Air Pressure - the pressure exerted by the earth's atmosphere at any given point.

Brushland - degraded or untimbered areas dominated by a discontinuous cover of shrubby vegetation.

Deforestation - the destruction of forest trees in such a manner as to leave practically little or no chance at all of normal recovery for a forest.  Some of the factors responsible for the destruction of forest products include: illegal loggers, illegal forestry product gatherers, timber smugglers, kaingeros, squatters, forest incendiaries, miners, atmospheric agents, biological agents.

Deforested Area - the area which has been denuded but has not been reforested as of the end of the reference year.

Fishpond - a body of water (artificial or natural) where fish and other aquatic products are cultures, raised or cultivated under controlled conditions.

Forest - areas of one hectare or more which are at least 10 percent stocked with forest trees (including seedlings and saplings), with palm, bamboo, or brush.  Narrow strips of land bearing forest must be at least 60 meters wide and one hectare in size to qualify as forest.  Industrial plantations and tree farms, one hectare or more in sizes, are also included.

Forest, Classified Land - also known as permanent forest or forest reserves.  It refers to those lands of the public domain which have been the subject of the present system of classification and declared as needed for forest purposes.

Forest, Commercial - forest of commercial tree species in which the volume of trees with 15 cm and over in diameter at breast height and merchantable height of at least 5 meters measured from the base up to the first branch, is 40 cubic meters or more per hectare.

Forest, Dipterocarp - a forest type dominated by trees of the dipterocarp species, such as red lauan, tanguile, tiaong, white lauan, almon, bagtikan, and mayapis of the Philippine mahogany group, apitong and the yakals.

Forest, Mangrove - the type of forest occuring on tidal flats along the sea cost extending along the streams where the water is brackish and composed mainly of bakauan, potolan, langarai, api-api, nipa palm and the like.

Forest, Mossy - a tropical rain forest of the high elevations dominated by Podocarpaceae, Myrtaceae and Fagaceae with trees of medium height and short boled, covered epiphytes.

Forest, Non-Commercial - a forest of commercial species in which the volume of trees with 15 cm in diameter at breast height and merchantable height of at least 5 meters measured from the base up to the first branch, is less than 40 cubic meters per hectare.

Forest, Old Growth - forest predominantly stocked with mature trees with less than 25 percent of the mature stand volume removed by cutting.

Forest, Pine Closed - pure stands of Benguet or Mindoro pine with a crown cover above 30 percent

Forest, Pine Open - pure stands of Benguet or Mindoro pine with a crown cover of 10-30 percent

Forest, Unclassified Land - also known as public forest.  Land of the public domain which has not been the subject of the present system of classification for the determination of which lands are needed for forest purposes and which are not

Game Refuge and Bird Sanctuary - refers to a forest land designated for the protection of game animals, birds and fish closed to hunting and fishing in order that the excess population may flow and re-stock surrounding areas.

Land, Alienable and Disposable - refers to those lands of the public domain which have been the subject of the present system of classification and declared as not needed for forest purposes

Land, Forest - includes the public forest, the permanent forest or forest reserves, and forest reservations

Land Classification - refers to the establishment of boundaries between alienable and disposable lands and forest lands

Land Use - refers to man's activities on land of which settlements, forestry, agriculture, mining, grazing and water use are the most predominant

Log - felled trees bucked into convenient length of at least 1.5 meters, with at least 15 cm in diameter.  It may either be poles, piles, pulpwood, saw log or veneer log

Lumber - solid wood nor further manufactured other than sawing, resawing and passing lengthwise through a standard planing machine cross-cut to length.

Minerals, Metallic - minerals with a high specific gravity and metallic luster, such as titanium, rutile, tungsten, uranium, tin, lead, iron, etc.  In general, the metallic minerals are good conductors of heat and electricity.

Minerals, Non-Metallic - of or pertaining to a non-metal.  In general, of mineral luster other than metallic.  Non-metals are naturally occuring substance that does not have metallic properties such as high luster, conductivity, opaqueness, and ductility.

National Park - refers to a forest land reservation essentially pf primitive or wilderness character which has been withdrawn from settlement or occupancy and set aside as such exclusively to preserve the scenery, the natural and historic objects and the wild animals or plants therein,  and to provide enjoyment of these features in such a manner as will leave them unimpaired for future generations.

Ore - a mineral or aggregate of minerals which contain sufficient grade and quantity to be mined and beneficiated at a profit.  The mineral or rock can be further described depending on the major element contained e.g., copper ore, gold ore, chromite ore, etc.

Rainfall - amount of water falling in rain within a given time and area usually expressed as hypothetical depth of coverage.

Reforestation - the act of planting trees on bare or open land which is used to be covered with forest growth.

Relative Humidity - the amount of water vapor in the air, expressed as a percentage of the maximum amount that the air could hold at the given temperature.

Reservation - refers to any tract/s of the public domain proclaimed by the President of the Philippines for government use or any of its branches or instrumentalities or of the inhabitants thereof, for public or quasi-public uses or purposes.  The different reservations are as follows:
     a) Civil - refers to lands of public domain which have been proclaimed by the President of the Philippines for specific purpose such as town sites, resettlement areas, ancestral lands, etc.
     b) Forest - refers to forest lands which have been reserved by the President of the Philippines for any specific purpose or purposes.
     c) Military - refers to land of the public domain which has been proclaimed by the President of the Philippines for military purposes such as Airbase, Campsite, Docks and Harbors, Firing Ranges, Naval Base, Target Range, Wharves, etc.
     d) Watershed - a forest land reservation established to protect or improve the condition of the water yield thereof or reduce sedimentation.

Temperature - the degree of warmth or coldness.

Timber - major product of forest; the standing tree.

Timberland - refers to lands of the public domain which have been the subject of the present system of land classification and determined to be needed for forest purposes.   Eventually, these lands will be proclaimed as forest reserves by the President.

Watershed - a land area drained by a stream or fixed body of water and its tributaries having a common outlet for surface run-off.