Friday, August 31, 2012

Earthworm Invasion

Northern Maple forest without earthworms.
As odd as it might sound, earthworms are not native to the northern United States and Canada.  Why? Well, as glaciers receded from the northern portion of North America 11,000 years ago, they left behind a bitterly cold and extremely muddy waste land.  These glaciers reached from the north to their southern the extent of present day norther Iowa, Illinois, and Indiana.  Along this southern extent of the glacial line and northward there have been no earthworms until recently.  Worms simply couldn't survive the frigidly cold temperatures and frozen tundra when glaciers were present in these areas.  Further south however, where glaciers never reached, earthworms have been around for a long time. 

Within recent decades however, earthworms began showing-up in these formerly glaciated soils of the north.  This might not seem that weird until you realize that earth worms travel an average of 5 or 6 yards a year.  Over 11,000 years that equals only about 40 miles, which is a ridiculously slow rate that wouldn't have even allowed them to travel across an entire state.  Even if you double or triple that distance it doesn't even come close to the distance the worms would need to travel to show up in these northern forests.  So how did they move thousands of miles in just a few decades?  The only explanation is that humans carried them.  Fishermen and gardeners are especially notorious for carrying earthworms long distances.  As a result, worms were accidentally introduced to new locations hundreds of miles away from the nearest native worms. 

Northern Maple forest with earthworms.
Most people might think this is a good thing.  Worms are very good for garden soil after all.  The reality is though, worms are not very good for northern forest soils.  Worms are extremely efficient at what they do, which is break down organic materials such as dead leaves.  They do this extremely rapidly, moving nutrients from dead organic materials into the soil quickly.  As a result, plants cannot absorb the nutrients as fast as need and much is lost when water washes it out of the soil.  The burrowing action of worms also functions to compact forest soils, making it more difficult for plants to survive.  While some plants are well adapted to earthworms crawling around through their roots, other plants are extremely sensitive.  Sugar Maples, one of the dominant plants in these northern forests, is extremely sensitive to earthworms. Establishment of maple seedlings where earthworms are present becomes very difficult.  Northern forests with earthworms have far fewer plants than forests without earthworms.  Simply by changing soil and forest floor structure, the earthworm has a huge effect on the overall habitat. 

Fortunately, earthworms have not taken over every single forest in these northern areas.  Also fortunate is the fact that worms only travel about 6 yards a year.  This means, if people quit transporting worms to new areas in the north, populations of worms aren't going to expand much. 

Great Lakes Worm Watch

Monday, August 27, 2012

Life of a Maple Part 3: The Maple Tree and Sunlight

When it comes to soil, Sugar Maples are pretty picky.  When it comes to sunlight however, maples aren't picky at all.  Other trees, such as oaks, prefer to have as much sunlight as possible through out their entire lifespan.  Maples however can do quite well with very low levels of light early on in life.  This is a very fortunate adaptation being the most ideal soils for maples are typically going to be located in the shade of large trees.  Lots of, but not complete, shade aids the germination and early sprouts of maples.  However, maple seedlings will often have stunted growth in very low light situations.  Small seedlings and saplings are capable of surviving many years in the shade of larger trees.  Other sun loving trees such as oaks simply would die due to lack of sunlight.  These small maple trees simply wait until the larger tree dies and is removed by ice storms, wind, or disease.  The wait for an older maple to die can be a long one though being they are capable of living 500 years. 

Once these over-story trees are out of the way, smaller trees that had waited patiently in the shade for years suddenly make a bolt for the sky until becoming a dominant tree in the forest canopy.  This cycle can then repeat itself many times over with younger maples replacing older maples.  This self sustaining process of the Sugar Maple forest will continue unless significant disturbance such as fire or major drought take place.  If disturbance does happen, plants that require more light, such as grasslands or oak forests, will replace the maple trees.  Given time though, and lack of disturbance, after a hundred or more years the maples will replace sun loving trees such as oaks and will again dominate the forest.  This process of one plant community replacing another plant community is called succession.  Maple forests typically are the last stage in succession, which is called the climax plant community. 

Slow growth, long life, and tolerance for shade are what make the maple a climax forest species.  Faster growing trees with shorter lives typically require lots of light and occupy areas after a major disturbance such as fire.  The slow growing maple tolerates the shade and out live these faster short lived species.   Shade tolerance is one of the most important adaptations maples have to being a late successional climax tree.  There are a number of more minor adaptations that aid in the overall shade tolerance of maple.  First off, maples form large thin leaves that gather light very well.  Leaves lack pubescence, or hairiness, which would block light.  These leaves also grow to orient themselves in a manner that helps them gather the most sun light.  Pigments inside of the leaves also are especially adapted to gathering far red light which is abundant in shady environments.  Lastly, maples produce a huge number of leaves in their canopies in order to catch as much light as possible.  Such a great density of leaves are produced by Sugar Maples that the top 10 percent of leaves gather 60 percent of the total sunlight. 

