Monday, August 31, 2009

Genetically Engineered "Forests"

ArborGen is seeking permission from the USDA to sell eucalyptus trees with genetically engineered cold tolerance (to allow plantations in the southern U.S.). The genetic engineering doesn't worry me, but I am a little wary of eucalyptus in general. They're somewhat invasive (and hated by the locals) in California, though I have no idea how competitive they are in the Southeast. They're also working on loblolly, one of the dominant native trees in this part of the continent. Either way, little work has been done to date to improve tree varieties (even by traditional breeding) for obvious logistical reasons. Once timber crops have been transformed into the twisted, dependent freaks that the rest of our domesticated plants and animals already are (by traditional breeding), ecological invasion will no threat at all.

At any rate, their improved varieties of loblolly pine should mature in 18 rather than 26 years, and their eucalyptus in 4 rather than 7! ArborGen's motto is "More Wood. Less Land." (which I love!), and if they can pull off these variety improvements they may be able to back it up. I would much rather consume wood and paper harvested from supercharged, intensively-managed (small!) plantations than from the massive clearcutting that's still dominant in the Pacific Northwest.

Remember, all the resources you consume have to come from somewhere - it's much better for the environment to split land between high-yield, high-tech ag and preserved wilderness, then the muddled, Pyrrhic "eco-agriculture" that tries to produce crops and preserve wilderness on the same land and fails to do either well.

Sunday, August 30, 2009

Save our Soils!

Real Agriculture currently has a nice interview with agronomist Ross McKenzie on the historic impact of agriculture on soil health. In this video, Ross describes the important role of organic matter (e.g. old crop debris) in soil health. These decomposing plant bits act as a natural glue, clumping the soil into granules that improve soil structure by creating pores.

One of my all-time favorite scientific figures from one of my favorite books, Water Relations of Plants and Soils, illustrates the concept of soil structure. Capillary pores are microscopic pits in soil particles that hold water (and nutrients) more tightly than gravity can pull them away. Non-capillary pores are larger (e.g. spaces left after roots decay) and are critical for proper aeration and water movement. This figure shows the natural pore structure of forest soil versus heavily-compacted farm soil. The lack of pore space in the farm soil prevents the absorption (and retention) of rain, leading to erosion and dry, nutrient-poor soils. As this figure demonstrates, soil structure can be compacted as deep as 2 feet by agricultural practices (e.g. driving heavy equipment on wet fields).

Soil texture (the distribution of soil particle sizes) is also critical. Extremely tiny particles (clay) hold the most water, but bind it too tightly for plants to completely utilize. Extremely large particles (sand) hold very little water, but bind it weakly. Excellent garden soil has a balanced soil structure and texture, low acidity and is black with organic matter.

Tillage was easily one of the most important inventions of early human history. This process, whereby the top few inches of soil are lifted up and mixed, aerates and loosens the topsoil, buries crop residue and kills pests, pathogens and weeds. Unfortunately, tillage also hastens the breakdown of organic matter, compacts the deeper layers of soil and leads to rampant erosion. It also has subtle ecological effects. One of my old professors once told me about a study of his that found that plows didn't kill many of the countless, microscopic, plant-parasitic nematode worms that inhabit farm soils, but DID kill their larger, rarer predator relatives.

Tillage worked pretty well in Europe, but when applied writ large in North America, it created the rampant erosion that led to the Dust Bowl. This picture* shows typical root growth produced by annual crops versus their wild, perennial relatives. These massive perennial root masses formed the thick sod that supported and protected North American prairie soils prior to European colonization.

Modern conservation tillage (aka no-till) is a tactic that attempts to build ecologically-functional soils while protecting the crop from weeds, pests and pathogens by other methods (e.g. planting cold-tolerant varieties very early in the year, planting varieties with transgenic (GM) glyphosate resistance and applying chemical pesticides).

