Post by Trade Coach on Jan 16, 2022 11:32:04 GMT 1
There are several types of trees that can be considered as economic trees because such trees are the source of food, timber, animal feed, stakes, firewood, and soil fertility restorers.
Nigeria is greatly endowed with numerous tree species of which majority of them are native while few are exotic. A report shows that a high percentage of man-made forests are dominated by exotic species. This is born from the assumption that exotic trees are fast growing. However, there are studies that show the growth of indigenous trees with that of exotic species with a purpose to clarify the assumption about the growth and conservation of indigenous species in natural forests.
INDIGENOUS SPECIES are native species of a country and grown/ bred in the same country by similar species.
EXOTIC SPECIES are species from other countries and grown/ bred within the same varieties or crossed with indigenous or other exotic species.
Trees are mostly used for timber purposes, but they are also important in restoring, reclaiming and rejuvenating denuded and disturbed soils. They are very important in their ecological, eco developmental and environmental uses, their educational and recreational value in gardening, landscaping and bio esthetic planning.
Trees are important to humankind not only economically, environmentally and industrially but also spiritually, historically and aesthetically, for they sustain human life through direct and indirect gains by providing a wide range of products for survival and prosperity.
However, it is not always easy to define “tree.” A tree is a large woody plant that attains a height of at least 6 m (20 ft) at maturity in a given locality and usually but not always has a single main self-supporting stem called Trunk, with spreading branches, twigs and foliage.
Palms: are typically unbranched trees with only one trunk (columnar stem), called the “caudex,” which ends in a crown of large leaves.
Bamboos: are trees without a main trunk but with a cluster of culms arising from the underground rhizome. These culms are unbranched, with distinct nodes and internodes that give them a jointed appearance.
The banana tree (plant): has only a thick false stem (pseudostem), which is not woody but made up of a central core of soft tissues concealed by the fibrous and sheathing bases of large leaves. Strictly speaking, the banana plant is a giant herb.
Tree ferns like Cyathaea and Alsophila: have erect rhizomes with generally unbranched trunks, topped by a crown of graceful, feathery fronds that form a rosette at the apex.
Bonsai: tailored or human made miniature or dwarfed living trees that have been prevented from reaching their normal size—are grown in pots and kept in greenhouses, drawing rooms, etc. This technique was first perfected by the Japanese.
In addition to the above definitions, the scientific distinction between trees, shrubs, lianas and undershrubs or semi shrubs is not always clear. For example, many species of trees e.g. Rhododendron spp., which are large under normal conditions become shrubs when growing near their altitudinal and latitudinal limits. Woody plants in which several branches arise from near the base, giving the plant a bushy appearance, are called Shrubs. Likewise, certain species of figs (Ficus spp.) begin their life as woody climbers but eventually end up as trees. The science that deals with the study of woody plants (trees and shrubs) is called DENDROLOGY.
Trees can be classified in several ways; “avenue,” “ornamental,” “shade bearing,” “fragrant,” “fruit bearing,” “medicinal” or “drug yielding,” “timber yielding,” “fodder yielding,” “nitrogen fixing,” “venerated,” “fuel yielding,” “fiber yielding,” “multipurpose trees,” etc, depending on their utility or end products.
BRIEF DESCRIPTIONS AND CHARACTERISTICS OF SOME TREE SPECIE
EVERGREEN TREES: Trees that remain green in their dormant season due to persistence of leaves. In such trees all the leaves do not fall off simultaneously, and the plants are never leafless.
DECIDUOUS TREES: Those trees in which all the leaves of a plant fall at the end of one growing season one by one or simultaneously, leaving the plant leafless in the dormant season.
CONIFERS or CONIFEROUS TREES: All cone-bearing trees with needle-shaped leaves. A conifer usually has a conical appearance and has an excurrent stem (i.e., its main stem is thickest at the base and gradually tapers toward the apex), with lateral branches in an acropetal succession.
