HomeMy WebLinkAbout20070812 Ver 1_11 Feb 2005 Invasive Exotic Plant Pest Species Draft Report (2)_20080502Yadkin Project
FERC No. 2197
INVASIVE EXOTIC PLANT PEST (IEPP)
SPECIES
DRAFT STUD YREPORT
FEBRUARY 2005
YADKIN PROJECT
FERC No. 2197
INVASIVE EXOTIC PLANT PEST (IEPP)
SPECIES
DRAFT STUDYREPORT
Prepared for
ALCOA POWER GENERATING INC.
Yadkin Division
293 NC 740 Highway
Badin, NC 28009-0576
Prepared by
NORMANDEAU ASSOCIATES, INC.
25 Nashua Road
Bedford, NH 03110
R-19556.002
February 2005
Invasive Exotic Plant Pest Species
Draft
Table of Contents
Page
SUMMARY ........................................................................................................................................ iv
1.0 INTRODUCTION ....................................................................................................................1
2.0 BACKGROUND ......................................................................................................................1
3.0 STUDY AREA ..........................................................................................................................1
4.0 STUDY PURPOSE AND OBJECTIVES ..............................................................................3
5.0 STUDY METHODS .................................................................................................................3
5.1 METHODS FOR DEVELOPMENT OF INVASIVE EXOTIC PLANT PEST SPECIES LIST ............ 3
5.2 PLAN AND SCHEDULE FOR CONDUCTING IEPP FIELD STUDIES .......................................8
5.3 FIELD SURVEYS ................................................................................................................8
6.0 SUMMARY OF EXISTING STUDIES AND INFORMATION ON THE
PROJECT AREA ...................................................................................................................11
7.0 RESULTS OF FIELD SEARCHES .....................................................................................11
8.0 EFFECTS OF PROJECT OPERATIONS AND FACILITIES ON IEPP
SPECIES .................................................................................................................................15
9.0 CONCLUSIONS ....................................................................................................................16
10.0 REFERENCES CITED .........................................................................................................16
APPENDIX A: List of rare threatened and endangered species for Yadkin Project search
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List of Figures
Page
Figure 1. Locus of Yadkin Project ................................................................................................ ........2
Figure 2. High Rock Reservoir dam facility ................................................................................ ........ 4
Figure 3. Tuckertown Reservoir dam facility .............................................................................. ........ 5
Figure 4. Narrows Reservoir dam facility .................................................................................... ........ 6
Figure 5. Falls Reservoir dam facility .......................................................................................... ........ 7
Figure 6. Invasive Exotic Plant Pest (IEPP) occurrence, 2004. Dark-pink areas represent
general locations of observed aquatic beds, with associated IEPP species
identified wherever found. Light-pink areas represent locations relatively
vulnerable to future IEPP invasions, should reservoir management practices
change to benefit aquatic IEPPs .................................................................................... ......13
List of Tables
Page
Table 1. List of Invasive Exotic Plant Pests potentially occurring in the Yadkin Project
Area ........................................................................................................................................ 9
Table 2. IEPP species observed within Yadkin Project Area ...........................................................12
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Invasive Exotic Plant Pest Species Draft
SUMMARY
The Invasive Exotic Plant Species Assessment Report presents the results of a survey of invasive
exotic plant pests (IEPPs) found within the Yadkin Project area. The study was conducted by
Normandeau Associates, Inc. (NAI) as part of the FERC relicensing process for the Yadkin Project
The study was conducted in accordance with the Final Study Plan that was developed by Yadkin in
consultation with the Wetlands, Wildlife and Botanical Issue Advisory Group (IAG). Specific
objectives identified in the Final Study Plan included:
¦ Identify potential impact areas within the Project area and inventory for the presence of IEPP
species.
¦ Evaluate the current status of known aquatic IEPPs.
¦ Evaluate potential impacts of IEPPs on natural communities in areas of concern.
Invasive exotic plant pests are plant species that are of long term management concern to resource
agencies and others. IEPPs are non-native plants that were introduced to this country over the years,
and possess characteristics or growth habits that allow them to out-compete native vegetation or
occupy new habitats. IEPPs are ubiquitous to developed areas of the United States, and the Yadkin
Project area is no exception. Common examples of IEPPs include Japanese honeysuckle and kudzu.
IEPPs are of concern in areas where they have the potential to threaten rare plant species or native
vegetation that provides important habitat for wildlife.
The focus of this study was to survey the Project area for IEPPs that pose a threat to rare plant species
or important wildlife habitats at the Yadkin Project. At the outset of the study, a list of IEPPs that
were considered likely to occur in the Project area and would be the focus of the inventory, was
developed and approved by the Wetlands, Wildlife & Botanical IAG. In total, 32 IEPPs, including
both aquatic and terrestrial plants, were included on the initial IEPP search list. Field searches for
IEPPs were conducted by NAI during the spring, summer and fall of 2003.
Results of the field surveys found 20 species of IEPPs in the Yadkin Project area, including 3 aquatic
species and 14 terrestrial species that had been included on the original search list. In addition, NAI
found 3 other terrestrial IEPP species in the Project area that were not included on the original search
list. Among the aquatic IEPP species located, only one, a small population of Hydrilla found on
Tuckertown, was of any concern. NAI concluded that this Hydrilla population "bears watching" to
see if the population is expanding or stable. Two aquatic IEPP species that were previously reported
to occur in one or more of the Project reservoirs, variable-leaf milfoil and Brazilian elodea were never
found during the 2004 surveys.
Among the terrestrial IEPP species found in the Project area, only one Lonicera X Bella (bush
honeysuckle), was determined to be of immediate management concern. On the Falls Reservoir
shoreline, this species was found growing in close associated with two RTE species, piedmont indigo-
bush (Amorpha schwerinii) and thick-pod white wild indigo (Baptisia alba). At this site, an area
commonly referred to as the "Yadkin River Scour Banks", the bush honeysuckle occupied most of the
available space that appeared to provide suitable habitat for the two RTE species.
