Saltcedar Tamarix Physiology a Primer

1
Saltcedar (Tamarix) Physiology - a Primer

• Dr. Curtis E. Swift
• Colorado State University Cooperative Extension

2
Tamarix uses in ancient times

• Charcoal from Tamarix twigs found in caves of
  Natufian culture (C. 12300-10500 BC) Mount
  Carmel, Israel

Ley-Yadun, S., and Weinstein-Evron, M. 1994. Late
Epipalaeolitic wood remains from el-Wad Cave,
Mount Carmel, Israel, New Phytol. 127391-396.
3
Tamarix uses in ancient times

• Manna from Heaven - Manna scale (Trabutina
  mannipara)
• Biblical manna - one of the food sources
  consumed by the Israelites during their
  wanderings in the wilderness of Sinai

Ben-dov, Y. 1988. Manna scale, Trabutina
mannipara (Hemprich Ehrenberg) (Homoptera
Coccoidea Pseudococcidae) Systematic Entomology
13387-392.
4
Manna scale Trabutina mannipara
5
Saltcedar in the United States

• Introduced by nurseryman in early 1800s as an
  ornamental
• Later used as an erosion-control plant in New
  Mexico
• 1920 - 40 or 50 thousand acres
• over one million acres by 1965

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
6
Saltcedar in the United States

• Since the early 1900s Tamarix has rapidly
  invaded the ecosystem of the lower Colorado River
  and its tributaries
• Resulted in the replacement of up to 90 of the
  riparian communities historically dominated by
  cottonwood-willow forests

Sala, A, and Smith, S.D. 1996. Water use by
Tamarix ramosissima and associated phreatophytes
in a Mojave desert floodplain. Ecological
Applications 6(3)888-898.
7
Saltcedar Genus Tamarix

• Native to the Mediterranean region, central Asian
  and north African deserts
• A naturalized shrub or small tree in U.S.
• Widely distributed phreatophyte in the
  southwestern United States

Ginzburg, C. 1967. Organization of the
adventitious root apex in Tamarix aphylla. Amer.
J. Bot. 54(1)4-8.
8
Floodplain survival

• Variety of environmental attributes affect the
  mechanisms controlling populational and
  ecological relationships between floodplain
  species.

Cleverly, J.R., Smith, S.D., Sala, A., and
Devitt, D.A. 1997. Invasive capacity of Tamarix
ramosissima in a Mojave Desert floodplain the
role of drought. Oecologia 11112-18.
9
Floodplain survivalof native species

• Willow is more tolerant of water and salt stress
  than cottonwood
• Responsible for the persistence of Salix vs.
  Populus on the Colorado River

Busch, D.E., and Smith, S.D. 1995. Mechanisms
associated with decline of woody species in
riparian ecosystems of the Southwestern U.S.
Ecological Monographs 65(3)347-370.
10
Tamarix success as an invasive plant

• Success in the floodplain results from
• ability to grow rapidly in wet years
• ability to tolerate or avoid extreme water and
  heat stress in drought years

Cleverly, J.R., Smith, S.D., Sala, A., and
Devitt, D.A. 1997. Invasive capacity of Tamarix
ramosissima in a Mojave Desert floodplain the
role of drought. Oecologia 11112-18.
11
Tamarix success as an invasive plant

• tolerant of desiccation of watercourses

Blackburn, W.H., Knight, R.W., and Schuster, J.L.
1982. Saltceder influence on sedimentation in
the Brazos River. J. Soil. Water. Conserv.
37298-301
12
Tamarix success as an invasive plant

• tolerant of salinization of surface soils

Busch, D.E., and Smith, S.D. 1993. Effects of
fire on water and salinity relations of riparian
woody taxa. Oecologia 94186-194.
13
Tolerance of Floods

• Salt grass and dwarf willow developing on sand
  bars shallow roots - swept away by floods
• Tamarisk is hardy enough to withstand floods,
  continue to grow, stabilize the underlying
  surface, and trap sediments

Graf, W.L. 1978. Fluvial adjustments to the
spread of tamarisk in the Colorado Plateau
region. Bulletin Geological Society of America
89(10)1491-1501.
14
Plant Success

• When a species is competitively superior under
  both wet years and drought, it would be expected
  to persist as the sole species through
  successional time.

