Forest and Wildlife: Forest Classification

Forests and Wildlife

The earth's total land area is approximately 144.8 million sq.kilometers, with forests covering about 28% of it.
Forests are defined as areas where trees are the dominant vegetation, covering extensive tracts of land with trees and undergrowth, sometimes intermingled with open spaces.
There are two types of forests: closed canopy forests (where leaves and twigs of adjacent trees touch) and open canopy forests (where leaves and twigs of adjacent trees do not touch).

Layers of a Forest

Forest floor: where trees start their lives, with fallen leaves, fruits, decaying trees, and fungi that provide food sources for many animals and enrich the soil for young plants.
Understory: the layer above the forest floor, consisting of tree trunks, saplings, small ground plants, and vines, inhabited by animals such as bees, snakes, frogs, and leopards.
Canopy: the third layer, where treetops form a dense "green blanket" that shields sunlight from the forest floor and understory, home to many animals like toucans, parrots, sloths, and monkeys.
Emergent: the highest layer, comprising tall trees (over 200 feet) that tower above the canopy layer, inhabited by birds of paradise, eagles, and macaws.

Forest Classification

Old-growth forests: virgin forests that have not been seriously disturbed for hundreds or thousands of years, characterized by large numbers of standing dead trees and fallen logs.
Second-growth forests: stands of trees resulting from secondary ecological succession after cutting, making up about 40% of tropical forests.

Forest Distribution

Table 3 shows the distribution of forest by continent, with Africa, South America, and the Former USSR having the largest forest areas.

Forest Types in the Philippines

Lowland evergreen rainforest: the most widespread type, found all over the country from 0-1000 meters above sea level, dominated by dipterocarps, palms, legumes, and orchids.
Lower montane forest: found in the Central Cordillera, Benguet, and Mt. Province at 1000-1500 masl, dominated by Lithocarpus and Liliaceous species.
Upper mountain forest: found on Mt. Pulag, Mt. Apo, Mt. Halcon, and Mt. Kitanglad at 1500-2400 masl.
Sub-alpine forest: found at altitudes over 2400 masl.
Pine forest: having a pure stand of Pinus insularis and Pinus merkussi, found at 1000 masl in Benguet, Central Cordillera, Zambales, and Mindoro.
Forest over limestone: a distinct type of vegetation found over karst or calcareous limestone substrates, exhibiting high endemism.
Forest over ultrabasic soils: yielding unique species highly adapted to substrates high in minerals like chromite, found in the Philippines where ultrabasic soils were exuded out by past major events of diastrophism.
Semi-deciduous forest: found in the eastern Sierra Madre Range and Palawan where distinct seasonally dry climate predominates.
Beach forest: a strand of vegetation composed of species adapted to sandy soils, found extending seaward.
Mangrove/Nipa forest: mangrove and other associated species occur as dense stands or narrow belts on shorelines extending seaward and in mouths of rivers where fresh and saltwater mix.
Freshwater swamp forest: inland to 200 masl, yielding successional forest formations of varying species composition depending on the water level.

Importance of Forests

Commercial importance: supply lumber, biomass, pulp, medicines, and other products, with more than half of the world's population depending on firewood or charcoal as their principal source of heating and cooking fuel.
Ecological importance:
- Forested watersheds act as giant sponges, regulating water flow and recharging springs, streams, and aquifers.
- They help control soil erosion, flooding, and sediment washing into rivers, lakes, and artificial reservoirs.
- Forests play a crucial role in the global carbon cycle and act as a defense against global warming.
- Trees remove carbon dioxide from the air and add oxygen to it.
- Forests provide habitats for a large number of wildlife species and are a major reservoir of biological diversity.

Forest Management and Conservation

Forest management involves planning for sustainable harvest, with attention to forest regeneration.
Miller classifies forest management systems into:
- Even-aged management: maintaining trees at the same age and size, harvested all at once, and replenished naturally or artificially.
- Uneven-aged management: maintaining trees at different ages and sizes, fostering continuous natural regeneration, with goals of biological diversity, long-term timber production, economic return, and multiple land use.

Tree Harvesting Method

Depends on the forest management system, tree species, site conditions, and owner objectives and resources.
Methods include:
- Selective cutting: removing individual or small groups of mature trees in uneven-aged forests, reducing crowding and encouraging growth, while maintaining biodiversity.
- Shelterwood cutting: removing mature trees in a series of cuttings, typically over 10 years, to regenerate a new crop.
- Seed-tree cutting: harvesting almost all trees on a site, leaving a few seed-producing trees to regenerate a new crop.
- Clear cutting: removing all trees from a given area to establish a new, even-aged stand or tree farm, which can lead to biodiversity loss.
- Strip logging: an alternative to clear cutting, allowing sustainable timber yield without widespread destruction.

The Extinction of the Philippine Forest

The Philippine rainforest is likely to cease to exist in the future, taking with it 3,600 species of plants, fungi, and animals found only in the Philippines, including the tarsier, flying lemurs, cockatoo, Philippine crocodile, and green turtle.

