Monday, August 31, 2009

Ecology lessons from the vegetable garden?

The strawberry patch, taken over by weeds

Lesson: No matter how many weeds you pull from the vegetable garden, you never exhaust the supply of weeds.

  • As long as there is bare soil (an empty niche as a result of disturbance), weeds will recruit. There are always more seeds - probably hundreds per cubic inch.
  • To fill a niche so weeds don't recruit, a robust desired plant needs to be occupying that niche.

A lot of my work is in invasive plant removal-- as a component of ecological restoration. What lessons are my garden teaching me that might apply to my work? Perhaps, that the supply of invasive plant seeds will never go away. That the only way to really "remove" invasives from the landscape is to prevent their recruitment, by:

  • Having the niche already filled by robust (i.e. not decimated by deer) native plants
  • Having the seedbank saturated with native seeds so that recruits after disturbance are at least as likely to be native as exotic. The corollary to this is that the seedlings need to survive, so deer browse must not take place. Also, I've noticed that many native shrubs and herbs are so browsed that they are not producing seed.

Native herbs cover the ground along Maine coast

I just got back from Maine, and the plants there are amazing - robust, densely packed, and producing tons of seeds. So many berries everywhere - we gorged on huckleberries and blueberries and nibbled an occasional bunchberry as well.

I kept asking myself on the car ride back to NJ - is it impossible to get NJ back to being as nice as Maine? Maybe - fragmentation and habitat destruction is much further along here, and all that unfragmented (though heavily harvested!) forest in Maine supports much greater densities of wildlife than here.

But what about our remaining wild areas, of which there are many? Is it impossible that they be as robust as Maine's wilderness? I don't think so... but just pulling weeds won't make it happen. We need to stop creating so many empty niches (bulldozers, thoughtless forestry, critically overpopulated deer). Then, we need to help put some of the missing pieces back. No virginia snakeroot left in Princeton township? Propagate and plant it in suitable habitats.

Although "just pulling weeds" doesn't make the landscape spring back to robust health, here's another lesson from the garden...

Lesson: If you don't pull the weeds, they'll overwhelm your vegetables.

I know that domesticated annual vegetables are not the toughest plants on the block. By contrast, I think our natives could easily overtake many of our invasives, given the chance (again, the deer issue). Nevertheless, I think that an established plant community is very hard to transform without radical disturbance. We see this time and again in the woods when we find slivers of remnant, mature forest. They may be diminshed, but they are frequently not invaded - until a major disturbance comes through (tree mortality, forestry etc.) that is.

Unfortunately, the same is true for non-native plant communities. An "invaded" forest with a shrub layer of oriental photinia and a ground cover of garlic mustard and japanese honeysuckle is likely to stay that way... unless there is a radical disturbance, like a crew of land stewards with chainsaws and herbicide.

The more that invasive plant infestations are allowed to spread, the more chainsaws and herbicide we'll need if we ever want to restore them to native plant communities - and the more patience too, because it ain't gonna be fast or easy, and the soil chemistry and fauna is going to be inhospitable to natives.

Now, I wrote earlier that there are always more weed seeds, and I believe this to be true in central NJ. I think our seedbank is saturated. In Maine, there are many weeds seeds too, but fortunately most of the "exotics" up there are only early successional weeds that get outcompeted as the robust northern forest reclaims disturbed land.

Despite the cut stump, invasives can't recruit in this Maine landscape!

I think our wild area seedbanks are saturated with invasive plant seed, but I don't think every place is yet saturated with every weed. Here's a garden analogy: My mom's garden is absolutely saturated with galinsoga, and every time she goes away for a week, she returns to a carpet of it. Here, we just have a few and I try to grab them as soon as I notice them. Up here the weed that would take over if we abandoned our garden is evening primrose. Not bad, huh?

I think that the same can be said about our invasive seedbank. I've seen "remote" spots in the Sourlands sprout wineberry, barberry, ailanthus just after logging. But, these spots aren't yet sprouting photinia or siebold's viburnum, the way an analogous spot in Princeton would. So, I think there is value to the "Early Detection/Rapid Response" strategy of stewardship. We don't need our seedbank to contain even more competitors with natives, each with slightly varied tolerances. The more of these we get, the fewer niches we'll have where natives are superior competitors, and the more likely we are too see local extirpations and possibly regional extinctions in the future - even if we solve the deer overpopulation crisis and cease disturbing or destroying so much wild habitat.

The native perennial Allium cernuum in the vegetable garden

Thursday, August 20, 2009

August Heat

The artist lives precariously.

The garden? Tomato fungus, groundhog crew cuts on the beans, okra, and squash, deer beheaded asters and Joe Pye weed.

Ruby cherries turning black. This native black cherry was tasty.

