Skip to main content

Terrestrial Ecosystem


A terrestrial ecosystem is a land-based ecological system where biotic components (living organisms) interact with abiotic components (non-living physical and chemical factors).

  • Covers approximately 28–29% of Earth's surface (land area).

  • Organized into large ecological regions called biomes.

  • Distribution is mainly controlled by:

    • Temperature

    • Precipitation

    • Latitude

    • Altitude

 Components

A. Biotic Components

  1. Producers (Autotrophs)

    • Green plants and photosynthetic organisms.

    • Convert solar energy into chemical energy through photosynthesis.

    • Form the primary productivity base.

  2. Consumers (Heterotrophs)

    • Primary consumers (herbivores)

    • Secondary/Tertiary consumers (carnivores, omnivores)

  3. Decomposers (Detritivores & Saprotrophs)

    • Bacteria and fungi.

    • Responsible for nutrient cycling and mineralization.

B. Abiotic Components

  • Soil (edaphic factors)

  • Climate (temperature, precipitation, humidity)

  • Solar radiation

  • Topography

  • Wind patterns

These factors regulate primary productivity, species distribution, and ecosystem functioning.

3. Functional Processes

  • Energy flow (unidirectional)

  • Biogeochemical cycles (carbon, nitrogen, phosphorus cycles)

  • Carbon sequestration

  • Ecological succession

  • Trophic dynamics

Forest Ecosystems

A forest ecosystem is a terrestrial biome characterized by high tree density, vertical stratification, and high biomass.

Classification Basis:

  • Latitude

  • Climate (temperature + rainfall)

  • Vegetation type (leaf morphology)

A. Tropical Forests

Location:

Near the equator (0°–10° latitude).

Climate:

  • High temperature (25–30°C average)

  • Annual rainfall > 200 cm

  • No distinct winter

Key Features:

  • High Net Primary Productivity (NPP)

  • Multi-layered canopy structure:

    • Emergent layer

    • Canopy

    • Understory

    • Forest floor

  • Extremely high species richness and endemism

  • Rapid nutrient cycling but nutrient-poor soils

Ecological Importance:

  • Major global carbon sink

  • High biodiversity reservoir

B. Temperate Forests

Location:

Mid-latitudes (30°–50°).

Climate:

  • Moderate rainfall

  • Distinct seasons

Types:

  1. Deciduous forests

    • Broad-leaved trees

    • Seasonal leaf shedding (adaptation to cold/drought)

  2. Temperate coniferous forests

    • Needle-leaved evergreen trees

Soil:

Relatively fertile compared to tropical forests.

C. Boreal Forest (Taiga)

Location:

High latitudes (50°–70° N).

Climate:

  • Long, severe winters

  • Short growing season

  • Moderate precipitation (mostly snow)

Vegetation:

  • Coniferous species (needle-leaved)

  • Adapted to cold and low evaporation

Ecological Role:

  • Stores large amounts of carbon in biomass and soils

  • Lower species diversity but large geographic extent

Specialized Forest Types

1. Mediterranean Forests

  • Hot, dry summers

  • Sclerophyllous vegetation (thick leaves)

2. Montane Forests

  • Altitudinal zonation

  • Temperature decreases with elevation

3. Mangrove Forests

  • Coastal intertidal zones

  • Salt-tolerant (halophytic) vegetation

  • Shoreline stabilization and storm buffering

2. Grassland Ecosystems

Grasslands are terrestrial ecosystems dominated by grasses and herbaceous vegetation, with insufficient rainfall to support dense forests.

Coverage:

~20% of global land surface.

Climate Control:

  • Moderate to low precipitation

  • Seasonal rainfall

  • Periodic fires and grazing

A. Tropical Grasslands (Savanna)

Features:

  • Wet and dry seasons

  • Scattered trees

  • High grazing pressure

Ecological Traits:

  • Fire-adapted vegetation

  • Large herbivore populations

B. Temperate Grasslands

Climate:

  • Cold winters

  • Hot summers

Soil:

  • Deep, fertile chernozem soils

  • High organic matter

Examples:

  • Prairies

  • Steppes

  • Pampas

C. Montane Grasslands

  • Occur at high altitudes

  • Short growing season

  • Alpine meadows

D. Flooded Grasslands

  • Seasonally inundated

  • High productivity

  • Important wetlands

E. Desert/Xeric Grasslands

  • Transition zones between grassland and desert

  • Sparse vegetation

3. Desert Ecosystems

Deserts are terrestrial ecosystems characterized by extremely low precipitation (<25 cm annually) and high evapotranspiration rates.

Key Characteristics

  • Large diurnal temperature variation

  • Low primary productivity

  • Sandy or rocky soils

  • Low organic matter

Types of Deserts

  1. Hot and dry

  2. Semi-arid

  3. Coastal

  4. Cold deserts

Adaptations

Plants:

  • Xerophytes

  • Succulents

  • Reduced leaf surface area

  • CAM photosynthesis

Animals:

  • Nocturnal behavior

  • Water conservation mechanisms

4. Mountain Ecosystems

Mountain ecosystems are characterized by altitudinal zonation, where climate and vegetation change with elevation.

Key Concepts

  • Environmental lapse rate (temperature decreases with altitude)

  • "Water towers of the world" (source of rivers)

  • High endemism

Zonation

  1. Foothill forests

  2. Montane forests

  3. Subalpine zone

  4. Alpine tundra

  5. Permanent snow

5. Tundra Ecosystems

Tundra is a treeless biome with extremely low temperatures and the presence of permafrost (permanently frozen subsoil).

