Continuing our monthly series of invasive species articles – this week we look at the first of the “Dirty Dozen”. The Dirty Dozen are the 12 worst, most problematic, established invasive species within the Six Rivers CISMA – as decided by the members of the Six Rivers CISMA. This month we look at the Japanese Climbing Fern (Lygodium japanicum).
Japanese Climbing Fern can quickly cover natural vegetation. Spores and small plants can be potentially transported in pine straw. Climbing ferns are a problem for managed timber and home landscapes. Photo by L. Scott Jackson
Define Invasive Species: must have all of the following –
Is non-native to the area, in our case northwest Florida
Introduced by humans, whether intentional or accidental
Causing either an environmental or economic problem, possibly both
Define “Dirty Dozen” Species:
These are species that are well established within the CISMA and are considered, by members of the CISMA, to be one of the top 12 worst problems in our area.
Native Range:
Japanese Climbing Fern is from eastern Asia.
Introduction:
The plant was introduced by humans intentionally in the 1930s as an ornamental plant.
EDDMapS currently list 28,649 records of this plant. Most are in the coastal states of the southeastern U.S.
Within our CISMA there are 3148 records. This is CERTAINLY underreported.
Description:
Japanese Climbing Fern is vine that grows from rhizomes below the ground. The stems and rhizomes are very thin and wire like. The leaves can be flat and finger-like to “lacey” and “feather-like” and are opposite on the vine. The broader leaves carry the sporangia housing the spores. The spores are very tiny and can be carried by the wind and by your clothes. The vines will develop massive thick mats covering fences, sides of buildings, and much of the native vegetation in the area. In winter the vines, and leaves, appear brown and dead, but they are not. It grows well in sun or shade, damp areas that have been disturbed but grows just as well in areas that have not been disturbed.
Issues and Impacts:
This plant forms massive dense mats that can completely cover all native vegetation in the area. This matting can reduce sunlight to existing plants and reduce their ability to germinate seedlings. The vines are known to grow as high as 90 feet into the tree canopy. The plant has been a problem for the timber industry trying to collect pine straw for sale. It was listed as a Florida Noxious Weed in 1999.
Management:
Hand removal, or any other means of mechanical removal, has not been effective.
Burning does kill the above ground biomass, but the below ground biomass usually returns the plant.
Puccinia lygodii, a rust found on many species of Lygodium, may be a biological control. Studies on this continue.
Chemical treating with a 2-3% solution of Glyphosate has been effective.
Any management of this plant should be done in the late summer/early fall when the spores are not present.
For more information on this EDRR species, contact your local extension office.
References
Japanese Climbing Fern, University of Florida IFAS Center for Aquatic and Invasive Plants
Define Invasive Species: must have all of the following –
Is non-native to the area, in our case northwest Florida
Introduced by humans, whether intentional or accidental
Causing either an environmental or economic problem, possibly both
Define EDRR Species: Early Detection Rapid Response. These are species that are either –
Not currently in the area, in our case the Six Rivers CISMA, but a potential threat
In the area but in small numbers and could be eradicated
Native Range:
Eurasian milfoil is native to Eurasia and north Africa.
Introduction:
There are two records of its possible introduction.
Introduced accidentally in ship ballast entering the Chesapeake Bay in the late 1800s.
Intentionally introduced in the Chesapeake Bay area in 1942.
EDDMapS currently list 20,532 records of this plant. Most are along the U.S. Canadian border.
Within our region there are 24 records. 11 in Bainbridge GA, one in Panama City, four in Apalachicola, and seven in south Alabama.
There are five records within Six Rivers CISMA, all in the Mobile delta.
Description:
Eurasian milfoil is a submerged, rooted, freshwater plant preferring slow moving waters.
It has long slender stems that are reddish-brown to whiteish-pink in color branching as it reaches the surface. The leaves are olive-green in color, less than 2” in length, and branching (feather-like). Leaf whorls along the stem are between 3-6 leaves but typically 4. Whorl nodes are 3/8” apart.
Flowers are reddish and attached to emersed spikes reaching above the water. The spike is about 8” long and the flowers are arranged in a whorl pattern around this. In Canada it flowers in late July and early August.
It can tolerate salinities up to 10 ppt and could be found in upper brackish systems.
The plant can grow in 20 feet of water but is most often found in waters less than 10 feet deep.
It can grow into large, dense mats, and can be the most common plant in the area.
Issues and Impacts:
Has been known to stop boat traffic.
Can completely cover the surface of the water reducing oxygen exchange and light for other submerged plants. Decaying mats can reduce dissolved oxygen even further.
Has been reported to negatively impact fish and birds.
Management:
Mechanical harvesters and chopping machines have been used but fragments can re-sprout.
Underwater vacuuming has been tried in Canada.