Many IEPP species appear to be irreversibly incorporated in their respective plant communities. In
most cases, attempts to eliminate or control them would be infeasible. Direct intervention may be
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Invasive Exotic Plant Pest Species
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justified in only one instance, to improve the survival prospects of the RTE species Baptisia alba.
Nevertheless, aquatic IEPP do have the potential to take hold at any time, particularly in response to
any change in reservoir operation. Therefore, periodic monitoring of aquatic IEPPs, in order to
identify and evaluate future management problems and practical strategies for solving them, should
be considered.
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1.0 INTRODUCTION
Alcoa Power Generating Inc. (APGI) is applying to the Federal Energy Regulatory Commission for a
new license for the Yadkin Project. The Project consists of four reservoirs, dams, and powerhouses
(High Rock, Tuckertown, Narrows, and Falls) located on a 38-mile stretch of the Yadkin River in
central North Carolina (Figure 1). The Project generates electricity to support the power needs of
Alcoa's Badin Works and its other aluminum operations, or is sold on the open market.
The presence of invasive exotic plant pest (IEPP) species in the Project area and their potential
impacts on natural terrestrial and aquatic plant communities is of concern to natural resource
agencies. The focus of this study was on areas of concern including Uwharrie National Forest (UNF),
Morrow Mountain State Park and Shoreline Management Plan (SMP) Conservation Zones (including
islands), and on areas with impact potential on Narrows Reservoir.
2.0 BACKGROUND
As part of the relicensing process, APGI prepared and distributed, in September 2002, an Initial
Consultation Document (ICD), which provides a general overview of the Project. Agencies,
municipalities, non-governmental organizations and members of the public were given an opportunity
to review the ICD and identify information and studies that were needed to address relicensing issues.
To further assist in the identification of issues and study needs, APGI formed Issue Advisory Groups
(IAG) to advise APGI on resource issues throughout the relicensing process. Through meetings,
reviews and comments, the IAGs assisted in developing the Study Plans for the various resource
issues, and will further review and comment on the findings resulting from the implementation of the
study plans. The Wetlands, Wildlife and Botanical JAG was interested in the presence of IEPP
species in the Project area, their potential impacts on natural terrestrial and aquatic plant communities
in areas of concern under existing conditions, and in assessing how these species could be affected by
existing Project operations. Any changes that may occur as a result of altered Project operations, if
proposed, were assessed. This report presents the findings of the IEPP Species studies, following
implementation of the Final Study Plan, dated June 2003.
3.0 STUDY AREA
The IEPP Study Area encompassed all four reservoirs under APGI management: High Rock,
Tuckertown, Narrows, and Falls. Upstream Project limits extended up the Yadkin River to the Project
limits defined by the 623.9-foot water level elevation (local datum). This point is approximately 1
mile north of Boone's Cave State Park. On the South Branch of the Yadkin, the Project limits were
defined by the same water level elevation, which occurred approximately 6 miles from its confluence
with the Yadkin River. The downstream Project limits extended approximately 0.5 miles below Falls
Dam, which was estimated to be the maximum extent of riverine flow in the Falls dam tailrace during
low water on Tillery Reservoir. All wetlands and riparian habitats within the zone of influence of
reservoir operations were included in the study area, as well as all lands within 200 feet of the
shoreline.
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Figure 1. Locus of Yadkin Project.
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IEPP surveys were also performed on the Falls and Narrows transmission corridors and Project land
within the vicinity of the four dams and powerhouses. The combined length of the two transmission
corridors is approximately 4.6 miles. The survey included the maintained corridor plus an additional
area extending 50 feet from either side. The land and facilities in the immediate area of the four dams,
including parking lots and access roads were also included (Figures 2-5).
4.0 STUDY PURPOSE AND OBJECTIVES
Over a series of meetings the Wetlands, Wildlife and Botanical JAG discussed objectives for IEPP
species study. Over the course of those discussions the following objectives were identified for the
study.
¦ Identify potential impact areas within the Project area and inventory for presence of IEPP
species.
¦ Evaluate the current status of known aquatic IEPPs.
¦ Evaluate potential impacts of IEPPs on natural communities in areas of concern.
5.0 STUDY METHODS
5.1 METHODS FOR DEVELOPMENT OF INVASIVE EXOTIC PLANT PEST SPECIES
LIST
A preliminary list of invasive exotic plant pest (IEPP) species was compiled from lists produced by
five sources: North Carolina Aquatic Weed Control Program (NCDACS 2003a); North Carolina
Department of Agriculture Noxious Weeds List (NCDA 2003b); North Carolina State University
Aquatic Weed Management Program (NCSU 2003); the Southeast Exotic Pest Plant Council (USDA
Forest Service 2001); and the USDA Forest Service Regional Invasive Exotic Plant Species List
(Miller et al. 2003). These species were divided into two groups, Aquatic and Terrestrial. Because
the Terrestrial species are commonly abundant in several habitat types, and because they are only
minimally affected by reservoir operations, these species were noted as they appeared in the field but
were not individually investigated.
The Aquatic species were divided into two groups via the assistance of Dr. Alan Weakley (UNC
Herbarium Curator), who has performed botanical surveys along the Yadkin Project, and recently
completed an invasives inventory for the Uwharrie National Forest (S. Sharp, 2004). Dr. Weakley
was recommended as the most appropriate reviewer for invasive plants by the other two botanists
who contributed to the development of the rare, threatened and endangered species list (Dr. Mom
Bates, Dr. Pete Diamond), and by Shannon Sharp, USFS botanist at the Uwharrie. Dr. Weakley
noted those species that are present, questionable, unknown or unlikely to occur within the Project
boundaries. Normandeau then ranked the species according to their likelihood of being influenced by
changes in Project operations. The following categories were used:
Primary Aquatic- aquatic species that are currently present, or their status is unknown but
potentially could occur;
Secondary Aquatic - aquatic species not known or unlikely to occur in the Project boundaries; and
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Invasive Exotic Plant Pest Species
HIGH ROCK
POWERHOUSE
HIGH ROCK
RESERVOIR
Normal Full Reservoir Elevation 623.9 ft
1
1
1
1
1 ?