Types

  1. Arctic tundra (high latitude)

  2. Alpine tundra (high altitude)

Characteristics

  • Short growing season (6–10 weeks)

  • Low precipitation (but low evaporation)

  • Poorly developed soil

Vegetation

  • Mosses

  • Lichens

  • Dwarf shrubs

  • Sedges

Faunal Adaptations

  • Thick fur/insulation

  • Migration

  • Hibernation

Comparative Analysis

FeatureDesertTundraGrasslandForest
Water availabilityVery lowFrozen waterModerate seasonalHigh (varies by type)
BiodiversityLowLow–moderateModerateVery high (tropical)
Soil fertilityPoorPoorHigh (temperate)Variable
TemperatureExtreme heat/coldPersistently coldSeasonalClimate dependent

Ecological Importance of Terrestrial Ecosystems

  1. Carbon sequestration

  2. Oxygen production

  3. Climate regulation

  4. Biodiversity conservation

  5. Soil formation

  6. Water cycle regulation

  7. Provisioning services (food, timber, fiber)

Core Controlling Factors

  • Latitude

  • Altitude

  • Precipitation

  • Temperature

  • Soil type

  • Disturbance regimes (fire, grazing, storms)


Comments

Post a Comment

Popular posts from this blog

Quantitative Revolution in Geography

The Quantitative Revolution was a major change in Geography during the 1950s and 1960s. It introduced mathematical, statistical and scientific methods to understand geographical phenomena. Before this revolution, geographers mainly described places, regions, landscapes and differences between areas. After the revolution, they increasingly used numerical data, statistical analysis, mathematical models and theories to explain why geographical patterns occur and how they may change. For example: Traditional approach: Describe the distribution of population in different regions. Quantitative approach: Use statistical methods to identify population patterns, explain the factors influencing population distribution and predict future population growth. The revolution helped establish Geography as a spatial science, focusing on the location, distribution, relati...
Post a Comment
Read more

Satellite Remote Sensing: Concepts and Imaging Systems

  Satellite remote sensing relies on detectors (sensors) that measure reflected/emitted electromagnetic radiation from the Earth. How sensors collect data depends on: Spectral coverage → Multispectral (few bands), Hyperspectral (hundreds), Thermal, Microwave. Detector type → Discrete detectors, linear arrays, or area arrays. Scanning mechanism → Scanning mirrors (whiskbroom) vs. linear arrays (pushbroom). Multispectral Imaging Using Discrete Detectors and Scanning Mirrors (Whiskbroom scanners) Principle : A single detector (or a few detectors) measures radiation one pixel at a time. A scanning mirror sweeps across-track (perpendicular to the satellite path) to build up the image line by line. The forward motion of the satellite provides the along-track dimension. Known as a whiskbroom scanner . Characteristics : Good calibration stability. Narrow instantaneous field of view (IFOV). Susceptible to mechanical wear (moving ...
Post a Comment
Read more

Spectral Signature vs. Spectral Reflectance Curve

Spectral Signature  A spectral signature is the unique pattern in which an object: absorbs energy reflects energy emits energy across different wavelengths of the electromagnetic spectrum. ✔ Key Points Every natural and man-made object on Earth interacts with sunlight differently. These interactions produce a distinct pattern , just like a "fingerprint". Sensors on satellites record these patterns as digital numbers (DN values) . These patterns help to identify and differentiate objects such as vegetation, soil, water, snow, buildings, minerals, etc. ✔ Examples of Spectral Signatures Healthy vegetation → High reflectance in NIR , strong absorption in red Water → Strong absorption in NIR and SWIR , low reflectance Dry soil → Gradual increase in reflectance from visible to NIR Snow → High reflectance in visible , low in SWIR ✔ Why Spectral Signature Matters It allows: Land cover classification Chan...
Post a Comment
Read more

Geometric Correction

When satellite or aerial images are captured, they often contain distortions (errors in shape, scale, or position) caused by many factors — like Earth's curvature, satellite motion, terrain height (relief), or the Earth's rotation . These distortions make the image not properly aligned with real-world coordinates (latitude and longitude). 👉 Geometric correction is the process of removing these distortions so that every pixel in the image correctly represents its location on the Earth's surface. After geometric correction, the image becomes geographically referenced and can be used with maps and GIS data. Types  1. Systematic Correction Systematic errors are predictable and can be modeled mathematically. They occur due to the geometry and movement of the satellite sensor or the Earth. Common systematic distortions: Scan skew – due to the motion of the sensor as it scans the Earth. Mirror velocity variation – scanning mirror moves at a va...
Post a Comment
Read more

RADIOMETRIC CORRECTION

  Radiometric correction is the process of removing sensor and environmental errors from satellite images so that the measured brightness values (Digital Numbers or DNs) truly represent the Earth's surface reflectance or radiance. In other words, it corrects for sensor defects, illumination differences, and atmospheric effects. 1. Detector Response Calibration Satellite sensors use multiple detectors to scan the Earth's surface. Sometimes, each detector responds slightly differently, causing distortions in the image. Calibration adjusts all detectors to respond uniformly. This includes: (a) De-Striping Problem: Sometimes images show light and dark vertical or horizontal stripes (banding). Caused by one or more detectors drifting away from their normal calibration — they record higher or lower values than others. Common in early Landsat MSS data. Effect: Every few lines (e.g., every 6th line) appear consistently brighter or darker. Soluti...
Post a Comment
Read more