Friday, August 24, 2012

The Amazing Potato

When we think of potatoes we probably think of Ireland, or Germany, or possibly Idaho.  Really though, we should think of ancient Peru and the South American Andes Mountains.  In the high elevations of these steep mountains is where the potato originated up to ten thousand years ago.  During these ancient times, literally thousands of varieties of potatoes were developed, a far cry from the handful of varieties typically available in the grocery store today.  It wasn't until the late 1500's through when explorers finally brought potatoes to Europe.  Then, by the 1700's potatoes had spread across Europe and provided the agricultural system and calories needed to start the industrial revolution.  It is very likely that without the potato being imported from South America the industrial revolution would have never happened.  Without the potato, today's society would be vastly different from what it is, and I'm not just talking about the supper table.  Without the food provided by the potato, much of the technology we have today probably wouldn't be around.

Today, many of the thousands of varieties of potatoes are still found in the Andes Mountains.  Modern varieties of potatoes developed for wide scale agriculture are more productive though.  This additional productivity is not without its cost though.  Old varieties, possibly thousands of years old, are more disease resistant, require fewer pesticides and fertilizers, are less prone to crop failure, and taste better.  The increased productivity of modern varieties comes at the cost of requiring more chemicals, being more prone to disease and failure, and don't taste as good.  Each of the old varieties has a distinct color, consistency, and taste making the potato a very diverse food fit for nearly every meal.  Columbia for example uses a great diversity of potatoes in nearly every distinctly Columbian recipe.

If you want to grow potatoes for yourself, the easiest thing to do is buy a potato at the store.  The potato can be planted whole in the soil.  Or, you can wait until "eyes" grow on the potato and cut a square inch or so size chunk of potato out around the eye.  Let the eye and attached chunk of potato dry out for a day and then bury an inch or so in the soil.  Potatoes aren't extremely picky on soil type, but do not do extremely well in high clay content soil or rocky soil.  Make sure the soil remains moist but not soaking wet. 

To see some of the variety of potatoes check out these National Geographic photos: Potato Variety

Also, check out this CNN article: American's just don't understand the potato.  Columbian's do.

Monday, August 20, 2012

Life of a Maple Part 2: Soil and Roots

A moist maple forest with rich soil.
A Sugar Maple seed doesn't get to choose where and what type of soil it gets to land on.  Typically, where the seed lands is a result of wind direction and strength at the time it falls.  Where ever the seed germinates and begins to grow is where it will spend the rest of its life.  The unfortunate majority will die long before reaching a foot in height.  Often, predators such as deer and squirrels, find the young seedling far to appetizing to pass it by.  Many seedlings will also unfortunately find themselves in soil that is less than ideal.  As far as deciduous forest trees go, the Sugar Maple is quite picky, much like Goldilocks.  The soil can't be too wet or the roots will suffocate as they drown in the water soaked soil.   Neither can the soil be too dry or the roots will dehydrate.  Nor can the soil have too much clay or too much sand.  They soil has to be just right. Even when the soil has just the right texture (meaning the right amounts of clay and sand) and the right amount of water, the soil might not be good enough.  The soil also has to have high levels of nutrients.  Soils with low nitrogen or calcium may prevent healthy growth and longevity of maples.  Even then, maples seem to prefer very deep soils deposited by glaciers over any other type of soil.  The maple is very picky...

The reason the maple is so very picky is because of its roots.  Just like branches of deciduous trees shed their leaves annually, larger roots also shed tiny roots annually and with dry weather.  Maples produce an abundance of these fine roots at very shallow depths, right where the nutrients are highest.  It has been estimated that 60 percent of annual productivity of maples is actually contained within these roots.  This is quite amazing when you consider the great density of leaves maple trees produce annually.  The fact that so much of the tree is in-fact these very sensitive tiny roots makes the whole tree very sensitive to whatever happens on or in the most shallow layers of soil.  Trampling by foot traffic, vehicles, or cattle can damage these roots as well as cause the soil to dry out, killing the roots and potentially killing the whole tree.  If fire burns across the ground, the surface soil will be significantly dried out also potentially killing the roots.  The heat of the fire can also kill the roots very easily.  Pollution, such as acid rain, can change the chemistry of the soil, also killing fine roots and damaging the overall tree.