Survey of 50' swath
outside of development
HIGH ROCK
DAM
Draft
1
1
Survey of 50' swath
loutside of development
1
TUCKERTOWN
RESERVOIR
Normal Full Reservoir Elevation 564.7 ft \
----- Full Pond Field Survey Areas Around High Rock
FERC Project Boundary Dam and Powerhouse
Roads
Fence Yadkin Project
- - - - 50' Perimeter
H-H+ Railroad Tracks
® Land impacted by 0 50 100 150 250 a
Dam Facilities ennngww?
Figure 2. High Rock Reservoir dam facility.
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1
\ Survey of 50'smth
outside of development
TUCKERTOWN RESERVOIR
Normal Full Reservoir Elevation 564.7 ft
This area inspected
visually from footpath
TUCKERTOWN TUCKERTOWN
POWERHOUSE
DAM . /
j NARROWS RESERVOIR
Normal Full Reservoir Elevation 509.8 ft
Survey of 50'swath
beyond dam sWCtures
----- Full Pond Field Survey Areas Around Tuckertown
FERC Project Boundary Dam and Powerhouse
Roads
Fence Yadkin Project
}}{-?? Railroad Tracks
- - - - 50' Perimeter a 75 150 225 375 H
® Land Impacted by
Dam Facilities
Figure 3. Tuckertown Reservoir dam facility.
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NARROWS RESERVOIR
Normal Full Reservoir Elevation 509.8 it
Visual inspection
from East end of d
NARROWS DAM
Survey of 50'swath \
outside of development
NARROWS
POWERHOUSE
/ Survey of bo
horelines b
/ t
NARROWS TRANSMISSION \
LINE CORRIDOR
\ l
o \ ll I
FALLS RESERVOI
rrnal Full Reservoir E evgtio 332.8 It
/ I
I (/ 1 \
/ I
/ I
O 1 j
O I - l
O
---- Full Pond Field Survey Areas Around Narrows
FERC Project Boundary Dam and Powerhouse
Roads Yadkin Project
--?-- Fence
- - - - 50' Perimeter
® Land Impacted by 0 100 200 400rt
Dam Facilities
Figure 4. Narrows Reservoir dam facility.
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FALLS DAM ??-
FALLS RESERVOIR c`
Normal Full Reservoir Elevation 332.8 ft
Survey of both
shorelines by boat
FALLS POWERHOUSE \ r
J
FALLS TRANSMISSION
LINE CORRIDOR /
j TILLERY
` RESERVOIR
?J
,
----- Full Pond Field Survey Areas Around Falls Dam
FERC Project Boundary and Powerhouse
Roads
-x- Fence Yadkin Project
---- 50' Perimeter
® Land Impacted by o W 100 ieo 250 n
Dam Facilities ITTTTSE?
Figure 5. Falls Reservoir dam facility.
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Invasive Exotic Plant Pest Species Draft
Secondary Terrestrial - terrestrial species that are likely to occur within the Project Area, but do not
typically occur within the full pond of the reservoirs.
The Preliminary IEPP list was distributed at the February 8, 2004 Wetlands, Wildlife and Botanical
Interagency Advisory Group meeting. It contained 7 Priority Aquatic species, 7 Secondary Aquatic
species and 18 Secondary Terrestrial species. No additional modifications were made following that
meeting, thus the list became final (Table 1).
5.2 PLAN AND SCHEDULE FOR CONDUCTING IEPP FIELD STUDIES
Two brief field surveys were performed in the Fall 2003 to look at emergent vegetation in High Rock
Reservoir and to perform some preliminary ground truthing. Three extended field surveys were
planned and undertaken during 2004. Each coincided with a different field season (spring, summer
and fall) and lasted 10, 9, and 13.5 days, respectively. Three NAI senior biologists participated for a
total of 55 person-days. For 2, 3 and 3 days respectively during each field season, they were joined
by a local botanist, Dr. Peter Diamond from the North Carolina Zoological Park in Asheboro.
Scheduling of the field surveys throughout the growing season ensured that all plant species on the
IEPP search list could be encountered, if present, in a reasonably detectable and identifiable condition
during at least one life-history stage. The search for IEPP species was only one component of the
work being performed during the field studies, along with rare, threatened and endangered species
and ground-truthing the vegetation cover type maps. However, during all types of surveys, data on
invasive species were collected when they were encountered. Most the entire shoreline of the Project
Area was visited one or more times in the course of 2003-2004 field work.
5.3 FIELD SURVEYS
Aquatic plants (submergent, floating, and emergent) formed the basis of the IEPP field survey, since
they were the species expected to undergo the direct impacts of any reservoir water-level
management change. The choice of search locations for aquatic IEPP species observed the following
criteria:
¦ Shallow bottoms (to 10 vertical feet below full-pool elevation, depending on water clarity).
¦ The slack water of creek mouths and embayments with low current and wave energy.
¦ Water bodies with presumed or observed high dissolved nutrient concentrations.
Other plant communities received attention commensurate with the degree to which human
disturbance appeared to be a factor, because of the frequent association of invasives with human
activity. Therefore, the immediate vicinity of dam facilities, power transmission lines and
transportation corridors became central to the relatively terrestrial component of the IEPP survey.
Incidental observations of IEPP occurrence were also made in the course of all study components.
Residential and commercial areas were not surveyed because of the frequent use of exotic plant
species in landscaping and gardens.
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Table 1. List of Invasive Exotic Plant Pests potentially occurring in the Yadkin Project Area.