Forests and Wildlife

The earth's total land area is approximately 144.8 million sq.kilometers, with forests covering about 28% of it.
Forests are defined as areas where trees are the dominant vegetation, covering extensive tracts of land with trees and undergrowth, sometimes intermingled with open spaces.
There are two types of forests: closed canopy forests (where leaves and twigs of adjacent trees touch) and open canopy forests (where leaves and twigs of adjacent trees do not touch).

Layers of a Forest

Forest floor: where trees start their lives, with fallen leaves, fruits, decaying trees, and fungi that provide food sources for many animals and enrich the soil for young plants.
Understory: the layer above the forest floor, consisting of tree trunks, saplings, small ground plants, and vines, inhabited by animals such as bees, snakes, frogs, and leopards.
Canopy: the third layer, where treetops form a dense "green blanket" that shields sunlight from the forest floor and understory, home to many animals like toucans, parrots, sloths, and monkeys.
Emergent: the highest layer, comprising tall trees (over 200 feet) that tower above the canopy layer, inhabited by birds of paradise, eagles, and macaws.

Forest Classification

Old-growth forests: virgin forests that have not been seriously disturbed for hundreds or thousands of years, characterized by large numbers of standing dead trees and fallen logs.
Second-growth forests: stands of trees resulting from secondary ecological succession after cutting, making up about 40% of tropical forests.

Forest Distribution

Table 3 shows the distribution of forest by continent, with Africa, South America, and the Former USSR having the largest forest areas.

Forest Types in the Philippines

Lowland evergreen rainforest: the most widespread type, found all over the country from 0-1000 meters above sea level, dominated by dipterocarps, palms, legumes, and orchids.
Lower montane forest: found in the Central Cordillera, Benguet, and Mt. Province at 1000-1500 masl, dominated by Lithocarpus and Liliaceous species.
Upper mountain forest: found on Mt. Pulag, Mt. Apo, Mt. Halcon, and Mt. Kitanglad at 1500-2400 masl.
Sub-alpine forest: found at altitudes over 2400 masl.
Pine forest: having a pure stand of Pinus insularis and Pinus merkussi, found at 1000 masl in Benguet, Central Cordillera, Zambales, and Mindoro.
Forest over limestone: a distinct type of vegetation found over karst or calcareous limestone substrates, exhibiting high endemism.
Forest over ultrabasic soils: yielding unique species highly adapted to substrates high in minerals like chromite, found in the Philippines where ultrabasic soils were exuded out by past major events of diastrophism.
Semi-deciduous forest: found in the eastern Sierra Madre Range and Palawan where distinct seasonally dry climate predominates.
Beach forest: a strand of vegetation composed of species adapted to sandy soils, found extending seaward.
Mangrove/Nipa forest: mangrove and other associated species occur as dense stands or narrow belts on shorelines extending seaward and in mouths of rivers where fresh and saltwater mix.
Freshwater swamp forest: inland to 200 masl, yielding successional forest formations of varying species composition depending on the water level.

Importance of Forests

Commercial importance: supply lumber, biomass, pulp, medicines, and other products, with more than half of the world's population depending on firewood or charcoal as their principal source of heating and cooking fuel.
Ecological importance:
- Forested watersheds act as giant sponges, regulating water flow and recharging springs, streams, and aquifers.
- They help control soil erosion, flooding, and sediment washing into rivers, lakes, and artificial reservoirs.
- Forests play a crucial role in the global carbon cycle and act as a defense against global warming.
- Trees remove carbon dioxide from the air and add oxygen to it.
- Forests provide habitats for a large number of wildlife species and are a major reservoir of biological diversity.

Forest Management and Conservation

Forest management involves planning for sustainable harvest, with attention to forest regeneration.
Miller classifies forest management systems into:
- Even-aged management: maintaining trees at the same age and size, harvested all at once, and replenished naturally or artificially.
- Uneven-aged management: maintaining trees at different ages and sizes, fostering continuous natural regeneration, with goals of biological diversity, long-term timber production, economic return, and multiple land use.

Tree Harvesting Method

Depends on the forest management system, tree species, site conditions, and owner objectives and resources.
Methods include:
- Selective cutting: removing individual or small groups of mature trees in uneven-aged forests, reducing crowding and encouraging growth, while maintaining biodiversity.
- Shelterwood cutting: removing mature trees in a series of cuttings, typically over 10 years, to regenerate a new crop.
- Seed-tree cutting: harvesting almost all trees on a site, leaving a few seed-producing trees to regenerate a new crop.
- Clear cutting: removing all trees from a given area to establish a new, even-aged stand or tree farm, which can lead to biodiversity loss.
- Strip logging: an alternative to clear cutting, allowing sustainable timber yield without widespread destruction.

The Extinction of the Philippine Forest

The Philippine rainforest is likely to cease to exist in the future, taking with it 3,600 species of plants, fungi, and animals found only in the Philippines, including the tarsier, flying lemurs, cockatoo, Philippine crocodile, and green turtle.