Cleverly, J.R., Smith, S.D., Sala, A., and
Devitt, D.A. 1997. Invasive capacity of Tamarix
ramosissima in a Mojave Desert floodplain the
role of drought. Oecologia 11112-18.
15
Tamarix invasiveness

• Plant spread upstream at 20 km/yr (12 mile/yr).
• Colorado and Green River in Utah

Graf, W.L. 1978. Fluvial adjustments to the
spread of tamarisk in the Colorado Plateau
region. Bulletin Geological Society of America
89(10)1491-1501.
16
Tamarix invasiveness

• Annual production of 600,000 windborne seeds for
  each mature tamarisk tree
• Spreads rapidly by layering

Robinson, T.W. 1958. Phreatophytes. US Geological
Survey Water-supply paper 142370-75.
Wilkinson, R.E. 1966. Adventitious roots on
saltcedar roots. Bot. Gaz. 127(2-3)103-104.
17
Tamarix invasiveness

• All the aboveground portions of saltcedar will
  develop adventitious roots and form new shrubs if
  kept wet in moist soil.
• 100 of stem cuttings sprout at all times of the
  year if kept moist and warm.

Horton, J.S. 1977. The development and
perpetuation of the permanent Tamarisk Type in
the phreatophyte zone of the southwest. USDA, FS,
General technical report RM 43124-127.
18
Tamarix invasiveness Fluvial Adjustments

• Islands have become longer and wider
• Channel-side bars have widened
• Some alluvial-fan surfaces have expanded
• Resulted in
• Reduction in channel widths
• Flooding over the bank

Graf, W.L. 1978. Fluvial adjustments to the
spread of tamarisk in the Colorado Plateau
region. Bulletin Geological Society of America
89(10)1491-1501.
19
Phreatophytes

• Plants that are tightly linked to aquifers for
  water uptake.
• Dependent on groundwater (water table and
  capillary fringe) as a moisture source.

Busch, D.E., Ingraham, N.L., and Smith, S.D.
1992. Water uptake in woody riparian
phreatophytes of the southwestern United States
a stable isotope study. Ecological applications
2(4)450-459.
20
Phreatophytes Phreat well phyte plant
Can absorb water deep and release it at or near
the soil surface. The soil surface is where
nutrients are most available.
Waisel, Y, Eshel, A., and Kafkafi, U. 1996. Plant
Roots the hidden half. Marcel Dekker, Inc. New
York, NY
21
Phreatophytes

• Classified on type of water required
• Groundwater water table or capillary fringe
• Moisture from unsaturated soils

Busch, D.E., Ingraham, N.L., and Smith, S.D.
1992. Water uptake in woody riparian
phreatophytes of the southwestern United States
a stable isotope study. Ecological applications
2(4)450-459.
22
Phreatophyte - Definitions

• Obligate - require uninterrupted access to
  saturated soil
• Roots in water table or capillary fringe
• Cottonwood and willow

Turner, R.M. 1974. Quantitative and historical
evidence of vegetation changes along the upper
Gila River, Arizona. USGS Professional Paper
655-(H)1-20.
23
Phreatophyte - Definitions

• Facultative
• able to use water from the water table and
  associated capillary fringe
• able to extract water and survive indefinitely in
  unsaturated soils.
• Tamarix

Everitt, B.L. 1980. Ecology of saltcedar a plea
for research. Environ. Geol. 377-84
24
Facultative Phreatophytes

• Ability to use water from unsaturated soil have a
  greater ability to
• withstand stress tolerance
• increase their nutrient uptake
• soil nutrients are often more abundant above the
  saturated zone

Pinay, G., Fabre, A., Vervier, P., and Gazelle,
F. 1992. Control of C, N, P, distribution in
soils of riparian forests. Landscape Ecol
6121-132.
25
The Vascular System
26
Water Uptake of Saltcedar
Straight ascent turning into ring ascent

• Waisel, Y., Liphschitz, N., and Kuller, Z. 1972.
  Patterns of water movement in trees and shrubs.
  Ecology 53(3)520-523.

