How will rapid climate change affect species and ecological communities?• Species phenology and growth• Phenotypic expression of species• Species’ population dynamics• Gene frequencies in populations (evolution)• Species distributions• Species interactions• Disturbance processes and community dynamics• Ecosystem structure and dynamics

Biomes: global patterns of plant response to climate

• Biomes are general ecosystem types that occur under a particular climate regime, and exhibits characteristic vegetation structure, community organization, and ecosystem processes.

Cold needle-leaved woodland (lodgepole pine) and cold shrub steppe (Great Basin sagebrush), Yellowstone National Park, 24 years after fire

Temperate deciduous broadleaf forest

Boreal needle-leaved evergreen forsst

Humid tropical broadleaved evergeeen forest

Montane tropical broadleaved evergreen forest

SW Australia Crete

CA

The Mediterranean Biome

Climate and Terrestrial Biomes, circa 1960

R. Whittaker

Bonan et al. Global Change Biology 2003

Biomes, circa 2000:Coupled vegetation-climate interactions at the global scale

Temperature and biological patterns

• Species and community range limits

• local distribution patterns

• population age structure

• genetic differentiation• ecosystem processes

Physical Constraints on organisms

• Microclimate– Radiation

– Temperature

– Energy

– Water & humidity

• Nutrients• Toxins• Mechanical stress

Dresig. 1980. Oecologia.

Climate and Habitat

• Habitat is “the resources and conditions present in an area that produce occupancy” (Hall et al. 1997. Wildlife Soc. Bull. 25: 173-182)

• Climate space – radiation, wind, temperature, humidity

• Microclimate

Post et al. Science, September 2009

Nemani RR, White MA, Cayan DR, Jones GV, Running SW, Coughlan JC, Peterson DLAsymmetric warming over coastal California and its impact on the premium wine industry. Climate Research Nov 01.

Janzen, F.J. Proc. Nat. Acad. Sci. 1994.

http://ndis.nrel.colostate.edu/herpatlas/coherpatlas/images/Species/Turtles/paintedhead.jpg

Heat balance of an animal

Energy balance of an organism

M + Qa = R + C + E + G + X

M Metabolic energyQa absorbed radiationR emitted radiationC energy exchanged by convectionE latent heat energyG energy exchanged by conductionX net energy loss or gain

Some considerations in bioclimatology of animal species

• Endotherms vs. ectotherms– 99.9% of species are ectotherms that rely primarily on

external sources for body heat

• Behavior– Diurnal vs. nocturnal– Fossorial, semi-fossorial vs. non-fossorial– Hibernation, torpor

• Nutritional status• Age and stage of development

Climate space (“Fundamental niche”) modeling

• Organism– Body mass– Voluntary min and

max T– Selected body T– Latent heat transfer

rate– Resting metabolic rate– Degree days for egg

development

• Environment– Solar radiation– Wind profile– Air Temperature

profile– Relative humidity– Soil temperature

profile

Scales of environmental temperature variation

• Global

• Regional

– Land/water

– Elevation

• Local

– Slope angle and aspect

• Microsite

– Vegetation canopy, soil moisture, etc.

Bay checkerspot butterfly

Murphy and Weiss (1992) Chapter 26 in Global Warming and biological diversity, ed. R. L. Peters and T. E. Lovejoy. Castleton, New York: HamiltonPrinting.

