During the exotic species discussion, several posters grumbled that removal
of exotic species often left barren ground that was worse habitat than
before. As just about every gardener knows, it's tough to get a young plant
to survive in a landscape dominated by established plants, native or not.
Once a plant has seized a patch of ground, it doesn't easily relinguish it.
It's as true in the natural world as in a perennial flower garden. Most
plants struggle to get started in life unless some disturbance (fire, flood,
hurricane, wind, trampeling bison herd, etc) clears a patch of ground.

The most effective way to replace exotic species is mass removal followed by
replacement with the species you want. It's the method I've come around to
using on my property. I'm working in manageable-sized areas of, say 300-400
sq ft, at a time. I nuke an area first by repeated Round-Up applications
over a growing season, then plant trees and shrubs the following spring. (I
know a lot of people hate Round-Up, but it's less damaging than many other
methods and the dead roots stay in place and help hold the soil.)

Clearing undeniably creates a temporarily bleak landscape. To partially
alleviate the barreness and to deal with part of our woody debris, I've
built brush piles. We have a never-ending supply of branches that come down
in high winds and that we create by pruning. I have four or five brush
piles in the swampy ditch I'm working on now. The largest brush piles have
about the volume of a compact car. Almost all of the passerine species in
the yard seem to spend a disproportionate amount of time in the brush piles.
The piles are especially popular with the juncos, house sparrows (yeah,
yeah, I know), robins, song sparrows, and, recently, the white-crowned
sparrows. Part of the attraction is that the piles are in standing water or
on squishy mud. (I put them there because brush piles are a fire hazard.)
The birds bathe in the water then dry and bask in the sun in the safety of
the brush piles. They forage for bugs in the mud.

Areas cleared for replanting present opportunities to build large brush
piles and maybe artificial snags where the woody debris would be less of a
fire hazard than if it were in a vegetated area.

Kelly Cassidy