IGCSE Geography: Climate, Natural Vegetation, and Ecosystems

Flashcards testing core terms, climate characteristics, ecosystem structure, plant/animal adaptations, and deforestation case studies for CIE IGCSE Geography.

Latitude (Climate Factor)

A primary factor influencing climate where temperatures and sunshine hours decrease with distance from the equator, as solar radiation becomes more dispersed and passes through a thicker layer of the atmosphere.

Continentality

The climatic effect in which locations situated far inland experience extreme temperature variations, heating up more rapidly in summer and cooling more rapidly in winter than coastal areas.

Equatorial Climate

A climate type found within low latitudes (23.5^\tag*{}\text{N} and $\text{S}$ of the equator) characterized by constant high temperatures ($26\text{--}28^{\text{o}}\text{C}$), annual precipitation over $2,000\text{ mm}$, high humidity ($75\text{--}80\text{\%}$), and an absence of distinct seasons.

Trade Winds

Prevailing winds blowing into the equatorial low-pressure zone from high-pressure belts, originating from the north-east in the northern hemisphere and from the south-east in the southern hemisphere.

Convectional Rainfall

Heavy daily rainfall occurring in equatorial regions, caused when intensely heated warm air stores high amounts of water vapour until late afternoon cooling causes condensation and cloud formation.

Hot Desert Climate

A climate found between $15^{\text{o}}$ and $30^{\text{o}}$ north and south of the equator, characterized by annual precipitation below $250\text{ mm}$, low humidity ($10\text{--}30\text{\%}$), offshore prevailing winds, and daytime temperatures reaching up to $50^{\text{o}}\text{C}$.

Subtropical High Pressure Belts

Zones located around $30^{\text{o}}$ north and south of the equator where descending cool air warms up, preventing rising motion, condensation, and cloud formation, thereby creating aridity and hot deserts.

Tropical Rainforest Biome Distribution

A major ecosystem located mainly between $15^{\text{o}}$ north and $15^{\text{o}}$ south of the equator, covering $6\text{\%}$ of Earth's land surface across the Amazon, Central America, Central Africa, and Indo-Malaysia.

Tropical Rainforest Nutrient Cycle

A rapid ecological cycle where warm temperatures and high moisture drive fast decomposition of litter and continuous plant uptake, resulting in naturally infertile soil as nutrients are quickly absorbed.

Tropical Rainforest Vegetation Layers

The five vertical structural layers of a rainforest: Ground layer ($0\text{ m}$), Shrub layer ($3\text{--}4\text{ m}$), Under canopy ($15\text{ m}$), Canopy ($30\text{ m}$), and Emergents ($45\text{--}55\text{ m}$).

Buttress Roots

Large, visible root structures above ground that anchor exceptionally tall rainforest trees in place, compensating for shallow nutrient-poor soils.

Drip Tips

Waxy leaf adaptations featuring pointed tips that allow rainwater to run off rapidly, preventing leaf breakage and inhibiting mould growth.

Epiphytes

Plants that grow harmlessly on the branches and trunks of taller trees to reach sunlight, obtaining nutrients from air, rain, and surrounding debris.

Lianas

Woody vines rooted in the rainforest soil that use tall tree trunks as structural support to climb into the canopy to access sunlight.

Hot Desert Nutrient Cycle

A slow nutrient transfer process restricted by extreme temperatures and lack of moisture, where most nutrients remain locked in coarse, sandy soil with minimal organic matter.

Deforestation

The large-scale clearing and felling of trees and forest cover, driven by human activities like agriculture, logging, mining, road construction, settlements, and hydropower projects.

Environmental Impacts of Deforestation

Ecological consequences including loss of biodiversity through monoculture, decreased evapotranspiration leading to lower precipitation, increased overland flow causing soil erosion, river sedimentation, and elevated atmospheric carbon dioxide.

Deforestation in Malaysia

The rapid felling of Southeast Asian tropical rainforests, averaging over $140,000\text{ ha}$ cleared per year since 2000 due to logging, palm oil plantations, highways, and infrastructure development.

Kapur Tree

A Malaysian rainforest tree adapted to reach heights up to $60\text{ m}$ for sunlight, featuring a straight, branchless trunk that deters epiphytes and lianas from climbing it.

Bakun Dam

A major hydroelectric project constructed in Sarawak, Malaysia, which flooded $700\text{ km}^2$ of rainforest land to generate electricity.

Palm Oil Plantations (Malaysia)

Commercial monoculture plantations accounting for over $30\text{\%}$ of global palm oil exports from Malaysia, causing a $35\text{\%}$ reduction in regional species diversity.

Benguela Current

A cold ocean current off the west coast of Southern Africa that cools the coastal edge of the Namib Desert and causes frequent fog formation for over half the year.

Welwitschia mirabilis

An endemic plant species in the Namib Desert that possesses only two long leaves that shade its roots, growing only in favourable conditions and turning red under high heat for solar protection.

Nara Plant

A Namib Desert succulent plant with spikes instead of leaves to prevent water loss and smooth waxy stems that capture water droplets directly from coastal fog.

Fog-basking Beetle

An endemic Namib Desert insect adapted to gather water by standing on its head in morning coastal fogs, directing condensed water down its back to its mouth.

Rössing Uranium Mine

A large mining operation near Swakopmund in the Namib Desert that degrades land, pollutes air and soil, and increases demand on scarce local water supplies.