In bodies of water where this can be done, water draw down has been effective.
Biological controls using fish and insects have had some success.
Aquatic herbicides have been used to help control but rarely eradicate the plant completely.
EDUCATE BOATERS TO CHECK THEIR BOATS AND TRAILERS WHEN ENTERING AND LEAVING WATER BODIES WHERE EURASIAN MILFOIL MIGHT EXIST.
DO NOT DISCHARGE UNWANTED AQUARIUM PLANTS INTO LOCAL WATERWAYS.
It is currently not listed as a federal noxious weed and continues to be sold as a plant for aquariums.
For more information on this EDRR species, contact your local extension office.
References
Eurasian milfoil, University of Florida IFAS Center for Aquatic and Invasive Plants
The native Florida landscape definitely isn’t known for its fall foliage. But as you might have noticed, there is one species that reliably turns shades of red, orange, yellow and sometimes purple, it also unfortunately happens to be one of the most significant pest plant species in North America, the highly invasive Chinese Tallow or Popcorn Tree (Triadica sebifera).
Chinese Tallow fall foliage. Photo courtesy of Daniel Leonard.
Native to temperate areas of China and introduced into the United States by Benjamin Franklin (yes, the Founding Father!) in 1776 for its seed oil potential and outstanding ornamental attributes, Chinese Tallow is indeed a pretty tree, possessing a tame smallish stature, attractive bark, excellent fall color and interesting white “popcorn” seeds. In addition, Chinese Tallow’s climate preferences make it right at home in the Panhandle and throughout the Southeast. It requires no fertilizer, is both drought and inundation tolerant, is both sun and shade tolerant, has no serious pests, produce seed preferred by wildlife (birds mostly) and is easy to propagate from seed (a mature
While Chinese Tallow can become established almost anywhere, it prefers wet, swampy areas and waste sites. In both settings, the species’ special adaptations allow it a competitive advantage over native species and enable it to eventually choke the native species out altogether.
In low-lying wetlands, Chinese Tallow’s ability to thrive in both extreme wet and droughty conditions enable it to grow more quickly than the native species that tend to flourish in either one period or the other. In river swamps, cypress domes and other hardwood dominated areas, Chinese Tallow’s unique ability to easily grow in the densely shaded understory allows it to reach into the canopy and establish a foothold where other native hardwoods cannot. It is not uncommon anymore to venture into mature swamps and cypress domes and see hundreds or thousands of Chinese Tallow seedlings taking over the forest understory and encroaching on larger native tree species. Finally, in waste areas, i.e. areas that have been recently harvested of trees, where a building used to be, or even an abandoned field, Chinese Tallow, with its quick germinating, precocious nature, rapidly takes over and then spreads into adjacent woodlots and natural areas.
Chinese tallow seedlings colonizing a “waste” area. Photo courtesy of Daniel Leonard.
Hopefully, we’ve established that Chinese Tallow is a species that you don’t want on your property and has no place in either landscapes or natural areas. The question now is, how does one control Chinese Tallow?
Prevention is obviously the first option. NEVER purposely plant Chinese Tallow and do not distribute the seed, even as decorations, as they are sometimes used.
The second method is physical removal. Many folks don’t have a Chinese Tallow in their yard, but either their neighbors do, or the natural area next door does. In this situation, about the best one can do is continually pull up the seedlings once they sprout. If a larger specimen in present, cut it down as close to the ground as possible. This will make herbicide application and/or mowing easier.
The best option in many cases is use of chemical herbicides. Both foliar (spraying green foliage on smaller saplings) and basal bark applications (applying a herbicide/oil mixture all the way around the bottom 15” of the trunk. Useful on larger trees or saplings in areas where it isn’t feasible to spray leaves) are effective. I’ve had good experiences with both methods. For small trees, foliar applications are highly effective and easy. But, if the tree is taller than an average person, use the basal bark method. It is also very effective and much less likely to have negative consequences like off-target herbicide drift and applicator exposure. Finally, when browsing the herbicide aisle garden centers and farm stores, look for products containing the active ingredient Triclopyr, the main chemical in brands like Garlon, Brushtox, and other “brush/tree & stump killers”. Mix at label rates for control.
Despite its attractiveness, Chinese Tallow is an insidious invader that has no place in either landscapes or natural areas. But with a little persistence and a quality control plan, you can rid your property of Chinese Tallow! For more information about invasive plant management and other agricultural topics, please contact your local UF/IFAS Extension office!