27
Phreatophytes

• Have roots that extend down to the water table or
  other periodically stable water supply
• Roots can extend to a depth of 53 meters

Waisel, Y, Eshel, A., and Kafkafi, U. 1996. Plant
Roots the hidden half. Marcel Dekker, Inc. New
York, NY
28
Tamarix

• The genus is generally characterized by a deep
  and intensively branched root system.
• Adventitious roots develop from the lenticels.

Ginzburg, C. 1967. Organization of the
adventitious root apex in Tamarix aphylla. Amer.
J. Bot 54(1)4-8.
29
Root Development

• Salix
• root elongation rates are slow
• emphasis on lateral root growth
• helps protect against late season flood scour
• Tamarix
• Greater root elongation rate
• Allows seedlings to persist in dry soils while
  Salix seedlings die

Horton, J.L., and Clark, J.L. 2001. Water table
decline alters growth and survival of Salix
gooddingii and Tamarix chinensis seedlings.
Forest Ecology and Management 140239-247.
30
Root Development

• Populus seedlings 0.6 1.3 cm/day
• 72-162 cm by end of first season
• Salix seedlings 1.0 2.1 cm/day

Horton, J.L., and Clark, J.L. 2001. Water table
decline alters growth and survival of Salix
gooddingii and Tamarix chinensis seedlings.
Forest Ecology and Management 140239-247.
31
Saltcedar

• Reputation as the heaviest water user of all the
  phreatophytes

Gay, L.W., Sammis, T.W., and Ben-Asher, J. 1976.
An energy budget analysis of evapotranspiration
from saltcedar. Hydrology and water resources in
Arizona and the southwest 7133-139.
32
Water Use by Saltcedar

• Able to desiccate floodplains and lower water
  tables

Blackburn, W.H., Knight, R.W., and Schuster, J.L.
1982. Saltcedar influence on sedimentation in the
Brazos River. J. Soil. Water. Conserv. 37 298-301
33
Saltcedar

• T. chinensis with adequate water transpires
  copiously
• Rates are similar to other phreatophytes in same
  area

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
34
Transpiration

• Exchange of water vapor between the plant canopy
  and the atmosphere
• depends upon air and leaf temperatures
• atmospheric humidity
• aerodynamic or boundary layer resistance
• leaf diffusive (stomata) resistance

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
35
Transpiration of Saltcedar

• Stomata respond to temperature, humidity, and
  light intensity

Gas exchange Vapor release
36
Transpiration of Saltcedar

• 20o C (68o F) and 45 RH
• saltcedar twigs transpire a weight of water
  greater than their own fresh leaf weight each
  hour.
• Similar rate to common herbaceous plants
• Not unusually high where compared with other
  plants with an abundant water supply.

Anderson, J.E. 1977. Transpiration and
Photosynthesis in saltcedar. Hydrology and
water resources in Arizona and the Southwest
7125-131.
37
Transpiration Rates

• At 30 C (85 F) and 45 RH
• Populus fremontii and Eleagnus angustifolia
  practically identical to saltcedar Tamarix
  chinensis.

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
38
Transpiration

• Tamarix is more drought tolerant than Salix
• Salix transpires more water per unit leaf surface
  area and is less tolerant of seasonal water
  stress than Tamarix

Cleverly, J.R., Smith, S.D., Sala, A., and
Devitt, D.A. 1997. Invasive capacity of Tamarix
ramosissima in a Mojave Desert floodplain the
role of drought. Oecologia 11112-18.
39
Saltcedar Flooding

• Inundation for 36 months results in 99 plant
  kill whether the trees were partially or entirely
  submerged.
• Inundated trees did not foliate the third growing
  season 24 months of inundation may be adequate