Theoretically, it would be extremely sustainable to develop perennial versions of our grain and legume crops with which to establish vast semi-natural "prairies," but this goal is much more difficult than it may seem and success is likely a long way off. Relatively few public sector labs are working on this goal, although the non-profit, The Land Institute, claims to be close to releasing varieties. Private seed companies can't be expected to contribute to this goal as it would appear to be an irresponsible business plan (a good reason to increase public funding of agricultural science!).

*Picture from "Prospects for Developing Perennial Grain Crops" BioScience August 2006 Vol. 56 No. 8

Friday, August 28, 2009

Corn Borers! Gross!

Here's some yummy, fresh sweet corn. The malformed white tip is composed of unfertilized kernels. A poorly pollinated corn cob may be dominated by a broad band of these white, undeveloped kernels

See the cob lying on the ground? See the black spot? That's a baby corn borer. We scanned our ears for two signs of borer damage when we picked them. I was disappointed to see these signs on two of the four ears I brought home for dinner.
1) Worm hole in the husk
2) Frass (usually on the stalk end)
3) Worm!

It actually isn't a big deal at all. I just cut them out.

Farm to Food Bank

One of the best things about working in agricultural research is the steady stream of fresh, leftover produce that accumulates in our hallways as experimental fields are harvested.

We are currently swimming in an absurd sea of extra sweet corn.

Luckily, the food bank agreed to accept perishable food. Our local USDA lab donated a few thousand pounds of potatoes to the food bank last year. This year, the government big bosses are again generously allowing employees to donate their work hours to glean harvested experimental fields. So 3 USDA employees, my boss and I headed out for a few hours this morning and picked several hundred pounds of sweet corn. The guy who orchestrated the delivery said it would all be given out by the end of the afternoon!

Highlights of the day?
My boss pointed out that individual leaves of some of the harvested corn plants were intensely purple. The entire plant this late in the season is doing nothing but making sugar at a breakneck pace and shoving it as fast as possible into the ears (for reproduction!). When you pick an ear, the plant is still shoving huge amounts of sugar into that (now empty) node. The plant deals with this huge surplus of sugar by conjugating the sugar molecules to anthocyanidin molecules, and stuffing them into the cells' central storage vacuoles within the nearest leaf. Anthocyanidins + Sugars = Anthocyanins, which are brightly colored pigments!

Later on, I was popping off ears, checking for corn borer damage and tossing them into bins when I noticed a splash of bright red on one of the husks. I showed it to the guy next to me, wondering if it was some weird fungal growth. He said it was blood from an animal - which I laughed at since, although corn leaves are notoriously sharp, it was too bright to be any older than a minute or two. Then the guy on my other side pointed out the blood pooling in my right hand!

Corn is sharp!

(I'm fine and I left those ears for the deer by the way)

Tuesday, August 25, 2009

What was "Natural" before Humans?

Environmentalism, to most people, means protecting the Earth's pristine ecosystems from the defiling impacts of humans. The problem is that these ecosystems never existed in a stable, "pristine" state.

A recent article in Science discusses this in addition to the difficulty of even knowing what these ecosystems "originally" looked like.

From a North American perspective, ecologists have traditionally looked to the writings of European pioneers in order to ascertain the original state of the continent's ecosystems. We've learned since that the Native Americans heavily manipulated these ecosystems (while living in surprisingly large, organized civilizations). One of their most dramatic tools was the prescribed burn. In the wooded Mid-Atlantic and Northeast, these burns selected for fire-resistant species, most notably nut trees such as oaks, which produced food both directly for humans, and indirectly, by supporting game species. As we speak, these "natural" oak forests are increasingly being overtaken by fire-sensitive species (e.g. maples) that are more tolerant of shade and compete better within intact forests - which more likely represents the state of these forests before humans.

