MEVE 014: Unit 03 - Ecosystem Diversity
3.1 Introduction
Ecosystem diversity refers to the variety of
ecosystems within a particular geographical area. It reflects the complex
interactions among living organisms (plants, animals, and microbes) and their
physical environments (soil, water, climate). This diversity includes different
types of natural, semi-natural, and human-modified ecosystems, each with
distinct structures, functions, and services. Understanding ecosystem diversity
is crucial for ecological balance, climate regulation, and sustainable
development.
3.2 Objectives
After completing this unit, you will be able
to:
- Define and understand the concept of ecosystem diversity.
- Describe the major terrestrial and aquatic ecosystems of the world.
- Examine the structure and functions of various ecosystems.
- Analyze the ecological significance and threats to different
ecosystem types.
- Appreciate the need for conserving ecosystem diversity at local and
global levels.
3.3 Tropical Forests
- Found near the equator (e.g., Amazon, Congo Basin, Southeast Asia).
- Characterized by high rainfall (200–450 cm annually), high
biodiversity, and dense canopies.
- Rich in flora and fauna; home to over 50% of terrestrial species.
- Ecological importance: carbon storage, climate regulation, genetic
resources.
- Threats: deforestation, agriculture expansion, mining, and logging.
3.4 Temperate Forests
- Located in mid-latitudes (e.g., Eastern North America, Europe, East
Asia).
- Moderate rainfall and four distinct seasons.
- Dominated by deciduous trees (oak, maple) or mixed forests.
- Support diverse fauna like deer, bears, and birds.
- Threats include urbanization, invasive species, and logging.
3.5 Boreal Forests (Taiga)
- Found in high northern latitudes (e.g., Canada, Russia,
Scandinavia).
- Cold climates, short growing seasons, and low species diversity.
- Dominated by coniferous trees (spruce, pine, fir).
- Important for carbon sequestration and climate regulation.
- Threats: climate change, oil exploration, pest outbreaks.
3.6 Grasslands
- Two types: tropical (savannas) and temperate (prairies, steppes).
- Dominated by grasses and herbaceous plants, with few trees.
- Support large herbivores (e.g., bison, antelope) and predators.
- Vital for agriculture, livestock grazing, and soil conservation.
- Threats: overgrazing, conversion to cropland, desertification.
3.7 Inland Wetlands
- Include marshes, swamps, peatlands, and floodplains.
- Saturated soils, high productivity, and biodiversity.
- Provide ecosystem services like water purification, flood control,
and habitat for migratory birds.
- Threats: drainage for agriculture, pollution, invasive species, and
urban development.
3.8 Open Oceans
- Cover 70% of Earth’s surface; largest ecosystem.
- Include pelagic (open water), benthic (sea floor), and deep-sea
habitats.
- Support plankton, fish, marine mammals, and seabirds.
- Crucial for oxygen production, climate regulation, and food
resources.
- Threats: overfishing, plastic pollution, ocean acidification, and
climate change.
3.9 Arid and Semi-Arid Land
- Characterized by low precipitation and high evapotranspiration.
- Include deserts (e.g., Sahara, Thar) and drylands.
- Vegetation: drought-resistant shrubs, succulents, and grasses.
- Fauna: reptiles, insects, nocturnal mammals.
- Fragile ecosystems, threatened by desertification, water scarcity,
and unsustainable land use.
3.10 Arctic and Alpine
Ecosystems
- Arctic: near North Pole; Alpine: high mountain regions.
- Cold climates, permafrost, short growing seasons.
- Vegetation: mosses, lichens, dwarf shrubs.
- Fauna: polar bears, snow leopards, mountain goats, migratory birds.
- Climate-sensitive ecosystems; facing rapid warming and habitat
loss.
3.11 Agro-Ecosystems
- Human-managed ecosystems for agriculture (croplands, pastures).
- Vary from subsistence farms to industrial monocultures.
- Support food production, but often at the cost of biodiversity.
- Soil degradation, pesticide use, and habitat conversion are key
challenges.
- Sustainable agriculture can help maintain biodiversity and
productivity.
3.12 Plantation Forests
- Monoculture forests grown for timber, pulp, and commercial crops (e.g.,
eucalyptus, teak, rubber).
- Fast-growing species, short rotation cycles.
- Low species diversity and poor habitat quality compared to natural
forests.
- Can provide economic benefits but may degrade native ecosystems.
- Sustainable practices and mixed plantations can reduce ecological
impacts.
3.13 Let Us Sum Up
- Ecosystem diversity encompasses a wide range of natural and
human-influenced ecosystems.
- Each ecosystem type plays a critical role in maintaining ecological
balance, supporting life, and providing services to humans.
- Major ecosystems discussed include forests (tropical, temperate,
boreal), grasslands, wetlands, oceans, deserts, polar regions,
agro-ecosystems, and plantations.
- Conservation of ecosystem diversity is vital to combat biodiversity
loss, ensure sustainable development, and mitigate climate change impacts.
3.14 Keywords
- Ecosystem Diversity – Variety of ecosystems
in a region.
- Tropical Forests – Equatorial,
high-biodiversity forests with heavy rainfall.
- Temperate Forests – Forests in
mid-latitudes with deciduous and mixed trees.
- Boreal Forests (Taiga) – Cold,
conifer-dominated forests in northern latitudes.
- Grasslands – Ecosystems dominated by grasses; important for grazing.
- Inland Wetlands – Freshwater ecosystems with saturated soils and rich fauna.
- Open Oceans – Largest aquatic ecosystem, covering most of Earth.
- Arid Lands – Deserts and drylands with low rainfall.
- Alpine Ecosystems – High-altitude
environments with cold climates.
- Agro-Ecosystems – Ecosystems managed for agriculture.
- Plantation Forests – Commercially planted
monocultures for timber.
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