Invasivores Andy and Matt take a perfect spring afternoon to collect burdock, Chinese mystery Snails, and garlic mustard.

A Subaru of edible invaders. Photo Credit: A. Deines

At the end of a long semester, the Invasivores needed some field work.  We are, above all, ecologists and there is no lab work for self respecting ecologists on this kind of day.  We couldn’t have asked for a better one to kick-start a summer of collecting edible invasive species.

First target: Phragmites

One of the first species we were able to collect last year was phragmities, a common perennial reed in wetlands.  Munching dandelion heads, we came several weeks later this year than last and with the much earlier spring, the forest underbrush was thick.  Stinging nettles turned us back to the path.

Target two: burdock

Chaco’d feet and short-bared legs stinging, we looped back and spotted the large leaves of burdock tucked at the margin of the grass and trees.  Success! We knelt and with gentle probing, large portions of the starchy tap-root revealed themselves.  Roots and comical leaves like elephant ears in tow, the sun and sweat propelled us toward the lake.

Target three: Chinese Mystery Snails

Kayakers and bass boats floating nearby, we stepped down into Worster Lake.  The Chinese mystery snail was our first featured species at Invasivore, and we were excited to give them another go.  The shallow water was warm on bare feet and soothing on still stinging and nettled skin.  Though not at the extreme densities of many mystery snail invasions, we found a meal’s worth with only a few minutes of searching.  Success! Aquatic ecologists to the core, we turned some rocks to find a few crayfish, though we couldn’t positively identify whether they were invasive or native.  Another meal for another trip with a trap, perhaps.

 Target four: Garlic Mustard

What a love-hate relationship we have with garlic mustard. While my ecology students may never forget garlic mustard relish, my friends will never forgive me for garlic mustard ice cream.  Garlic mustard is ubiquitous this time of year in the midwest, so we thought for sure we would find a bundle.  It turns out that the park has an active program to remove garlic mustard and we found only a few plants.  Such a failure is truly a rare success!

Overall, it was quite a successful trip for these invasivores.  Keep an eye out for some recipes describing what we did with our delicious harvest!

A buffet of eating invasive species news and notes from around the internet

• Talking invasive species over beers in Austin- wish we could have been there!
• WI Sea Grant’s Tim Campbell reflects on eating Asian carp
• We love stories about goats eating invasive species
• Invasive species field course to be taught in Michigan June 25-27
• New scientific paper sorts out the advantages and disadvantages of eating invasive species

When it comes to invasives, three key words are prevention, prevention, and prevention.  We know that an efficient and strategic way to combat invasive species is to keep them from establishment in the first place, such as through quarantines, screening mechanisms, or black lists.  A useful question for such prevention policies is, “Which are the probable future invaders, where and how should we target our efforts?”  Well, particular traits (high resource allocation to reproduction, wide environmental tolerance) and a “bad reputation” (invasiveness elsewhere) can be useful predictors.  Now, a recent article in Frontiers in Ecology and the Environment demonstrates a new and interesting way of predicting future invasives.  They analyze trends in the global trade and climate change to identify emerging scenarios of foreign plant introduction and establishment, e.g., where are plants coming from, where are they being planted, and what are their characteristics.

The authors focus on plant introductions to the USA via the horticulture trade- legal sale of ornamental species.  Among these species, climate change is likely to reduce need for cold-hardy plants and increase the need for drought-tolerant plants.  Simultaneously, several regions of the world are rapidly increasing their involvement in global trade, primarily the Middle East, the tropics, and Eastern Europe.  Putting these two facts together, one sees that “global change will influence not just the success of introduced plants but the introduction process itself.”    As most new plant introductions occur soon after trade partnerships are formed, these regions are expected to contribute a “wave” of new introductions.

Desert plants in southern California. From wiki commons

This may be especially relevant for the relatively dry, low population density Central-Western USA, where introduced species currently make up 10 to 15% of the flora, compared to 25 to 30% for many mesic, Eastern states.  Human populations are now expanding in the West, which will likely increase propogule pressure of non-natives.  Gardeners are also planting more drought-tolerant species (called xeriscaping), due to increased recognition of water scarcity. The authors point out that there is much potential for native species to play a role in xeriscaping, but a survey of nursery catalogs shows an uncertain future: despite a trend for greater use of native species, more than half of currently offered drought-tolerant species are non-native.

The authors also look at temperature trends, specifically at a northward shift in hardiness zones, a way of predicting where plants can survive, based on low winter temperatures.  Strong northward shifts are expected for warmest zones 8 and 9.  The authors predict two main consequences for these areas: native species will show decreased fitness in these areas while newly introduced, pre-adapted non-natives can show increased performance.  This imbalance in competitive ability makes invasions more likely here.

