I'm rooting for the deer hunters, again

(White-tailed deer congregated in a feeding yard.  The number of deer here suggests a high density of deer in the area.)

I am a wildlife biologist, so I like all forms of wild animals and plants.  I don’t think there is an organism that I don’t appreciate biologically, including mosquitoes and deer ticks that cause Lyme disease.  I also love white-tailed deer; after all, I conducted my Ph.D. research on this species in the 1970s. But enough is enough.

Whitetails are probably about 10 times more abundant in the Northeast now than they were before whites arrived here.  Long story, but humans have inadvertently created fantastic deer habitat by breaking up the original forest, which is not good deer habitat, into a mosaic of cropland, fields, and forests of several age classes, which is great deer habitat.

The result of the high deer density is that they exert tremendous browsing pressure on native plants in the forests. The species composition of future forests is being determined by the selective removal of certain kinds of trees by deer that is occurring today.

In addition, damage to vegetable gardens and ornamental shrubbery by deer results in a significant cost to homeowners; New York State residents in two areas of the state paid $200-$500 per year to replace lost trees and shrubs due to deer. Deer browsing is a general frustration to hobby horticulturists throughout much of the country.

I could hunt deer to help contribute to herd reduction, which I used to do. But after chasing deer around with a dart gun every day for two years during my research days, chasing them around with a rifle is simply too much like work. Besides, my wife doesn’t even like venison, so what is the point?

We live on 12 acres of mostly wooded land in upstate New York. When the deer season opens, deer tend to congregate on my little “refuge” to escape hunters. So I chase them off and into the surrounding “killing fields” in hopes of seeing a reduction in the herd overall. But, of course, this is all like spitting in the ocean.

White-tailed deer have been a part of my life for 40 years. It is truly a species I love to hate and hate to love. I guess I am just hoping we find a balance. You know, not too hot, not too cold; not too hard, not too soft; not too many, not too few.

Article first published as I'm Rooting for the Deer Hunters, Again on Technorati.

Tree planting programs: another form of greenwash?

(Is embedding tree seeds in cardboard a good idea, or just another round of greenwash?)

We hear a great deal about programs to encourage us to plant a tree.  It always sounds good, because most of us love trees, appreciate their value to us emotionally and ecologically, and understand the importance of wood and paper products that come from trees.  But when I scratch the surface of the suggestion to plant more trees for the environment, I find it is more confusing than amusing.

The supposition in these tree-planting programs seems to be that by planting a tree seedling or tree seed that we are rebuilding our forests.  But for this to be correct, it matters where you plop the baby tree, and what species it is that you are plopping.  Most ecologists are completely convinced that we should encourage vegetation native to a particular region to grow in that region.  I have often lamented in this blog the invasion of our local habitats by non-native plants.  So when someone gives you a tree seed and tells you to plant it, you need to know what species it is and if that species is indigenous to your area.

This week on Treehugger I read about a new "invention" where tree seeds are embedded in cardboard boxes.  When you are finished with the box, you bury the cardboard and a tree grows in that location.  Apparently, the company, which is called Life Box, has chosen tree seeds that are native to every major region of the country.  They think this has covered any criticisms about non-native species or invasive plants getting where they should not be (see comment by MycoKat here).  But it is not as simple as that.  For example, white birch is native and common in forests about 150 miles east of Ithaca, NY, where I live, but it is not found in the forest around Ithaca. If those seeds were used in their boxes, would those boxes only be used for shipping to eastern NY and not central NY?  I doubt it.  Humans have this tendency to superimpose their mental image of a map on the landscape, and it rarely matches the ecological reality that has been in place for centuries.

Let's assume you now have the seed of a tree species that is truly native to the exact location where you live.  But then, where do you put the darn thing?  You can always plant a tree in your front yard.  Nothing wrong with that.  That tree can be appreciated for its beauty for decades, and it produces oxygen and sequesters carbon dioxide during its life just like the next tree.  But this has nothing to do with regenerating a forest.  If you were interested in helping out our forests, I guess you might plant the thing next to or inside an existing forest.  But that is really unnecessary.  Forests produce plenty of seeds from the trees that are already there and don't benefit from our putting one more seed in the ground.  Evidence of the abundance of forest tree seeds can be found in your gutter every year, when you clean out the maple, ash, and elm seeds that have blown in there.  Squirrels and blue jays are moving nut seeds around the forest and planting them all the time.  Let nature do its thing.  It knows more than we do anyway about where to put these propagules.

So where should you put tree seeds if you have them?  I suggest putting them where they are really needed; put them where there is absolutely no forest at present, but in a location where there WAS once a forest that contained the species of trees you are about to plant.  An abandoned lot in a city would be a great place to undertake such a project, assuming there is still viable soil there.  That is, create a forest, however small, where there was not one before (or, at least, not in a very long time). Or what about an area that was once mined for some commodity, where the vegetation was skimmed off the surface of the earth for miles around?  That area needs help.  These examples would be true efforts at restoration.  Abandoned hayfields or meadows rarely need this kind of help; seeds from trees in nearby forests will find their way there.

My point is that planting a tree sounds as American as apple pie.  What could be wrong with a wholesome activity like that?  But this "movement" has all the characteristics of a program that makes us feel good without accomplishing anything substantive for the environment.  As a conservation biologist, we don't need more trees, we need more habitat.  And habitat, whether it is forest, or prairie, or marshland, mostly needs protection to develop on its own.  Only then will it contribute to viable populations of biodiversity, as well as provide all those "ecosystem services" like carbon sequestration that are so important.