The house? A dehumidifier driving up the electric bill and finally drying up the basement flood of two weeks ago. Large invading ants that died all at once and were replaced (briefly) by minute black ants. Mold growing on every surface. Piles of papers, books, ponytail holders, frames, trash picked buck saw and two-man saw, overflowing compost, a sweaty toilet tank, piles of dishes and leftover containers, fern gametophytes, damp sneakers, a very ugly archery target. Some more mold.

Native blackberries yet to ripen. Are they like corn? If not pollinated properly do these fruits become mishapen?

At work? It's hot. I wear linen pants in the field rather than Dickies or denim. My legs raked over and covered in red speckles from multiflora rose thorns. I'm ignoring the herbicide label that recommends wearing a long sleeved shirt while applying. Lots of dead invasive plants. Gratitude to volunteers.

Early goldenrod is more diverse than the R train during rush hour.

In the skies? A dozen and a half cedar waxwings in two flocks met and joined as one. Occasional partial oriole song. Flocks of chickadees and titmice and nuthatches. Woodpeckers calling. Less wood pewee song. Nighttime screech owl in the distance. Flocks of sparrows along the sides of slow country roads. An elderly woman in a sedan stopped in the road in the oncoming lane. Why? She's smiling, mouth open. Why? She's looking up. I've passed her and look in the rearview mirror. A small hawk on the power line. I'd like to turn around and gape, too, but I know the hawk will fly. She's still stopped. The hawk is still there. I have a good feeling.

In the meadows? Joe Pye, ironweed. Sweetflag is fading. Shrubby dogwoods in fruit. A small patch of phragmites surprises me with beautiful purple flowers (over it once I see the male model in the Urban Outfitters catalog scowling and posing a phrag patch). Common yellow throat chicks.

Grey dogwood fruit

It's the time of the goldfinch, New Jersey's state bird. With that, the beginning of the summer's end...

Thursday, August 13, 2009

Two wrens inside your pocket

The gold finch sings on the up sweep and the spicebush swallowtails crowd around the joe pye and ironweed. I try to stay outside and make a few observations in between rainstorms and gnatstorms. I've had it with the rain.

Between rainstorms, I hid from the gnats inside, but the sound of two young Carolina wrens brought me to the window one late July morning.

Wednesday, August 5, 2009

The scent of Queen Anne's Lace

I inhaled. Briefly, I was a young girl standing under sweet gum trees that grew next to the Rahway River.

Then, the river was called the river. The park, the park. The sweet gum tree had no name but its seed capsules were called sticky balls.

The plant that grew abundantly next to the warehouse sign on the way to the other park (the more distant park with the very good playground) was called milkweed. I can see my father cutting the milkweed with his pocket knife. I see the milkweed in my hands. It is a huge plant, and the sap is not milky. It is clear. Milkweed still seemed like a good name for the plant.

Queen Anne's Lace was a good flower to pick, though I rarely picked flowers. It could maintain vigor most of the walk home from the park. On longer walks, the stem just below the flower would begin to droop, but revived with water.

The blue one was tough. Once the flower was mine, the stem was bruised and my palms were red from pulling the stem. A tough plant whose flower were the opposite. They wilted visibly, and water did no good. Once my friend yanked a blue flower for me. I carried it for awhile, and when we began to cross the bridge, I tossed it into the river. She asked why I did that. I didn't know. I didn't answer.

I think the milkweed was probably Japanese knotweed. I now know the blue flowered plant is called chicory, can be roasted, is fairly tasty though bitter, looks similar to dandelion, and is not native to North America. I think my childhood understanding of the tough, pretty, blue flower that I tossed into the Rahway River from the bridge on Whittier Street was solid.

Sunday, August 2, 2009

George Orwell and An Ugly Brown Book

Something, perhaps vanity or feigned intellectualism, made me purchase an ugly brown book called Eight Modern Essayists, forth edition, copyright 1985, at Holland Township's semi-annual garage sale about a decade ago. I was a college drop out, and I was living at home while I worked and wondered what I might do next.

Like may well-intentioned book buyers, I hardly read the book.

Never read Virginia Woolf's "The Death of the Moth" or E.B. White's "Death of a Pig." Edward Hoagland's essay, "Cold Water, Warm Sun, No Biting Flies" sounds interesting, but I didn't even glance at that title until today.

I picked it up because it included one essay I had read and liked: "Shooting an Elephant" by George Orwell. Only 25 cents. OK, the ugly brown book goes home with me and sits on my shelf.

Eight Modern Essayists has had numerous pardons. It has remained on my shelf through many moves and garage sales, curb sales and yard sales. "What about this one?" Jared asks as we cull the bookshelves for a sale. He has the ugly brown book in his hand. "Mmm. No." "Really?"

It's only one essay that keeps Eight Modern Essayists on our bookshelf: "Politics and the English Language" by George Orwell. Thirteen pages well worth seeking out.