Reforestation: not quantity but quality of trees

The Jan. 6 editorial (“Genuine growth”) was right on target in highlighting the urgency of reforestation efforts and the establishment of the National Greening Program (by Executive Order No. 23), under which millions of seedlings have reportedly been planted in over 292,000 hectares nationwide.

Quantity however is not everything; attention must also be focused on what to plant. Unfortunately, many, if not most, of the nonfruit trees planted are mahogany, gmelina and other introduced species. Such fast-growing trees are suitable for commercial plantations, but not for watershed rehabilitation and biodiversity conservation. A case in point is the Tigum-Aganan (Maasin) watershed that provides water to the greater Iloilo area: Around 60 percent of the 7,000-hectare forest is covered with planted mahogany and other exotics. The trees reportedly release substances that are toxic to the microbiota, accounting for very little organic matter in the soil. For lack of an absorbent upper soil layer, heavy rains from Typhoon “Frank” flowed downstream to create the floods that devastated Iloilo City in 2009. In contrast, native flora have coevolved over time with local organisms, including the bacteria and fungi of decay, hence such forests have a healthy layer of decomposing litter.

Clearly, we should plant indigenous trees for reforestation—but which kinds? As many of the planting sites are barren, ecology dictates that colonizers should be the species of choice over climax flora such as dipterocarps. (By definition, “climax” should come at the end and “pioneers” at the beginning.) May I therefore recommend the beach forest species, hardy colonizers, which are suitable for blighted landscapes. Beach trees start at the beach but do not end there—some can grow up to 200 kilometers inland and 200 meters above sea level. A remarkable example is Millettia pinnata, aka bani or balukbaluk. Bani seeds that I collected and germinated in 2007 produced seedlings outplanted in 2008, and in turn gave flowers and fruits in 2011—a new generation after only three years! I speak from 40 years of planting experience, from which the latest include 5-year-old and 1-year-old trees belonging to 15 species in a churchyard in Jaro, Iloilo. These are among the 140 species described in the book “Beach Forest Species and Mangrove Associates in the Philippines” (which I wrote with R.B. Sadaba).

Native seedlings are produced by a few nurseries such as those of RAFI in Cebu, the Visayas State University in Leyte, and the Department of Environment and Natural Resources-National Capital Region. May I suggest that other DENR nurseries stop producing seedlings of mahogany—leave such profit-making ventures to commercial groups— and redirect government resources to planting native trees, especially beach forest species.

—J.H. PRIMAVERA, PhD,

Pew fellow in Marine Conservation, Scientist Emerita, SEAFDEC Aquaculture Department,chief mangrove scientific advisor,

Zoological Society of London,

48 Burgos St., La Paz, Iloilo City 5000