Links and Feedbacks Between Climate, Links and Feedbacks Between Climate, Ecosystems, and Geomorphic Change Ecosystems, and Geomorphic Change Grant Meyer, Joe Galewsky, Les McFadden Department of Earth and Planetary Sciences Department of Earth and Planetary Sciences University of New Mexico University of New Mexico Joseph R. McAuliffe Research Ecologist, Desert Botanical Garden, Phoenix, Arizona Research Ecologist, Desert Botanical Garden, Phoenix, Arizona • also thanks to also thanks to Jen Pierce, Tom Swetnam, Jed Frechette, Ben Burnett, Lyman Persico Jen Pierce, Tom Swetnam, Jed Frechette, Ben Burnett, Lyman Persico
Transcript
Links and Feedbacks Between Climate, Links and Feedbacks Between Climate, Ecosystems, and Geomorphic ChangeEcosystems, and Geomorphic Change
Grant Meyer, Joe Galewsky, Les McFadden Department of Earth and Planetary SciencesDepartment of Earth and Planetary Sciences
University of New MexicoUniversity of New Mexico
Joseph R. McAuliffeResearch Ecologist, Desert Botanical Garden, Phoenix, ArizonaResearch Ecologist, Desert Botanical Garden, Phoenix, Arizona
• also thanks toalso thanks to
Jen Pierce, Tom Swetnam, Jed Frechette, Ben Burnett, Lyman PersicoJen Pierce, Tom Swetnam, Jed Frechette, Ben Burnett, Lyman Persico
Major Links Between Climate, Ecosystems, and Major Links Between Climate, Ecosystems, and Geomorphic ChangeGeomorphic Change
Ecosystems linked to the atmosphere through modulation of water and energy fluxes by vegetation.
Vegetation exerts a strong control on geomorphic processes: • weathering and soil development • surface and subsurface runoff• slope erosional resistance and stability re. landsliding• and etc. …
Climate controls the structure, function of plant communities• however, climate-induced geomorphic changes (e.g. affecting soil hydrology) may have greater long-term impacts than direct climate effects on plant function.
The Climate System (after Saltzman, 2002; Bartlein and Hostetler, 2004)
slow forcing through tectonics-geomorphology
Long-term geomorphic and ecosystem change and atmospheric connections, Hawaii (Chadwick et al. 1999; Hotchkiss et al. 2000)
long-term mean phosphorus input from dust
P loss rate from soil
% phosphorus contribution from
atmosphere
Modeled erosion and trade wind change, Kauai
4 Myr
present
3 Myr
2 Myr
The Climate System (after Saltzman, 2002; Bartlein and Hostetler, 2004)
Geophysical, Geomorphic
Biosphere-Atmosphere Feedbacks and Links
to Geomorphic Changesimulated surface T change (°C) with
future land-cover change (Feddema et al. 2005)
Deforestation, Rondonia district, Brazil NOAA/AVHRR images (http://www.tric.u-tokai.ac.jp/)
Mamoré River (Rolf Aalto/Geotimes)
Sonoran desert piedmont near Yuma, AZ with desert pavement and dark varnish on late Pleistocene fan surfaces
(J. McAuliffe photo)
GEOMORPHIC-ECOLOGIC-CLIMATE LINKAGES in an ARID ENVIRONMENT
Desert pavement: low albedo, high surface temperature,
reduced plant cover
Plant scars on desert pavement showing Holocene vegetation contraction (McAuliffe and McDonald 2006)
Aspect-related microclimatic effects on weathering, vegetation, and slope processes produce valley asymmetry on same rock types, NE Arizona
Dec Mar Jun
Insolation differences with aspect, NE Arizona canyons
(Burnett, 2004)
Weathering of Morrison Fm sandstone by hydration of clay cement- stripping exposes bare bedrock, increases runoff generation (positive feedback)
Fire-climate-vegetation-geomorphic process linkages…
burned area >600 km2:decreased albedo, warmer, drier surface
POTENTIAL IMPACT OF BURNED AREAS ON PRECIPITATION, ALASKA (Mölders and Kramm, 2006)
GEOMORPHIC IMPACT OF SEVERE FIRE
Postfire erosion by reduced infiltration and surface runoff in brief, intense convective storms (e.g. 10 mm/15 min)
1988 fire, 1989 storm, Yellowstone NP
Debris flows-flash floods result:
OR, postfire erosion following loss
of root strength; saturation and
slide failure of colluvium with rain
on snow in winter frontal storm:
1989 fire-1997 storm, central Idaho
debr
is
f
low
s
central Idaho ~xeric central Idaho ~xeric ponderosa pine, dominant ponderosa pine, dominant
regime of light surface fires, regime of light surface fires, RI 5-30 yr fueled by RI 5-30 yr fueled by grassgrass, ,
BUT still subject to severe BUT still subject to severe
fires in extreme droughtfires in extreme drought
Yellowstone subalpine Yellowstone subalpine lodgepole-mixed conifer lodgepole-mixed conifer forest, large, severe stand-forest, large, severe stand-replacing fires, RI 200-400+ replacing fires, RI 200-400+ yryr