Fortunately, the maple tree does have some adaptations that help make it at least a little less sensitive to changes in the surface soil.  For one, the overall root system of maples is capable of hydraulically redistributing moisture from deep within the soil to more shallow soils.  The thick shade of maples also helps to prevent evaporation of moisture from the soil.  Also, the fact that maples transpire, or "exhale", large amounts of water vapor while photosynthesizing helps cool the environment and increase humidity.  Fallen leaves are very absorbent and are a very effective mulch that help hold moisture in the soil.  All of this helps moisture to be retained within the soil where it can be utilized by the tree and prevents moisture from evaporating into the environment.  All around, the maple works to keep its environment as moist as possible.
Sugar Maple tree in fall.

Friday, August 17, 2012

Life of a Maple Tree: Part 1 Seed to Sprout

I'll be starting a new series on the blog about the life cycle of the maple tree, specifically the sugar maple.  This is sort of a follow-up to the series on oaks and hickory trees.  Maples are sort of a logical follow-up to the oak-hickory forest being they are later successional species to the oaks and hickories.
Sugar Maple leave

The life of a maple tree begins with the charismatic "whirlybird" seed which fall like helicopters from the mother maple.  Often masses of these seeds will blow off of mature maples and twirl to the ground on windy fall days.  Technically, these "whirlybird" seeds are called samara, which are simple seeds with a flattened papery wing-like portion.  The whirlybird nature of these seeds helps the wind to carry them a long to new locations, often hundreds of yards away.  Then hopefully, the seed will be able to sprout and develop into a new tree.

Once on the ground, the maple seed prefers moist and undisturbed locations, such as in a maple forest or an oak-hickory forest that has not been disturbed by fire.  This is because the maple seed is not well protected.  While the wing portion of the samara is good for transporting the seed with the wind, it doesn't do much else.  The seed requires a moist area, and is easily killed by damage from trampling animals, dehydration, or heat from fire.  Once on the ground though the seed becomes actively searched out for by numerous small animals such as rabbits, squirrels, and mice.  Predation really isn't too much of a problem though, the maple tree typically produces so many seeds that it overwhelms predators.  Predators have plenty to go around and there are still plenty of seeds left over to germinate and sprout. 
Sugar Maple samara seeds.
If not found by seed predators on the ground, the seed than requires the cold of winter in order for it to germinate.  Without cold, the seed will not germinate.  Many species of trees, such as oaks, have a difficult time establishing themselves in soil covered with a thick layer of leaves.  Oaks therefore require the ground to be disturbed by fire so their acorns can sprout and grow.  The maple however, does not have this problem and prefers undisturbed forest ground cover, often thickly covered with dead leaves.  Once germinated, the root easily penetrates through thick moist layers of leaves from the previous year. 

Another oddity of the maple is that it prefers shade.  The maple does not like competition with other small plants such as grasses and shrubs.  It does to quite well though when growing under the canopy of mature trees that shade-out other plants.  In-fact, maple seeds germinate and grow best where there is 50 percent or more shade.  In these areas tiny maple seeds can sprout by the thousands, often leading to a carpet of young maple trees.  The problem though is, once germinated there is so little light in these areas the trees will not grow very large and growth will be stunted.  Again though, the maple is adapted to this situation, being able to survive, but not grow, in minimal light retirements for many years.  The tiny stunted tree simply waits until older larger trees casting shade on the forest floor die.  Once these larger trees die, the tiny maple tree grows rapidly in the new sunlight. 

During the potentially long period of time that a maple seedling remains a small stunted tree it is important that the forest remains undisturbed.  Fire and drought both will easily kill these seedlings.  Predators, such as deer, also heavily browse on "carpets" of small maple seedlings.  Usually though, plenty of seedlings survive predation with drought and fire being the big killers. 

Wednesday, August 15, 2012

grounded design by Thomas Rainer: Why I Don't Believe in Low Maintenance Landscapes

I love this blog post I came across.  I personally believe landscapes are meant to be productive elements of our lives, and this requires maintenance.   This maintenance, and the products of the landscape, benefit us in innumerable ways.  From: Grounded Design

grounded design by Thomas Rainer: Why I Don't Believe in Low Maintenance Landscapes: The American obsession with low maintenance landscapes is a problem. Here’s why. There are several phrases I’ve learned to dread from clients. “I want to swim by Memorial Day,” is always a heart-stopper, particularly when you were hired in March to design a swimming pool and garden. “I want this garden to look perfect for my daughter’s wedding,” is perhaps the most dreaded phrase of all. If you ever hear that one, run far away. But the phrase that makes me cringe the most is a phrase I hear all the time: “I want this to be low maintenance.”