Scientific Name Common Name Life Form Source State Fed Occurrence
Primary - Aquatic
Egeria densa Brazilian elodea SAV* 2, 5, 6 undocumented report
Hydrilla verticillata Hydrilla SAV 1, 2, 3,5, 6 Class A Y undocumented report
Ludwigia hexapetala/uruguayensis Uruguay waterprimrose SAV 2, 3, 5 Class B may be present
Myriophyllum aquaticum Parrotfeather SAV 1,2, 5 may be present
Myriophyllum heterophyllum Variable-leaf milfoil SAV 2,5 undocumented report
Myriophyllum spicatum Eurasian watermilfoil SAV 1, 2, 3, 5, 6 Class B may be present
Najas minor Brittle naiad SAV 2,5 may be present
Secondary - Aquatic
Alternanthera philoxeroides Alligatorweed SAV 1, 2, 5, 6 unlikely in the area
Azolla pinnata Feathered waterfern SAV 2, 3, 5 Class A Y not known anywhere in the vicinity
Crassula helmsil Swamp stonecrop SAV/emer 3,5 Class A not known anywhere in the vicinity
Lagarosiphon major African elodea SAV 3,5 Class A Y not known anywhere in the vicinity
Polygonum perfoliatum Mile-A-Minute Emergent 3, 5, 6** Class A not known anywhere in the vicinity
Salvinia molesta Giant salvinia/ water fern SAV 1, 2, 3, 5, 6 Class A Y not known anywhere in the vicinity
Trapa natans Water chestnut SAV 3,5 Class A not known anywhere in the vicinity
Secondary - Terrestrial
Ailanthus altissima Tree of Heaven Tree 5, 6,7,8,9,10 definitely present
Albizia julibrissin Mimosa Tree 4, 5, 6 definitely present along shorelines
Arthraxon hispidus Small carpgrass/hairy jointgrass Grass 5,6 definitely present
Elaeagnus umbellata Autumn/Russian olive Tree 5, 6,7,8,9,10 definitely present
Lespedeza bicolor Bicolor lespedeza Shrub 4,5 definitely present
Lespedeza cuneata Chinese lespedeza Grass 5, 6,8,9,10 definitely present
Ligustrum japonicum Japanese privet Shrub 4, 5, 6 may be present
Ligustrum sinense Chinese privet Shrub 4, 5, 6 definitely present
Lonicera japonica Japanese honeysuckle Vine 4, 5, 6 definitely present
Lonicera spp (morrowii, Bella, tartarica) Bush honeysuckle Shrub 5, 6, 7 definitely present
Melia azedarach Chinaberry Tree 4, 5, 6 definitely present along shorelines
Microstegium vimineum Nepalese browntop Grass 5,6,8,9,10 definitely present
Miscanthus sinensis Chinese silvergrass Grass 5,6,8,9 definitely present
Pueraria montana Kudzu Vine 4, 5, 6 definitely present
Rosa multiflora Multiflora rose Shrub 4, 5, 6 definitely present
Sapium sebiferum Chinese tallowtree Tree 4,6 not known anywhere in the vicinity
Vinca minor Common periwinkle Forb 5,7,8,10 definitely present
Wisteria sinensis Chinese wisteria Vine 4, 5, 6 definitely present
O
(continued)
Fn Table 1. (Continued)
° Notes
v
Class A, any noxious weed on the Federal list or is not native to the State and poses a serious threat
Class B, any noxious weed not native to the State, is of limited distribution statewide and poses a serious threat
0
1 = NC Aquatic Weed Control Program
0 2 = NCSU Aquatic Weed Management
3 = NCDA Noxious Weeds List
4 = Invasive Plants in Southern States, as occurring in NC
5 = Dr. Alan Weakley, UNC Herbarium Curator, Chapel Hill
6 = USDA Forest Service Southern Region
7= Tennessee
8 = Kentucky
9 = Georgia
10 = Virginia
* Submerged aquatic vegetation
* * Not listed as occurring in NC
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Invasive Exotic Plant Pest Species Draft
It had been the hope that toward the end of the 2004 growing season, with plant biomass at or near its
peak, falling reservoir water levels would have exposed emergents and aquatic beds sufficiently to
facilitate the description of these plant communities by their extent and species composition. Instead,
the passage of two successive tropical storms through the Project Area kept reservoir water at or near
full-pool elevation, with high turbidity, during the Fall Project-Area inspection. Aquatic beds had to
be sampled primarily by scraping the bottom and grappling water-column growth with a 10-foot-long
extensible rake. Some of the shorter species components of the emergent plant community were
inundated in a mature, inflorescent state. The degree to which an aquatic invasive like Hydrilla
verticillata constituted a current threat to its native counterparts had to be deduced by its frequency of
appearance and relative abundance in rake-head samples. Qualitative assessment of the relatively
terrestrial IEPPs was effected by field notes and photographs.
6.0 SUMMARY OF EXISTING STUDIES AND INFORMATION ON THE
PROJECT AREA
Invasive exotic plants have been listed for the southeastern USA (USDA Forest Service 2001, Miller
et al. 2003). The same exercise has been performed for the State of North Carolina (North Carolina
Department of Agriculture and Consumer Services 2003a, 2003b; North Carolina State University
Aquatic Weed Management Program 2003). Additional Project-specific information on invasives
was garnered during discussions in the JAG meetings with individuals familiar with the reservoirs,
and Yadkin personnel (R.Smet 2004).
7.0 RESULTS OF FIELD SEARCHES
Observations of IEPP species fall into five discrete categories: water, forested wetland and floodplain,
dam facilities, power transmission lines and travel corridors, and forested upland. Excepting
Nepalese Browntop (Microstegium vimineum), different IEPP species were found in association with
each of these categories (Table 2).
Water. Of all five categories, this one proved most free of domination by IEPP species. Figure 6
shows the shallows (within about 10 vertical feet of full pool elevation) where aquatic bed vegetation
and aquatic IEPP species were found during the 2004 NAI survey of the Project Area. Two Primary
Aquatic target species listed in Table 1 as occurring in the Project Area, Variable-leaf Milfoil
(Myriophyllum heterophyllum), and Brazilian elodea (Egeria densa) were never found. Hydrilla
(Hydrilla verticillata), another previously reported Primary Aquatic, occurred just once, in a rake
sample in Flat Creek, Tuckertown Reservoir, among abundant native submergents. The only other
listed IEPP aquatic species found was Uruguay Water-primrose (Ludwigia uruguayensis (L.
hexapetala)), and this species occurred in a large monotypic stand in only one location, Abbotts
Creek, High Rock Reservoir, just downstream of the Rte. 47 bridge (Figure 2). Elsewhere (chiefly
Tuckertown and Narrows Reservoirs), it appeared to compete on no better than equal terms with its
closest congener, Floating Seedbox (L. peploides), in small backwater patches among many other
aquatic species.