Similarly, concern arose in Yosemite National Park recently as trees began to die of fungal root rots - often collapsing onto buildings in the process. These dense forests hardly resembled those encountered by European travelers over a century earlier - when an oxcart could easily be driven between trees. Fire was again the explanation. With this human-selective pressure removed, the forests reverted to a common Western conifer disease cycle. Shade-intolerant tree species are increasingly out-competed by shade-tolerant species (that are susceptible to fungi). When enough of these shade-tolerant, but susceptible trees accumulate, root rot epidemics take hold and expand each year - leaving open land for the shade-intolerant species to recolonize.

Even when paleontological techniques have been applied to identify ecosystem parameters before any humans were present, the picture remains fuzzy. Currently, North American forests are known for existing in certain combinations of key species (e.g. oak-hickory, oak-hickory-pine, beech-maple and maple-basswood). When ancient deposits of pollen were analyzed, it was found that many of these ecosystems had different combinations of dominant trees in the past. We're still living in a period of oscillating ice ages and interglacial periods. North American ecosystems retreated south each time glaciers advanced and expanded north again as temperatures increased. Because each species has unique tolerances of not only temperature, but also soil type and rainfall, they all shuffled and re-assorted with the changing climate.

The author specifically points to the Big Woods of Minnesota, which apparently formed on the site of a great savanna-prairie around 1300 C.E. as successive years of drought reduced fire fuel load, allowing trees to invade the grasslands. Ironically, these forests are now being changed again as earthworms are re-invading (very slowly!) since the glaciers last wiped them out. Many of these "invasive" earthworms were formerly native!

I think environmentalists who are too hung up on the "restoration" of ecosystems do a disservice to conservation as a whole. It's important to understand how our activities impact the Earth's ecosystems, but not all these changes are necessarily negative. One day we'll all be gone and the Earth will evolve completely new organisms and ecosystems just fine without us - so there's no moral argument to "protect" ecosystems. The environment is only valuable to the extent that humans assign it value. I propose we take a practical approach:

1) Maximize the environment's ecosystem services
e.g. invasive zebra mussels are cleaning up Lake Michigan
2) Work to restore culturally-important ecosystems
e.g. breeding blight-resistant chestnut trees
3) Stop worrying so much
It just prevents the average citizen from taking action

Monday, August 24, 2009

Chesapeake Oyster Reef Restoration

The July 31st and May 29th issues of Science had some updates on the restoration of the Chesapeake bay. This bay teemed with an incredible diversity and abundance of life when Europeans discovered it. It's since been largely destroyed by agricultural and industrial pollution.

It sounds like they may be making some progress at least. Oysters previously formed extensive reefs that filtered the water and supported much of the ecosystem. These reefs previously existed as giant piles of empty shells that oyster larvae would settle (and eventually die) on, leaving their shells behind. A research project has been able to establish a few new reefs by dumping huge numbers of oyster shells into piles at the mouths of rivers. One of the key discoveries was that these piles had to be very high to prevent being covered by mud.

Hopefully this strategy will continue to work as they try it around the bay.

Corn v. Western Corn Root Worm

A group in Germany has recently used genetic engineering to integrate an ecologically-based pest resistance into corn.

They cut the gene for (E)-beta-caryophyllene synthase out of an oregano plant and pasted it into a corn plant. This allowed the corn to produce (E)-beta-caryophyllene, a volatile scent chemical. This chemical has been shown to attract insect-eating entomopathogenic nematodes, which arrive to feed on an important corn root pest, the western corn root worm. Fighting pests with their natural enemies is a tactic known as biological control. Biological control is one of the key components of IPM (integrated pest management), an ecological-based strategy that aims to reduce pests to an economically-acceptable level, as opposed to scorched-earth eradication.

The really neat part of this story is that old varieties of corn made this chemical naturally - and European varieties still do. It's a natural consequence of plant breeding that you only keep traits you value very highly (and can detect!). If you grew your breeding lines in a field without adequate populations of both the insect and the nematode, you'd have no way of knowing that some of your plants contained a resistance trait.

