of Survival

Best Model:Mean = 57% (± 3.4%)Whole model: R2 = 0.34, p<0.0031

Terms Estimate p-valueTempSeas -0.14<.0001 MAT -0.08

0.0373 PrecipSeas -0.070.0799

SummaryBOGR2 garden study

• Genetic variation in functional traits– SLA and leaf size/length

• And it is correlated with source environment– Suggests local adaptation

• At Flagstaff, survival predicted by temp/precip

• Ploidy not correlated with response variables

Garden Studies

• Time & Cost: High

• Inference limited by grow out site climate

• Garden X source site choice critical

Alternative Approaches

• Provisional maps

• Genome scans to ID adaptive genetic variation

• Species distribution modeling– Informed provisional

Genetic Markers Only

Genotype populations

Identify putatively adaptive markers

Map seed zones with climate by adaptive genetic correlations

Sphaeralcea ambigua

Species Distribution Models

• Model suitable habitat

• Data free, analysis cost modest

• Can determine most important climate limiters––globally and regionally

• Sensible to use these limiters for a more informed provisional map? Testable…

Modeling Methods

• Occurrences from digitized herbaria GBIF + SEINET

• Use uncorrelated climate variates to predict habitat suitable, training and testing phases

• Perform with ensemble of models (8)• Evaluate climate variable importance

Blue grama: current and future (2080)

Red = present, not futureBlue = future, not presentPurple = stasis

Blue grama: current and future (2080)

MAT0.26,0.05TDiurn 0.29,0.04TSeas 0.47,0.06TWetQtr 0.16,0.04MAP0.07,0.03PSeas 0.08,0.02PWrmQtr 0.14,0.03

Blue grama: current and future (2080)

MAT0.26,0.05TDiurn 0.29,0.04TSeas 0.47,0.06**TWetQtr 0.16,0.04MAP0.07,0.03PSeas 0.08,0.02PWrmQtr 0.14,0.03

CP ONLYMAT 0.06

TDiurn 0.1TSeas 0.22TWetQtr 0.03MAP 0.23

PSeas 0.26PWrmQtr 0.39

Fire Regime Fire Regime GroupsMean Fire Return Interval% Low-severity Fire% Mixed-severity Fire% Replacement-severity FireSuccession Classes

DisturbanceDisturbance 1990-2008Fuel DisturbanceVegetation Disturbance

Next – IntersectCurrent Suitability

Landfire Layers

Hindsight Model

Identify Where Estimate Abundance (Who)Which Can Be IncreasedHow Many Sources Are PracticalWhich Source(s) Minimize Transfer EcoDistance

--refine estimates of EcoDistance with empirical data

Concluding Remark

All preceding approaches based on judgment:

“Hence, in determining whether a [group] should be ranked as an [ecotype], the opinion of naturalists having sound judgement and wide experience seems the only guide to follow.”

–Darwin, The Origin

Summary

• Funding BLM, USGS• SEGA and the Arboretum at Flagstaff• Kris Haskins, Amy Whipple and Tom Whitham• Stewart Sanderson, USFS• Rachel Ostlund, Patty West, SOS

Acknowledgments