Three small specimens of an unlisted IEPP species, the floating Water Lettuce (Pistia stratiotes),
were found stranded near one another by autumnal floodwaters in Narrows Reservoir, apparently far
from their point of origin. Two native submergents, Broad Water-weed (Elodea canadensis)
IEPP Draft Report 2/18/05 11
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Table 2. IEPP species observed within Yadkin Project Area
Scientific Name
Common Name Life
Form
Habitat
Aquatic
Hydrilla verticillata Hydrilla SAV Aquatic bed
Ludwigia hexapetala/uruguayensis Uruguay waterprimrose SAV Aquatic bed
Pistia stratiotes Water lettuce SAV Aquatic bed
Terrestrial
Ailanthus altissima Tree of Heaven Tree Upland, dams
Albizia Julibrissin Mimosa Tree Upland, dams
Arthraxon his idus Small ca ass/hai oint rass Grass Powerline
Les edeza cuneata Chinese les edeza Grass Powerline, dams
Ligustrum japonicum Japanese privet Shrub Upland
Ligustrum sinense Chinese privet Shrub Upland, forested wetlands
Lonicera japonica Japanese honeysuckle Vine Upland, forested wetlands
Lonicera spp (morrowii, Bella, tartarica) Bush honeysuckle Shrub Upland, forested wetlands
Melia azedarach Chinaberry Tree Powerline
Microstegium vimineum Nepalese browntop Grass Powerline, upland, forested wetlands
Miscanthus sinensis Chinese silvergrass Grass Powerline
Pueraria montana Kudzu Vine Dams
Rosa multiflora Multiflora rose Shrub Upland, dams
Wisteria sinensis Chinese wisteria Vine Dams
New Listings
Glechoma hederacea Gill-over-the-ground Herb Forested wetlands
Lysimachia nummularia Moneywort Herb Forested wetlands
Rosa wichuraiana Memorial rose Vine Dams
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Ludwigia
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)h Rock
Dam
Flat Cree
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Tuckerlrtown
Hydrilla
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Ellis Creek
i
?'Tuckertown
Ludwigia ?? Darn
uruguayensis
Yadkin Project
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Invasive Species Habitat
NORMANDEAU ASSOCIATES INC.
ENVIRONMENTAL CONSULTANTS
2.5 Nashua Road Bedford. New Hampshire 03110-5500 ti
d 6-000 12.000 24.000
Feet Dale: Dec. 10. 2004
,r Albemarle _ J410
_ I/ Lexington
Figure 6. Invasive Exotic Plant Pest (IEPP) occurrence, 2004. Dark-pink areas represent general locations of observed aquatic beds,
with associated IEPP species identified wherever found. Light-pink areas represent locations relatively vulnerable to future
IEPP invasions, should reservoir management practices change to benefit aquatic IEPPs.
Potential Invasive Speck
Known I nvasive Swedes
03
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Invasive Exotic Plant Pest Species Draft
and Thread-like Naiad (Naias gracillima), were abundant in quiet shallows in Narrows and
Tuckertown, but their two respective lookalike IEPP species, Brazilian Elodea (Egeria densa) and
Brittle Naiad (Naias minor), both on the Primary Aquatic list, were not detected. Instead of the listed
IEPP Feathered Water Fern (Azolla pinnata), its lookalike the native Mosquito Fern (A. carohniana)
was observed, as a minor constituent of floating duckweed mats.
Forested wetland and floodplain. Floodplain habitat at the around the Yadkin Project reservoirs is
limited and occurs primarily on the upper end of High Rock Reservoir along the Yadkin mainstem
and the SouthYadkin River. In this area, upstream of the Interstate 85 bridge, typical floodplain
structure is apparent: a clearly defined river channel bordered by natural levees of well-drained
sediment, behind which the alluvium slopes down gradually into forested wetland and often semi-
permanent standing water. The floodplain area invaded most aggressively by IEPP species coincides
with the relatively high and dry levees, some of which comprise an essentially upland understory
flora. At least three IEPP species occur here as understory dominants: Chinese Privet (Ligustrum
sinense), Japanese Honeysuckle (Lonicera japonica), and Nepalese Browntop (Microstegium
vimineum). Gill-over-the-Ground (Glechoma hederacea) and Moneywort (Lysimachia nummularia),
naturalized European species often listed as invasives in North America, were ground-cover
dominants. All but the browntop are semi-evergreen at this latitude, an attribute that confers a
competitive advantage over the many native species also present.
Dam facilities. Seven IEPP species were found to be most invasive around the dams and related
facilites. Three were trees: Tree-of-Heaven (Ailanthus altissima), Mimosa (Albizia julibrissin),
Japanese Privet (Ligustrum japonicum); four were climbers: Memorial Rose (Rosa wichuraiana), not
listed in Table 1, Multiflora Rose (R. multijlora), Kudzu (Pueraria montana), and Chinese Wisteria
(Wisteria sinensis). All are light-demanding, fast-growing species with an ability to exploit canopy
gaps and, in this instance, the openings created by periodic removal of robust woody growth in the
immediate vicinity of the fenced dam compounds, buildings and roads. Although often subject to the
same routines of periodic cutting and herbicide treatment as all other species, the dominant IEPP
species proved able by their superior powers of regeneration to outcompete much of the native
vegetation.
