Principles of Forestry Study Notes

DNR 108: Principles of Forestry

Instructor: Latif Iddrisu Nasare
Faculty: Natural Resources and Environment
Department: Forestry and Forest Resources Management

Course Outline

1.0 Definitions, Components, and Characteristics of Forest

  • Definitions

  • Vegetation Types and Distribution

  • Structure and Physiognomy of Forest

  • Morphology of Forest Plants

  • Floristic Composition

2.0 Importance of Ghana’s Forest

  • Economic Role

  • Employment

  • Environmental Role

  • Social Role

  • Recreational Role

  • Problems and Prospects of the Forest Industry

3.0 Forest Types in Ghana

  • Wet Evergreen Forest

  • Moist Evergreen Forest

  • Moist Semi-Deciduous Forest

  • Dry Semi-Deciduous Forest

  • Southern Marginal Forest

  • South-East Outliers

  • Upland Evergreen Forest

4.0 Integrated Savannah Woodland Management

  • Types of Savannah

  • Morphology of Savannah

  • Physiognomy and Structure of Savannah

  • Floristic Composition of Savannah

  • Seasonal Changes in Savannah

  • Management Strategies for Savannah Woodlands

5.0 Principles of Plantation Forestry

  • Purpose of Plantation Development

  • Factors Favoring Plantation Development

  • Plantation Organization and Structure

  • Tropical Plantation Species

  • Characteristics of Plantations

  • Plantation Life History

  • Plantation Forestry and Carbon Sequestration

6.0 Natural Forest Dynamics

  • Forest Regeneration

  • Functions of Regeneration

  • Types of Regeneration

  • Pioneer Species and Climax Species

  • Species Diversity

  • Diversity Indices (Jaccards, Simpsons, and Shannon-Weiner)

References

  • Sharpe, Grant. Introduction to Forest and Renewable Resources

  • Evans, Julian. Plantation Forestry in the Tropics (Second Edition)

  • Hawthorne, William & Gyakari, Ntim. Photoguide for the Forest Trees of Ghana: A Tree-Spotter’s Guide for Identifying the Larger Trees

  • Hopkins, Brian. Forest and Savannah

  • Lawson, G.W. Plant Life in West Africa

  • Whitmore, T.C. An Introduction to Tropical Rain Forest

  • Nanang, David. Plantation Forestry in Ghana: Theory and Applications

Definition of Terms

  • Forest:
    An ecosystem characterized by dense and extensive tree cover or woody perennials (trees, shrubs, herbs, and climbers) where grasses are virtually absent. Defined by varied species composition, structure, age class, and associated processes; commonly includes meadows, streams, fish, and wildlife (Helms, 1998). According to FAO, it spans more than 0.5 hectares with trees higher than 5 meters and a canopy cover exceeding 10 percent.

  • Forest Components:
    Woody plants consist of two main types:

    • Trees: Large woody plants with a well-defined stem and a crown.

    • Shrubs: Woody plants generally not exceeding 3 meters in height with several persistent woody stems.

  • Herbs:
    Seed-producing annual, biennial, or perennial that does not develop persistent woody tissue; dies down at the end of a growing season.

  • Forestry:
    The science of managing forest ecosystems aimed at sustaining the production of goods and services. It is a profession that encompasses the science, business, and art of creating, conserving, and managing forests for the continuous utilization of resources.

  • Plantation:
    A forest crop or stand established artificially through sowing or planting.

  • Silviculture:
    The art and science of controlling the establishment, composition, structure, and growth of a forest stand to meet specific ecological, economic, and social objectives sustainably.

  • Reforestation:
    The re-establishment of forest through planting or deliberate seeding following harvesting or other disturbances.

  • Afforestation:
    The introduction of trees to sites that did not support forests or had no forest cover previously.

  • Sustainability:
    The enhancement of resource productivity on a long-term basis to meet present needs without compromising future generations' needs and aspirations. It aims for sustainable natural, built, and economic environments and equitable social conditions within nurturing communities.

Savannah

  • A grassy plain found in tropical and subtropical regions characterized by few trees intermixed with grasses, tall bushes, and open formations of trees.

Vegetation Types and Distribution in West Africa

  • West Africa is located in the tropics.

    • Rainfall ranges between 2500 mm per annum along latitude 5ºN and 250 mm per annum at latitude 15ºN.

    • The primary vegetation types are forest and savannah.

Ecological Zones

  • Ghana comprises six agro-ecological zones categorized based on climate, affecting vegetation due to varying soil types:

    • Sudan Savannah

    • Guinea Savannah

    • Transition

    • Semi-Deciduous Forest

    • Rain Forest

    • Coastal Savannah

Vegetation Zones of Ghana

  • Sahel Savannah

  • Guinea Savannah

  • Transitional Zone

  • Moist Semi-Deciduous Forest

  • Tropical Rain Forest

  • Coastal Savannah

Ecological Zones Characteristics

  • Ecological Zone | Area (Km²) | Mean Annual Rainfall (mm) | Major Rainy Season | Minor Rainy Season

    • Rain Forest | 9,500 | 2,200 | March - July | Sept - Nov

    • Deciduous Forest | 66,000 | 1,500 | March - July | Sept - Nov

    • Transitional Zone | 8,400 | 1,300 | March - July | Sept - Oct

    • Coastal Savannah | 4,500 | 800 | March - July | Sept - Oct

    • Guinea Savannah | 147,900 | 1,000 | May - Sept

    • Sudan Savannah | 2,200 | 1,000 | May - Sept

Structure and Physiognomy of Forest

  • Physiognomy:
    Refers to the overall structure or physical appearance of a plant community, dominant species height, spacing, and canopy cover.

  • Forest Structure:
    The horizontal and vertical distribution of layers within a forest, including trees, shrubs, and ground cover, which consists of diverse vegetation and dead/down woody material.

    • Five Layers/Storeys:

    1. Emergent Layer

    2. Canopy Layer

    3. Understory Layer

    4. Shrub Layer

    5. Forest Floor/Subterranean

  • Emergent Layer:
    The uppermost layer populated by the tallest trees that can grow between 40 and 48 meters to capture direct sunlight.

  • Canopy Layer:
    Contains tall trees (canopy trees) whose crowns interlock to form a continuous canopy, which blocks much of the sunlight from reaching lower layers.

    • Non-parasitic plants such as lianas (climbing woody plants) and epiphytes (plants growing on others for support) are prevalent here.

  • Understory Layer:
    Comprising shorter trees, epiphytes, and lianas.

  • Shrub Layer:
    Contains shrubs and young trees.

  • Ground Layer:
    Hosts ferns, mosses, fungi, and other small plants that do not require much sunlight for growth.

Morphological Characteristics of Forest Trees

  • Trees tend to have tall, unbranched trunks that taper gradually.

  • Barks are thin, smooth, and easily damaged.

  • Roots are generally shallow.

  • Cauliflory:
    The bearing of fruit on the trunk rather than the tips of branches (e.g., cocoa).

  • Buttresses:
    Commonly found on large trees for structural support.

  • Leaves:
    Often have entire margins and possess drip tips for effective water drainage.