480 Francis E. Putz and Pieter A. Zuidema
Where the objective of forest management is
sustained timber yield (STY) of shade-tolerant
tree species with abundant regeneration in the
forest understory, RIL is tantamount to STY unless
harvests exceed 60–80 m^3 ha−^1 (e.g., Sist and
Nyuyen-Thé 2002). In contrast, where the com-
mercial tree species are light-demanding and
regenerate only after substantial opening of the
canopy, then silviculturalists intent on sustain-
ing timber yields may call for increased harvest
intensity, liberation of future cro ptrees from
competition by poison-girdling their near neigh-
bors, and even mechanical soil scarification to
promote seed germination and seedling establish-
ment (Fredericksen and Putz 2003, Peña-Claros
et al. 2008b). Such treatments substantially and
intentionallychangepre-interventionforeststruc-
ture and composition often beyond the assumed
“historical” range (which is seldom based on
more than 5–10 years of stand monitoring), but
presumably the light-demanding trees that dom-
inated the pre-logging canopy did not regenerate
under the closed-canopy conditions to which they
contributed later in their lives. Given that many
light-demanding tropical trees of high commer-
cial value can live 100–200 years (e.g., Brienen
and Zuidema 2006), forests may reach equilib-
rium structure and composition only after more
than 500 years following substantial natural or
anthropogenic disturbance (e.g., van Gemerden
et al. 2003, Worbeset al. 2003, Bakeret al. 2005).
It should therefore not be surprising that many of
the tropical forests that are richest in tree species
and wildlife benefited from centuries of husbandry
by hunters, gatherers, and other traditional for-
est users (e.g., Gómez-Pompaet al. 1987, Balée
1994, 2000, Peters 2000, but see Parker 1992).
The extent of historical humanization of tropical
forests, particularly by pre-Columbian Amerindi-
ansinAmazonia,ishotlycontested(e.g.,Roosevelt
1991, Meggers 2001, Bush and Silman 2007),
but widespread occurrence of anthropogenic soils
(i.e., “terra preta do indio”) suggests that many
forests were indeed substantially modified before
European diseases decimated human populations
in the basin (e.g., Erickson 2003, Lehmannet al.
2004).
If we accept that the remaining tropical forests
of the world cannot all be fenced off and otherwise
protected in people-less preserves, then conser-
vation values are maximized across the land-
scape where ecologically informed land-use plans
are implemented responsibly. Although ease of
access often overwhelms other considerations in
determining how forest-lands end u pbeing used
(e.g., Kaimowitz and Angelsen 1998, Chomitz
2007), biodiversity value (e.g., species richness
or the presence of rare or endemic taxa) as
well as soil characteristics (e.g., fertility and
erosion-proneness), costs of silvicultural man-
agement (versus timber mining), slope, and ele-
vation should figure prominently in land-use
planning. The importance of these ecological
attributes notwithstanding, socioeconomic and
political conditions such as contested land own-
ership, spontaneous and planned land coloniza-
tion by people from other regions, and cultural
traditions often coupled with the activities of
smugglers, illegal loggers,wildlife poachers, and
bandsof guerrillasoftendeterminehowforestsare
treated. Even when conservation is approached
in a quantitative manner by skilled ecologists,
normative rather than technical issues typically
prevail (McCool and Stankey 2004), which is to
say that culture generally trumps ecology.CONSERVATION SOLUTIONS
REFLECT VARIOUS
SOCIOECONOMIC CONTEXTS
In discussing the tropical conservation problem,
many environmentalists disregard the fact that
most tropical forests are in sovereign nations of
which they are not citizens (Romero and Andrade
2004). Just as the government of the USA might
object to international attempts to intervene in the
cutting of the few remaining old-growth forests
in the Pacific Northwest or the continued pol-
lution of Everglades National Park with effluent
from highly subsidized sugarcane plantations in
Florida, tropical nations expect recognition of
the legitimacy of their own political processes
(Escobar 1998).
Deforestation and conversion of tropical forests
to other land uses are often portrayed as sim-
ple consequences of population pressure and
ignorance. As described by Corlett and Primack