[MUD-Dev] Java, applets, forests and ecologies.

[Chris Gray]

[Ling L:]

:Okay, today's stupid question:  Forests!  How do they start?  I mean,
:seriously!  I've always lived in rurban areas, and the forests near me
:seem to have been pruned a bit.  Do forests really start off with a wall
:of trees?  Does nature define a sharp boundary in Her mysterious ways?

I can only speak of the ones I've seen close up - North American alpine
forests. There doesn't have to be a sharp boundary, but there often will
be, because of events in the past that have shaped things, or because of
terrain features that affect growth. If you go into the foothills west
of here, heading towards the Rocky Mountains (which are heavily forested
with conifers, when left to themselves), you start with prairie grasses,
with some tree growth in protected spots like ravines and river valleys.
As you head into the foothills, the percentage of tree growth increases,
since the terrain offers more protected spots. Higher up, there is more
moisture, so big trees can grow more readily. Eventually you get to where
the normal situation is old-growth forest of conifers (fir if its really
old, otherwise mixtures of fir, spruce and pine, with occasional stands
(often near swampland and streams) of deciduous trees (mostly cottonwood
and poplar, with some birch, etc.). As you go higher, the slope of the
mountains increases, and rockfalls and avalanches are more common. In
those areas there are few trees, since they have all been smashed down.
Higher still you hit the snowline, and you have just snow and rock.

So, there are lots of reasons why there might be sharp lines between forest
and non-forest: avalanche paths, recent rock slides, recent forest fires
(they often burn out on the crests of hills), streams, rock outcroppings,
etc. The "alpine meadows" are usually fairly level areas where the trees
don't grow (often because the area is too close to the snow line), so
the meadow is full of long grass, perhaps mosses, and lots of flowers.
The physical shape of the mountain affects what happens. There can be
dead-end valleys which fill up with water (fly over the Rockies up here,
and you'll see hundreds of small lakes up near the mountaintops), steep
skree-slopes that periodically slip and smash the trees below them, empty
slopes and ridges that are bare because they are too exposed, cupped valleys
full of really old trees that have been protected from fire, etc.

--
Chris Gray   cg at ami-cg.GraySage.Edmonton.AB.CA