A similar story shaped the modern rose. In the Middle Ages, roses were largely appreciated for their scent, but as generations of plant breeders created bigger and more colorful flowers, the genes for scent were lost. A few laboratory groups are now working on restoring the rose's scent through genetic engineering approaches similar to the above.

It would take years to move this natural corn gene back into North American varieties with traditional breeding techniques. The same thing could be done in a few months with genetic engineering techniques, but would probably require years and millions of dollars worth of regulatory tests. Either way, I hope it happens. I'm a big fan of technologies that encourage farmers to tend to the ecological integrity of their farms. Biological control doesn't do any good if you kill all the good bugs.

Degenhardt et al. 2009. Restoring a maize root signal that attracts insect-killing nematodes to control a major pest. PNAS August 3.

Sunday, August 23, 2009

Transgenic Rice for Iron Deficiency

ETH Zurich has announced the development of a transgenic (GM) rice variety with a 6-times elevated level of iron, a nutrient that is one of the most important causes of malnutrition in the developing world.

Rice actually has a lot of iron in its seed coat, but it quickly spoils in tropical climates unless the seed coat is removed (aka "polished"). Additionally, eating polished rice is culturally important to most of these peoples (probably because brown rice tastes terrible!).

The team accomplished this by modifying the synthesis of two enzymes - one that pulls iron out of the soil and into the plant (nicotianamin synthase), and another that stores the iron in the endosperm of the seed (ferritin).

I was initially skeptical because the increased presence of a nutrient doesn't necessarily mean that humans will be able to absorb and use more of the nutrient. Plants are notorious for locking up nutrients (especially iron) in chemicals that bind (aka "chelate") the nutrients so strongly that the human digestive system can't separate them. The press release mentioned that ferritin is also used by human cells, so presumably this wouldn't be a problem.

At any rate, it'll be many years before this new variety is released to the public. As can be seen with ETH Zurich's previous work with Golden Rice, which has elevated levels of vitamin A, numerous laboratory and field trials are required before this plant can be approved for human consumption. Different cultures tend to be really picky about the varieties of rice they like to eat, so part of the development process will probably involve moving this trait into locally-adapted varieties.

Original: J. Wirth et al. (2009) Rice endosperm iron biofortification by targeted and synergistic action of nicotianamine synthase and ferritin. Plant Biotechnology Journal, 7: in press.

Saturday, August 22, 2009

An Open Letter to Vegetarians

I've enjoyed watching the seasons turn over in the meadows around my home. The fields are dominated by a resurgence of yellows and whites while roadside ditches are noticeably bare of pink and orange. The local fawns are losing their spots (and thankfully seem to be gaining caution around cars) while some bucks have sprouted velvety, 8+ point antlers.

This reminds me of a question I've always wanted to ask an intellectual vegetarian - "why?"

I admire those who make this big sacrifice in order to (profoundly) decrease their environmental footprint. Even a small decrease in meat consumption across the developed world would dramatically decrease agriculture's footprint.

I don't understand the moral argument though (as opposed to religious ones). Well, I do at first. It seems that all of ethics boils down to "it's wrong to hurt people." It's obvious and intuitive to extend this to animals, at least the more person-like ones.

A former professor of mine made the interesting observation that domesticated cats are obligate carnivores. Unlike dogs, cats can't be kept on a diet of rice and veggies. Does this mean it's unethical to keep cats as pets? I guess I could accept this corollary of vegetarianism, but it starts to lose me as I keep following it to its logical end.

Almost all vegetarians/environmentalists I've run into are big fans of reintroducing charismatic megafauna back into the wild lands our ancestors extirpated them from. The wolves of Yellowstone have been a particularly striking example. Biologists were amazed at the ecological transformation that followed the return of wolves. Wolves not only thinned out the overpopulated deer and elk herds, but created a "landscape of fear" that influenced where these herbivores travelled. Along streams, huge willow trees sprung up, spared from being browsed to the ground. Biologists hadn't even realized the willows were supposed to be there! Any Easterner who thinks hardwood forests are generally open and free of herbs and scrub have experienced this effect.

