5.6.3.2.2. Industrial timber
Recent industrial timber studies link equilibrium ecological models to economic
models to measure market impacts to potential climate change and include adaptation
(Joyce et al., 1995; Perez-Garcia et al., 1997; Sohngen and Mendelsohn, 1998;
McCarl et al., 2000; Sohngen et al., 2000). Conclusions from regional studies
are similar to those in the SAR (Solomon et al., 1996) for temperate regions,
suggesting that wood supply in these regions will not be reduced by climate
change. Studies in the United States that consider only changes in forest growth
find small negative or positive impacts on timber supply (Joyce et al., 1995;
McCarl et al., 2000). Studies that consider growth effects and species redistribution
effects (dieback of existing forests, followed by redistribution), as well as
alternative economic scenarios, find that welfare economic impacts in U.S. timber
markets could change by -1 to +11% (Sohngen and Mendelsohn, 1998). Generally,
consumers are predicted to benefit from increased supply and lower prices. Producers
in some regions of the United States may lose because of lower prices and dieback,
although productivity gains could offset lower prices (Sohngen, 2001).
In contrast to the SAR (Solomon et al., 1996), more recent global market studies
suggest that climate change is likely to increase global timber supply and enhance
existing market trends toward rising market share in developing countries (Perez-Garcia
et al., 1997; Sohngen et al., 2000). One study that uses TEM (Melillo et al.,
1993) to predict growth changes finds that global timber growth rises, global
timber supply increases, prices fall, and consumers and mill owners benefit
(Perez-Garcia et al., 1997). Landowners in regions where increased timber growth
does not offset lower prices perceive losses. A study using the BIOME3 model
(Haxeltine and Prentice, 1996) suggests that producers in temperate and boreal
forests could be susceptible to economic losses from short-term dieback effects
and lower prices, although long-term (>50 years) supply from these regions
is predicted to increase (Sohngen et al., 2000). Alternatively, studies that
do not consider global market forces, timber prices, or adaptation predict that
supply in boreal regions is likely to decline (Solomon and Leemans, 1997).
5.6.3.2.3. Recreation and non-wood forest products
There is considerably less published literature available to assess the effects
of climate change on nonmarket services from forests (Wall, 1998), including
recreation and non-wood forest products. Climate change is likely to have direct
effects on forest-based recreation. For example, lengthening of the summer season
may increase forest recreation (Wall, 1998). Changes in the mean and variance
in daily temperature and precipitation during peak seasons will affect specific
activities differently, however. In the United States, some studies suggest
that higher temperatures may negatively affect camping, hiking, and skiing but
positively affect fishing (Loomis and Crespi, 1999; Mendelsohn and Markowski,
1999; Joyce et al., 2000).
Climate change also will have indirect effects on forest recreation. For example,
changes in the structure and function of natural forests that are used for recreation
could alter visitation patterns by causing users to substitute alternative sites.
Alternatively, some recreational industries may have large adaptation costs—for
example, snow-making costs in skiing areas may increase (Irland et al., 2001).
In addition, institutional factors are likely to play a strong role in mediating
the response of recreation because much of it occurs on public, natural forests
where adaptation may be less economically feasible. Many forest-based activities,
such as hunting, rely on management decisions by agencies that will have to
adapt to climate change as well (Brotton and Wall, 1997).
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