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Transcript
Ann Spearing
Steve Young
Jennifer Payne
Stephanie George
SARP Proposal
Research Question
How can the Department of Wilderness effectively manage nonnative invasive terrestrial plant
species in Vermont’s Wilderness areas?
The purpose of my research is to develop an inventory and management plan for nonnative
invasive terrestrial plant species in Vermont’s Wilderness areas. The management plan will be
used by my SARP sponsor, the Green Mountain National Forest Department of Wilderness.
Throughout the rest of the paper I will refer to the Green Mountain National Forest by the
acronym, “GMNF”, and nonnative invasive terrestrial plant species simply as “invasives”. The
management plan will direct how to incorporate invasive management into the daily routine of
Wilderness rangers. All steps of implementation will also help further the GMNF in their 10year Wilderness Stewardship Challenge.
Background
A nonnative invasive plant is a plant that establishes in a new, often far away from its origin, area
where it reproduces, spreads, and persists to the detriment of the ecosystem it has invaded (Mack
et al. 2000). Invasives can disrupt natural ecosystems by altering physical, chemical, and
biological components of the ecosystem (Osborn et al. 2002). It is a normal ecological process
for plant species to migrate into new ranges by many forces including water, wind, etc., and
human-driven processes (Mack et al., 2000). It can be unfavorable for an offspring to compete
with the parent plant. By design, many plant seeds invite means of transport. Plant fruit and/or
seeds develop wing-like designs for air travel, low densities for flotation, and hooked barbs for
snagging rides with whoever passes by. Yet there is a relative rate of dispersal (Marler 2000)
and probability of colonization success. The scale of plant migrations has drastically increased
in the past 200 years. The growth of transport and commerce has gone hand in hand with the
growth of nonnative species introductions; invasions are largely human-driven phenomena
(Mack et al. 2000). “Few habitats remain free of species introduced by humans” (Mack et al.
2000).
Westman (1990) asks an important and controversial question, “how unnatural is the invasion
process?” An invasive is actually a rare phenomenon. Most plants will die on their way to a new
location or are quickly killed upon arrival from innumerable biological and physical forces. Even
if a plant defeats all odds and establishes in a new area, it will likely face extinction from the
locality within a few generations. Only a tiny fraction of the number of transported plants and
seeds will persist to become naturalized so far beyond their native ranges. Of the naturalized
nonnative species, only a small fraction will go on to become invasive (Mack et al. 2000). Some
public sentiment suggests that humans are only playing a part in the existing migration processes
of plant species. Plant migration, the process in which nonnatives become naturalized, and the
basic exchanges of one green plants for another are natural, they assert, and therefore invasives
are neither a problem nor a valid human concern.
Humans have played an explicit role in the transportation and introduction of nonnative plants
and seeds both intentionally and unintentionally. When supplemented to the natural scale of
species dispersal rates, humans have strongly enhanced the scale at which species can disperse.
Through global travel, humans have superseded the geographic barriers that normally control
species dispersal capabilities (Marler 2000). Humans have carried seeds over mountains and
across oceans. From the Viking Age in 1000 A.D. to the widespread colonial settlements from
the 1500’s, Europeans transported Old World species to new locations as part of their livelihood
and potential crops. Also many species have been transported as unintentional byproducts mixed
in with cargo (Mack et al. 2000). It is argued that unintentional importation through international
trade is one of the most important pathways of nonnative plants, stating “exotics frequently
‘stowaway’ in ships, planes, trucks, shipping containers, and packing materials, or ‘hitch-hike’ on
nursery stock, fruits, vegetables, seeds, and other imports” (Jenkins 1996). Of the human
introduced species, some have maintained a life within human agriculture and commerce, some
have become naturalized immigrants among native assemblage, and some have gone on to
become invasives. All exert an effect on the new ecosystem in which they live. Although
human-driven movement of species’ ranges have occurred over considerably less time, their
affects are said to rival the changes induced by the continental glaciations and deglaciations
cycles of the past ice age (Mack et al. 2000).
There are some commonalities between species on the path from an immigrant to an invasive.
After successful introduction, there is often a lag period, followed by a period of rapid
exponential growth. It is in this growth period that plants are recognized as invasive. Spread will
continue until the species reaches the bounds of its new range. The lag period can last decades,
where an invasive plant is indistinguishable from naturalizing or doomed populations. “Most
extinctions of immigrant populations occur during the lag phase yet the dynamics of such a
population are often statistically indistinguishable from those of a future invader…” (Mack et al.