So if carnivores are required to maintain healthy and balanced ecosystems, why is it wrong for humans to participate? What difference am I missing between humans re-establishing wolves into Yellowstone and humans taking some of the prey directly? We're not really even an exotic species. Humans integrated into North American ecosystems after traveling over the Bering land bridge thousands of years ago, the same as any other major terrestrial carnivore.

I hesitate to wonder if the wolves are doing our "dirty work" for us. Most people don't hesitate to buy shrink-wrapped ham, but I don't know how many could bring themselves to kill and butcher a pig. I can't help but feel that vegetarianism might be a symptom of our disconnect with nature. No one likes death, but it's just the way this world works. We are part of the natural world, not foreign observers.

I'm especially concerned about the future ecological integrity of the eastern forests as the white-tailed deer population continues to explode. Much of this region is too densely-populated to re-establish wolves, mountain lions or bears and the number of U.S. hunters is cratering. What's the solution? Am I missing something?

Ultimately, it may be too much to ask people to explain their ethics. I'm reminded of a thought experiment that demonstrates how illogical morality is. Paraphrasing:
Imagine you see a speeding train. You know that if it continues on its track, it will kill 50 workmen around the next bend. If you throw the track switch in front of you, it will divert the train so it only kills 1 man. What would you do?
Now imagine there are still 50 men around the bend but there is no switch, only a man working near you. If you shove him in front of the train, it will stop before killing the other 50. What would you do then?
Most people would say "yes" to the first and "no" to the second, and most couldn't tell you why.

Friday, August 21, 2009

New Book - Where Locavores Get it Wrong

Science Friday today featured a feeble "debate" between James McWilliams, author of the new book "Just Food: Where Locavores Get It Wrong and How We Can Truly Eat Responsibly," Michael Pollan and Brian Halweil.

I was disappointed that none of the guests pointed out how silly it is to lump all pesticides and transgenic crops into a single category - as opposed to evaluating them individually by their unique properties - but overall I was glad to hear a more nuanced discussion of sustainability in agriculture then we are usually subjected to.

It's encouraging that the talking heads are making some progress towards a more sophisticated and accurate view of the world.

Wednesday, August 19, 2009

I Heart Smut Fungi

I was excited to find a fair amount of corn smut (Ustilago maydis) in our corn field today. It's one of my favorite fungi.

This fungal parasite has a complex lifecycle that culminates in the infection of a corn plant and the transformation of that plant (usually the kernels) into tumor-like mushrooms. When ripe, these rubbery gray growths rupture, releasing greasy, black spores.

But BEFORE this fungus produce spores, this "maize mushroom" exists as a yummy Mexican delicacy, known as "huitlacoche." It can be cooked up like any other mushroom. Sometimes you can find the canned version in specialty grocery stores, but I doubt it's as good as it is fresh.

Unfortunately, all the smut I found today had already gone to spores...

Another smut disease caused some pretty dramatic agricultural disasters at the turn of the century (before last). A series of devastating wheat smut outbreaks caused hundreds of combine fires as the vehicles stirred up massive clouds of oily smut spores, which were ignited by the movement of the machinery.

A third pretty incredible smut fungus is Microbotryum violaceum. This "anther smut" fungus parasitizes various flowers in the Caryophyllaceae (especially the campions, Silene spp.).

This fungus colonizes and spreads systemically throughout its host plant, permanently sterilizing it. It does this by forcing the plant's female flowers to grow male anthers (which usually contain pollen) and then REPLACING the pollen with its own spores (see picture) - which are then spread by pollinating insects to uninfected plants!

Yellow vs. White Corn

I spent today pollinating maize. My reward was an armful of sweet corn! (currently boiling...)

