Zoning

Society values forests as an economic resource – a source for jobs, community stability, and wood products.  Society also values forests for non-economic reasons –  biodiversity, water quality, and wilderness are just a few examples.  Thus, forest management objectives can be divided into two classes that compete: extraction-based objectives (i.e. timber harvest) and those that require an intact forest.

Integrated-use is currently the major management philosophy that is used to balance competing objectives.  Integrated-use, or multiple-use, mixes all objectives together across the same landbase.  It is a very efficient management style when objectives only partially compete.  For example, forest harvesting can be detrimental to the habitat requirements of some game species, but forestry roads can be used by hunters for access to game populations.  Integrated-use becomes less efficient when some objectives are seriously impacted by timber harvesting, such as wildness values.

One way to help resolve land-use conflicts is to divide the landscape into separate management zones, each with different management objectives.  Management zones can be large regions, from 5 000 to 50 000 hectares, or even more. Conflicting objectives are separated into different zones, while complementary objectives are grouped together. The main argument for zoning is that the segregation of incompatible objectives allows for more specialized practices.  The intent is to maximize returns from intensive practices by concentrating them on a portion of the landbase, instead of using less intensive practices across the whole landbase.

Computer models can be used to assist in the allocation of zones.  The basic requirements for an ideal zoning model are that it be able to: 1) create zones according to ecological representation targets; 2) organize the zones into regions with basic size and shape objectives; and 3) allocate priority objective areas into specific zone types. The model must be able to handle large spatial datasets, and should find optimal solutions, or the best alternative possible. The Zoning Allocation Model presented here was designed to these specifications. It is a spatial, landscape-level planning tool designed to help planners zone forest activities.  It uses the Simulated Annealing Algorithm to search for optimal allocations of land into one of three zone types.