Espm 111 Ecosystem Climate Interactions

ESPM 111 Ecosystem Ecology

Ecosystem-Climate Interactions

Dennis BaldocchiUC Berkeley

2/1/2013

Topics

• Climate and Vegetation Correspondence– Holdredge Classification

• Plant Functional Types• Plant-Climate Interactions• Canopy Microclimate


ESPM 111 Ecosystem Ecology 3

Plant communities were integrative with numerous emergent properties

Von HumboldtLinneaus

Ecosystems are a random assemblages of adapted species

Plants are associated with Climate

Theophratus

Arthur Tansley & Frederick Clements

Henry Gleason


Biogeography:• How Does Climate affect the Global

Distribution, Structure and Function of Vegetation?– The roles of rainfall, evaporation, potential

evaporation and minimum and maximum temperature


Vegetation and Climate:Holdredge Classification Scheme

Pros and Cons of Holdredge Classification


Pro: •Simple•Driven with Easy to measure Climate Variables

Con: •Annual Mean Climate Variables can be poor surrogates for functional biophysical variables, like sunlight, evaporation and soil moisture

•e.g. annual rainfall does not equal available water in soil; •e.g. annual mean temperature does not reflect growing season temperature or length of growing season


Relation with plant functional types and water balance in North America

adapted from Stephenson, 1990

Potential Evaporation minus ppt

ESPM 111 Ecosystem EcologyIPCC dataset

Virtual Field Trip



Tropical Evergreen Broadleaved Rainforests

• Latitude: 14 +/- 9 degrees• Rain > 1500 mm• ET: ~ 1000-1300 mm• Potential ET: < 2000 mm/yr• Tmin > 15 C• LAI ~5.2 +/- 1.2 m2 m-2

• Ht: ~28 +/- 9 m• Tree Density: 385 +/- 221

stem/ha• Biomass: 11389 +/- 5284 gC m-2

• Stand Age: > 100 years• Year-Round Growing Season


Temperate Deciduous Broadleaved Forests

• Latitude: 44 +/- 9 degrees• Rain: 700-1500 mm• ET: 300 to 600 mm• Potential ET: < 1000 mm/yr• Tmin > -5 to -20 C• LAI: 6.1 +/- 3.5 m2 m-2

• Ht: 19 +/- 7 m• Above Ground Biomass: 10,882

+/- 5670 gC m-2

• Stem density: 1723 stem/ha• Stand Age: 75 +/- 50• Spring-Summer Growing

Season, 120 – 180 days


Boreal Conifer Evergreen Forest

• Latitude: 58 +/- 7 degrees• Rain: ~400-900 mm• ET: ~200- 400 mm• Potential ET: < 500 mm/y• Tmin < -40 C• LAI: ~4.1 +/- 3.0• Ht: 14 +/- 7m• Biomass: 5761 gC m-2

• Tree Density: 3767 +/- 5652 stem/ha

• Stand Age: 72 +/- 52 years• Summer Growing Season, ~

100 days


Temperate Conifer Forests• Year Round Growing Season in Snow-

Free Zones• Rain

• Xeric: 250-600 mm• Mesic: 900-1500 mm

• ET: 250 – 700 mm• Potential ET: ~ 1000 mm/yr• Tmin:

• > -20 C (Xeric)• >-5 C (Mesic)

• Leaf area Index• < 3 (Xeric) • 6-10 (Mesic)

• Biomass• 200 g m-2(xeric)• 500 g m-2(mesic)

• Ht: • 15 to 40 m (Xeric)• 40 to 100 m (Mesic)


Mediterranean Woodlands: Deciduous and Evergreen Broadleaved

• Rain: ~500-800 mm/year

• ET: < 500 mm/yr• Potential ET 1000-

2000 mm/yr• Tmin: -1 to 15 C• LAI: ~1-3• Height: ~5 to 15 m• Hydrological Growing

Season, Autumn-Winter-Spring; System Shuts down in Summer


Tropical/semi-Tropical Savanna: Drought Deciduous and Evergreen Broadleaved

Woodland with C4 Grass Understory

• Hydrological Growing Season, wet summer

• Rain: 400-1500 mm/year• ET: < 1000 mm• Potential ET ~ 4000 mm• Tmin: > 0 C• LAI: ~2-3 • Height

– Deciduous: ~10 to 30 m;– Evergreen: to 70 m

Synopsis

Luyssaert et al. 2008 GCB


Grasslands


Grasslands

• Perennial Grasses, Summer Growing Season

• Annual Grasses, Winter-Spring Growing Season

• Rain: 200-500 mm/year• ET: < 400 mm• Potential ET: < 1000

mm/y• Tmin: -1 to 15 C• LAI: ~1-3• Biomass: 3 g m-2

• Height– Perennial, < 1 m– Annual, < 1 m

Exceptions: Grasslands with High Rainfall (1-3 m)

• Llanos, Venezuela– Seasonal Flooded Tropical

Grassland, with sparse Trees

– Grassland or Savanna? (Blydenstein, 1969, Ecology)

• Highly leached, inundated, hardpan soils limit tree growth

• Man and fires push back tree growth and sustain grasses

• Abandoned pasture reverts to brush



Wetlands

Wetlands: Fens, bogs, Marsh

• Short Summer Growing season in Boreal Zone, Year-round in Tropics

• Tave: -1 to 15 C• LAI: ~1-3• NPP: up to 1000 gC

m-2 y-1

• Biomass: g m-2

• Height– boreal, < 1 m– Temperate/tropical, 3

mESPM 111 Ecosystem Ecology


Climate-Plant Interactions

• How does Climate Constrain Vegetation Structure and Function?– Why do certain plants have big leaves and others have small

ones?– What biophysical factors limits plant height, density and

vigor?– How does Climate affect Biodiversity?