Like the picture to the right, today's ears contain a mix of white and yellow kernels.

The yellow of maize kernels (along with most yellows, oranges and reds of other fruit) is caused by the accumulation of carotenoids. This chemical class has often been associated with human health and includes such famous members as lycopene and beta-carotene.

One particular enzyme, phytoene synthase, plays a particularly important role in the accumulation of carotenoids. Maize has two different versions of this gene - one for synthesizing carotenoids in the kernel endosperm, and the other for synthesizing it everywhere else. White kernels lack a functional copy of the former phytoene synthase gene, and therefore aren't able to accumulate (yellow) carotenoids.

Ultimately, the color is determined by the combination of the mother plant's genotype in addition to the genotype of the individual pollen grain that fertilized each kernel.

Saturday, August 15, 2009

Pam Ronald on GM Food Labeling

Here's a quick video of Pam Ronald (UC Davis Plant Pathology) on the labeling of "genetically modified, GM" food.

Knowing simply that a crop has been genetically engineered gives you no information about its safety. In order to make a safety judgment, the consumer would need to know what specific gene was put into the plant - but this raises complications.

Her example: You could label all non-organic U.S.-grown papaya as containing a small genetically engineered fragment of the papaya ringspot virus (the source of disease resistance that saved the industry) - but then you'd also have to label organic papaya that are naturally infected with the virus (and therefore have orders of magnitude more foreign viral nucleic acid and protein than the "transgenic" ones).

She didn't have a solution in this short sound bite, but she pointed out that alerting consumers that their foods are full of viruses would freak them out unnecessarily. Plant viruses can't infect humans.

Know your Salads!

My biggest problem with the organic movement is that it observes a complex, nuanced and largely unknown world, and quickly cuts it up into two categories: natural (safe + healthy), and synthetic (destructive and dangerous). This pre-Enlightenment philosophy is anti-intellectual, silly and dangerous.

, Phillip Broadwith from ChemistryWorldBlog describes a case in Germany where a botanist noticed that pre-cut salad mixes at his local supermarket contained a poisonous weed that closely resembles arugula.

The state minister for consumer protectionism, Margit Conrad, warned:
"Not everything that looks like fruit and vegetable is edible...

No one should eat plants or parts of plants that have an unusual taste."
Here, by the way, is arugula and common groundsel.

Plants are ultimately identified by their flowers. Arugula makes the simple, 4-petaled flower that's typical of the Brassicaceae. Groundsel is in the same family as the dandelion (Asteraceae) and makes similar yellow flowers that produce fluffy white seeds.

The world is a complicated place and if you don't take the time to learn about it, you can get hurt.

Monday, August 10, 2009

Same Day Sweet Corn

For as much as corn gets a bad rap, it's really an excellent veggie - it's hard to beat the sweet crispness of corn picked within a few hours. No tasteless, chewy/mealy kernels here!

If you plan to plant your own corn next year, you'll want to have at least 100-200 square feet to assure good pollination (otherwise you'll have a lot of missing kernels on your cobs).

Maize breeders make specific cross by (Day 1) cutting the tip off of young ear shoots and covering both them and the pollen-shedding tassels with two small paper bags and (Day 2) after a burst of fresh, receptive silks (stigmas) have grown out, dump the pollen-filled tassel bag onto the new silks. This does two things - It assures that each little future kernel gets pollinated and prevents contaminating pollen from other corn varieties.

On another subject, my two little 3-foot salad boxes on my deck have been very successful this year. I bet one or two rows a little bigger than this (actually planted in the ground) could easily keep a person in salad most days of the week. I don't know if it's better to eat the old leaves (keeping the plant alive) or to pull up entire plants once they get really big and then re-seed. It'll be an experiment for my future yard!

Friday, August 7, 2009

How to Grow Tomatoes

I'm a big believer in heavily pruning fruit crops. I've never really looked into the research, but it's the way my mom taught me and it's worked out well so far.

