On May 2004, on my way from Detroit-Nagoya-Manila, I wrote this short observation:
From the Pacific Ocean, first, I saw several islands around the bigger Polillo Island, Quezon province. Thickly forested, lots of white sand beach around those tiny islands. Polillo Island itself has thick forest cover, including wide coconut plantation.
Sierra Madre is a huge, long mountain range, from Cagayan to Isabela, down to Aurora, Quezon and Camarines Norte provinces. The one I see from the plane is in Quezon province, in the municipalities of Infanta and Gen. Nakar. Really thick forest! About 95% forest cover, I guess. As you traverse the mountain range towards Rizal province, the mountains have lesser forest cover as agricultural, residential and industrial activities intrude into previously forest lands.
Last May 2007, or exactly 3 years after, on my way home from Honolulu-Manila, I have observed from the plane that forest cover in the uninhabited parts of the mountain range remains thick. There are small patches of deforestation on scattered parts. I suspect that there are some people who are living there. The first thing you do if you live in a forest land is to cut some trees to have an open space, use the trees for your house, then cut more trees and clear the area so you can plant food crops for yourself and your family.
As you go from the high mountains of Sierra Madre down to its western side, mainly Rizal province in the south (Bulacan, Nueva Ecija and Nueva Vizcaya in the center-north), the deforestation (or conversion from forest to non-forest land use) becomes more prominent.
Tanay and Antipolo have the biggest land area in Rizal province, especially in the Sierra Madre mountains side. And it’s here where many economic activities and human settlements are wide.