ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

INTRODUCTION
The use and future needs of wood fiber in the forms of lumber, paper products,
chemicals, and as a source of energy have been escalating at an alarming rate. To
alleviate these demands, wood resources can be increased by (1) recycling, (2)
accelerating timber production, (3) the replacing of wood and conventional wood
usage by a1 ternative materials, (4) intensifying silvicul tural practices, (51
intensive utilization of forest residues, and (6) protection from biological and
physical degradation.
Part of our purpose has been to assess the significant long-term imp1 ications,
from short- term experimental approaches, of intensive residue (biomass/fi ber)
utilization. We are questioning how much fiber, in specified quantity, form, and
distribution, can be removed from any given site by prescribed harvesting wSthout
precipitating short- or long- term deleterious consequences.
In addition to fiber removal by man, natural agents--notably decay and fire--
play an integral role in reducing organic resources. While decay is usually viewed
as a long-term process of biomass volume reduction, fire produces immediate and
long-term environmental effects similar to those of near-complete biomass utilization.
In any given forest ecosystem there is a finite amount of energy available for
biomass production, and decay and fire maintaln a balance between production and
decomposition. Therefore, there is a need to define the optimum levels of the end
products of decay in terms of site needs for existing or long-term site productivity
and to integrate these needs into forest management.
THE ROLE OF BIODEGRADATION IN FOREST ECOSYSTEMS
Decay or biodegradation are caused by a variety of pracesses, organisms, and
interactions between the two. Decomposition is an ongoing, everpresent process in
1 iving and dead plants. A myriad of microorganisms including auto- and heterotrophic
fungi and bacteria, streptomycetes, protozoa, and invertebrates contribute indi-
vidual ly or collectively toward decay. Climatic weathering and interactions of the
substrate with existing flora also have significant impacts. The end products ~f
biodegradation of woody substrates are carbon dioxide, water, and a stable (but
biodegradable) complex of phenolic components derived from the lignin portions of
woody plants and, in some instances, fungal melanines. A major influence of this
organic matter, which is phenolic in nature, is the enhancement of soil structure
and function. Therefore, the principal role of decay is the recycling of carbon in
the ecosystem. During this recycl ing process, decaying organic matter influences
the structure and function of the system and acts as a nutrient source. The rates
of decomposition and nutrient re1 ease are functions of the environment,
THE NATURE OF CONIFEROUS AND ANGIOSPERMOUS WOODY SUBSTRATA
To understand the processes of decay and its functional end products, an
understandi n of the compositions of woody material of angiosperms (hardwoods) and
gymnosperms 9 softwoods) is necessary. Also, their major geographic and climatic
distribution appear to be of fundamental importance.