Here's a picture of the less ragged of the two tomatoes I have on my deck. It's a lot smaller than it would be if it was in real soil and the nights didn't keep going into the 40s, but I'm pretty happy with it. Each of the two plants has over two dozen unripe fruit.

I aggressively pinch off all suckers (shoots that appear out of the axils) and flower buds until the plant forms one strong stem about 4 feet tall. If my plants were in the ground, I'd allow them to grow 2-3 of these stems, generally by sparing suckers near the ground when the previous stem reaches full height. Suckers supposedly sap the plant's strength and are structurally weak, and definitely lead to a bushy plant that shades its own leaves and forms a tangled haven for pests and pathogens. Notice how open the canopy is on the plant in the picture - almost all the leaf tissue catches the sun at the same time.

Once the plant reaches a decent size, I allow the plant to pour its energy into making flowers, which I pollinate myself if there don't seem to be many bugs around. New shoots generally push out flower buds just ahead of leaf buds. I try to pinch the leaf section off, sparing the flowers. If I catch a sucker after it's already started to put out leaves I generally pinch the smallest part of the bud (meristem and leaf primordia), allowing the leaves that the plant has already invested energy in to finish expanding.

The lowest leaves tend to drop towards the end of the summer, but this is beneficial as it allows air flow around the plant when cool, humid fall weather begins to encourage diseases. In some greenhouses, they actually train tomato plants up chains hung from pulleys in the ceiling. As the plant keeps growing taller, they lower the chain, allowing the leafless cane to coil on the ground.

When I get a yard, I plan to build post and wire trellises to rotate tomatoes, melons and legumes on, and stronger ones for grapes, cane berries and espalier fruit trees.

btw, I'm shocked and annoyed at how much Miracle-Gro I have to dump into my patio veggies to keep them green. I grew up on deep black forest loam and cultivated a pretty serious compost pile with my roommate in grad school. I never thought that my attention to soil was really that necessary.

Urban Farming part 2

The radio's been buzzing this week with urban farming stories. and I mean urban farming. i.e. raising pigs and bees in vacant lots in Oakland fed with dumpster diving! and aquaculture fish in Milwaukee. and a story on urban bees!

Will Allen - Milwaukee
Novella Carpenter's new book Farm City - Oakland



Wednesday, August 5, 2009

Know Your Insects!

So two of our lab's techs returned from the field today with the bad news that at least one of our potatoes is being eaten alive by little red bugs.

"Did they look like ladybugs?" I asked, opening the Wikipedia page to the most obvious pest that occurred to me, the notorious Colorado potato beetle.


"Was this it?"

"No, they didn't have stripes."

"Howabout the larvae?

"That's it!"

I love it when things are easy!

Saturday, August 1, 2009

Vacation in Zone 63d

Bioregionalism is the celebration of the unique cultural and ecological features of small geographic areas - and is the philosophical basis of Buy/Eat Local campaigns.

I love the EPA Ecoregion project. Follow the link to the most detailed (IV) ecoregion map and click on your favorite part of the country. There you'll find your local ecoregion as defined by climate, soil type and native vegetation.

The drive south from upstate New York to the Atlantic beaches of Delaware took me through the jigsaw geography of the Appalachians, accompanied by dozens of ecoregion transitions. Hugging the southeastern foothills of the Appalachians, the Piedmont plateau stretches from New Jersey to Alabama. This plateau then falls steeply along the Fall line to the Atlantic Coastal Plain, which gently slopes into the Atlantic Ocean and Gulf of Mexico.

Delaware is a low, flat and marshy place. It exists almost entirely within the Middle Atlantic Coastal Plain (zone 63). Zone 63 is the middle section of the full Atlantic Coastal Plain, includes all of the Delmarva Peninsula and is most prominent in the eastern Carolinas. The beaches and bays of Delaware's short Atlantic Coast (as opposed to it's long border with the Delaware Bay) belong specifically to zone 63d, the "Virginian Barrier Islands and Coastal Marshes."