2000). Many small widespread populations generally produce faster invasions than one large
invasion. During the first years of naturalization, it is suggested that natural selection may be
weeding out unsuccessful genotypes, creating successful species for the new location. Often
human cultivation has protected small populations of nonnative species from environmental
hazards, when they would otherwise have become extinct. Eventually populations become
naturalized and may become invasive (Mack et al. 2000). “The response of a plant to the sudden
breaching of a previously impassible geographic barrier often illustrates the inherent limits to
population growth and the ecological constraints to a species’ distribution” (Huenneke et aI.
1988).
The concept of a nonnative invasive species was considered by the mid-1800’s, but was not well
known until the 1958 publication by Charles Elton, The Ecology of Invasions by Animals and
Plants, described species introductions and the sometimes dramatic effects of successful
invasions (Randall 2000). Much research has been conducted to determine whether there are
certain attributes that make some species more invasive than others (Randall 2000). In a 1996
study by Rejmanek and Richardson, 12 invasive pines, known to be spreading in two continents,
were compared to 12 noninvasive, known to be planted without spreading on three continents.
The invasive pine species were found to have short juvenile periods and short intervals between
seed crops. This means “early and consistent reproduction and hence rapid population growth”.
Another commonality found among invasive pines was a small seed size. They suggest that
energy maybe used to produce more seeds of a small size, or that a small seed size may have
faster germination (Rejmanek and Richardson 1996). Other common attributes remain elusive
(Randall 2000). There has also been a considerable amount of research done questioning
whether invasions are a function of certain environmental or ecosystem characteristics (Randall
2000). Areas of lower biodiversity are considered more susceptible, because it is suggested that
simpler webs of interaction within these ecosystems do not use resources sufficiently (Stohlgren
1999). There are available niches in these ecosystems, but it is suggested that the structure of
plant community may be more of a variable than the number of species in a community (Mack et
al. 2000). Many invasives do not have natural predators or parasites in their new environment,
giving them great advantage in all aspects of performance. Growth, longevity, and fitness can be
much greater (Mack et al. 2000). Landscape disturbances also affect invasibility (Lonsdale
1999). European expansion may have encouraged invasions because of sudden disturbances to
the environments the colonists entered (Mack et al. 2000). Also areas affected by floods, fire,
agricultural practices and grazing, major changes in water levels or salinity may create an
environment susceptible to invasions (Mack et al. 2000). “Invasibility is an emergent property of
ecosystems, manifested in the rate of mortality of exotic species, but at the same time potentially
affected by the climate, the properties of the native species, the level of disturbance, and the
ecosystem’s resistance to invasion” (Lonsdale 1999).
Such large and fast dispersal of new plants in a new area greatly alters the overall plant
community and entire ecosystem of invaded landscapes. Invasives out compete native plants for
resources (Huenneke et al. 1988). Taking over water supplies and shading out natives are two of
the most common tactics of invasives. They will often hybridize with native plant species,
mutating native population strains, and sometimes creating a new invasive species (Mack et al.
2000). In many areas invasives will replace native species in a plant community. Invasives
displace native plants and therefore displace native animals (Randall 2000). Nonnative plants
alter the nutrient cycles, soil composition, water pH values, fire regimes, hydrology, and the
wildlife in an area. Invasives are “a threat to the composition, structure, and function of
ecological entities or levels of biological hierarchy ([from] genes, [to] populations, [to]
communities, [to] ecosystems, [to] landscapes)” (Cole and Landres 1996). If left unmanaged,
many unique ecosystems may become a few homogenized ecosystems.
Invasives are considered one of the greatest threats to biodiversity and regional distinctiveness
worldwide (Marler 2000). Imagine how much land on earth is currently being invaded by
nonnative species at rates the earth has never seen. The unique and somewhat disheartening truth
is that unlike the contamination of air sources and water sources, invasives will not dissipate with
time if unassisted. They will continue impoverishing ecosystems on their own, causing their own
extinctions (Randall 2000). Those managing land for healthy populations of native species and
those preserving and restoring ecosystems to a “natural state”, the state that existed before
extensive human influences, have added invasives as a major concern (Huenneke et al. 1988,
Westman 1990).
In order assure that an increasing population, accompanied by expanding settlement and growing
mechanization, does not occupy and modify all areas of the United States and its possessions,
leaving no lands designated for preservation and protection in their natural condition, it is hereby
declared to be the policy of Congress to secure for the American people of present and future
generations the benefits of the enduring resource of wilderness.