FLOWERING TREES or BROAD-LEAVED TREES: All trees that are flower bearing. Whereas conifers have needle-shaped leaves, flowering trees have broad or flattened leaves. A flowering tree usually has a dome-shaped appearance and a deliquescent or decurrent stem in which the main trunk divides at some distance from the ground into several branches, which branch again and again, making the trunk appear to deliquese or melt away.
ORNAMENTAL FLOWERING TREES: Ornamental trees that have showy flowers and they are usually deciduous.
ORNAMENTAL FOLIAGE TREES: Ornamental trees with beautiful foliage and inconspicuous flowers and evergreen.
GYMNOSPERMS: Those trees in which seeds are borne naked.
ANGIOSPERMS: Those trees in which seeds are enclosed within an ovary/fruit wall. Trees belonging to gymnosperms and angiosperms not only constitute the dominant component of any vegetation but also add to the biodiversity or biological diversity of any particular region.
Trees represent one of the important components of each and every terrestrial ecosystem and are a part of nature’s precious gifts. Some are deciduous; others are evergreen. Some have beautiful flowers; others have beautiful fruits or foliage. Some are scented; others are ugly but economically very important. The welfare of humankind is affected not only by their density and diversity but also by their direct and indirect values, which are beyond estimation. In fact, each letter of the plural word “TREES” has a logical meaning (Seth, 2002):
T- Timber, the first and the foremost use of trees
R- Restoration, reclamation and rejuvenation of denuded and disturbed soils by using trees to control soil erosion and desertification, protect watersheds, improve soil nutrient status (by growing nitrogen-fixing trees) and retain moisture in the soil
E- Ecological, ecodevelopmental and environmental use of trees for effective and efficient purification of the environment because trees act as oxygen banks and eliminate air pollutants; for abating or moderating temperature, noise and wind by planting trees as environmental screens, thus affecting the microclimate; for harboring wildlife; for maintaining biodiversity; and for conserving energy
E- Educational and recreational value in gardening, landscaping, bioesthetic planning, art, culture and religion
S- Source of sustenance; i.e., food, fuel, fodder, fertilizer, fiber, medicine, tannin, dyes, oils, etc.
ECONOMIC IMPORTANCE OF TREES
TREES AS A SOURCE OF TIMBER
Trees are woody perennial plants, i.e. they are capable of producing wood.
TREES IN THE RESTORATION, RECLAMATION AND REJUVENATION OF DENUDED AND DISTURBED SOILS
Planting trees on denuded and waste land, along roads, railway tracks, deserted areas, watersheds, etc. protects soil from erosion by wind or water by firmly binding it with roots and by diverting runoff during rains.
ECOLOGICAL, ECODEVELOPMENTAL AND ENVIRONMENT USES OF TREES
Natural Purifiers of the Environment
Plants, including shrubs and trees, act as biological filters by helping cleanse the environment. They are the best natural purifiers of environment pollution; i.e., they improve the quality of the air we breathe.
Environmental Screens
When properly grown in urban and rural areas, trees act as wind barriers by decreasing the force of the wind and reducing the level of noise and outside light
The Physical Environment
Trees help to reduce temperature by providing shade and by intercepting, absorbing and reflecting solar radiation, especially in warmer places. Trees also function as natural air conditioners by evaporating water from their leaves through the process of transpiration.
Wildlife
Trees, both native and ornamental, harbor wildlife. They directly feed and house the majority of the world's creatures and animals like insects, birds, small mammals and reptiles.
Urban and Rural Afforestation
ProgramsLarge-scale urbanization and industrialization have led to the development of severely eroded, barren and denuded areas, rocks, cliffs, etc. on which direct plantation of trees is difficult.
Road SafetyThe presence of shrubs and trees along roadsides makes their edges and curves conspicuous, thus making a natural guide for safe driving, and for this purpose the lower portions of their stems are usually in most places, painted white
Protection of Road SurfacesThe semi melting of tar or bitumen in summers, cracking of road surfaces during hot weather and mechanical damage to road surfaces by heavy downpours and hailstorms can largely be prevented by growing roadside trees with thick crowns.