References:
Langeland, K.A, and S. F. Enloe. 2018. Natural Area Weeds: Chinese Tallow (Sapium sebiferum L.). Publication #SS-AGR-45. Printer friendly PDF version: https://edis.ifas.ufl.edu/pdffiles/AG/AG14800.pdf
We have written about this guy before. The Cuban Treefrog is a potential threat to the Florida panhandle. According to EDDMapS, there are 13 records between Pensacola and Madison County. The records I am aware of are single individuals who appeared after the homeowner purchased landscaping plants (or flowers) from a local “box store”. In the last couple of weeks, I have again heard of two cases where individuals were found either at the “box store” garden center – or on their property after purchasing plants from such.
Image by Dr. Steve A Johnson 2005.
We all know that one individual does not a problem make. However, if multiple people continue to find them and they escape. Then eventually the numbers could get high enough where breeding populations could form. It is known that CTFs prefer to hang around humans and are not common in natural areas. So, this COULD make it easier for them to find each other over time and populations begin to establish themselves. We do not want this.
Why? What problem can a small frog cause?
Well, first – they are (as many invasive species are) aggressive consumers – feeding on local treefrogs to where their populations begin to decline. With that “space” left open, the invasive species quickly fills in and increases their populations. Over time you have a “monoculture” of CTFs and lower biological diversity within the local frog populations.
Is this a problem? Does it matter which frog is occupying the space?
It can. Lower biodiversity can make it difficult for frog populations to recover from environmental stress, such as changes in habitat, damage due to storms, changes in prey species. Lower biodiversity can make populations more susceptible to the spread of disease and the potential elimination of the species because no one in the population is genetically different enough so that there are those with resistant genes. Then there is the case as to whether the native frog predators will eat the invasive CTFs. They do have a strong enough toxin in their skin to cause allergic reactions in humans. This could be enough to keep the predators from eating. This will cause the CTFs populations to increase even more (classic invasive story – fewer predators) and the decline of native frog predators – some of which can directly, or indirectly, can have an economic impact on our community. So, yes – it can matter.
Second, CTFs are known to “hang out” in electrical panels. As many as 30 were found in one electric panel at the zoo in New Orleans. Inhabiting such places have been known to cause electrical problems, including short circuiting HVAC systems. We do not want this.
This Cuban Treefrog was found at the site of the building of a new home in the Pensacola area. Photo: Keith Wilkins
Third, their calls have been described as “loud and sounding like a squeaky screen door”. This apparently drives some folks crazy. The noise is just too much. Of course, you would need a lot of CTFs to create such an unwanted serenade, but (reading above) you can see this could happen.
So, we would like to stop this before they become established, like the brown anoles and the lionfish.
What can we do?
First, be aware of what you are bringing home when you purchase landscaping plants from local vendors. Find out where their plants are grown and, if from the central/south Florida area, inspect the plant BEFORE you bring it home to make sure you are not bringing home anything else.
Second, if you find one – please consider reporting it. You can do this at www.EDDMapS.org. Log in (you will need a password – it is free) and report new sighting. If you get confused on how contact your local extension office and they can help walk you through it.
Get a photo if possible. We want to verify that it is a CTF and not one of the local native ones.
Cuban Treefrog Photo: UF IFAS
How do you tell them apart?
First, it must be a treefrog. Treefrogs will have webbed feet but there are large toepads at the end of each toe so that it can cling to trees, and the side of your house.
Second, CTFs are much larger. Our native treefrogs will reach about 2”, CTFs can reach 5”.
Third, what if it is a small CTF? If you turn them over, you will see their skeleton through the skin – and it will appear blue – the native species are not blue.
Fourth, they have “warty” skin. Many of the natives will have smooth skin. The local cricket frogs will have warty skin, but they are smaller and have a triangle shaped dark spot on top of the head between the eyes – the Cuban Treefrog does not have this.
Fifth, they do not have stripes. They may be solid in color or have patches of darker areas. They can change color and have been seen as green, gray, brown, and even a light beige/white color.
Sixth, the skin between their eyes is fused to their skulls – not so in the native frogs.
Note: the CTF does produce a strong toxin through the skin. Though not deadly, it can be irritating to the skin and more so to the face. If you handle without gloves, you should not touch your face until you have washed well.
Third, educate your neighbors to let them know. Not just about the CTF but other potential invasive threats that could be hitchhiking up this way. With a community effort we should be able to keep them from establishing here.
But there could be reason to keep an eye out. We are not talking about the common ribbed or hooked mussels we found in the Pensacola Bay area. We are talking about an invasive species called the green mussel (Perna viridis).
The green mussel differs from the local species by having a smooth shell and the green margin. Photo: Maia McGuire Florida Sea Grant
Why be concerned?