A wilderness…is hereby recognized as an area where the earth and its community of life are
untrammeled by man, where man himself is a visitor who does not remain. …an area of
underdeveloped Federal land retaining its primeval character and influences…which is protected
and managed as to preserve its natural conditions and which generally appears to have been
affected primarily by the forces of nature, with the imprint of man’s work substantially
unnoticeable. (Wilderness Act 16 U.S.C. 1 1 21).
In 1964, the United States made a huge step in the world of land management. For the first time
the purpose of a land was not to be managed for a particular resource, but the resource being the
natural existence of the land. There are four main values promoted by the concept of Wilderness:
the value of the wilderness experience; the value of wilderness as a scientific resource and an
environmental baseline; the symbolic and spiritual value of wilderness to the nation and to the
world; and the value of wilderness as a commodity or place that generates direct or indirect
economic benefits (Davis 1966-67). Wilderness areas have “tremendous long term value to
society because they have the potential to provide the best remaining standards of relatively
unmodified land in the United States” (Cole and Landres 1996). Within the healthy native
vegetation lies the foundation of wilderness values (Asher and Harmon 1996).
The natural characteristics of wilderness ecosystems are constantly threatened by nonnative
invasions, an event beyond the reins of human law. Most wilderness areas already host some
invasives, and are undergoing ecosystem changes (Osborn 2002). The management of invasives
can be a controversial issue. The average wilderness visitor may not know the history of humans
and invasive plant species introduction (Asher and Harmon 1996). Wilderness areas are
historically managed with defined guidelines with the goal of minimum human intervention
(Osborn 2002) yet they are also managed to restore human aided devastation. As demonstrated
earlier, invasions have been greatly induced by humans. Wilderness areas in the East are
especially vulnerable to invasions because much of the land was previously privately owned and
manipulated, and are now returning to a natural state. Much of the land also borders private
property and developed lands, and is very accessible to invasions.
Some objectives of wilderness management include maintaining the distinctive qualities,
naturalness and solitude, which define and separate wilderness from adjacent lands (Oye 2001).
Wilderness is to be managed to remain unspoiled and without degradation. “If nothing is done
to curb their expansion or eradicate them, the principal of nondegradation has been violated”
(Asher and Harmon 1996). Other important Wilderness management principals include
managing human influences while managing to guide long term wilderness stewardship. Only
the minimum tools should be used in wilderness area. The public should be involved for
successful management, and written plans should guide wilderness management with specific
area objectives.
Methodology
In order to answer my question, I will:
 Complete an inventory will be taken of the non native invasive plant species in and around
Vermont’s six Wilderness areas: Breadloaf, Bristol Cliffs, Big Branch, Lye Brook, Peru Peak,
and George Aiken Wilderness areas.
 Examine Big Branch Wilderness and Lye Brook Wilderness will in depth, including all trail
heads, trails, boundaries bordering roads, developed camping areas such as shelters and tenting
platforms, and major water sources. Breadloaf, Bristol Cliffs, Peru Peak, and George Aiken
Wildernesses will be examined only at trail heads and various other points of interest.
 Document sites where invasive plants are found will on forest maps and by GPS.
 Record information about the invasive species found at each site. Species will be identified,
along with its growth pattern and type, its percent canopy, the area of occupancy, the growth type
of surrounding vegetation, and if possible the names of some adjacent plant species.
Once I have taken the inventory, I will map the GPS points with a GIS mapping system.
Throughout the inventory process and thereafter, I will conduct research on invasive plants, the
specific species found throughout the study, what may make the invaded areas susceptible to
invasions, the role of invasives in Wilderness systems, and the effective management for invasive
plants within the appropriate Wilderness guidelines.
I will write a small management plan to help incorporate the management of nonnative invasives
easily into the daily routine of a Wilderness ranger, including:
 Maps of invasives sites
 Background of Individual species
 Identification Techniques
 Calendar describing the best times for eradication
 Eradication techniques appropriate for Wilderness lands
I will make an interpretive poster will be made to hang at trailheads to increase public awareness
of the threat of invasives.
I will carry out some eradications.
I will attend at least two conferences on the subject of invasives management.