THE EDUCATIONAL AND RECREATIONAL VALUE OF TREES
Increased urbanization and industrialization have resulted in isolating humans from nature. Trees can help make urban areas green, livable and beautiful. Trees with colorful flowers or foliage add extra attractiveness. They are the dominant elements of gardens and contribute substantially to the garden atmosphere.
Shade and Shelter (or Avenue Trees)
Ornamental Flowering Plants
Ornamental Foliage Plants
Ornamental Fragrance Plants
Ornamental Fruiting Plants
Live Screens and Fences
Sculpture and Topiary
Education
Landscaping and Bio Aesthetic Planning
Veneration
Art and Culture.
TREES AS SOURCE OF SUSTENANCE
Trees are one of the major sources of sustenance, i.e.,:
Food
Sugars
Starches;
Spices and Condiments
Non Alcoholic Beverages
Fumitories, Masticatories and Narcotics
Medicines
Essential Oils
Fatty Oils and Vegetable Fats
Waxes
Soap Substitutes
Vegetable Ivory
Fodder
Fuel, Bioenergy or Biofuel
Fertilizers
Paper and Pulp
Fibres
Tannins
Rubber and Other Latex Products
Dyes
Resins
Gums
Cork
Trees are of great importance to people, not only economically and ecologically but also ornamentally and bio aesthetically. Because trees meet the needs of humans, the primary objective of any afforestation, biodiversity, ecodevelopment, bio aesthetic or landscape plan must be both to protect native trees–growing areas from further destruction and to plant trees in large areas. For any society, planting and care of trees serve as important endeavors and symbolize hope for the future. Multipurpose trees and shrubs have the capacity to provide for a variety of end uses while reversing the process of land degradation.
Most of our environmental problems can be solved to a great extent if we grow more trees, especially in urbanized localities and cities. Because people in different parts of the world have become aware of the needs of trees and forests, many countries have started celebrating annual “Forest Festivals” or “Tree Festivals” or “Greening Weeks”
Nigeria is greatly endowed with numerous tree species of which majority of them are native while few are exotic. A report shows that a high percentage of man-made forests are dominated by exotic species. This is born from the assumption that exotic trees are fast growing. However, there are studies that show the growth of indigenous trees with that of exotic species with a purpose to clarify the assumption about the growth and conservation of indigenous species in natural forests.
INDIGENOUS SPECIES are native species of a country and grown/ bred in the same country by similar species.
EXOTIC SPECIES are species from other countries and grown/ bred within the same varieties or crossed with indigenous or other exotic species.
Trees are mostly used for timber purposes, but they are also important in restoring, reclaiming and rejuvenating denuded and disturbed soils. They are very important in their ecological, eco developmental and environmental uses, their educational and recreational value in gardening, landscaping and bio esthetic planning.
Trees are important to humankind not only economically, environmentally and industrially but also spiritually, historically and aesthetically, for they sustain human life through direct and indirect gains by providing a wide range of products for survival and prosperity.
However, it is not always easy to define “tree.” A tree is a large woody plant that attains a height of at least 6 m (20 ft) at maturity in a given locality and usually but not always has a single main self-supporting stem called Trunk, with spreading branches, twigs and foliage.
Palms: are typically unbranched trees with only one trunk (columnar stem), called the “caudex,” which ends in a crown of large leaves.
Bamboos: are trees without a main trunk but with a cluster of culms arising from the underground rhizome. These culms are unbranched, with distinct nodes and internodes that give them a jointed appearance.
The banana tree (plant): has only a thick false stem (pseudostem), which is not woody but made up of a central core of soft tissues concealed by the fibrous and sheathing bases of large leaves. Strictly speaking, the banana plant is a giant herb.
Tree ferns like Cyathaea and Alsophila: have erect rhizomes with generally unbranched trunks, topped by a crown of graceful, feathery fronds that form a rosette at the apex.
