It can be extremely expensive to restore an ecosystem and it
may not make sense to do so when natural processes could also do
the job. Holl and Aide (2011) introduce this section by examining
when and where ecosystems need to be actively restored. These
authors introduce a simple decision framework that managers can
use to decide if they should actively intervene. Dry forests are one
of the most threatened forested biomes in the world (Murphy and
Lugo, 1986; Janzen, 1988). Griscom and Ashton (2011) review the
history of land conversion and ecosystem services provided by dry
forests of Mesoamerica. They adapt the Ashton et al. (2001) frame-
work for restoration pathways for Southeast Asia to this forest type
with the goal of guiding land managers and practitioners in the
decision making process depending upon social and biological site
conditions.
Three manuscripts in this section describe experimental stud-
ies undertaken to test hypotheses related to species growth under
different conditions and potential approaches to restoration tech-
niques. Celis and Jose (2011) test the early growth performance
of six native tree species on pastures dominated by two differ-
ent grass species. van Breugel et al. (2011) describe a large scale
project in Panama (PRORENA) to assess the growth of 49 species (47