Wiedemann, H.T., and Cross, B.T. 1978.Water
inundation for control of saltcedar along the
periphery of lakes. Proceedings, Southern Weed
Science Society 31229.
40
Photosynthesis in Saltcedar

• Photosynthetic tissue
• Cladophylls
• Cylindrical leaf-like photosynthetic stems
• Bear two sizes of whorled clasping leaves
• scale-like 3 mm in length
• Cauline leaves 8 9 mm long
• Covered with a white salt bloom

Wilkinson, R.E. 1966. Seasonal development of
anatomical structures of saltcedar foliage. Bot.
Gaz. 127(4)231-234.
41
Saltcedar leaf surface has a waxy covering

• Composition and quantity varies seasonal
  differences in temperature and rainfall
• Quantity and composition of waxes on leaves of
  salt cedar is thought to be the basis for
  differences in sensitivity to herbicides

Mayeux, J.S., Jr., Jordan, W.R. 1984. Variation
in amounts of epicuticular wax on leaves of
Prosopis gladulosa. Bot. Gaz. 145(1)26-32.
42
Tamarix Cuticle development
Wilkinson, R.E. 1966. Seasonal development of
anatomical structures of saltcedar foliage. Bot.
Gaz. 127(4)231-234
43
Tamarix Cuticle development
Wilkinson, R.E. 1966. Seasonal development of
anatomical structures of saltcedar foliage. Bot.
Gaz. 127(4)231-234
44
Tamarix Cuticle development
In addition, the quantity and composition of wax
on leaf surfaces of tamarisk varies during the
season
Wilkinson, R.E. 1966. Seasonal development of
anatomical structures of saltcedar foliage. Bot.
Gaz. 127(4)231-234
45
Tamarix Cuticle development
Wilkinson, R.E. 1966. Seasonal development of
anatomical structures of saltcedar foliage. Bot.
Gaz. 127(4)231-234
46
Photosynthesis

• optimum leaf temperatures for photosynthesis
  between 23 and 28 C (73 82 F)
• at 35 C (95 F) photosynthesis reduced about 20

Anderson, J.E. 1977. Transpiration and
Photosynthesis in saltcedar. Hydrology and
water resources in Arizona and the Southwest
7125-131.
47
Photosynthesis

• net photosythetic rate
• transpiration rate

Anderson, J.E. 1977. Transpiration and
Photosynthesis in saltcedar. Hydrology and
water resources in Arizona and the Southwest
7125-131.
48
PhotosynthesisOptimum temperature 23 - 28 C (73
82 F)

• Photosynthesis is optimum in early part of day
• Time with lower evaporation and transpiration
  demands

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
49
PhotosynthesisObserved optimum temperature23 -
28 C (73 82 F)

• To maximize photosynthesis during hottest
• part of the day would result in much higher
  transpiration losses relative to carbon gains

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
50
Stomata

• Close in response to increasing temperature
• Saltcedar
• insures seedling survival until the root system
  taps water table
• enables plant to invade and succeed in areas
  subjected to periodic drought.

Anderson, J.E. 1977. Transpiration and
Photosynthesis in saltcedar. Hydrology and
water resources in Arizona and the Southwest
7125-131.
51
Photosynthesis Saltcedar

• Light saturated at 44 of full sunlight
• 1100 nEinstein m-2 s-1 at 400 to700 nm
• Rate of photosynthesis is considerably lower than
  the rates for herbaceous plants.

Anderson, J.E. 1977. Transpiration and
Photosynthesis in saltcedar. Hydrology and
water resources in Arizona and the Southwest
7125-131.
52
Photosynthesis

• Light cloud cover reduces irradiation below
  saturation, reducing photosynthesis
• Stomata close to conserve moisture when light is
  limiting to photosynthesis

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
53
Stomata close to conserve moisture when light is
limiting

• Similar conclusion in other studies
• Populus spp.
• Picea engelmanii

Pallardy, S.G., and Kozlowski, T.T. 1979. Stomata
response of Populus clones to light intensity and
vapor pressure deficit. Plant Physi90logy
64112-114..
Kaufman, M.R. 1976. Stomatal response of
Engelmann spruce to humidity, light, and water
stress. Plant Science Letters 3898-901.
54
Stomata and light intensity