A low maintenance landscape is a rather innocuous request. It is also, of course, an absolutely sensible one. After all, who has the time or resources to pour endless hours into a landscape? Plus, traditional maintenance often focuses on chemical inputs and gas-powered machinery, all of which are bad for the environment. Perhaps low maintenance landscapes are both good for people and the environment, right?

Yes and no. “Low maintenance” is not just an idea, it is an ideology. It is the promise of more for less. As Americans, we still believe cheap, fertile land is our manifest destiny. We deserve bounty without labor, satisfaction without commitment.

The ideology of low maintenance has received new fervor from advocates of sustainable landscapes. In eco-speak, maintenance is a dirty word. Maintenance means gas-powered machinery, irrigation systems, and petro-chemicals. A low maintenance landscape is natural.

The promise of low maintenance landscapes is an empty one. The very idea that you can do less and have more is a mythology. Landscapes constantly change and require input—lots of it—to look the way we want them to. Lines blur, plants suffer without water, and weeds move in. Nothing stays the same. Even naturalistic and native landscapes require heavy interventions to look natural. In nature, thousands of years of natural selection create relatively stable environments. In our yards, our active engagement is the sine qua non of a garden. The less we do, the worse our yards look. 

Friday, August 10, 2012

Three Sisters Garden: Companion Plants, Corn, Beans, Squash

Companion plantings seem to one of the latest rages in the gardening world right not.  There is of course very good reason for this, but it really isn't anything new.  In-fact, companion planting has been around for thousands of years.  It seems that only recently as people have tried to return to more sustainable, organic food production has the practice of companion planting been rediscovered.  Companion planting simply is growing two different plants in close association with one another in order to increase productivity.  For example, tomatoes and basil grow well together.  One of the better known companion planting is also possibly the oldest, known as the three sisters.  The three sisters are corn, beans and squash.  These three plants have been grown together for many thousands of years in North America.  Originally, the three sisters were used in present day Mexico but spread north and south throughout the Americas.  The spread and success of these associated crops is owed to there agricultural and nutritional compatibility. 

Agriculturally, corn, beans, and squash grow extremely well together.  The corn grows, providing a trellis for the beans to grow on.  The beans fertilize the soil for the corn and squash.  The squash provides ground cover, helping to cool and hold water in the soil for all of the plants.  Nutritionally they also work extremely well together.  Beans and corn individually do not provide the correct amino acids required by the body.  Together though they provide all the necessary amino acids making them a complete protein.  Squash provides essential vitamins and squash seeds provide healthy fats.  With all of these complementary agricultural and health benefits it is easy to see why the three sisters became dietary staples for Native Americans through out the Americas.

Today, the three sisters still work well together and can still be grown in the garden.  Planting these though requires a little more thought than just planting a patch of corn.  In order to get the three sisters to succeed corn must be planted first.  Then, after corn has grown to six inches tall, pole beans can be planted six to 12 inches away from the corn.  Squash, or melons, can also be planted at that time 12 inches away from the beans, but furthest away from the corn. I have found that if all the seeds are planted at once, the beans and squash can easily over-run the corn.  Once the beans are large enough the beans may need to be trained to climb up the corn stalk.  Squash vines also can be oriented to grow where you want them to.  Historically, some Native Americans grew their three sisters in patches of several corn stalks, several bean plants, and a few squash plants.  This seems to work best only when there is a lot of space available.  With the limited space in most peoples gardens, widely spaced rows seem to work well.  Widely spaced rows in the three sisters in was historically and still is today most common in central Mexico.  Farmers in central Mexico also add numerous other crops such as tomatoes, sweet potatoes, and tomatillos to the three sisters.  I have made numerous attempts at growing the three sisters with moderate success and plan to keep experimenting in the future until I can get a good working system.

Wednesday, August 8, 2012

Invasive Species: Eat Them Before They Eat Everything

Article and photo from Eatocracy:
A growing number of conservationists are advocating the consumption of invasive species in an effort to fend off environmental destruction.
Invasive species, as defined by the USDA’s National Agricultural Library, aren't native to the local ecosystem and may cause economic, environmental or medical harm. They can exist in many forms: plants, animals or even microorganisms.
Many of the invasive plants, such as dandelion and purslane, were originally introduced by settlers for medicinal or ornamental reasons, while many of theinvasive animals like Asian carp and green iguanas were brought in as food sources, pets or for pest control.