Of invasive plants and Big Macs

(A McDonalds in Cairo.  Your order please.  Hamburger or hummus?)

One of the first-hand observations I have made over the past few years is the tendency to homogenize the world’s biota, especially plants. Jacaranda trees native to Brazil are common as ornamentals in Nairobi, Norway maples native to Europe are common on the streets of eastern U.S. cities, and the bird of paradise flower native to South Africa is found in nearly every city in the tropics worldwide. The botanical situation reminds me of the proliferation of franchised fast food restaurants, where you can now find Kentucky Fried Chicken outlets in Cairo and Kampala as easily as in Louisville. The homogenization of biota and the homogenization of cultures disturb me.

I tend to bond with habitats like most people bond with their friends or their pets. I also bond with humans and dogs, so I am not totally weird. But I have a close affinity to every place where I have spent considerable time: the meadows of upstate New York, the riparian habitat along the San Pedro River in Arizona, the sagebrush community in Idaho, the rain forests of Costa Rica, and, of course, the forest around my home in Ithaca. When a real estate agent is asked to name the three most important aspects of a home’s value, they usually say “location, location, location.” Similarly, we biologists often say when asked to name the three most important elements in conservation, “habitat, habitat, habitat.”

Very simply, habitat is where an organism lives. It is comprised of the plants, animals, and microorganisms in a particular location. The species composition of a habitat is determined by many factors, but it includes the climate, the historical path leading to species’ colonization or evolution in that location, the interaction of species over time, geology, soils, and more. Each habitat on earth is absolutely unique—they each have their own physical appearance, their distinctive sounds of birds, frogs, and insects, and their complex blend of odors. I am convinced that if I were blindfolded and dropped into any habitat where I have ever spent any amount of time that I could identify where I was by simply smelling the air. The ponderosa pine forest of the Kaibab Plateau and the cloud forest of Costa Rica come to mind. The sounds would make it even easier—vermilion flycatchers along the San Pedro River, bellbirds and black-faced solitaires in Monteverde, cicadas (different species) in Ohio or Las Cruces.

Now, before my ecology friends jump all over me, I realize fully that habitats are not static. Habitats change over time. The habitats I love will not be the same a century from now. During that amount of time, some ecologists would say that the habitat has changed or matured; some would say that it has become a different habitat altogether. I am not interested in that debate. I just do not want readers to think that I think these entities are unchanging. I have watched the woodland around my house change dramatically in 30 years. Therefore, I am not arguing that we do whatever we can to prevent habitats from changing. That would be folly, and would be an unwise strategy biologically.

But I am arguing that we do what we can to allow habitats to develop along a more or less “normal” path. We can also argue for a week about what is meant by “normal” or “natural.” I am bored with that argument. Simply put, there are certain events or conditions that I define as “unacceptable”, and which I think are an impediment to following a normal path to change.

One of the unacceptables is the human-assisted invasion of a habitat by plants or animals that are native to some other part of the world. That is a no-brainer for me, and a reason I spend many hours per month eliminating Tartarian honeysuckle, multiflora rose, autumn olive, and common buckthorn from my woodland, four species indigenous to Eurasia. I know they were not here a century or so ago, so when I see them it offends my sensibilities. From a conservation perspective, I am not even sure there is a practical reason to eliminate them. Certainly, if they became superabundant, they would exclude native plants from growing there, with the result that some ecological interactions between those native plants and other organisms would be disrupted or extinguished. But when they are in limited abundance, their greatest danger may be that they will not remain at such low densities. I eliminate these plants because I can; the large Lumbricus earthworms that are so common in my part of the world are not native here either, but there is little I can do to diminish their numbers.

To me, there is a certain parallelism between what I observe in our native habitats and what I observe in cities around the world. When I am in a foreign country, the last place I want to eat a meal is in a Pizza Hut or a McDonalds (in fact, I guess they even kind of offend me here). And when I am in a forest near Ithaca, NY, the last plant I want to see growing there is a European or Asian species. In both cases, something is being lost and, although I can not put to words exactly what that loss is, I believe it is important.  But it goes something like this for me: The invasion of our landscapes with non-native plants is like a technician at the Louvre deciding to "touch up" the Mona Lisa with watercolors.  The average person would not even see the difference, but the art expert probably would.  The act of changing the Mona Lisa, the most famous painting in the world, would transform this important and beautiful object from what it was to a different piece of art.

On the other hand, are Costa Ricans or Egyptians offended when they see an American franchise restaurant in their cities?  Possibly not.  They might even think it is chic that they have this international influence.  I don't get offended to see a Chinese restaurant in Ithaca, but seeing a Pizza Hut in Alexandria bothered me a great deal.  Maybe I am uncomfortable because I fear that these restaurants, and these invasive plants, will not simply be an addition to what was already there, but that they will come to replace the original.  This creeping sameness makes the world less diverse and less interesting, but does that bother anyone else?
 
So I pull and cut and sometimes spray and my students think I’m that crazy ex-prof who would rather declare war on invasive plants than talk on a cell phone.  How weird.  And I eat rice and beans in Costa Rica instead of Big Macs, and I eat hummus in Egypt instead of pizza.  Is this what happens to us as we age?  We rebel at "progress"?  We cuss at the automobile for replacing the horse, or lament that email caused the extinction of the hand-written letter.  Or that friends were replaced with acquaintances. Or that family time was replaced with sitcoms.  I wonder, maybe I just have too much time on my hands.