Power transmission lines and transportation corridors. About a dozen of the IEPP species listed in
Table 1 as terrestrial invasives were found in the primarily upland vegetation of both the Falls Dam
and Narrows Dam transmission lines. However, only two occurred with sufficient frequency and
abundance to indicate a state of pre-emptive dominance: Chinese Bush Clover (Lespedeza cuneata)
and Nepalese Browntop (Microstegium vimineum). With its erect, unspreading growth habit, the
bush clover never grew in closed, monotypic stands to the exclusion of all other species, but its
numbers clearly amounted to significant biomass over a wide variety of open upland conditions,
particularly in the drier sites. By contrast, the browntop's distribution was far more restricted in its
transmission-line distribution, but where conditions were suitable (relatively high soil moisture
content), it could overwhelm almost all competition in patches up to 25 mZ. It compensates for its
relatively small size by lateral spreading with a density and rapidity that inhibits germination and
establishment of most other species, and its matted overwintering remains serve effectively as a
mulch that deters regenerating competition well into the next growing season. One listed IEPP
species, Hairy Joint Grass (Arthraxon hispidus), peaked in abundance in association with the wet
meadow of Wetland 1 on the Falls Dam power transmission line.
IEPP Draft Report 2/18/05 14
Invasive Exotic Plant Pest Species Draft
Upland forest. This fifth category includes essentially all forest not associated with the preceding
four. As it constitutes generally the least disturbed of any category, it also appears less threatened by
IEPP domination. Only two IEPP species, a hybrid bush honeysuckle (Lonicera X Bella) and the
Nepalese Browntop, were observed in situations that appeared threatening to native flora.
On the Falls Reservoir shoreline, Lonicera X Bella was found in close association with two RTE
species, Piedmont Indigo-bush (Amorpha schwerinii) and Thick-pod White Wild Indigo (Baptisia
alba) in an area referred to as the Yadkin River Scour Banks (Baranski 1994, Normandeau 2004).
The bush honeysuckle occupied the preponderance of the available space in this particular site, a
rocky shelf under a thin tree canopy near enough to the reservoir to undergo occasional flood-water
scouring. The Amorpha may be of a size to hold its own against the bush honeysuckle, albeit at some
possibly reduced level of viability. However, the Baptisia, which attains little more than I in in
stature and dies back to the root every winter, is probably more vulnerable.
Nepalese Browntop may be found in lowland and mesic forest almost anywhere in the Project Area,
often as a major component of the understory flora. Although its very presence in a habitat always
precludes the use of certain habitat resources by other species, it attains a fully aggressive state
(maximum biomass) in forest canopy gaps and other situations of relatively strong light. Because of
its recumbent growth habit and short stature, it is likely to prove most injurious to other species of
small size, e.g. members of the Violet Family (Violaceae).
8.0 EFFECTS OF PROJECT OPERATIONS AND FACILITIES ON IEPP
SPECIES
The only direct impacts of current Project operation on IEPP species are those caused by the
movement and elevation of water within the reservoir system. Such movement affects the hydrologic
regime of all aquatic and swamp forest lakeshore habitats. Qualitative observations from the 2004
NAI surveys indicate that current reservoir management practices have not resulted in the presence of
large or diverse aquatic IEPP populations. In fact, two species reported from previous years on High
Rock, Variable-leaf Milfoil and Hydrilla, were not observed in 2004. A small population of Hydrilla
in Tuckertown noted in the 2004 field surveys bears watching to see if the population is expanding or
stable.
IEPP species of the floodplain plant community are comparatively numerous and well established.
Because of their location on floodplains at the upper end of High Rock Reservoirs, they are chiefly
influenced by river flows and flooding rather than reservoir operations.
IEPP species would be expected to continue to flourish around the four dam facilities and the
Narrows and Falls connecting power transmission lines, now (2004) in the process of being widened.
In both cases, vegetation management by APGI introduces disturbance that sets back plant
succession, and often promotes the dominance of certain IEPP species. IEPP species response at the
dam facilities includes primarily woody plants; along the power transmission lines, IEPP species are
primarily herbaceous.
Any changes in Project operations could alter the potential for IEPPs. For example, aquatic
vegetation is limited in shallow water areas of High Rock Reservoir due to fluctuations in reservoir
water levels and periodic exposure that these areas experience under existing Project operations.
These shallow areas in High Rock have high potential for establishment of aquatics should reservoir
IEPP Draft Report 2/18/05 15
Invasive Exotic Plant Pest Species Draft
levels be maintained at a more constant elevation, some of which could be IEPPs. In general, the
longer that stable reservoir pool elevations are maintained during the growing season, the more
aquatic plant biomass will be produced, including that of IEPP species. Winter drawdown would
serve to control this vegetation, but not to eliminate it. By this reasoning, alternative Project
operations that produce more stable water levels year-round would produce conditions most
conducive to the growth and spread of IEPP aquatics, while a greater or longer winter drawdown than
currently seen would promote the least favorable conditions.
Overall, modifying the operation of the Project, and thereby the water level regime of High Rock
Reservoir, creates the risk of a corresponding increase in undesirable IEPP aquatics. For instance, the
North Carolina Extension Service (1992) reminds us that "the explosive growth of this weed and its
competitiveness with native vegetation make Hydrilla the most serious weed threat in North
Carolina's inland waters".
The only IEPP species that seems in need of immediate control is Lonicera X Bella at the site where it
is suspected of inhibiting the survival of Baptisia alba (Section 7.0). The area in question amounts to
a few hundred square meters, since the Baptisia population is so small and strictly confined. A
manual search-and-destroy operation to root out the Lonicera bushes or apply a contact herbicide
would be the work of a single day for a knowledgeable botanist or two.
9.0 CONCLUSIONS
In aquatic plant communities, IEPP species constitute no apparent threat to native species, navigation,
or water quality under existing conditions. In forested lakeshore upland, IEPP species appear to be
relatively inconspicuous, but perhaps most deleterious to the survival of known RTE species, e.g.
Baptisia alba. IEPP species did occur in large numbers and high biomass in some habitats in the
Project Area. Around the dams and associated facilities, they often assumed dominance. In the
Project Area's only extensive remaining floodplain, in the upper mainstem Yadkin River above the
185 bridge, IEPP species dominate the herbaceous ground cover and shrub understory. In the
Narrows and Falls transmission-line corridors, they reach peak species diversity.