Bonsai: tailored or human made miniature or dwarfed living trees that have been prevented from reaching their normal size—are grown in pots and kept in greenhouses, drawing rooms, etc. This technique was first perfected by the Japanese.
In addition to the above definitions, the scientific distinction between trees, shrubs, lianas and undershrubs or semi shrubs is not always clear. For example, many species of trees e.g. Rhododendron spp., which are large under normal conditions become shrubs when growing near their altitudinal and latitudinal limits. Woody plants in which several branches arise from near the base, giving the plant a bushy appearance, are called Shrubs. Likewise, certain species of figs (Ficus spp.) begin their life as woody climbers but eventually end up as trees. The science that deals with the study of woody plants (trees and shrubs) is called DENDROLOGY.
Trees can be classified in several ways; “avenue,” “ornamental,” “shade bearing,” “fragrant,” “fruit bearing,” “medicinal” or “drug yielding,” “timber yielding,” “fodder yielding,” “nitrogen fixing,” “venerated,” “fuel yielding,” “fiber yielding,” “multipurpose trees,” etc, depending on their utility or end products.
BRIEF DESCRIPTIONS AND CHARACTERISTICS OF SOME TREE SPECIE
EVERGREEN TREES: Trees that remain green in their dormant season due to persistence of leaves. In such trees all the leaves do not fall off simultaneously, and the plants are never leafless.
DECIDUOUS TREES: Those trees in which all the leaves of a plant fall at the end of one growing season one by one or simultaneously, leaving the plant leafless in the dormant season.
CONIFERS or CONIFEROUS TREES: All cone-bearing trees with needle-shaped leaves. A conifer usually has a conical appearance and has an excurrent stem (i.e., its main stem is thickest at the base and gradually tapers toward the apex), with lateral branches in an acropetal succession.
FLOWERING TREES or BROAD-LEAVED TREES: All trees that are flower bearing. Whereas conifers have needle-shaped leaves, flowering trees have broad or flattened leaves. A flowering tree usually has a dome-shaped appearance and a deliquescent or decurrent stem in which the main trunk divides at some distance from the ground into several branches, which branch again and again, making the trunk appear to deliquese or melt away.
ORNAMENTAL FLOWERING TREES: Ornamental trees that have showy flowers and they are usually deciduous.
ORNAMENTAL FOLIAGE TREES: Ornamental trees with beautiful foliage and inconspicuous flowers and evergreen.
GYMNOSPERMS: Those trees in which seeds are borne naked.
ANGIOSPERMS: Those trees in which seeds are enclosed within an ovary/fruit wall. Trees belonging to gymnosperms and angiosperms not only constitute the dominant component of any vegetation but also add to the biodiversity or biological diversity of any particular region.
Trees represent one of the important components of each and every terrestrial ecosystem and are a part of nature’s precious gifts. Some are deciduous; others are evergreen. Some have beautiful flowers; others have beautiful fruits or foliage. Some are scented; others are ugly but economically very important. The welfare of humankind is affected not only by their density and diversity but also by their direct and indirect values, which are beyond estimation. In fact, each letter of the plural word “TREES” has a logical meaning (Seth, 2002):
T- Timber, the first and the foremost use of trees
R- Restoration, reclamation and rejuvenation of denuded and disturbed soils by using trees to control soil erosion and desertification, protect watersheds, improve soil nutrient status (by growing nitrogen-fixing trees) and retain moisture in the soil
E- Ecological, ecodevelopmental and environmental use of trees for effective and efficient purification of the environment because trees act as oxygen banks and eliminate air pollutants; for abating or moderating temperature, noise and wind by planting trees as environmental screens, thus affecting the microclimate; for harboring wildlife; for maintaining biodiversity; and for conserving energy
E- Educational and recreational value in gardening, landscaping, bioesthetic planning, art, culture and religion
S- Source of sustenance; i.e., food, fuel, fodder, fertilizer, fiber, medicine, tannin, dyes, oils, etc.
