Plant Selection, Installation, and Management to Affect Groundwater - Introduction to Phytoremediation of Contaminated Groundwater - page 163

considerable amount of time to produce any benefit for
groundwater control. As a testament to its growth habit, it
has been called the graveyard tree because if it is planted
when a person is born, by the time it has reached its full
height of 40-50 ft (12-15.2 m) the person usually has
reached full maturity and may be nearing death.

Table 7.3 Representative woody phreatophytes native to the eastern
United States that may have phytoremediation potential and range of
transpiration rates (Modified from the Virginia Natural Heritage Pro-
gram and Interstate Technology Regulatory Council (2009)).
Common name Scientific name Range of

transpiration
(mm/day)

Canada service berry Amelanchier

Canadensis

-

7.1.3 Natural Plant and Groundwater
Interactions as an Analogy to Plant
Selection

Silky dogwood Cornus amomum -

Sweetbay magnolia Magnolia virginiana -

Redbay Persea borbonia -

Willow Salix spp 2.0-50

Red maple Acer rubrum -

The relation of plant distribution to the occurrence and depth
of groundwater in the arid United States was introduced in
Chap. 1. For example, cacti are more likely to be found in
well-drained, nutrient-poor soils; weeping willows are more
likely to be found near lakes, streams, and rivers than at the
tops of mountains; and conifers are likely to be found in
cooler, drier areas. These observations between plant distri-
bution and water source were later confirmed to be true in
humid areas using geochemical techniques, such as the sta-
ble isotopes of water.
Based on the process of natural selection, the distribution
of plants is the result of a particular plant species being best
suited to inhabit the environmental conditions provided by
that niche; in other words, the prevailing plant has properties
that provide it with a selective advantage against competing
plants. This is especially true for plant survival and repro-
duction under natural, non-agricultural conditions, where
plant distribution primarily is a function of seed-germination
characteristics.

River birch Betula nigra 9.1-15

Atlantic white cedar Chamaecyparis thyoides -

Sweet gum Liquidambar styraciflua -

Water tupelo Nyssa aquatic -

Pond pine Pinus serotina -

Loblolly pine Pinus taeda 6.5-12

Longleaf pine Pinus palustris -

Sycamore Plantus occidentalis -

Swamp white oak Quercus bicolor -

Swamp laurel oak Quercus laurifolia -

Swamp chestnut oak Quercus michauxii -

Pin oak Quercus palustris -

Willow oak Quercus phellos -

Taxodium distichum

Baldcypress 11-18

White cedar Thuja occidentalis -

Poplar Populus heterophylla 13-200

Populus deltoides

- none reported
Note: Caution is advised with the application of some of these trees at
potential phytoremediation sites, especially those trees that produce
acorns or other seeds that may be used by wildlife or human
populations

7.1.4 Plant Succession

United States, from Canada to Florida. In fact, Cedar Key,
Florida is named for the abundance of Eastern red cedar that
used to grow there. There are no cedars there currently
because a pencil factory had been constructed there,
depleted the eastern red cedar, and had to shut down after
all the trees had been harvested. It also explains why the
Eastern red cedar is sometimes referred to as the pencil tree.
This evergreen tree prefers moist, well-drained soils and is
often found growing near springs in limestone terrain.
Because of its small size and use of deeper sources of soil
moisture and groundwater, the Eastern red cedar may be a
perfect candidate for installation at sites to address concerns
of the lack of groundwater uptake by plants during the winter
when poplars and willows go dormant; this issue of dor-
mancy with respect to phytoremediation and alternatives are
discussed in Chaps. 10 and 16. The Eastern red cedar has a
drawback for phytoremediation projects, however, in that it
has a slow to moderate growth rate, such that it may take a

The environment is always in a state of change. Some
changes are more obvious than others. For example, the
seasonal change in color of deciduous trees in the
northern hemisphere occurs because of shorter days, lower
light levels, decreased water availability, and cooler
temperatures. The period over which these changes occur
is variable and is a function of tree species; typically, how-
ever, change occurs over a few weeks.
Other changes take much longer to observe. One such
example is called succession. If an area of land becomes
barren by fire or clear cutting and is left alone, a predictable
pattern of colonization by plants can be observed (Ricklefs
1979). The plants that typically invade such barren or dis-
turbed areas are annual herbaceous plants from seeds that
entered the soil after deposition by wind, water, or animal
action. These plants tend to become established first because
of rapid germination, fast growth, and high seed production
and are classified by ecologists as r-specialists. The source of