Tne main conclusion is that emerging trade partners have climatic conditions just suited to trends in changing temperature and water conditions in the USA, so policy should focus on these regions and types of species.  One policy is weed risk assessments, a pre-emptive examination of an imported species’ ability to invade, to create “white lists” of allowed species.  Unfortunately, information on biology, ecology and invasive potential of species new to the horticulture trade will likely be low.  The authors caution that low information does not mean low invasion probability.  The authors propose increasing communication between invasive species biologists and the buyers and sellers of plants, especially to identify and encourage native alternatives for gardening.  In the other direction, nurseries can share information with biologists about the results of field trials of new plants.  Collaboration among industry, local gardening clubs, government and scientists, could effectively prevent many new invasions.

Effective prevention might spell the end of our invasivore diets, but I think we would agree that would be for the best!

Eating invasive species news and notes from around the internet!

• Bizarre Foods expert Andrew Zimmern talks eating invasive species in an interview with NPR
• The Queen will soon dine on sea lamprey pie
• High school students in Michigan learn about invasions while cooking Asian carp
• CNN reports on eating lionfish in Florida
• Controversy over the feral swine legislation in Michigan
• Invasive species alert: an early spring means now is a great time to get out and harvest garlic mustard
• Rock snot discovered in the Delaware River- does anyone know if it’s edible?

Necessary equipment:

• Medium pan
• Slow cooker or large pot/dutch oven

Ingredients:

• 1 whole rabbit cut into 6 equal pieces
• 1/2 cup flour seasoned with salt and pepper
• 1 medium yellow onion sliced into thick strips
• 1/2 – 1 lb of baby portobello mushrooms (aka crimini mushrooms), washed
• 1 whole bulb of garlic
• Some olive oil
• Some white wine
• 2 medium sized turnips peeled and cut into ~2 cm (3/4 inch) pieces
• 8 small red potatoes, rinsed, with skin
• Salt and pepper
• 4 cups flavored stock (I didn’t have enough chicken bouillon to make 4 cups, so I supplemented it with vegetable)
• 2-3 sprigs of fresh thyme
• 3 Tablespoons of cornstarch slurried in 1/8 cup of water (for thickening, leave out if you like your stews thin)

Optional ingredients:

• Liver from the rabbit

Instructions:

1. Preheat the oven to 375°F
2. Cut the top third off of the garlic bulb, drizzle it with olive oil, then loosely wrap in aluminum and bake for 45 min

Meanwhile…

1. Heat a pan to medium/medium-low heat (this part depends on your burners, you want it hot enough to lightly sauté your onions, no burning or charring)
2. Season rabbit pieces with salt and pepper while pan is heating
3. Pour enough olive oil to lightly cover the bottom of the pan and sauté onions and the few bits of garlic that were in the top third of the garlic bulb you just cut (waste not; want not right?)
4. While the onions and garlic are sautéing, dredge the rabbit pieces in your seasoned flour (shaking off excess flour)
5. When the onions and garlic pieces are soft, turn up the heat to medium and brown the rabbit pieces on both sides 
6. When you have time during the browning process, peel and cut the turnips and put them at the bottom of your slow cooker/stew pot and then throw in the rinsed potatoes
7. DON’T FORGET ABOUT YOUR ROASTING GARLIC IN THE OVEN! Take it out when it is done and allow to cool
8. If your pan is not large enough to hold all the rabbit pieces and onion/garlic mix, rotate the mix and browned rabbit pieces into the pot as well
9. Once there is space in the pan, add a little more oil to the pan and briefly sauté the mushrooms 
10. Remove any remaining rabbit from the pan (leave the mushrooms), and deglaze the pan with some of that white wine and allow to cook down to about half the volume of the liquid.
11. Extract half of your roasted garlic cloves from their skin and throw them in the pot (save the other half to spread over bread with a soft ripened cheese).
12. Throw the mushrooms and remaining liquid into the pot along with the thyme 
13. Add enough stock to fill the pot
14. Fire up the slow cooker to high for 30 min to 1 hour, then turn down to low and it go for ~6 hours.  If you’re using a pot, bring the liquid to a boil and then lower the heat to medium and cook for another hour or so until the rabbit meat is falling off the bone (but still maintains structural integrity).
15. When nearly ready to serve, pour in cornstarch slurry, mix well, and heat until liquid thickens.
16. When done, turn off the heat stir in the chopped up liver and (the liver will cook with the heat of the stew).

Happy Earth Day from invasivore.org!  Here’s a helping of eating invasive species news and notes to help you celebrate.

Hopefully appetites for invasive species are bigger in Texas, too.

