|Forest and Mountain Biodiversity: Overview|
The Ad Hoc Technical Expert Group on Forest Biological Diversity (AHTEG) of the CBD defines forest as a land area of more than 0.5 hectares, with a tree canopy cover of more than 10%, which is not primarily under agricultural or other specific non-forest land use. In the case of young forests or regions where tree growth is climatically suppressed, the trees should be capable of reaching a height of 5m in situ, and of meeting the canopy cover requirement. The CBD treats forests as “a functional ecosystem unit which should be conserved, used sustainably and the benefits derived from it should be shared equitably. In this sense, the CBD’s view of forests is function and ecosystem-oriented”.*
The Philippine government adopts the Food and Agriculture Organization (FAO) definition of forest as “an area of more than 0.5 hectares and tree crown cover (or equivalent stocking level) of more than 10% which includes natural and plantation and production forests”. Based on this definition, the DENR estimates that 7.2 million hectares comprise the forest ecosystem, which is approximately 24 per cent of the total land area.
The forest ecosystem plays a crucial role in soil and water conservation and major ecological services and directly supports approximately 30% percent of the population including some 12 to 15 million indigenous peoples who depend on forests for their survival and whose cultures revolve around their interactions with their natural environment.
The Philippine forests consist of patches of primary (old growth) and secondary growth forests. The largest remaining forest patches in the Philippines are found in northern and southern Luzon (especially the Sierra Madre mountain range), Palawan, Mindanao, and Eastern Visayas. Of the total land area and the remaining forest cover, 12% are dipterocarp/lowland rainforest and 3.5% mossy/montane/cloud forest. Only 0.4% are coastal and mangrove forest. The pine forests found in Mindoro, Mountain Province and Zambales accounts to 0.77%, and 1.6% sub-marginal forest areas are found in various locations in the country. Catibog-Sinha and Heaney (2006) cited that this estimate is based on 20% cover; but cover per forest type will be lower if estimates were based on 12-13% natural forest cover (Mackinnon, 2002 in Ong et al, 2002), or more if based on 24% forest cover (Philippine Environment Monitor 2004). The disparities in forest cover estimate is largely due to different methodologies and systems employed and on how forest cover is defined.
There are also patches of beach forests, current data for which are still being generated. Ferreras et al (2008) also noted the emergence of a new forest type, the peat swamp forest or peat dome found in Agusan Marsh based on a floristic survey done in Barangay Kaimpugan, San Francisco, Agusan del Sur and in Bunawan, Agusan del Sur. This is a distinct and unique forest type and is considered as among the least botanized of Philippine terrestrial habitat types.
Legal measures are being instituted to protect and conserve the country’s forests, foremost of this is the declaration of protected areas (PAs). As of 2008, there are 234 PAs under the National Integrated Protected Areas System (NIPAS) covering a total area of about 5,234 million hectares and a buffer zone of 222,634 hectares. Terrestrial PAs occupy a total of 4,092,635.87 hectares and a buffer zone of 202,922.08 hectares while marine PAs cover about 1,141,918.68 hectares and a buffer zone of about 19,712.86 hectares (DENR-PAWB, 2008). Six PAs covering a total area of 121,668 are under the jurisdiction of other government agencies, such as the National Power Corporation, Philippine National Oil Corporation, and the National Irrigation Administration. So far, only 10 have completed the process of establishment by enactment of site-specific law.
The Philippines is also home to a diversity of species that rely wholly or partly on the forest ecosystem for survival. Identifying critical sites for biodiversity conservation remains crucial and urgent as evident in the number of threatened species that the country has.
DENR Administrative Order (DAO) No. 2004-15 establishes the national list of threatened faunal species that includes 34 species of mammals, 80 species of birds, 18 species of reptiles and 14 species of amphibians (Table 1). Among the critically endangered are the Tamaraw (Bubalus mindorensis) which is endemic to Mindoro and the Philippine Eagle (Pithecophaga jefferyi). This list, however, includes some non-forest dependent species of birds, a marine mammal (Dugong dugon) and 4 species of marine turtles.
In 2007, the DENR came out with DAO 2007-01 which established a national list of threatened plants (Table 2). The DAO also prohibited the collection and trade of species in this list unless a permit is granted by the DENR pursuant to the Wildlife Act.
Ninety nine (99) species were identified as critically endangered. Most of these belong to Family Dipterocarpaceae, Orchidaceae and Palmae species. Some critically endangered Dipterocarps are Hopea acuminate, Shorea astylosa and Vatica pachyphylla. Genus Paphiopedilumhas the most number of critically endangered species in the Orchidaceae Family and Genus Hetorospathe and Pinanga for Palmae. Under the category of endangered, many species belong to Family Orchidaceae, Cyatheaceae, Asclepiadaceae and Melastomataceae.
* 6th Conference of Parties to the Convention on Biological Diversity Information Note: Expert Meeting on Harmonization of Forest-related Definitions for Use by Various Stakeholders, Rome, 23-25 January 2002.