Climate change and plant species

• Temperature

• Soil water balance

• Carbon dioxide

• Dispersal and adaptation

Wollemia nobilis

Climate and Photosynthesis

• Photosynthesis6 CO2+ 6 H2O ----sunlight----> C6H12O6 + 6 O2

• Rate controlling factors– Radiation– Temperature– Water– Carbon dioxide– Nutrients (nitrogen)

Photosynthesis and plant water balance

Absorption depends on: soil water soil water osmotic potential root osmotic potential soil temperature, oxygen

Transpiration depends on: leaf water, temp. air temp, humidity leaf shape, resistance

H2O

Equisetum

http://www.fhsu.edu/biology/thomasson/stomate.htm

Scurf-pea

CO2 response curve of photosynthesis

• Diffusion limitation affected by stomata• Biochemical limitation affected by

light/enzymes• Plants equalize physical and biochemical

limitations

Inherent tradeoff between CO2 gain and H2O loss

Influence of different parameters on the efficiency of the carbon dioxide uptake (ordinate) of a C3 plant (Atriplex patula, yellow line)

and a C4 plant (Atriplex rosea, green line). Measured parameters

(from left to right): light intensity, leaf temperature and concentration of carbon dioxide within the intercellular space (according to O. BJÖRKMAN and J. BERRY, 1973).

Water use efficiency

• C3 plants 1-3 g CO2 intake / kg H20 loss

20-35°C optimal temperature

• C4 Plants 10-40 g/kg

30-45 C

• CAM Plants 20-40+ g/kg

20-35 C

GPP, NPP, and NEP

• Photosynthesis usually measured in units of moles carbon/leaf area/time (usually reported as net photosynthesis)

• Gross Primary Production (GPP) is a measure of photosynthetic activity– carbon uptake per ground area per time – Around 50% of GPP is used in respiration

• Net primary production (NPP) = GPP – Respiration– Net carbon (or biomass) per ground area per time

• Net ecosystem production (NEP) measures change in total organic matter per area per time– NEP = GPP – Respiration of Autotrophs and Heterotrophs

Components of NPP % of NPP

New plant biomass 40-70Leaves and reproductive parts (fine litterfall) 10-30Apical stem growth 0-10Secondary stem growth 0-30New roots 30-40

Root secretions 20-40Root exudates 10-30Root transfers to mycorrhizae 10-30

Losses to herbivores, mortality, and fire 1-40Volatile emissions 0-5

Components of NPP

What do we usually measure??LitterfallSometimes stem growth

Source http://www.faculty.uaf.edu/fffsc/PPTChap6.ppt.

Patterns of NPP vary strongly with climate

Possible responses of plants to increased atmospheric CO2

• Decreased stomatal conductance

• Decreased transpiration

• Increased water use efficiency

• Increased photosynthetic rate

• Decreased nitrogen concentration

• Increased phenolic concentration

• Long term Acclimation

http://www.esd.ornl.gov/facilities/ORNL-FACE/goals.html

Predicting plant species responses to rapid climate change• Plants can

– Tolerate– Adapt– Disperse

• Issues– Local phenotypic and genotypic variation?– Rate of adaptation vs. rate of climate change?– Dispersal rates in fragmented landscapes?– Photoperiod vs. climate controls on phenology

Predicting future plant species distributions

• Lessons from the past• Approaches

– Bioclimatic modeling (realized niche models)– Physiological models (fundamental niche

models)– Spatial population and community models– Dynamic [global or regional] vegetation models

• Dispersal through fragmented habitats

Neotoma sp. (packrat)

Packrat midden,Grand Canyon, 13000yrs. BP

Alder pollen

Present potential veg Vegetation 15,000 YBP

Measured rates of spread for tree genera during postglacial period

• Oak 7 km/generation

• Spruce 0.3-1(8) km/generation

• Hemlock 0.5-3 km/generation

• Dispersal in fragmented habitats?

Summary points

• Microclimate is the climate experienced by organisms

• Species occupy distinctive habitats that reflect their physiology, interactions with other species, and dispersal. Species respond individualistically to climate variation

• Species persistence under a changing climate can occur through tolerance, adaptation or dispersal

A few summary points (2)

• Oceans and humid forests account for roughly 2/3 of the earth’s net primary production.

• Gross and net primary production increase in warmer and wetter climates

• Plants interact with the atsmophere to modify local, regional and even global climate.

• Increased CO2 increases water use efficiency of plants, especially C3 plants