Fragile Lands of Latin America Strategies for ... - PART - USAID

2 76 Gerardo Budowski
ing on the alluvial river banks ("diques") that are periodically replen-
ished by alluvion from short term flooding of the rivers, has proven
to be in several cases, a striking success (CONIF, 1986). Growth has
been spectacular for various species, notably the valuable "roble" (Ta-
bebuia rosea) that produces a cabinet wood. Over a short period of 4-
5 years, roble trees reach annual diameter increments of 6-7 cm for
the 25% best trees in some experimental plots. This is extraordinary
in any part of the world. The form is very acceptable too. The results
are also excellent for the valuable "laurel" trees (Cordia alliodora),
very much in demand for construction and hrniture for its valuable
properties including resistance to termites. Here average diameters
reach 3-4 cm a year for the 25% best trees coupled with a spectacular
growth in height and an excellent form, typical of that fast growing
and self-pruning species, making this tree extremely promising (Baquero
and Budowski, 1987). Although Cordia alliodora is not native, it is well
accepted by local farmers, and CONIF which launched the planting
program is meeting large local demand for seedlings. It is likely that
once the trees flower and fruit profusely, they will easily regenerate
naturally as indeed has been the case in wet regions of Costa Rica and
Ecuador (both Pacific and Amazonian) where natural regeneration has
"exploded" into the open niches, provided soils are acceptable. What
is more, laurel lends itself well to agroforestry combinations because
of its small crown and self-pruning ability. The same can be said for
a few other promising tree species. Many crops can be grown with
trees as several experiments have shown (Leguizamo et al., 1985; Vega,
1985, Vega et al., 1985). However, it should be stressed again that
success stories have been witnessed only on the best soils such as the
alluvial river banks that are periodically replenished in nutrients from
periodic flooding.
In conclusion, forestry offers some real options but for a rather
limited set of conditions. These opportunities are presently not suffi-
ciently exploited. For the majority of the forests on well drained soils,
however, sustained yield is a problem that demands long-term research.
It is likely that most of these forests at present offer little scope for
sustained management.
3. Promote sustainable exploitation of freshwater fisheries. Research
on tropical freshwater fisheries, like so many other fields, is just be-
ginning. Most of the fish are unknown or not well-known. There is
certainly some prospect to increase fresh water fishing practices on a
sustainable yield basis, both for local consumption and for commercial
purposes. Research leading to devices such as submerged traps, as well
as careful management of certain lakes and rivers by local communities