About
coneflowers....
The smooth purple coneflower (Echinacea
laevigata) is a perennial herb that grows up to 1.5
meters tall. Each plant produces one or more clusters of
basal leaves from a stout rootstock. These leaves may reach
20 cm in length, although those on young plants are smaller.
Leaves generally emerge in March and die in the fall. Flowering
plants produce a smooth stem with a few smaller leaves and
a single flower in May or June. In sunny habitats, plants
may produce a second flower in late summer. The petal-like
rays of the flower are light pink to purplish, usually drooping,
and 5-8 cm long.
Typical coneflower habitat is open woods,
cedar barrens, roadsides, clearcuts, dry limestone bluffs,
and power line rights-of-way, usually on magnesium- and
calcium-rich soils. Optimal sites have abundant sunlight
and little competition in the herbaceous layer. Natural
fires, as well as large herbivores, are part of the history
of the vegetation in this species’ range; coneflowers
are dependent upon periodic disturbances to reduce the shade
and competition from woody plants.
The reported historical range of the smooth
purple cone-flower included Pennsylvania, Maryland, Virginia,
North and South Carolina, Georgia, Alabama, and Arkansas.
The species now is known to survive only in Virginia, North
and South Carolina, and Georgia. Of the seven populations
known from South Carolina, two are located on the Department
of Energy’s Savannah River Site (SRS), one on Burma
Road and the other in a power line right-of-way along Road
B-9. Echinacea laevigata was listed as federally
endangered on October 8, 1992 and also is listed as a sensitive
species by the U.S. Forest Service; it is the only known
federally endangered plant on the SRS. These designations
require that DOE avoid actions with deleterious impacts
to the populations.
The Savannah River Ecology Laboratory (SREL)
and the USFS Savannah River Institute (SRI) have been collaborating
for several years to develop methods to maintain population
viability of the smooth purple coneflower on the SRS. Both
populations are exposed to threats such as power line maintenance
activities and accidental herbicide application. Collaborative
research also tests management activities, including forest
thinning and burning, that might improve coneflower habitat.
Management
of the smooth purple coneflower on the SRS....
The objectives of endangered species management
go beyond protection of existing populations. Management
can improve habitat quality and encourage population expansion,
with the ultimate goal of achieving a natural, self-sustaining
coneflower population. Future management of SRS coneflower
populations is guided by these goals. Past management of
the two SRS smooth purple coneflower populations focused
on protection of the immediate area surrounding each population.
Over time, complete protection of these areas from most
management activities has led to slight degradation
of habitat quality and no obvious increase in population
size at one site.
SRI now will take a more proactive approach
to smooth purple coneflower management on the SRS. A management
plan has been drafted and is pending approval by site managers
and the U.S. Fish and Wildlife 
Service.
If approved, future management will include expanding both
of the areas being managed for coneflower habitat to allow
populations to expand without impacts from other land uses.
These areas will become open, fire-maintained woodland savanna
settings with enhanced plant diversity and fewer, but larger
trees. Such habitat, thought to have once been commonplace
throughout the Coastal Plain, is highly suited for the smooth
purple coneflower. Smaller trees will be hand-removed to
create sunny-to-partially sunny conditions on the forest
floor. Controlled fires will be set at regular intervals
to reduce the establishment of competing plants and encourage
smooth purple coneflower flowering and seedling establishment.
Changes in habitat quality and coneflower population size
will be monitored to determine response to the management
strategies.
Future management may also include the establishment
of a research coneflower population from SRS seed sources.
This research population will further improve the status
of the smooth purple coneflower on the SRS and provide opportunities
for study of the species’ biology and its habitat.
Such opportunities will include manipulative studies and
activities that could not be performed on naturally existing
federally protected populations.
Research....
SREL has been monitoring the two SRS populations
of smooth coneflower since 1988 (Burma Road) and 1994 (Road
B-9). Associated research is investigating population biology,
including pollination biology and genetics, and response
to experimental burning and overstory thinning to provide
a baseline for assessing response to disturbance or management
activities. SREL research collaborates with and complements
SRI programs for rare and endangered species. In collaboration
with the Coneflower Man-agement Plan being pre-pared by
SRI, SREL will monitor the effects of alternative management
practices on the research coneflower population.
Population
status and research results....
- Echinacea seedlings and small
plants were observed in early summer 1998 at the Burma
Road location. This was the first time in recent years
that new individuals were documented.
- The Burma Road coneflower population
fluctuates, with the number of individuals varying from
146 plants in 1995, to 150 in 1996, 137 in 1997, and 156
plants in 1998. All of these recent counts indicate
fewer plants are now present than the approximately 250
plants documented in this population in the late 1980’s.
- The Burma Road population has declined
because plants are dying, but very few new plants are
establishing. Recruitment varied from no new plants in
most years, to 1 new plant in 1991 and 1993, 4 new plants
in 1989, and 5 new plants in 1992. Mortality of established
plants varied between 7 and 38 plants per year.
- The Road B-9 coneflower population,
when first discovered in 1994, was documented to contain
600 plants and 740 stems. The 1995 census of this population
included 609 plants and 851 stems; the 1998 census included
655 plants and 1,492 stems.
- In th Road B-9 population, Echinacea
flowers in the open received more visits from potential
pollinators, including butterflies, honeybees, and bumblebees,
than did plants in the shade. Management strategies
that maintain a more open canopy may promote cross pollination
and help maintain genetic diversity.
- Along the geographical range from Georgia
to Virginia, nearby Echinacea populations are more
similar genetically to one another than they are to more
distant populations. The Burma Road population on the
SRS is slightly different genetically from all other populations.
- Past management treatments (limited to
minimal experimental burning and overstory thinning) have
had little effect on the population dynamics of the Burma
Road population. Treatments proposed in the new management
plan will provide further information on whether such
treatments result in cumulative beneficial effects.
The Smooth Purple
Coneflower on the SRS 
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