Skaneateles Conservation Area/Invasive species

• List of invasive or potentially invasive plants that could be found at the SCA
• List of invasive or potentially invasive animals that could be found at the SCA
• List of invasive or potentially invasive microorganisms that could be found at the SCA

Invasive plants

Invasive plant species are a primary cause of biodiversity loss and undoubtedly the main cause in former agricultural natural areas like the Skaneateles Conservation Area (SCA). The lists on this page show the plants known to be present in significant amounts at or very near the SCA. They are ranked here according to the Non-Native Plant Assessments provided by the New York Invasive Species Information Clearinghouse. Ranks range from very high (VH), high (H), moderate (M), to low (L).

The New York Invasive Plant Ranking System considers invasive plants to be non-native species that have spread into native or minimally managed plant systems in New York State, where they would likely cause economic or environmental harm or harm to human health by developing self-sustaining populations and becoming dominant and/or disruptive to those systems.

Note that the order in which these species are listed reflects their invasiveness ranking for the whole of New York State at the time the assessments were made and doesn’t necessarily indicate how important they will be for managers at the SCA to consider in the management decisions. But the order does provide some indication of how concerned we should be about their presence at the SCA.

It should also be noted that there are undoubtedly invasive plants present that we are not aware of. Land managers should continue to be watchful for newly identified invasive plants. Aside from the normal problems seen in in abandoned agricultural lands, invasive plants may be a particular problem at the SCA because the Town of Skaneateles transfer station is located in the center of the nature preserve. This transfer station accepts yard waste from town residents and creates mulch out of it. It seems quite likely that propagules from this waste have been escaping for years to the surrounding conservation area.

State prohibited and regulated invasive plants at the SCA

According to New York State law, a Prohibited invasive species is one that "poses a clear risk to New York's economy, ecological well-being and/or human health and is listed as prohibited" under New York Codes, Rules and Regulations, Title 6, Chapter V, Subchapter C, section 575.3, which states that

• "no person shall knowingly possess with the intent to sell, import, purchase, transport, or introduce any prohibited invasive species" and that
• "no person shall sell, import, purchase, transport, introduce or propagate any prohibited invasive species."

The legal definitions of introduce and propagate need to be examined to determine whether we are breaking the law by even allowing prohibited plants to remain at the SCA. According to Section 575.2 (Definitions),

• Introduce: "...the intentional or unintentional escape, release, dissemination, or placement of a species into an ecosystem as a result of human activity."
• Propagate: "...to cause to continue to increase by sexual or asexual reproduction."

Anyone who realizes how easily invasive plants can be spread might interpret that to mean that one would be guilty of introducing and propagating prohibited species simply by walking across an infested property, much less by allowing prohibited species to thrive there. But, the Q&A paper published by the DEC concerning the regulation says: "No, existing populations of non-native invasive species listed as prohibited or regulated and established prior to the implementation of the final part 575 regulations do not require management by the owner. However, once implemented, the final regulations do prohibit commerce involving those species listed as prohibited species and the release of regulated species into a free-living state." These regulations took effect on March 10, 2015.

New York State law defines a Regulated invasive species as one that "has the potential to cause significant harm to New York's economy, ecological well being and/or human health and could be effectively contained through regulatory programs and is listed as regulated under section 575.4."

• "no person shall knowingly introduce into a free-living state or introduce by a means that one knew or should have known would lead to the introduction into a free-living state any regulated invasive species, although such species shall be legal to possess, sell, buy, propagate and transport."

• "Free-living State means unconfined and outside the control of a person," including within "...lands identified as public lands, ...natural areas," and "...waters identified as public waters."

This begs the question of whether a town resident "should have known" that taking their yard waste containg invasive plants or insects to the transfer station would place it in jeopardy of being introduced to a free-living state in the surrounding conservation area.

Note that the Regulatory System for Non-Native Species, proposed by the New York Invasive Species Council in 2010, specified that species ranked "High" and "Very High" would be Prohibited and species ranked "Moderate" would be Regulated in New York State. However it appears that economic and likely political forces have lead to some highly- and very-highly-invasive plants being regulated but not prohibited and most moderately-invasive plants not being regulated at all.

Invasive Species Tiers

The following is a generalization of the system used by the New York State PRISMs for assigning tiers to be used for prioritizing invasive species detection and management efforts. A similar system could be used for prioritizing invasive species at the SCA. Only the definitions of "larger area" and "buffer" would need to be adjusted.

Tier 1. Prevention / Early Detection

The species is not known to be present in the area.

