Riparian Cottonwoods: Hydrology, Hydraulics and Health
Transcript of Riparian Cottonwoods: Hydrology, Hydraulics and Health
Riparian Cottonwoods:
Hydrology, Hydraulics and Health
Stewart Rood, David Pearce, Karen Zanewich and Larry Flanagan
Cottonwood Park
Lethbridge, AB
January
2019
Balsampoplar
Prairiecottonwood
Blackcottonwood
Narrowleafcottonwood
A Continental
Convergence of Cottonwoods
5 Poplars,
4 Interbreeding Cottonwoods
Cooke & Rood (2007) Botany
*
P. tremuloides
Hydrology – Water in open systems
≈ 0 MPa
Stream Flow: Declining due to human use & climate change
Alluvial Groundwater: Recharged with stream flow
Hydraulics – Water in constrained systems
≠ 0 MPa
Plant Hydraulics: < 0 MPa, negative tension
Water Potential (, psi) – Water availability
Alluvial Groundwater
(Phreatic, 0 MPa)
River
Capillary fringe
Soil moisture
(Vadose)
Transpiration, Tension, Cohesion
Xylem water: strands
Dry air, -100 MPa
Vapor Pressure Deficit
Demand
Supply
Leaf
Pre-dawn -0.5 MPa
~ Root zone
Mid-day -2 MPa
> Cavitation thresholds = Healthy
Pressure
Chamber
$2K
peltate trichomes
Elaeagnus commutata
Decre
asin
g
Water table
Water tracking – 2H,18O
Trees
Trout
Big Lost R., ID
Aquatic and Riparian
Ecosystems
Require Instream Flow
Healthy
Unhealthy
Stressed
(Dead)
Rood et al. (2003) Tree Physiol
Health
Lower St. Mary River
male
female
Rood et al. (2016) River Res Appln
Chronology: ~99% mortality – 1951-2015
Aerial photos, tree cores, river Q, groundwater patterns
Flow restoration
Indicators = Health Measures
Diagnostic
Quantitative
Near Real-Time
‘Dendroscope’
Bridge Grove
Irrigated
Golf Course
Oxbow &
Wetland
River
Gauge
Flux
Tower
*
*
*
*
Groundwater
Well
Lethbridge – High Level Bridge
5
15
25
m
Seasonal & Interannual Variation
Yang, Rood, Flanagan (in press) Ag For Meteor
wet drydry
5
2. 5
0
10
20
30
40
0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00
Sa
p F
low
(g
h-1
cm
-2)
Time (hour)
After Irrigation
DOY 240
‘Maria’ – P. angustifolia
Diurnal Variation
~(Cox et al. (2005) W N Am Nat)
Thermal Dissipation Probes
(TDPs)
High Flow & Wet = Healthy8/13/2014
Low Flow & Dry = Stressed8/8/2018
Irrigated
Golf Course
Riparian
Woodland
Normalized Difference Vegetation Index (NDVI, below), and
Near Infrared Reflectance of Vegetation (NIRV; Badgley,Field,Berry (2017) Sci Advances)
What does this reveal?
Assim
ilatio
n?
Tai, Mackay, Sperry, Brooks, Anderegg,
Flanagan, Rood, Hopkinson
Perc
ent Loss C
onducta
nce
0
10
20
30
40
50
60
70
80
90
100
-3.5 -3 -2.5 -2 -1.5 -1 -0.5 0
Xylem pressure (MPa)
Pe
rce
nt
loss
co
nd
uct
ivit
y
PLC = 100/(1+ ea(ψ-ψPLC50))
Male tree 1, shoot 1
ψPLC50 = -2.11 MPa
Female tree 1, shoot 1
ψPLC50 = -1.94 MPa
-2.5
-2
-1.5
-1
-0.5
0
Females Males
ψP
LC5
0 (
MP
a)
4 trees, 3 shoots per tree
Cavitron embolized
functional
P. angustifolia P. x acuminata P. deltoides
Complexity or Opportunity?
$2K
Water
River Q, stage, regime
Groundwater depth
Soil water
Source tracking – 2H,18O
Hydrology – Hydraulics
Health Indicators
Canopy
Leaf Area Index
Phenology
Thermal Imaging
Branch Sacrifice
Dieback
Weather: T, Ppt
Vapor Pressure Deficit
Ecosystem
Fluxes
Satellite Derived
Vegetation Indices
Leaf
Morphology/Stomata
Water Potential
Conductance/Transpiration
Photosynthesis/Water Use Efficiency13C, N
Branch
Seasonal & Annual Growth
Sap Flow
Xylem Water
Water Potential
Hydraulic Conductance
Xylem Cavitation
Trunk
Seasonal Growth
Annual Rings – 13C, 18O
Sap Flow
Root
Distributions
Symbionts
0.55
0.60
0.65
0.70
232 234 236 238 240 242 244 246 248
Wate
r le
vel (m
)
Time (DOY)
2017 - Dry
2012 - Normal
Water Table
Daily Drawdown
Year Diurnal
Amplitude
Phreatic
Water Use
Condition
2012 ~ 2 cm 5 mm/d Healthy
2017 ~ 1 cm 2.5 mm/d Stressed
specific yield
$2K – 2 & telemetry
Rood et al. (2013) Plant Cell Environ
Scale
Leaf to woodland,
Spatial area
Accessibility
Cost, Time effort,
Complexity,
Instrumentation
Diagnosis
Useful information,
Time frame &
Dynamics
0
2
46
810
0
1
2
3
4
5
6
7
8
9
10
0 1 2 3 4 5 6 7 8 9 10
Dia
gn
osis
Remote Sensing
Vegetation Indices
Flux Tower
Scale
Accessibility
Water Well
Observation
Riparian Cottonwoods:
Hydrology, Hydraulics and Health
Stewart Rood, David Pearce, Karen Zanewich and Larry Flanagan
Cottonwood Park
Lethbridge, AB
January
2019
Perf
orm
ance
low highelevation
wet dryflood drought
water
reproductiveallocation
female male
broaderniche
♀♂
seedlingrecruitment
pollen
seeds