Credit: A. Shcherbina
Connie Millar and
Toni Lyn Morelli
USDA Forest Service
PSW Research Station
Albany, CA USA
Strategic Approaches to
Managing for Climate Change
A Toolbox of Adaptation Options
-- Develop Resistance
-- Promote Resilience
-- Assist Response
-- Realign Highly Altered Ecosystems
Millar et al. 2007
Refugia -- Adaptation Strategy for Climate Change
112 articles reviewed,1975-2007;
Ranked into 16 categories
Heller & Zavaleta 2008
Rank Recommendation
12
Protect Refugia
Current & Future
# Articles
5
2008-2009: 14 new articles recommend Refugia
Refugia: “The part of a species range where climate
remains stable” Vos et al. 2008
“Given that dispersal is a risky strategy for species, conserving
refugia should be one of the first priorities for conservation
planning under climate change” Araujo 2009
Refugia – Quaternary Science
Isolated areas of favorable climate where populations of
species survived during Pleistocene glacial periods before
migrating outward once again, Huntley & Webb 1988
Ice-Free LGM
Beringia Refugia
Hulten 1937
Brubaker et al 2005
Petit et al. 2002
LGM Oak Refugia & Dispersal Corridors
Range Contraction
In situ -- Resistance
Petit et al. 2002
Displaced –
Range shift
Araujo 2009
“The advantage of
long holidays”
Characteristics
-- Range contraction
-- Source for dispersal
-- Favorable, stable climate & rapid recolonization
-- High species diversity
-- Centers of evolutionary
-- High genetic diversity
divergence
Petit et al. 2002
Climate-Adaptation Context
Redefining Refugia as a Cross-Cutting Strategy
Areas within or beyond current native ranges where
species persist during periods of climatic change,
climatic variability, and climatic extremes
-- C l i m a t e m a y o r m a y n o t b e s t a b l e
-- P h y s i c a l e n v i r o n m e n t m a t t e r s ( t o p o g r a p h y ,
substrate)
-- S m a l l v s l a r g e ; s i n g l e v s m u l t i p l e ( n e t w o r k s )
-- D i s p e r s a l c o r r i d o r s
-- S p e c i e s c h a r a c t e r i s t i c s
-- M a n a g e m e n t p a s s i v e o r a c t i v e
1. Climate-Buffered Environments
In-Situ Range Contractions
Heusser 2000
% pollen
% pollen
California Floristic Province
2487 spp, Loarie et al 2008
% Change in Range Size
Coast Redwood, Paleorelict
In-Situ Range Contractions
Autonomous processes mitigate local thermal regimes
E.g., Thermal regimes of talus
-- Balch circulation
-- Chimney flow ventilation
-- Positive lapse rates
Internal temps differ from
ambient air conditions,
summer & winter
Delaloye & Lambiel 2005
2. Climate Buffered Environments
Displaced Ranges e.g., Species Naturalized
or Assisted Translocation
Monterey
Pine
3 native
populations
Naturalized at
paleo locations
Brewer
Spruce
assisted
native
Millar 1998, 1999
In-Situ or Displaced
Increasing Cold-Air-Drainage
Lundquist, Forsyth, Westfall
Daly 2008
Upper Middle Fork
San Joaquin River, CA
Devils Postpile
Nat’l Monument
3. Areas of High Heterogeneity
Patchy Climate, Species Diversity, or Environment
- Escape Opportunities (gradients)
Intersection of
Biogeographic Provinces
Mammoth Pass,
Sierra Nevada, CA
Klamath Bioregion
NW California
Acidic Podsols
4. Unique Substrates
ph < 3, Toxic metals,
Perched hardpans
Jenny 1973
Pgymy forest, Mendocino, CA
Ultramafic Soils
Klamath Mtns CA
Low Ca:Mg,
Low NPK,
High Fe
Metal toxicity,
Poor waterholding,
Harrison et al. 2006
“Island” Substrates
Mt Rainier, WA
Ice-Free Nunataks
Mt Dana, CA
Debris-Covered Glaciers
Key Pleistocene Refugia
Fickert et al 2007
5. Stable Environments,
Persistent Resources
Axelrod 1944
Riparian
Habitat
Mohawk
Miocene Flora
N Sierra Nevada
Invasive Proof
E.g., Mountains
Pauchard et al 2008
Rock Glacier Forefields
Millar & Westfall 2008
6. Species Life History Favors Persistence
e.g., long-lived species, Bristlecone pine
-- 8702 year old tree-ring chronology;
-- 200-300 year gap
-- dead wood dated ~11,000 yrs old
Holocene refugia, +/- 150m elev shifts
Current: 2890-3650m
Pleistocene
widespread distribution
~1000m lower
7. Cultural Refugia
Temples, Sacred Groves, Cemetaries
Ginkgo
biloba
Arctostaphylos hookeri
- Mesozoic fossil record
- Discovered in temples
- Unknown in native stands
- Cosmopolitan in gardens
- Widespread in SF through1800s
- Eliminated by urban growth to
4 SF cemetaries, then lost altogether
- One individual found 1952
- Now in UCB Botanical Garden
Metasequoia
glyptostroboides
8. Ex-Situ Archives
Seed Banks, DNA Archives, Tissue-Culture Collections
Arborta & Zoos, Provenance Plantations
Monterey pine plantations
in New Zealand
Refugia For Climate Adaptation
Design & Management Considerations
- Single vs multiple species
- Single vs many refugia
- Combined refugia types
- Dispersal considerations
- Passive or active management
Types of Refugia
1.
2.
3.
4.
5.
6.
7.
8.
Climate Buffered; In-situ Contraction
Climate Buffered; Displaced Contraction
Heterogeneous (Patchy) Environments
Unique Substrates
Stable Areas, Persistent Resources
Favorable Species Characteristics
Cultural Refugia
Ex-situ Archives