by Carl Strang
Northeast Illinois would have been intrinsically forested under recent climatic conditions, but was mainly prairie because fire prevented the forest from manifesting itself until European-Americans moved in and stopped it. Until then trees grew in fire shadows, small areas where wetlands or topographic breaks blocked fires pushed by the prevailing westerlies. A few of our trees, notably oaks and cottonwoods, reach sizes that arguably can be called “large,” but to appreciate how big trees (and therefore living things) can get, we need to travel. In North America, that means California. I haven’t experienced giant sequoias yet, but I found the coastal redwoods to be plenty impressive on a brief conference trip out there a few years ago.
The trail there was quiet, I would have to say “hushed,” despite the presence of plenty of people. In part that no doubt was because of inspired awe, but the structure of the place absorbed sounds efficiently.
The place didn’t seem hugely diverse, but as in the tropics some of that diversity was in the form of epiphyte communities.
There is no shame in being the rube who gawks upward in such a place.
The biggest of them are amazing in their girth as well.
Redwood forests can burn, though fire is not the frequent presence it was in Illinois. The trees have some resistance to it, and they also have the advantage of living in the coastal fog zone, much moister than northeast Illinois. Now we shift to Tasmania, to Mount Field National Park, to take a look at another big tree, the swamp gum.
A rainforest climate again makes possible this kind of growth. And again, one plays the rube.
As with the whales I featured recently, the contrast in size provides perspective on our place. It encourages us to think about how large size is itself an adaptation that is advantageous in some environments or conditions, but size, whether large or small, results from a balance of selective factors that must fit a species into its community. Each organism succeeds in part because it is just the right size. It is somewhat mind boggling to realize that every species always displays a range of sizes, selective factors constantly are pushing and pulling to influence what the right size for each species is at a given time, the species all are balancing against one another simultaneously, and size is only one of many such characteristics.