Restoration of Tropical Forests - Restoration Ecology: The New Frontier - page 113

2007). However, there is some evidence that payments
to small farmers and indigenous groups in Costa Rica
have helped to cover the initial costs of tree planting
and increase the number and diversity of trees planted
(Cole 2010 ).
Secondly, as discussed previously, as part of regional,
national, and global effort to reduce carbon and other
greenhouse gas emissions, there has been an enor-
mous amount of discussion about programmes to pay
landowners in the tropics to reduce net carbon emis-
sions from tropical deforestation, and enhancing long-
term carbon storage in degraded lands. Certainly, such
efforts must focus fi rst on preserving intact forests.
Moreover, there are complicated issues related to
respecting indigenous peoples' rights, establishing
baseline rates of deforestation and ensuring that pay-
ments are effective in reducing the drivers of deforesta-
tion (Blom et al . 2010 ; Brown 2010 ). Nonetheless,
funding from such programmes may soon dramati-
cally increase the amount of funding available for
tropical forest restoration. Regenerating forests have
the potential to sequester a considerable amount of
carbon, particularly over the fi rst few decades (Marín-
Spiotta et al . 2008). However, there are certain to be
trade-offs to consider between maximizing carbon
sequestration or other ecosystem services, on the
one hand, and maximizing biodiversity conservation
in restored tropical forests, on the other (Lamb et al .
2005 ).
Finally, agro-successional restoration (i.e. incorpo-
rating a range of agroecology and agroforestry tech-
niques as a transitional phase early in forest restoration)
could be used as a means to defray restoration costs
and provide for human livelihoods (Lamb et al . 2005 ;
Vieira et al . 2009). Many of the management tech-
niques used by farmers for decades to reduce weed
competition and enhance soil fertility when cultivat-
ing tropical crops and trees are similar to those used
for restoration. For example, interplanting some forest
tree species with shade-tolerant agricultural crops,
such as cacao or coffee, may help to reduce the initial
costs of planting and maintaining tree seedlings.
Others have suggested managing cows to both disperse
seeds of some hard-seeded tree species (Miceli-Méndez
et al . 2008), as well as to reduce grass biomass in areas
where forest tree seedlings have been established.
However, using grazing animals as a restoration tool
requires careful management to minimize damage to
forest seedlings.

9.6 PERSPECTIVES

Tropical forest restoration is critical to both conserve
biodiversity and maintain ecosystem services. It is not,
however, a substitute for preventing deforestation of
existing forests. It is heartening that some tropical
forests are able to quickly recover the structure and
species composition of intact forests (Chazdon et al .
2009b). But rates of recovery are extremely variable
depending on factors illustrated in Figure 9.3, and
there are many other cases where it appears that less
common and mature forests species have not recovered
after a number of decades.
There is a strong mismatch between the temporal
scale of human decision making and that of ecosystem
recovery. In other words, humans want to see change
quickly, or even immediately, but most ecosystems take
years to decades to recover from disturbance without
active interventions aimed at restoration. In most
cases, a bit more patience to allow systems to follow the
natural recovery process is needed. By waiting for at
least a few years, it is possible to assess whether inter-
vention is necessary and, if so, how to best allocate
efforts. This caution is necessary not only because of
the lack of resources available for restoration, but also
because extensive human intervention can actually
redirect recovery to a state quite different from the pre-
vious forest.
This chapter has focused on restoring plant com-
munities, but certainly it is also necessary to consider
whether faunal species colonize and utilize sites target-
ing for restoration (Bowen et al . 2007 , Lindell 2008 ).
This will depend on both nearby source populations
and habitat quality. Two recent reviews of faunal utili-
zation of naturally regenerated secondary tropical
forests (Bowen et al . 2007 ; Chazdon et al . 2009b )
reported that the number of faunal species generally
increases with time from abandonment, but that the
degree to which the number and composition of faunal
communities recover is highly variable and that, not
surprisingly, it is infl uenced by past land use and the
surrounding landscape. There have been fewer studies
of fauna in actively restored sites, and additional
research is needed. Studies suggest that restoration
efforts that succeed in enhancing vegetation structural
complexity increase the number of both insects and
birds (Grimbacher & Catterall 2007; Morrison et al .
2010), and that proximity to intact forest is important
(Anderson 1993 ; Grimbacher & Catterall 2007 ).