Timeline
Fall 2006
Data collection for invasive plant species inventory
December 2006
Analysis of data and continued research of plant species found
Meeting with SARP advisor, Ann Spearing
Writing process begins
-management plan
-research results
-final SARP paper
January 2007
Writing process continues
First draft of final SARP paper due
February 2007
SARP presentation
Final SARP paper due
Conclusion
The last two years of my life and education have been dedicated to getting to know the landscape
and learning about the environment in Vermont. Not very long ago, most of Vermont was land
for agriculture. The forest is young, but I had always assumed succession was taking place in a
natural state. Upon first learning about invasives and how to identify them at the beginning of
the 2006 summer season, it was astonishing to have these new eyes that spotted invasives out of a
crowd. I saw invasives as I drove in upstate New York and southern Vermont. Invasives
bombarded the plant identification game I played as I ran in upstate New York, and every once in
a while I saw invasives while I hiked in Southern Vermont. I noticed large differences in the
amount of invasives I saw in different areas. I was absolutely amazed to realize that I have been
looking to these Vermont woods for education for two years without ever noticing the
shortcomings of the “natural” landscape.
Vermont’s woods are highly prized for their native species. The people of the area have a history
of living from the land and it is obvious that the government and its citizens care about the
landscape. Looking at Vermont’s history, it is a prime victim for invasions. It has a temperate
climate and has been heavily disturbed over the past 200 years for long periods of time. Yet for
some reason, I have heard from land managers and have seen that Vermont’s invasions are still
small and therefore manageable. But as I have learned, time is limited.
Invasives are at the forefront of conservation. The Forest Service lists them as one of the top 4
threats to the public landscapes, yet I believe they are under the radar of the public. People’s
lawns and gardens are saturated with invasives. Although the plants persist without the aid of
human assistance, if invasives were managed solely in people’s yards, most of the problem
would be under control. As a neighbor, I cannot control what happens in people’s yards, but as a
student and a wilderness ranger I can do my best to learn about invasives, educate the public
about invasives, and help do my part in starting the management process for invasives. I can help
keep those areas that by law should uphold the naturalness and native beauty in Vermont.
Literature Cited
Asher JE, Harmon DW. 1996. Invasive Exotic Plants are Destroying the Naturalness of
U.S. Wilderness Areas. International Journal of Wilderness 2(1):35-37.
Cole DN, Landres PB. 1996. Threats to Wilderness Ecosystems: Impacts and Research
Needs. Ecological Applications 6(1) :168-184.
Davis MC. 1966-67. The influence of Emerson, Thoreau, and Whitman on the early American
naturalists, John Muir and John Barrows. Living Wilderness 39(95) :19-23.
Huenneke L, Glick D, Waweru FW, Brownell RL, Goodland R. 1988. SCOPE Program
on Biological Invasions: A Status Report. Conservation Biology 2(1) :8-10.
Jenkins PT. 1996. Free Trade and Exotic Species Introductions. Conservation Biology
10(1) :300-302.
Lonsdale WM. 1999. Global Patterns of Plant Invasions and the Concept of Invasibility. Ecology
80(5) :1522-1536.
Mack RN, Simberloff D, Lonsdale WM, Evans H, Clout M, Bazzaz FA. 2000. Biotic
Invasions: Causes, Epidemiology, Global Consequences, and Control. Ecological
Applications 10(3) :689-710.
Marler M. 2000. A Survey of Exotic Plants in Federal Wilderness Areas. USDA Forest
Service Proceedings RMRS-P-15-VOL-5 :318-327.
Osborn S, Wright V, Walker B, Cilimburg A, Perkins A. 2002. Understanding and
Managing Invasive Plants in Wilderness and other Natural Areas: An Annotated
Reading List. USDA Forest Service General Technical Report RMRS-GTR-79-VOL-4
Oye G. 2001. A new Recreation Strategy for National Forest Wilderness. International
Journal of Wilderness. &(1) :13-14.
Randall JM. 2000. Improving Management of Nonnative Invasive Plants in Wilderness and
Other Natural Areas. USDA Forest Service Proceedings RMRS-P-15-VOL-5 :6473.
Rejmanek M, Richardson DM. 1996. What Attributes Make Some Plant Species More
Invasive? Ecology 77(6) :1655-1661.
Stohlgren TJ, Binkley D, Chong GW, Kalkhan MA, Schell LD, Bull KA, Otsuki Y,
Newman G, Bashkin M, Son Y. 1999. Exotic Plant Species Invade Hot Spots of Native
Plant Diversity. Ecological Monographs 69(1) :25-46.
U.S. Public Law 88-577. The Wilderness Act of September 3, 1964. 78 Stat. 890. Sect 2.
Westman W E. 1990. Park Management of Exotic Plant Species: Problems and Issues.
Conservation Biology 4(3) :251-260.
Including references from
Hendee JC, Dawson CP. 2002. Wilderness Management: Stewardship and Protection of
Resources and Values Third Edition. Colorado: Fulcrum Publishing. 640 p.