• 1a. High-impact species is inside a designated buffer (e.g. 100 mi.) surrounding the area, but not in the area (e.g. FL-PRISM) itself
• 1b. High-impact species is in a larger area (e.g. eastern North America), but not in a buffer surrounding the area nor in the area itself
• 1c. Introduction pathway may exist but high-impact species is not in the larger area.

Tier 2. Eradication

High-impact species is inside the area with a low population or removal cost.

If eradication or full containment is possible, this should have the highest level of response to a high or very impact being detected in the area.

Tier 3. Containment

Medium population & cost, with strategic management may contain, slow or prevent spread to adjacent area.

Tier 4. Local control

Populations are established and/or widespread. Concentrate on protecting high priority resources, which may include rare species and unique habitats.

Tier 5. Monitor

Populations of low impact species may be present but only require watching to ensure that they don't become higher impact.

Degree of Establishment

The Darwin Core Degree of Establishment Vocabulary defines the concepts:

Concept	Cat.	Definition	Notes
native	A	Not transported beyond limits of native range.	Considered native and naturally occurring.
captive	B1	Individuals in captivity or quarantine (i.e., individuals provided with conditions suitable for them, but explicit measures of containment are in place).	Only for cases where specific actions have been taken place to prevent escape of individuals or propagules.
cultivated	B2	Individuals in cultivation (i.e., individuals provided with conditions suitable for them, but explicit measures to prevent dispersal are limited at best).	Examples include gardens, parks and farms.
released	B3	Individuals directly released into novel environment.	For example, fish stocked for angling, birds for hunting.
failing	C0	Individuals released outside of captivity or cultivation in a location, but incapable of surviving for a significant period.	For example, frost-tender plants sown or planted in a cold climate.
casual	C1	Individuals surviving outside of captivity or cultivation in a location with no reproduction.	Trees planted in the wild for forestry or ornament may come under this category.
reproducing	C2	Individuals surviving outside of captivity or cultivation in a location. Reproduction is occurring, but population not self-sustaining.	Offspring are produced, but these either do not survive or are not fertile enough to maintain the population
established	C3	Individuals surviving outside of captivity or cultivation in a location. Reproduction occurring, and population self-sustaining.	The population is maintained by reproduction, but is not spreading.
colonising	D1	Self-sustaining population outside of captivity or cultivation, with individuals surviving a significant distance from the original point of introduction.	The population is maintained by reproduction and is spreading.
invasive	D2	Self-sustaining population outside of captivity or cultivation, with individuals surviving and reproducing a significant distance from the original point of introduction.	The population is maintained by reproduction, is spreading, and its progeny are also reproducing and spreading.
widespread invasive	E	Fully invasive species, with individuals dispersing, surviving and reproducing at multiple sites across a spectrum of habitats and geographic range.	This term is only used for those invasives with the highest degree of encroachment.

Interfering native plants at the SCA

Occasionally beneficial native plant species such as grape vines (Vitis spp.) or even some ferns can become a problem.

• Large contiguous dense forests do not generally have many vines.
• Vines require light, so they are most prevalent on forest edges where they can easily overtop the edge trees, slowing their growth and increasing their mortality and causing forest edges to recede.
• Native vines do provide substantial food for birds and small mammals.

Invasive animals

• Earth worms
  • European earth worms
  • Asian jumping worms
• Deer
• Insects
  • Emerald ash borer
  • Hemlock woolly adelgid
  • Beech bark disease
  • Spotted lantern fly

Prioritizing invasive species control

The density of an individual invasive species is not necessarily an indicator of the priority that should be assigned to that species. Often invasive species that are the most rare or newly discovered in an area are given higher priority because they are easier to control than more established species.

The physical size of invasive species also should be taken into account when ranking them for local control. When told that there is an invasive species problem at the SCA, a common response is “Oh, you have garlic mustard?” Well, yes, here is a relatively small amount of garlic mustard present at the SCA, but that may be because there are larger, more dominant species like buckthorn that don’t even allow garlic mustard to spread. Keeping the garlic mustard out of more pristine part of the SCA is important, but searching for garlic mustard to pull in the large buckthorn infestations is probably a waste of time.

On the other hand, removing large invasives like buckthorn usually release numerous smaller invasives to grow from the ground that they were shading. Removing invasive plants requires continued monitoring of the location from which they were removed in order to ensure that only native plants return to replace them. Often it will be mostly other invasives or more of the same species that will return form the seed bank, root suckers, or wherever. Even when stumps are chemically treated to kill an individual that has been cut down, other invasives will probably return.