• With most plants
• Drop in light intensity
• Stomata close slowly
• Increase in light intensity
• Stomata open rapidly

Woods, D.B., and Turner, N.C. 1971. Stomatal
response to changing light by four tree species
of varying shade tolerance. New Phytologist
7077-84.
55
Stomata and light intensity

• Saltcedar
• Drop in light intensity
• Stomata close rapidly
• Increase in light intensity
• Stomata open slowly
• A mechanism to reduce water loss

Anderson, J.E., 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 63(1)48-56.
56
Water use efficiencyPhotosynthesis vs. water
uptake

• Tamarix has the highest water use efficiency of
  the woody riparian taxa investigated Populus,
  Salix
• Based on carbon isotope research

Busch, D.E., and Smith, S.D. 1995. Mechanisms
associated with decline of woody species in
riparian ecosystems of the southwestern U.S.
Ecological Monographs. 65(3)347-370.
57
Water use efficiencyPhotosynthesis vs.
transpiration

• Tamarix chinensis
• 4.3 mg water/g dry weight of tissue (dwt)
• Populus fremontii
• 6.8 mg/g dwt
• Eleagnus angustifolia
• 6.7 mg/g dwt

Anderson, J.E. 1982. Factors controlling
transpiration and photosynthesis in Tamarix
chinensis Lour. Ecology 6348-56.
58
Water use efficiencyPhotosynthesis vs.
transpiration

• Salix and Tamarix - comparable rates - Mojave
  desert

Cleverly, J.R., Smith, S.D., Sala, A., and
Devitt, D.A. 1997. Invasive capacity of Tamarix
ramosissima in a Mojave Desert floodplain the
role of drought. Oecologia 11112-18.
59
Salt effect on Photosynthesis and Transpiration

• Rates of photosynthetic carbon fixation and
  transpirational water loss changed very little
  with increasing salt treatment
• Reduction in growth with increased salt levels
  were due to increased respiration and/or salt
  pumping

Kleinkopf, G.E., and Wallace, A. 1974.
Physiological basis for salt tolerance in Tamarix
ramosissima. Plant Sci. Ltr. 3157-163.
60
Salts and plant growth

• Excess soluble salts in the soil
• Decrease absorption of essential nutrients
• May have a direct toxic effect
• May increase osmotic gradient and prevent
  adequate water uptake

Hayward, H.E., and Berstein, L. 1958.
Plant-growth relationships on salt-affected
soils. Bot. Rev. 24584-635.
61
Salts and plant growth

• Osmotic effects of soluble salts are the most
  detrimental single factor to vegetation in saline
  areas.

Hayward, H.E., and Wadleigh, C.H. 1949.
Plant-growth relationships on salt-affected
soils. Advances in Agron. 11-38.
62
Salt uptake

• Trees capable of accumulating salts can maintain
  turgor and high leaf conductance as tissue water
  potential declines other plants are required to
  close their stomates to maintain turgor.

Osonubi, O., and Davies, W.J. 1978. Solute
accumulation in leaves and roots of woody plants
subjected to water stress. Oecologia 323223-332.
63
Tamarix survival on saline soils

• maintain high uptake of ions
• a. salt extrusion by salt glands
• b. cellular compartmentation
• c. utilization for osmoregulation

Greenway, H., and Munns, R. 1980. Mechanisms of
salt tolearance in nonhalophytes. Annual Review
of Plant Physiology. 31149-190.
64
Salt glands and epidermal salt hairs

• Function in ion regulation
• salt hairs accumulate ions and excrete them from
  leaves, regulating cellular ionic content

Karimi, S.H., and Ungar, I.A. 1989. Development
of epidermal salt hairs in Atriplex triangularis
willd. in response to salinity, light intensity,
and aeration. Bot. Gaz. 150(1)68-71.
65
Salt Hairs Glands of Halophytes