ESPM 129 Biometeorology 26

Plant-Habitat Interactions and Constraints

• Plants that grow rapidly under conditions with sufficient soil moisture are unable to survive under dry conditions.

• Tolerance to low light and soil moisture is interdependent and inversely correlated.

• Plants that can photosynthesize at high rates and grow rapidly under high light are unable to survive at low light (they are shade intolerant)

• Shade tolerant plants have low growth rates and photosynthetic potentials, even under high light conditions.

Smith and Huston, 1989


General Constraints of Climate and Environment on Plants

• Sunlight– Available sunlight drives photosynthesis.– ~1.4 g dry matter is produced for 1MJ of intercepted sunlight (2.5%

efficiency).– Heats Surface and Evaporates Water

• Water– Hydrates cells– Causes turgor for growth and cell expansion– Transfers nutrients– Water vapor is lost as stomates open to acquire CO2

• Temperature– Regulates rates of biochemical and enzymatic reactions – Determines if water is gas, liquid or solid


Photosynthesis Scales with Water Use:Wet EcoSystems Transpire a lot and can Achieve High Photosynthesis

Dry EcoSystems cannot afford to Transpire a lot, so they have limited photosynthesis

Rosenzweig, 1968 AmNat


Dominant Environmental Controls on Net Primary Productivity

Churkina and Running, 1998, Ecosystems

ESPM 111 Ecosystem EcologyKleidon and Mooney, 2000 GCB

Species Diversity has Links with Climate, too


BioClimatology:

• How does Vegetation, Disturbance or Land Use Change affect Climate? – Roles of albedo, surface roughness, surface conductance,

leaf area & physiological capacity– Role of Forests in Climate Mitigation


Energy PartitioningNet RadiationBudget

Solar Radiation

TerrestrialRadiation

Latent heat

Sensible heat

Soil HeatConduction

Biophysics: Energy Exchange


PBL:1500 m

PBL:1000 m

S = 0.08 Rn

G = 0.02 Rn

H = 0.3 Rn

LE = 0.6 Rn

= 0.15 Rg

Rn = 0.65 Rg

LEn = 0.8 Rn

= 0.25 Rg

H = 0.05 Rn

Rn = 0.85 Rg

S = 0.15 Rn

Energy Balance Partitioning: Crops vs Forests


Clearing for agriculture in W. Australia altered climate30% less ppt over farmlands10% more ppt over heathlands

Photo: S. ChambersChapin Lecture Notes


Vegetation effects on climate:Role of Tropical Deforestation

Shukla et al. 1990


Plant-Atmosphere Interactions

• Change Net Radiation– Albedo

• vegetation color, height and density– Surface Temperature and Longwave emission– Surface Resistance to Moisture Loss– Snow Melt and Albedo Feedback

• Change Surface Resistance– Evaporation– Sensible Heat exchange– Photosynthesis and Carbon Capture– Cloud Formation and Precipitation Feedbacks

• Change Structure– Wind and Turbulence– Light Capture

Climate Services by Vegetation

ESPM 111 Ecosystem EcologyBonan, 2008, Science

Red Arrow: WarmingBlue Arrow: Cooling

Rain and CloudsRunoff to Streams and LakesWarming or Cooling the SurfaceCarbon and Pollution Sink


How Forests affect the Chemical Composition of the

Atmosphere

C5H8

NO + O3 = NO2

O3

OH

NO

RO2 NO2

h

ROOH

f(PAR, TL)

NO2 + h =NO + O


Microclimate• Sunlight• Temperature• Wind and turbulence• Humidity• Trace gases, CO2, O3,

VOCs• Aerosols

• Sources of Variation• Spatial

• Vertical,horizontal• Temporal

• Hour, day, season


Sunlight in Forests

Radiation andForests

direct sunlight Diffuse Sunlight


Vertical Structure of Wind: Impact of Canopy Roughness

Wind andTurbulence


Temperature and Plants

TemperatureDay

Night

• Plant Structure and Function are linked to available sunlight, temperature and rainfall

• Plant Functional Types are a useful concept for explaining how plants respond to Climate

• Links between PFT and Climate can explain Geographic Distribution of Plants

• Plants affect the Local Microclimate, and Vice Versa


Summary

ESPM 111 Ecosystem EcologyLaothawornkitkul et al New Phytologist Tansley review .pdf

Vegetation-Atmospheric Chemistry-Climate Interactions

Aerosols which scatter/reflect sunlight, cool, enhance photosynthesis by better light capture; VOC emission =f(temperature)

VOCs contribute to photochemical ozone production, in presence of NOx, and aerosol production

VOCs transmit biological signal and are defense compounds against insects and pathogens

Espm 111 Ecosystem Climate Interactions

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