Canadians banding together to fight invasive garlic mustard.  (Just don’t eat the weeds pulled from the side of the road!)

And here’s a little food science humor.

This species profile is a guest contribution from Dr. Sean Hoban, a postdoctoral scholar and food blogger in Italy. 

“Here we go round the mulberry bush… in search of an invasive treat.”

The fruits of white mulberry (Morus alba) resemble blackberries in appearance and taste- sweet and tart.  White mulberries are available from late spring to summer.  They are ripe when you can gently pull them from their branches.  One particularly efficient method of harvest (and a method that will help avoid staining your hands purple!) is to spread a sheet on the ground and shake the tree.

The fruit can be eaten raw (especially good with fresh cream), put into pies or tarts or jams, or made into wine.  Eat or prepare the fruit promptly- they will ferment or mold after just a few days in the fridge.  They can, however, be frozen for longer storage.

White mulberry photo courtesy of Will Cook http://www.duke.edu/~cwcook/trees/moal.html

Fast facts:

The release of mulberry pollen grains is literally explosive!  Grains are propelled from the catkins (male flowers) at a speed of 350 mph, among the fastest movements in plants.

The name “white mulberry” can be misleading.  The berries are not necessarily white (although sometimes they are), and they are not even true berries.  Rather, they are a fruit known as an aggregated drupe.

The wood of mulberry trees is used in hockey sticks.

Commander Ben- A small Texan makes a big splash.   This kid is awesome.

Invasives for Biofuels- Growing Risks.  Report from the National Wildlife Federation.

 First axis deer reported killed on Big Island

 This species profile is a guest contribution from Dr. Sean Hoban, a postdoctoral scholar and food blogger in Italy.  

“I still remember discovering a row of small trees with a fruit like a blackberry and leaves vaguely resembling sassafras on my path to school.  After a little research, I began to gather handfuls of fruit each day on my walk home.”  

White mulberry (Morus alba), a fast-growing (as a seedling, four feet per year!), deciduous, medium size (generally 10 to 20 m tall) tree, was introduced from northern China to North America from the 16^th to the 19^th century to feed silkworms.  Though my own row of trees still bore silken nests full of wriggling worms, the silk industry never came to fruition and white mulberry was here to stay, finding use as an ornamental tree and as supplemental feed for livestock in the dry season.  Due to its strong branches, it is also planted as a windbreak and apparently makes a great climbing tree.  It is tolerant of drought, poor soil, and pollution, so is common in urban environments.  Some homeowners plant mulberry because of its propensity to attract many birds- it is a favorite food of cardinals, robins, orioles, finches, thrushes and more.

White mulberry leaves (though considerable variation in leaf structure exists). Photo courtesy of Wikimedia Commons.

With widespread planting over more than two centuries, and continued distribution by nurseries, white mulberry has naturalized in semiurban and rural areas in most states and three Canadian provinces as well as central Asia and southern Europe.  A detailed description of its invasive occurrence, by region, is found here.  Rapid growth, aggressive and deep roots, tolerance of poor soils, and efficient dispersal mechanism (small mammals and birds eat the berries, spreading them far and wide) makes white mulberry a terrific invader.  White mulberry can be particularly difficult to eradicate once established.  If cut down, stumps can sprout and grow vigorously into a new tree.  It can form dense stands that exclude other plants.  One of the main recognized threats of white mulberry is to the native red mulberry (Morus rubra), found throughout the eastern hardwood forest.  The species are weakly differentiated genetically and ecologically, and are highly interfertile.  Therefore, the non-native is a direct and successful competitor for space, and is gradually replacing the native with hybrids- white mulberry and hybrids may now outnumber the native red mulberry!

Distinguishing the two species is difficult, but guides with excellent pictures of buds, bark and leaves can help.  One way you can control this invader is to make sure that your next nursery purchase is a native red mulberry rather than its invasive relative (and request that your nursery promote indigenous species in general).  Also, inquire with your local, state, or regional authorities to see if parks and roadsides are landscaped with natives.

If you are able to identify the white mulberries in your neighborhood or local woodlot, you can help limit reproductive success through delicious harvest!  Stay tuned for our tips on white mulberry harvest and preparation.

A buffet of invasive species news and notes from around the internet

Make way for the Easter Bilby! seeks to raise awareness about invasive rabbits (and endangered bilbies) in Australia.

Volunteers are taking back the forest in Fairfax County, Virginia.  While they’re at it, perhaps they’ll help save Virginia’s ecosystem through invasivory.

A recent study finds evidence of much higher hybridization between native and invasive trees in human-influenced landscapes compared to undisturbed forests

Identifying and Eating Japanese Knotweed

Encouraging invasivory isn’t always a good thing as evidenced by ongoing struggles in biofuels development.