• Form in early stages of development
• Critical for the salt tolerance of young
  developing halophytes

Karimi, S.H., and Ungar, I.A. 1989. Development
of epidermal salt hairs in Atriplex triangularis
willd. in response to salinity, light intensity,
and aeration. Bot. Gaz. 150(1)68-71.
66
Salt hairs secondary functions

• Reduction of intense illumination
• Insulation against excessive heat to reduce
  transpiration
• Water storage
• Water absorption

Ehleringer, J., and Bjorkman, C.J. 1978. Leaf
hairs effects on physiological activity and
adaptive value to a desert shrub. Oecologia
37183-200.
67
Tamarix Salt Gland
Cuticle
Pore
Secretory Cells
Collecting Cell
Fahn, A. 1988. Tansley Review No. 14. Secretory
tissues in vascular plants. New Phytol
108229-257.
68
Tamarix Salt Gland

• Salts (chlorides) move through the apoplast from
  the xylem to the salt glands
• Cuticle almost completely separates salt glands
  from the mesophyll tissue
• A subcuticular space (collecting chamber/cell)
  between the cuticle and the gland

Campbell, N., and Thomson, W.W. 1975. Chloride
localization in the leaf of Tamarix. Protoplasma
831-14.
69
Tamarix Salt Gland
Numerous mitochrondria
Nuclei
Requires energy
Fahn, A. 1988. Tansley Review No. 14. Secretory
tissues in vascular plants. New Phytol
108229-257.
70
Tamarix Salt Glands

• Young and mature stems and leaves possess
  numerous salt glands

Bosabilidis, A.M., and Thomson, W.W. 1984.
Ultrastructural differentiation of an unusual
structure lining the anticlinal walls of the
inner secretory cells in Tamarix salt glands.
Bot. Gaz. 145(4)427-435.
71
Salt Glands

• Assumed salt glands secrete sodium chloride in
  large quantities
• Sodium chloride secretion has been used
  synonymously with salt secretion

Arisz, W.H. Camphuis, J., Heikens, H. and van
Tooren, A.J. 1955. The secretion of the salt
glands of Imonium latifolium. Acta Bot. Nerr.
4322-338.
72
Sodium in Halophytes

• The level of sodium in halophytes is low
• cytoplasm is largely by-passed by sodium perhaps
  by transport in small vesicles

Hall, J.L. and Flowers, T.J.1973. The effect of
of salt on protein synthesis in the haloophyte
Suaeda maritina. Planta. 110361.
73
Sodium transport in Tamarix

• Most of Na transported to leaves is excreted by
  salt glands
• Na accumulates in large quantities when present
  in high concentration in the nutrient solution
• Na concentration in roots and stems is much lower
  than in leaves

Kleinkopf, G.E., and Wallace, A. 1974.
Physiological basis for salt tolerance in
Tamarisd ramosissima. Plant Sci. Ltr. 3157-163.
74
Tamarix survival on saline soils

• Ions detected in high concentration in leaf
  tissue are also found at high concentrations in
  soil and water
• Secreted ions represent ions in the soil and
  solution

Berry, W.L. 1970. Characteristics of salt
secreted by Tamarix aphylla. American Journal of
Botany 571226-1230.
75
Salt Secretion

• Bicarbonates are excreted in large amounts (60)
  even when not in the soil solution
• metabolically produced requires energy
• Tamarix secretes actively even under low salt
  conditions

Berry, W.L. 1970. Characteristics of salt
secreted by Tamarix aphylla. American Journal of
Botany 571226-1230.
76
Physiology

• a branch of biology that deals with the functions
  and activities of life or of living matter (as
  organs, tissues, or cells) and of the physical
  and chemical phenomena involved
• the organic processes and phenomena of an
  organism or any of its parts or of a particular
  bodily process

Merriam-Webster Collegiate Dictionary
http//m-w.com/cgi-bin/dictionary
77
Tamarix Physiology

• An effective invader of riparian areas
• Successful competitor with native species
• Thank you!