Tropical wolf tree

Every forest has a history.

Recently, I was hiking in Costa Rica and I came across this tree far from the edge of the forest.  I was a little surprised to see it.  To me, the tree tells a story about the history of the forest around it. The first thing that struck me was its size.  It is obviously much larger than its neighbors, which probably means that it’s much older. (Although a larger tree doesn’t always mean an older tree, in this case it’s likely.)

The second thing I noticed was that the main limbs are growing low on the trunk and they spread outward more than you would expect for a tree in a dark forest. This probably means that the tree used to grow in the open where there would have been plenty of sunlight.  Another clue to this forest’s history is that most of the neighboring trees are not only smaller, they are also all about the same size … so they are probably around the same age.

If I were hiking in a forest in New England (where I hike quite a bit), I would immediately say that this tree had started growing in the open sometime recently, perhaps along a rock wall between two pastures. Growing in full sunlight supports the growth of widely spreading limbs from the top to bottom of a tree. During the 1800s, most of the landscape in New England was open … more than 60%, in fact, at the peak of agriculture. Over the past century or more, these pastures and fields were abandoned, and the smaller trees that naturally regrew now surround the old, open-grown pasture trees.

Single, large trees like these growing in a sea of younger forest are often called “wolf trees” in New England. The origin of the term is not clear, but it seems to have been popularized by foresters in the 20th century to describe large, remnant trees that would “steal” resources (sunlight, nutrients, etc…) from the valuable trees growing around them.

However … I wasn’t hiking in New England. I was hiking in Costa Rica, where I have much less experience.  Actually, I’ve spent a total of only six weeks there, so I’m just beginning to get a sense of the forests there and the human history of the landscape. And I haven’t heard of anyone using the term “wolf tree” in the tropics.

I also wasn’t expecting to find this kind of recent history in the middle of the Children’s Eternal Rainforest, the largest protected area in Costa Rica. But perhaps I should have. The first pieces of land protected there were set aside in the 1990s (just twenty years ago). The landscape at the time included not only intact, primary forest but also open pastures that had been cleared decades before. So, it was possible that I was hiking in forests that were, in fact, old pastures.

Natural reforestation in a recent pasture (fenceposts in the foreground).

As I hiked along further and started looking more closely, there were many other signs that people had shaped the forest more recently. Many of the trees were smaller and similar in size. There were some patches of forest that were clearly younger and growing in recent fields. It wasn’t too hard to find barbed wire fencing or fence posts.

An old, unused pasture.

There were also a couple of open pastures at the edge of the forest where I had been hiking. The protected area within the Children’s Eternal Rainforest isn’t one complete, unbroken parcel of land. It still contains several sizable chunks of private land, some of which are still devoid of trees (though not necessarily being used to grow animals or food).

A lone tree in an old pasture.

In the middle of one of these open pastures, there was one large tree growing on its own. In full sunlight, it had large low-growing, outward-reaching branches. It also had a full load of sun-loving epiphytes. Perhaps someday this field will be allowed to grow back into a forest, and the small trees that will surround this old one will remind us that every forest has a history.