Mongooses, one example, were originally imported from Southeast Asia to control rodent and snake populations in Caribbean and Hawaiian agricultural fields.  The Hawaii Invasive Species Partnerships has since estimated that the species causes $50 million in damages each year in Puerto Rico and Hawaii alone.
From feral hogs running wild in Texas to lionfish eating their way through the Gulf of Mexico to kudzu, whose nickname “the vine that ate the South” speaks for itself, the United States is facing an invasion of the natural resource snatchers.
While kudzu may have swallowed up the South, conservationists and food activists are encouraging American consumers to bite back.
“Why not combine the growing locavore movement with an ecological awareness and try and reduce some of these species?” says Joe Roman, conservation biologist, author and editor of “It’s unlikely we’re ever going to eat them to extinction but we can reduce the numbers that are there and also get an excellent meal.”
Because these species typically won’t encounter natural predators, it’s primarily up to humans to control or remove the invaders. Some managerial methods involve mechanical control, like digging or mowing, or chemical control, like pesticides and herbicides. Or, people could eat them.
There are, of course, major hurdles with upping the consumption of invasive species. For one, most could use an image overhaul.
“Here in America, we’ve raised two generations of consumers to think that only luxury cut from the center of the animal is what we should eat,” says Andrew Zimmern, the host of “Bizarre Foods” on the Travel Channel. “And only from three or four animals, I might add.”
Nutria, for example, is a giant water-born rodent – but many chefs compare the taste to that of a succulent rabbit. It’s all about consumer perception.
“You start to stretch our food imagination, we can take it in sorts of great directions,” says Zimmern.
“Think of a species that now shows up on menus that people wouldn’t have dreamed of eating maybe a decade or two ago. There is certainly an ‘ick factor’ we’re going to have to get over to promote this,” says Roman.
Chef Bun Lai, at his restaurant Miya’s in New Haven, Connecticut, actively pursues this sort of rebranding.
Miya’s offers an invasive species menu, with ingredients like European green crabs, lionfish, knotweed and wild swans, that threaten the local ecosystems.
“We hope that this will do a few things. First of all, it could potentially curb the dominance of invasive species in the ecosystem. Secondly, it would provide the seafood industry a greater supply of native seafood and reduce the stresses on those populations already fished,” Lai explains on the restaurant’s website. “Finally, we hope that it would encourage greater balance in the inter-regenerative relationship between man and the oceans.”
As with any strategy though, there are always risks. First, not all invasive species are safe for human consumption. Providing educational resources about how to prepare certain species (for lionfish, remove the poisonous spines) and what is and is not safe to forage is crucial.
Secondly, marketing an invasive species could encourage less scrupulous entrepreneurs to move these species where they didn’t already exist because they are potentially lucrative, Roman says. That could easily backfire and spread the species’ destruction even further.
Then, there are concerns of depleting the population, which Zimmern adds, wouldn’t be a bad thing because, after all, they’re not naturally supposed to be there.
“Let’s get to the point where they’re extinct or nearly extinct and then they’re a manageable resource. Let’s farm them, let’s do other things with it, but we can’t just let these invasive species be out in the wild,” he says.
Although population control is obviously at the forefront of the invasive species battle and consumer appeal is only part of the invasive solution, Zimmern says there is another opportunity: take them out of the ecosystem and find a way to feed hungry people.
“The biggest problem with the invasive species argument - in terms of not eating them - is people are hungry, these are good foods,” he says.
With protein’s high expense and one in six people living in hunger, Zimmern advocates in collecting invasive species and using that meat to feed children, seniors, people in the jail system and other people living below the poverty line.
“I will tell you right now, as someone that’s had a bologna sandwich in jail, I would prefer to eat nutria every day of the week,” he says.
Spaghetti and Periwinkles (Snails)
Serves 4 to 6
Used with permission from
About 2 cups of periwinkles in shells
3 cloves garlic
1 teaspoon dried parsley
1 tablespoon olive oil
3 cups plum tomatoes from the garden, or a 20 oz. can of imported Italian plum tomatoes
Salt and pepper to taste
1 pound spaghetti
Grated Parmesan cheese
Italian bread
Wash the snails in cold water. Add periwinkles to a pot of boiling water, along with a small handful of salt to shrink and toughen the meat. (This eases their removal.) The snails are ready when the operculum falls off.
Remove the periwinkles from their shells with a nutpick or pin. (This can be time consuming, find an assistant if you can.)
Sauté garlic in olive oil. Add parsley and tomatoes, and cook for about 30 minutes.
Boil four quarts of water. Add spaghetti, and remove when soft but still firm to the bite. At the same time that you add the spaghetti, add the periwinkles to the sauce.
Mix the pasta and sauce in a warm bowl. Serve hot, with crusty Italian bread and grated Parmesan cheese.