ECONOMIC IMPORTANCE OF TREES
TREES AS A SOURCE OF TIMBER
Trees are woody perennial plants, i.e. they are capable of producing wood.
TREES IN THE RESTORATION, RECLAMATION AND REJUVENATION OF DENUDED AND DISTURBED SOILS
Planting trees on denuded and waste land, along roads, railway tracks, deserted areas, watersheds, etc. protects soil from erosion by wind or water by firmly binding it with roots and by diverting runoff during rains.
ECOLOGICAL, ECODEVELOPMENTAL AND ENVIRONMENT USES OF TREES
Natural Purifiers of the Environment
Plants, including shrubs and trees, act as biological filters by helping cleanse the environment. They are the best natural purifiers of environment pollution; i.e., they improve the quality of the air we breathe.
Environmental Screens
When properly grown in urban and rural areas, trees act as wind barriers by decreasing the force of the wind and reducing the level of noise and outside light
The Physical Environment
Trees help to reduce temperature by providing shade and by intercepting, absorbing and reflecting solar radiation, especially in warmer places. Trees also function as natural air conditioners by evaporating water from their leaves through the process of transpiration.
Wildlife
Trees, both native and ornamental, harbor wildlife. They directly feed and house the majority of the world's creatures and animals like insects, birds, small mammals and reptiles.
Urban and Rural Afforestation
ProgramsLarge-scale urbanization and industrialization have led to the development of severely eroded, barren and denuded areas, rocks, cliffs, etc. on which direct plantation of trees is difficult.
Road SafetyThe presence of shrubs and trees along roadsides makes their edges and curves conspicuous, thus making a natural guide for safe driving, and for this purpose the lower portions of their stems are usually in most places, painted white
Protection of Road SurfacesThe semi melting of tar or bitumen in summers, cracking of road surfaces during hot weather and mechanical damage to road surfaces by heavy downpours and hailstorms can largely be prevented by growing roadside trees with thick crowns.
THE EDUCATIONAL AND RECREATIONAL VALUE OF TREES
Increased urbanization and industrialization have resulted in isolating humans from nature. Trees can help make urban areas green, livable and beautiful. Trees with colorful flowers or foliage add extra attractiveness. They are the dominant elements of gardens and contribute substantially to the garden atmosphere.
Shade and Shelter (or Avenue Trees)
Ornamental Flowering Plants
Ornamental Foliage Plants
Ornamental Fragrance Plants
Ornamental Fruiting Plants
Live Screens and Fences
Sculpture and Topiary
Education
Landscaping and Bio Aesthetic Planning
Veneration
Art and Culture.
TREES AS SOURCE OF SUSTENANCE
Trees are one of the major sources of sustenance, i.e.,:
Food
Sugars
Starches;
Spices and Condiments
Non Alcoholic Beverages
Fumitories, Masticatories and Narcotics
Medicines
Essential Oils
Fatty Oils and Vegetable Fats
Waxes
Soap Substitutes
Vegetable Ivory
Fodder
Fuel, Bioenergy or Biofuel
Fertilizers
Paper and Pulp
Fibres
Tannins
Rubber and Other Latex Products
Dyes
Resins
Gums
Cork
Trees are of great importance to people, not only economically and ecologically but also ornamentally and bio aesthetically. Because trees meet the needs of humans, the primary objective of any afforestation, biodiversity, ecodevelopment, bio aesthetic or landscape plan must be both to protect native trees–growing areas from further destruction and to plant trees in large areas. For any society, planting and care of trees serve as important endeavors and symbolize hope for the future. Multipurpose trees and shrubs have the capacity to provide for a variety of end uses while reversing the process of land degradation.
Most of our environmental problems can be solved to a great extent if we grow more trees, especially in urbanized localities and cities. Because people in different parts of the world have become aware of the needs of trees and forests, many countries have started celebrating annual “Forest Festivals” or “Tree Festivals” or “Greening Weeks”