Any changes in Project operations that alter reservoir water levels would directly affect aquatic plant
communities (submergent, floating, emergent), and to a lesser extent on the contiguous forested
wetlands and floodplains on the reservoirs. Maintaining relatively stable reservoir water levels may
promote an increase in the number and biomass of many aquatic plant species, including IEPP
species, wherever these can exploit previously unvegetated reservoir shallows. However, the limited
availability of such shallows imposes limits on the magnitude of this impact, and the sedimentation
dynamics in the most extensive shallows (the upper High Rock Reservoir) would probably continue
to favor exploitation by native floodplain trees rather than IEPP species.
10.0 REFERENCES CITED
Baranski, M.J. 1993. Natural areas inventory for Yadkin River corridor in Davie, Davidson and
Rowan counties, North Carolina. Conservation Trust for North Carolina, Raleigh, NC.
Batcher, M. S. undated. Element stewardship abstract for Hydrilla verticillata. The Nature
Conservancy, Arlington, Virginia.
IEPP Draft Report 2/18/05 16
Invasive Exotic Plant Pest Species
Draft
Miller, J. H., E. B. Chambliss and C. T. Bargeron. 2003. Invasive plants of the thirteen southern
states. University of Georgia Bugwood Network, USDA Forest Service, USDA APHIS PPQ.
Internet website: www.invasive.org
North Carolina Agricultural Extension Service. 1992. Hydrilla-a rapidly spreading aquatic weed in
North Carolina. Publication No. AG-440.
North Carolina Department of Agriculture and Consumer Services. 2003a. North Carolina Aquatic
Weed Control Act of 1991, and Aquatic Weed Control Regulations. Internet website:
www.agr.state.nc.us/plantind/regs/gqlaw.htm
North Carolina Department of Agriculture and Consumer Services. 2003b. North Carolina Noxious
Weeds List. Internet website: www.agr.state.nc.us/plantind/plant/weed/noxweed.htm
North Carolina State University Aquatic Weed Management Program. 2003. North Carolina State
University Aquatic Weed Management Website,
www.weedscience.ncsu.edu/aquaticweeds/Publications.html
Sharp, S. 2004. Personal communication. Botanist, USDA Forest Service. Uwharrie National
Forest, Troy, NC.
Smet, Robert. 2004. Personal communication. Natural Resource Coordinator, Alcoa Power
Generating Inc, Yadkin Division, Badin, NC
USDA Forest Service. 2001. Regional invasive exotic plant species list. Southeast exotic Plant Pest
Council. Internet website: www.invasive.org/seweeds.cfm
Weakley, A. S. 2004. Personal communication. University of North Carolina Herbarium, University
of North Carolina, Chapel Hill, North Carolina.
IEPP Draft Report 2/18/05 17
Invasive Exotic Plant Pest Species
Draft
APPENDIX A
List of Rare, Threatened and Endangered Species
for Yadkin Project Search
IEPP Draft Report 2/18/05
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Appendix Table 1. Final List of Rare, Threatened and Endangered Species for Yadkin Project Search for Terrestrial and Wetland
Species only, Including Insects. Birds and Aquatic Wildlife were handled by others.
Scientific Name Common Name Source State* Federal- County Habitat Notes
Priority
Amorpha schwerinii Piedmont indigo-bush 1 SR-T M, R, S, Dd dry forests
Aster georgianus Georgia aster 1,2 T Cl M, R, S, Dd open woods and roadsides
Aster mirabilis Piedmont aster 1 SR-T S rich slopes and bottomlands
Baptisia alba Thick-pod white wild indigo 1 SR-P M, S open woodland clearings
Baptisia albescens Thin-pod white wild indigp 1 SR-P M, R, S open woodland clearings
Cardamine dissecta Dissected toothwort 1 SR-P M, R, Dd rich woods, bottomlands
Carex impressinervia Ravine sedge 1,2 SR-T FSC M wet forests
Cirsium carolinianum Carolina thistle 1 SR-P M, R forests, disturbed areas, basic soils
Helenium brevifolium Littleleaf sneezeweed 1 E M, R bogs, seeps, riverbanks
Helianthus schweinitzii Schweinitz's sunflower 1, 2, 3 E E M, R, S, Dd open woods and roadsides
Plantago cordata Heart-leaf plantain 1 E Dd beds of small, slate-bottomed perennial streams
Porteranthus stipulatus Indian Physic 1 SR-P M, Dd forests and open woods, mainly over mafic rocks
Solidago plumosa Yadkin River goldenrod 1,2 E FSC M, S riverside rocks
Solidago radula var. radula Western rough goldenrod 1 SR-P S dry woodlands over mafic rocks
Secondary
Ambystoma talpoideum Mole salamander 1 SC M, R fish-free semipermanent woodland ponds
Anemone berlandierz Southern anemone/thimbleweed 1 SR-P M, R, S thin soils around rock outcrops
Carex bushii Bush's sedge 1 SR-P R open wet areas
Collinsonia tuberosa Piedmont horsebalm 1 SR-P M rich hardwood forests
Corynorhinus rafinesquii Rafinesque's big-eared bat * * * E FSC old buildings, hollow trees, caves, mines, near water
Crotalus horridus Timber rattlesnake 1 SC M, S, Dd rocky, upland forests
Fothergilla major Large witch-alder 1 SR-T M, S dry ridgetop or bluff forests
Gomphus abbreviatus Spine-crowned clubtail 1 SR M rivers
Gomphus fraternus Midland clubtail 1 SR S rocky rivers
Hemidactylium scutatum Four-toed salamander 1 SC M wetlands in hardwood forests
Hexalectris spicata Crested coralroot 1 SR-P S, Dd, D dry or mesic woods on basic soils
Quercus austrina Bluff oak 1 SR-P M bluff and bottomland forests
