A single tree growing in a spot a mile or two from the nearest other tree does not qualify that spot as a forest. No one would argue this point. But thinking about it a little more deeply, exactly how many trees are needed to make a forest? And what do we call those places with scattered trees?
All forests are treelands, but all treelands are not forests.
The terms “grasslands” and “shrublands” are well established in the disciplines of plant ecology, biogeography, range management and resource management. But the term “treelands” has never been widely adopted into these subjects as a companion term.
Nevertheless, three major treeland types are specifically defined and well understood:
- Forest trees grow close together so that their crowns form a canopy above ground;
- Savannah trees are spaced apart enough that they do not form a canopy;
- Swamps are wetlands grown with trees.
Shrublands are categorized by the dominant shrub in a given area. Various species of sagebrush, saltbush and mountain-mahogany form the familiar shrublands around Colorado.
Fens are wetlands grown with shrubs such as alders, birches and especially willows.
Grasslands also exhibit differences distinctive enough to categorize them. The most familiar is prairie, an ecosystem well known in general but so poorly understood that only people who study it can explain what it truly is and what it truly isn’t.
All prairies are grasslands, but all grasslands are not prairies.
By standards in plant ecology, prairies are grass-dominated ecosystems that exhibit three specific traits. Prairies grasses:
- Grow 1 meter tall or taller;
- Crowd together leaving little or no bare soil; and
- By their growth exclude shrubs.
Steppes qualify as grasslands and significantly differ ecologically from prairies. Steppe grasses grow less than a meter tall, are dispersed enough to leave bare soil and are interspersed by shrubs. Wildlife knows the difference.
Our state bird, the lark bunting, inhabits steppe but not prairie. And five squirrel species unique to western North America not only inhabit steppe but sculpt it into a unique ecosystem. People call them “prairie dogs” even though they are not dogs and don’t live in prairies.
Unfortunately, our culture has been shredding American steppes for two full centuries. If they are to survive, steppe ecosystems and their wildlife need our help.
Just as some scattered trees do not make a forest, isolated patches of steppe and isolated colonies of steppe-squirrels do not constitute functional ecosystems. To save them, we must save the animals responsible for making them. And we start by getting their name right!
Nature talk
Monthly nature programs at Loveland Public Library have resumed via Zoom. The next program — “Saving a Unique Ecosystem” — will be Wednesday, July 7 at 10 a.m. The free program sponsored by Friends of the Loveland Library will richly describe steppes and the wildlife that inhabits them and more fully explain the need to preserve them. To get the Zoom link, visit https://bit.ly/3d7ftLc.
