“Autumn Goddess” flitted through the woods easing green foliage to the warm colors of her namesake season. After her passing, the changed leaves fluttered to the forest floor, a carpet of randomly scattered browns, reds, oranges, and yellows. She whistled to the forest birds reminding the migrators of their long trips to warmer climes; reminding those that stay behind to start getting their winter nests in shape. For now, the days were still warm, but the nights were crisp and quickly becoming cold. It would not be very long before the days would also become cool.
Winter demanded entry even as Summer refused to let up her hold.
They came to a compromise leaving Autumn rushing about a much curtailed region.
I love trees and have done for as long as I can remember. Their structure, especially, fascinates me. They reach up so high in the sky and spread out so wide – at least they do when you are a small child. The word, “forest” for me evokes images of lush foliage especially that of a temperate forest, but I have a friend for whom “forest” and “tree” means conifer. Having seen only photos of these, I can’t fault him. Their leaves are needle-like but their height and structure are nothing if not majestic. And they wear their Winter cloaks of snow with breathtaking grandeur.
According to the University of California Museum of Paleontology there are three main classes of forest defined by global latitude: tropical, temperate, taiga. Tropical forests are further divided into subtypes based on rainfall (UCM of P):
- evergreen rainforest: no dry season.
- seasonal rainforest: short dry period in a very wet tropical region (the forest exhibits definite seasonal changes as trees undergo developmental changes simultaneously, but the general character of vegetation remains the same as in evergreen rainforests).
- semievergreen forest: longer dry season (the upper tree story consists of deciduous trees, while the lower story is still evergreen).
- moist/dry deciduous forest (monsoon): the length of the dry season increases further as rainfall decreases (all trees are deciduous).
Sadly, over half our planet’s tropical forests no longer exist (UCM of P).
Temperate forests exist in Earth’s temperate zones (both northern an southern hemispheres have these). These are regions with both Winter and Summer, (and the transitional seasons of Sprjng and Autumn) and between four and six months of no frost which encourages a lengthy growing season. The climate is generally considered mild. These forests, too, are further subdivided by rainfall characteristics (UCM of P):
- moist conifer and evergreen broad-leaved forests: wet winters and dry summers (rainfall is concentrated in the winter months and winters are relatively mild).
- dry conifer forests: dominate higher elevation zones; low precipitation.
- mediterranean forests: precipitation is concentrated in winter, less than 100 cm per year.
- temperate coniferous: mild winters, high annual precipitation (greater than 200 cm).
- temperate broad-leaved rainforests: mild, frost-free winters, high precipitation (more than 150 cm) evenly distributed throughout the year.
These are rare with only scattered remnants of these once extensive forests left on Earth.
The last class, Taiga or Boreal forests actually represents the largest biome. These forests have the shortest growing period as they are all located at much colder latitudes of the northern hemisphere (50º to 60º). There are no further subdivisions. These forests, as well, are disappearing, mostly due to logging.
So that’s 10 different kinds of forests and all are in danger of disappearing. Not a good thing for life on Earth.
The Forest Biome, University of California Museum of Paleontology, www.ucmp.berkeley.edu/exhibits/biomes/forests.php
The Taiga or Boreal Rainforest, Marietta College, w3.marietta.edu/~biol/biomes/boreal.htm