1. FOREST
• Is a large area dominated by trees. Hundreds of more precise definitions of
forest are used throughout the world, incorporating factors such as tree density,
tree height, land use, legal standing and ecological function. According to widely
used Food and Agriculture Organization definition forests covered four billion
hectares (15 million square miles) or approximately 30 percent of the world’s land
area in 2006.
• The first forest on Earth arose in the Late Devonian (approximately 380 million
years ago), with the of evolution Archaeopteris.
Archaeopteris was a plant that was both tree-like and fern-like, growing to 10
meters (33 ft) in height.
• Are dominant terrestrial ecosystem of Earth, and are distributed across the globe.
• 75%- account of the gross primary productivity of the Earth’s biosphere, and
contain 80% of the Earth’s plant biomass.
• ETYMOLOGY
• The word forest comes from the Middle English, from Old French forest (also
fores) “forest”, vast expose covered by trees.
Foresta- open wood
• - was first used by Carolingian scribes in the Capitularies of
Charlemagne to refer
• EVOLUTION
• Late Devonian- the first forest on earth arose (approximately 380 million years
ago) with the evolution of Archaepteris.
• Archaeopteris- was a plant that was both tree- like and fern-like, growing
to 10 meters (33 ft) in heigh
• -quickly spread thrughout the world, from the equator
to subpolar latitudes.
• - formed the first forest by being the first known species to
cast the shade due to its fronds and forming soil from its roots,
• - was deciduous, dropping its fronds onto the forest floor.
• ECOLOGY
2. • 75%- account of the gross primary productivity of the Earth’s biosphere, and
contain 80% of the Earth’s plant biomass.
• COMPONENTS
• A forest consist of many components that can be broadly divided into two
categories that are biotic (living) and abiotic (non-living) components.
• The living parts includes trees and shrubs, vines , grasses and other
herbaceoous (non-woody) plants, mosses, algae, fungi, insects, mammals,
reptiles, amphibians, and microorganisms living on the plants and animals and in
the soil.
LAYERS
A forest is made up of many layers. Starting from the ground level and moving up, the
main layers of all forest types are the forest floor, the understory and the canopy. Each
layer has different set of plants and animals depending upon the availability of sunlight,
moisture and food.
• Forest floor- contains decomposing leaves, animal droppings, and dead trees, All
of decay on the forest floor supports ferns, grasses, mushroom and trees
seedlings.
• Understory- is made up of bushes, shrubs, and young trees that are adapted to
living in the shades of the canopy.
• Canopy- is formed by the mass of intertwined branches, twigs and leaves of the
mature trees. This is the most productive part of the trees where maximum food
is produced. The canopy forms a shady, protective “umbrella” over the rest of the
forest.
• Emergent layer- exists in the tropical rain forest and is composed of a few
scattered trees that tower over the canopy
• Podocarpaceae) occur in mixtures with broadleaf species, and are classed as
broadleaf and mixed forests. Temperate broadleaf and mixed forests include a
substantial component of trees in the Anthophyta. They are generally
characteristic of the warmer temperate latitudes, but cool temperate ones;
particularly in the southern hemisphere. They include such forest types as the
mixed deciduous forests of the United States and their counterparts in China and
Japan, the broadleaf evergreen rainforests of Japan, Chile and Tasmania, the
sclerophyllous forest of Australia, central Chile, the Mediterranean and California,
and the beech Nothofagus forest of Chile and New Zealand.
3. • SPARSE TREES AND SAVANNA
• Sparse tress and savanna are forests with lower canopy cover of trees. They
occur principally in areas of transition from forested tonon-forested landscapes.
The two major zones in which these ecosystems occur are in the boreal region
and in the seasonally dry tropics. At high latitudes, north of the main zone of
boreal forest, growing conditions are not adequate to maintain a continuous
closed forest cover, so tree cover is both sparse and discontinuous. This
vegetation is variously called open taiga, open lichen woodland and forest
tundra.
• A savanna is a mixed woodland grassland ecosystem characterized by trees
being sufficiently widely spaced so that the canopy does not close. The open
canopy allows sufficient light to reach the ground to support an unbroken
herbaceous layer consisting primarily of grasses. Savannas maintain an open
canopy despite a high tree density
• SPARSE TREES AND SAVANNA
• Sparse tress and savanna are forests with lower canopy cover of trees. They
occur principally in areas of transition from forested tonon-forested landscapes.
The two major zones in which these ecosystems occur are in the boreal region
and in the seasonally dry tropics. At high latitudes, north of the main zone of
boreal forest, growing conditions are not adequate to maintain a continuous
closed forest cover, so tree cover is both sparse and discontinuous. This
vegetation is variously called open taiga, open lichen woodland and forest
tundra.
• A savanna is a mixed woodland grassland ecosystem characterized by trees
being sufficiently widely spaced so that the canopy does not close. The open
canopy allows sufficient light to reach the ground to support an unbroken
herbaceous layer consisting primarily of grasses. Savannas maintain an open
canopy despite a high tree density.
Submitted by:
Daryll B. Langres
Dionisio Danila