Ruellia purshiana Pursh's wild-petunia 1 SR-O M glades, woodlands over mafic/calcareous rocks
Spartina pectinata Freshwater cordgrass 1 SR-P M freshwater marshes
Stachys sp I Yadkin hedge nettle 1 SR-T M sandy edges of forested floodplains
Tradescantia virginiana Virginia spiderwort 1 SR-P M rich woods on circumneutral soils
Verbena rzparia Riverbank vervain 1,2 SR-T FSC S habitat not known
Transmission lines
Echinacea laevigata Smooth coneflower 1, 2, 3 E-SC E M glades and open areas over mafic rocks
Gnaphalium hellerz var hellerz Heller's rabbit tobacco 1 SR-P M, R, Dd dry woodlands, openings, glades over mafic rocks
Helianthus laevigatus Smooth sunflower 1 SR-P M, R, S shaly open woods and roadsides
(continued)
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Appendix Table 1. (Continued)
Scientific Name Common Name Source State* Federal- County Habitat Notes
Lotus helleri Carolina birdfoot-trefoil/Heller's trefoil 1,2 SR-T FSC R, S, Dd, D open woods over clay soils, roadsides
Parthenium auriculatum Glade wild quinine 1 SR-T M glades and openings over mafic rocks
Excluded
Arabis missouriensis Missouri rockcress 1 SR-P S thin soils around basic rock outcrops
Aster laevis var concinnus Narrow-leaf aster 1 SR-P S forests, woodland borders over mafic rocks
Baptisia minor Prairie blue wild indigo 1 T S glades and open forests on basic soils
Clemmys muhlenbergii Bog turtle 2,3 T T/SA Dd bogs, wet pastures
Cyperus houghtonii Houghtons umbrella sedge 1 SR-P dry soil
Desmodium ochroleucum Cream ticktrefoil 1,2 SR-T FSC D sandy/rocky woodland openings
Dicanthelium annulum Ringed witch grass 1 SR-P dry, sandy or rocky woods, borders of thickets
Dodecatheon meadia var meadia Eastern shooting star 1 SR-P S, Dd rich rocky woods over mafic or calcareous rocks
Erynnis martialis Mottled duskywing 1 SR M upland woods, needs Ceanothus americanus
Fixsenia favonius ontario Northern oak hairstreak 1 SR M dry oak-dominated woods
Gomphus consanguis Cherokee clubtail 1 SR D spring-fed streams
Helenium pinnatifidum Dissected sneezeweed 1 SR-P R savannahs and open mucky sites
flex amelanchier Sarvis holly 1 SR-P M blackwater swamps and riverbanks
Isoetes piedmontana Piedmont quillwort 1 T R granite flatrocks and diabase glades
Isoetes virginica Virginia quillwort 1,2 SR-L FSC R upland depression swamp forests
Juglans cinerea Butternut 2 FSC S coves, stream benches, rock ledges
Lilium canadense ssp editorum Red Canada lily 1 SR-P S bogs, wet meadows
Lindera subcoriacea Bog spicebush 1,2 E FSC M streamhead pocosins, white cedar swamps, bogs
Masticophis flagellum Coachwhip 1 SR S dry sandy woods, pine/oak sandhills
Matelea decipiens Glade milkvine 1 SR-P S, Dd thin woodlands over mafic or calcareous rocks
Minuartia unifiora Single-flowered sandwort 1 E R granite flatrocks
Oxypolis ternata Savanna/Piedmont cowbane *** FSC wetlands, wet swales, bogs
Pellaea wrightiana Wright's cliff-brake 1 E-SC S rock outcrops, mafic or with nutrient-rich seepage
Pituophis melanoleucus melanoleucus Northern pinesnake 1,2 SC FSC M dry, sandy woods, pine/oak sandhills
Platanthera integra Yellow fringeless orchid 1 T R savannas
Portulaca smalhi Small's portulaca 1 T R granite flatrocks and diabase glades
Puma concolor couguar Eastern cougar 1, 2, 3 E E M needs open forest
Quercus prinoides Dwarf Chinquapin oak 1 SR-P S dry, rocky slopes
Rhus michauxii Michawes sumac 1, 2, 3 E-SC E D sandhills, sandy forests, woodlands and edges
Silphium terebinthinaceum Prairie dock 1 SR-P D diabase glades, open/semi-open areas, mafic rocks
Sistrurus miliarius Pigmy rattlesnake 1 SC M pine flatwoods, pine/oak sandhills
Solidago ptarmicoides Prairie goldenrod 1 E R diabase glades
(continued)
03
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Appendix Table 1. (Continued)
Notes:
1 NC Natural Heritage Program County lists updated May 2003,
NHP List of Rare Animal Species 2001, and NHP list of Rare Plant Species, 2002
2 US Fish & Wildlife Service North Carolina County lists updated 2/2003
3 US Fish and Wildlife Service TESS State list updated 2/2004
* based on NCNHP County lists updated May 2003
** based on USFWS County lists updated 2/2003
*** State and/or Federally listed but not found in counties
CI = Consideration for listing- no protected status
E = Endangered
E/PT = Endangered Potentially Threatened
E-SC = Endangered but available commercially
FSC = Federal Special Concern - no protected status
SC = Special Concern
SR = Significantly Rare
SR-L = Significantly Rare Limited
SR-O = Significantly Rare Other
SR-P = Significantly Rare Peripheral
SR-T = Significantly Rare Throughout
T = Threatened
T/SA = Threat. due to Similarity of Appearance -
no effect on land-management activities by private landowners
Counties
S Stanly
R Rowan
M Montgomery
Dd Davidson
D Davie
Expert Reviewers
Dr. Alan Weakley, Curator, UNC Herbarium, Chapel Hill, NC
Dr. Moni Bates, NC Plant Conservation Program
Dr. Peter Diamond, NC Zoological Park, Asheboro, NC
Sarah McRae, Natural Heritage Program, Raleigh, NC
Dr. Mary Kay Clark, NC Museum of Natural Sciences, Raleigh, NC
Mr. Mark Lewis, NC Zoological Park, Asheboro, NC
Dr. Dennis Herman, NC Museum of Natural Sciences, Raleigh, NC
rz)