9/15/08
Physical environment
Smith and Smith, 2006 Biogeography
Prof. J. Hicke
1
Physical environment Soil moisture controls on woody plants in desert Southwest
Lomolino et al. 2006 Biogeography
Prof. J. Hicke
2
Physical environment Moisture stress on plants: mortality
Pinyon pine in SW
Croplands
Photo by Craig Allen - USGS
Biogeography
3
Prof. J. Hicke
1
9/15/08
Physical environment Soil moisture controls on tree species distribution in PNW
Barnes et al., 1998 Biogeography
Prof. J. Hicke
4
Physical environment Rooting depth in arid landscape controls species distribution
Biogeography
Elmore et al., 2003
Prof. J. Hicke
5
Physical environment Controls of soil moisture at larger scale Precip Biomass Veg type
Biogeography
6
dry
none
none shrublands savannas
wet
high
dense forest
dry
none
Friedl et al.
Prof. J. Hicke
2
9/15/08
Physical environment Plant strategies to deal with drought: 1. Escapees • Perennials (dormancy) • Annuals (“emphemerals”)
www.desertusa.com/wildflo/wildupdates.html Biogeography
Prof. J. Hicke
7
Physical environment Plant strategies to deal with drought: 2. Avoiders
Slide courtesy C. Still Biogeography
8
DeFries et al., 2000
Prof. J. Hicke
Physical environment Plant strategies to deal with drought: 2. Avoiders
Slide courtesy C. Still Biogeography
9
Prof. J. Hicke
3
9/15/08
Physical environment Adaptation to low moisture conditions: Idaho forest Soil water redistribution-water flows uphill!
Biogeography
slide courtesy of K. Kavanagh
Prof. J. Hicke
10
Physical environment Annual water balance Sierra Nevada, CA: Coniferous
Eric, PA: Deciduous
soil water recharge
deficit surplus
surplus
Water supply PET AET
Stephenson, 1990
Stephenson, 1998 Biogeography
Prof. J. Hicke
11
Physical environment Three reasons conifers dominate over deciduous trees energy limited => low AET Water supply PET AET
water limited => low AET
asynchrony in energy, water supplies => low AET
Biogeography
12
Stephenson, 1990
Prof. J. Hicke
4
9/15/08
Physical environment Distribution of major N. America plant formations AET: separation of different forest types
Deficit: separation of forest types from prairie
Biogeography
13
Stephenson, 1990
Prof. J. Hicke
Physical environment Rain isn’t everything: N. California coastal forest
fog is 22-46% of hydrologic inputs; timing is everything! Dawson 1998 Biogeography
Prof. J. Hicke
14
Physical environment Extremely wet soils Adaptations:
adventitious roots
longitudinal air spaces
aerating roots Mangroves (Avicennia)
www.mpil-ploen.mpg.de/mpiltppa.htm www.sprrs.usda.gov/aerenchy.htm
Biogeography
15
en.wikipedia.org/wiki/Root
Prof. J. Hicke
5
9/15/08
Physical environment Adaptations to low water availability kangaroo rat (Dipodomys spectabilis) • • • • • •
can live entirely on dry food without ever drinking free water 100 g dried seed => 54 ml of water through oxidation only very small quantities of feces, urine do not sweat; little evaporation nocturnal behavior during milk production, females need to eat green and moist plants
museum.utep.edu/chih/theland/animals/mammals/dipospect.gif
Vorhies, 1922 Biogeography
16
Prof. J. Hicke
Physical environment Adaptations to low water availability Namib Desert beetle (Onymacris unguicularis) morphology adaptations to capture fog: bumps on back channels to mouth head down behavior can capture 40% of body weight in one morning
www.nacoma.org.na/Pictures/Photos/Beetle.jpg
http://www.biomechanics.bio.uci.edu/_html/nh_biomech/namib/beetle.htm
Biogeography
17
Prof. J. Hicke
Physical environment Soil type controls on species distributions Example: Serpentine soils • dry and nutrient poor • toxic to most plants • support grasses adapted to these conditions as a result, associated animals are also located in these areas
Biogeography
Smith and Smith, 2006
18
Prof. J. Hicke
6
9/15/08
Physical environment % of total basal area within stand
Soil fertility influences plant species distribution: Tolerance to calcium
Replaceable calcium Waring and Major, 1964 Biogeography
Prof. J. Hicke
19
Physical environment Soil texture (moisture) effects on distributions rapid water infiltration: plants need to respond quickly
greatest water availability: greater productivity, diversity
poor water infiltration: sparse, shallow rooted shrubs
Biogeography
siz
t
ien
rad
eg
ticle
par
Prof. J. Hicke
20
Physical environment Soil texture influences on biogeography
Biogeography
21
Smith and Smith, 2006
Prof. J. Hicke
7
9/15/08
Physical environment Anoxic conditions Result from: • lack of plants • lack of mixing
Excess fertilizer => phytoplankton blooms => zooplankton blooms => decomposer bloom => O2 depletion
Ferber 2004 Biogeography
Prof. J. Hicke
22
Physical environment Acid rain Tolerance of acidification within lakes Little Echo Pond
www.terradaily.com/reports/ Acid_Rain_And_Forest_Mass_Another _Perspective.html
Increasing acidification
www.epa.gov/acidrain/effects/surface_water.html Biogeography
23
Prof. J. Hicke
Physical environment What factors limit white spruce at its northern and southern extent? Summer temperatures
Moisture stress (high summer temps, low precip) Biogeography
24
Prof. J. Hicke
8
9/15/08
Physical environment Controls on Net Primary Production
Nemani et al., 2003 Biogeography
25
Prof. J. Hicke
Physical environment Transect across Pacific Northwest
transect
Biogeography
26
Prof. J. Hicke
Physical environment Transect across Pacific Northwest
Biogeography
27
Prof. J. Hicke
9
9/15/08
Physical environment Transect across Pacific Northwest
forests
Biogeography
shrublands /croplands
forests
grasslands /croplands
Prof. J. Hicke
28
Physical environment Transect across Pacific Northwest
forests
Biogeography
shrublands /croplands
forests
grasslands /croplands
29
Prof. J. Hicke
Physical environment Range and density
Biogeography
30
Prof. J. Hicke
10
9/15/08
Physical environment Population density follows physiological functioning (which is controlled by environment)
Gradients in physiological functioning often follow Gaussian distribution
Environmental gradient Biogeography
Prof. J. Hicke
31
Physical environment Environmental gradients control niches
Pinus ponderosa
Pseudotsuga menziesii
Pinus ponderosa
Pseudotsuga menziesii
McKenzie et al., 2003 Biogeography
Prof. J. Hicke
32
Physical environment Variability among species in tolerance to environmental conditions Redwood (Sequoia sempervirens): large range of ecological optimum Others: narrow range
Which are generalists? Specialists?
Biogeography
Waring and Major, 1964 33
Prof. J. Hicke
11