Driving south on DE-1 quickly removed me from the highly-populated Philadelphia metropolitan area to the state's more rural majority. Below the capital of Dover and Miles the Monster, Delaware begins to stretch into the ecological South. The flat landscape fragments into a fine-grained patchwork of corn, soybeans, woodlots and wetlands, speckled with little evangelical churches and beach-oriented tourist traps. In between small towns, wide creeks slowly seep out towards the tidal marshes of the Delaware and Chesapeake bays.

Landmarks in this part of the state carry unique names that often seem to allude to a more difficult past: Hardscrabble, Old Furnace, Muddy Branch, Gumboro, Skeeter Neck, Black Hog Gut, Slaughter Beach and the Murderkill River. Neck, gut, branch and beach are landform-specific nouns that are frequently encountered along this drive. Aside from the legendary fisheries of Maryland's Eastern Shore (blue crabs!), this region was originally best known for peaches (Delaware's state flower), melons and other warm climate high-value crops. Today, it's probably best known for chicken factories. Much of this soggy peninsula was never really inhabited, at least following European colonization. To some extent this may be changing as the coastlines are developed for resorts and vacation homes.

Trap Pond State Park is one of many great, small parks scattered within an easy drive of Peninsula resort towns. It's in many ways typical of Southern coastal forests. It's a swampy bottomland, topped by strong straight loblolly pine, mixed with oaks, gums and the smooth and sinewy, lichen-splattered limbs of understorey holly (Delaware's state tree). I was there for it's atypical feature: possibly the most northern natural stand of baldcypress trees. The first image is one most usually associated with alligator-filled bayous, the main haunt of these trees. The second is an up close and personal view of the trees' "knees." The third image is as close as I could get to an "island" of baldcypress trees in the middle of the lake.

See the frog in the last picture? There were a few that appeared to be adults, and hundreds of (juveniles?) less than an inch long, that scattered underfoot along parts of the trail. There were also some large, colorful beetles and butterflies (and a large snapping turtle diverting traffic on our way back to the beach). Subtropical forests like this are also known for mosquitoes, biting flies, ticks and chiggers. Thankfully, I encountered few of these.

My week over and full of crabs and vitamin D, I headed back north.

For many Delawareans, The Canal (along with the "vertical" section of the Mason-Dixon Line) cuts off the top of Delaware's most populated (of 3) counties, and associates them with the Urban Northeast, and forms a psychological barrier between them and the long, slow, punctuated gradient through "Slower, Lower [Delaware]" to the cultural South.

I'm always fascinated by such arrogant local nationalism. Growing up along the Mason-Dixon Line, I was accustomed to people aggressively asserting whether they belonged to the "North" or "South." At the extremes, I've listened to Georgians derogatorily refer to anyone north of South Carolina as yankees, and have heard that Bay Staters tend to proudly retain the same word only for their brethren who have lived in New England for a sufficient number of generations.

At any rate, crossing north on the Canal bridge lifts you above the Middle Atlantic Coastal Plain and presents a view of the rolling hardwood forests that define the Piedmont Uplands of southeast PA. Shortly after crossing the Canal, I lost sight of formerly plentiful roadside southern pines - likely a result of land history, not climate.

Just a little farther north, where I-95 briefly traverses Delaware, the state's largest city sits on the marshes of the Delaware Bay. Wilmington is a small, successful city, powered by highly-subsidized bank and chemical companies and surrounded by the converted rural estates of 19th-century industrialists and the extensive suburbs that voraciously metastasize across all farmland within reach of the BosWash megalopolis. One or two highway exits brought me back up onto the Piedmont, up through the rippled Appalachians and back to the Eastern Great Lakes and Hudson Lowlands.


Related Posts with Thumbnails