By nature, invasive species can be environmentally and/or economically problematic. In this case, it is more economic – which is unusual, most are more environmental concerns. The big problem is as a fouling organism. Like zebra mussels (Dreissena polymorpha), green mussels grow in dense clusters, covering intact screens to power plants, intact pipes to water plants, and can displace native spaces by competing for space. It has been determined they can grow to densities of 9600 mussels / m2 (that’s about 10 ft2) and they can do this on local oyster reefs – displacing native, and economically important, oysters. They grow quickly, being sexually mature in just a few months, and disperse their larva via the currents. To make things more interesting, they may be host to diseases that could impact oyster health.
So, what is the situation?
They are from the Indo-Pacific region, found all across southeast Asia and into the Persian Gulf. In this part of the world they are an aquaculture product. There was interest in starting green mussel aquaculture in China, and in Trinidad-Tobago. After they arrived in Trinidad, they were discovered in Venezuela, Jamaica, and Cuba – it is not believed this was due to re-locating aquaculture, but rather by larva dispersal across the sea… they got away.
This cluster of green mussels occupies space that could be occupied by bivavles like osyters.
It would be an easy jump from Cuba to Florida – and they came. The first record was in 1999 in Tampa Bay. They were found while divers were cleaning an underwater intake screen. Dispersal could have happened via larva transport in the currents, but it could have also occurred via ship ballast discharge at the port – this is how folks think it got there, they really do not know. From there they began to spread across the peninsula part of the state. They have been reported in 19 counties, most on the Gulf coast, and there is a record from Escambia County – however, that one was not confirmed.
How would I know one if I saw it?
They prefer shallow water and are often found in the intertidal zones – attached to pilings, seawalls, rocks. As mentioned, they grow in dense clusters and should be easy to find. They are long and smooth, with a mean length of 3.5 inches. There was one found in Florida measuring 6.8 inches, which they believe is a world record. Mussels differ from oysters in that they attach using “hairy” fibrous byssal threads – in lieu of cementing themselves as oysters do. As mentioned, the shell is smooth and may have growth rings, but it lacks the “ribbed” pattern we see on the local ribbed and hooked mussel. It will have a green coloration along the margin – hence its name, and the interior of the shell will be pearly white.
The shell at the far right is the common ribbed mussel native to our local salt marshes. Just to the left is the invasive green mussel. Can you tell them apart? Photo: Maia McGuire Florida Sea Grant
They prefer salinities between 20-28‰, which would be the lower portions of the Pensacola Bay system (Santa Rosa Sound, Big Lagoon, maybe portions of Pensacola Bay). They are not a fan of cold water. They do not like to be in water at (or colder) than 60°F. Some biologist believe it is too cold in the panhandle for these bivalves, but we should report any we think may be them – to be sure.
What do we do if found?
1) Get a location and photos. Pull some off and get up close photos of an individual.
2) Report it. You can do this by contact the Escambia County extension office (850-475-5230 ext.111), or email me at roc1@ufl.edu.
3) If there is a method of removing all of them, do so. But this should be done only after the identification is verified. When removing try to collect all the shell material. The fertilized gametes within, if left, can still disperse the animal.
4) They are suggesting boat owners check their vessels when trailering. Avoid transporting them from one body of water to another.
5) I would recommend that marina owners do the same – check boats and pilings.
It appears the mean temperature of the Gulf is increasing. With this change it is possible some of the tropical species common in south Florida could disperse to our region, and that could include the green mussel. The most effective (and cheapest) way to manage an invasive species is catch them early and remove them before they can become established.
Chinese Tallow, also known as the Popcorn Tree, was introduced in the US over 200 years ago. Ben Franklin sent seeds over in 1772. Although Franklin was blamed for the invasion in the U.S. Gulf Coast, scientists performed genetic testing and have concluded that the blame actually lies with federal biologists who imported some Chinese tallow trees around 1905. Popcorn trees have continued to spread throughout the US since then.
For many years, people have planted them in their landscape for shade and fall color. Once established, they invade natural areas, pastures, wetlands and yards. They out-compete native and non-invasive trees and shrubs. In 1998, Chinese Tallow was added to the Florida Department of Agriculture and Consumer Services Noxious Weed list. Plants on the Florida Noxious Weed list may not be introduced, possessed, moved, or released without a permit.
Landowners and homeowners can help with this problem tree by removing and replacing them with a native or non-invasive tree like black gum, maple, dogwood, or crepe myrtle. Mature trees can be cut down with a saw and the stump promptly treated with an herbicide with the active ingredient, triclopyr amine. You should try to make the final cut as low to the ground as possible. You can use a paint brush to apply the herbicide to the stump. A basal bark application of triclopyr ester plus a basal oil carrier can be used on smaller trees. Treat the trunk to a height of 12 to 15 inches from the ground, thoroughly wetting it with the herbicide mixture. Basal bark treatments are only effective on saplings and seedlings less than 6 inches in stem diameter. Sometimes suckers may sprout from remaining roots. A foliar application can be used on these sprouts from July to October, before onset of fall color.