FIRE REGIMES ARE FIRE REGIMES ARE STRONGLY CLIMATE-STRONGLY CLIMATE-ECOSYSTEM ECOSYSTEM DEPENDENTDEPENDENT
Blue Gum Creek, SE Australia Blue Gum Creek, SE Australia eucalypt foresteucalypt forest
X
5 MONTHS AFTER severe fire (Rick Shakesby photos)
GEOMORPHIC GEOMORPHIC
RESPONSE TO RESPONSE TO
SEVERE FIRE IS SEVERE FIRE IS
ECOSYSTEM-ECOSYSTEM-
CLIMATE CLIMATE
DEPENDENTDEPENDENT
Cataract River basin, SE Australia, shortly after severe fire (Rick Shakesby photo)
ant burrows promoting deep infiltration in burned area, SE Australia – limits runoff and erosion (Rick Shakesby photo)
litter dam trapping sediment in burned area, SE Australia (Geoff Humphreys photo)
weighted mean cal yr BP
buried soil
Fire-related deposits shaded
Medieval “warm period”, 900-1300 AD: 25% of fan Medieval “warm period”, 900-1300 AD: 25% of fan deposition in last 4000 yr, Idahodeposition in last 4000 yr, Idaho
Idaho ‘large events’ (n = 29)
Holocene drought-fire-geomorph linkages, Yellowstone and Idaho: Holocene drought-fire-geomorph linkages, Yellowstone and Idaho: fire-related alluvial fan sedimentationfire-related alluvial fan sedimentation
Idaho ‘large events’ (n = 34) including high-elevation sites
Fire-related debris flows in Fire-related debris flows in Idaho ponderosaIdaho ponderosa
Medieval “warm period” or “climatic Medieval “warm period” or “climatic anomaly”, 900-1300 ADanomaly”, 900-1300 AD
(AD)
Late Holocene drought, fire, and geomorphic change in the Late Holocene drought, fire, and geomorphic change in the Northern Rockies Northern Rockies
(Pierce et al., 2004)(Pierce et al., 2004)
Fire-related debris flows in Fire-related debris flows in Yellowstone lodgepole – mixed Yellowstone lodgepole – mixed coniferconifer
Medieval “warm period” or “climatic Medieval “warm period” or “climatic anomaly”, 900-1300 ADanomaly”, 900-1300 AD
(AD)
Late Holocene drought, fire, and geomorphic change in the Late Holocene drought, fire, and geomorphic change in the Northern Rockies Northern Rockies
(Pierce et al., 2004)(Pierce et al., 2004)
Frequent small events in Frequent small events in Idaho ponderosa; very few Idaho ponderosa; very few events YNPevents YNP
Late Holocene drought, fire, and geomorphic change in the Late Holocene drought, fire, and geomorphic change in the Northern Rockies Northern Rockies
(Pierce et al., 2004)(Pierce et al., 2004)
(AD)
Warmer, drought-prone periods
Cooler, wetter periods
Yellowstone NPYellowstone NP
central Idahocentral Idaho
FIRE VULNERABILITY:FIRE VULNERABILITY: control by snowmelt timing, from Westerling et al., 2006 from Westerling et al., 2006
YNP, Idaho fire YNP, Idaho fire vulnerability increases vulnerability increases with low snowpack, with low snowpack,
earlyearly snowmelt snowmelt
Sacramento Sacramento MtnsMtns
SE New Mexico fire SE New Mexico fire vulnerability not as vulnerability not as
sensitive to snowmelt sensitive to snowmelt timing – summer timing – summer
monsoon IMPORTANTmonsoon IMPORTANT
comparison of Yellowstone & southern New Mexico fire-erosion recordscomparison of Yellowstone & southern New Mexico fire-erosion records
Yellowstone fire-related sedimentation and debris flows
major fan aggradation
“Great Pueblo Drought”
DROUGHT-VEGETATION-GEOMORPHIC PROCESS LINKAGES (and feedbacks?):
Initiation of runoff-generated debris flows in recent drought with intense convective storms, central Idaho
30 km
Nebraska Sand Hills
Wind shift in Medieval
droughts (Sridhar et al.
2006)
modern
Medieval Warm Period
Bartlein and Hostetler (2004)
Geophysical
The Climate System (after Saltzman, 2002; Bartlein and Hostetler, 2004)
-provide paleoclimate proxy data
Heat flow (boreholes); Geomorphic including dunes, fans, fluvial systems, ...
Summary Questions-ChallengesSummary Questions-Challenges• What are the important biosphere properties and dynamics
to consider in climate-landscape linkages?
• Given fast vegetation response times to climate change, can real-time ecologic-geomorphic field studies yield data relevant to landscape-evolution timescales (YES … )
• How can paleo data (climatic, biologic, hydrologic, geomorphic) best provide insights on long-term climatic control of landscape evolution? (aided by OSL, AMS 14C, CRN dating …)
• What time and space scales of (paleo)climate models can best be used to understand ecologic-geomorphic change?
• How can we more effectively integrate historical and numerical modeling approaches to climate-landscape evolution?
