Dynamic Ecosystem

DYNAMIC ECOSYSTEM

ECOLOGY • Ecology: the scientific study of the interactions of living organisms with other living organisms and with the physical environment. • Environment = Biotic components + Abiotic components. • Biotic components: Living organisms • Abiotic components: Nonliving components.

ABIOTIC COMPONENTS • • •

pH value: pH of the soil and water. Most organisms survive well in neutral or nearly neutral environment Light intensity: affects the distribution and growth of plants and animals Temperature: most living organisms can only tolerate a narrow range of tempearture (0oC to 45oC): exceptional to certain species, example: termophilic bacteria that can survive in hot springs.

ABIOTIC COMPONENTS 4. Humidity: amount of water vapour present in the air. Humidity affects the rate of water loss by plants and animals 5. Topography: physical features of land. Topographic factors are altitude, gradient and aspect

TOPOGRAPHIC FACTORS 1. Altitude: Higher altitude associates with lower athmopheric pressure and temperature. Different plants grow at different altitudes. 2. Gradient : The steepness of a slope. Steep slopes result in rapid drainage and run off. 3. Aspect: associated with the direction of the wind. The slopes of a mountain facing the direction of the wind received more rain. 4. Microclimate: climate of a microhabitat. Microclimated includes the humidity, temperature, light intensity and atmopheric conditions

BIOTIC COMPONENTS • Consists of producer (green plants), primary consumer, secondary consumer, tertiary consumer and decomposer (bacteria and fungi).

FOOD CHAIN, FOOD WEB & TROPHIC LEVELS • Food chain: a sequence of organisms through which energy is transferred • Each stage of food chain is known as a trophic level • Food web: Interconnected food chains • In a food web, the source of energy is sunlight • Only 10% of energy is transferred to each trophic level: see pyramid of numbers • Energy loss is in the form of heat energy, decaying and etc.

INTERACTION BETWEEN BIOTIC COMPONENTS IN RELATION TO FEEDING

• Symbiosis: a close relationship between two or more different species which live closely together and interact with each other. • Symbiotic relationships: commensalism, mutualism and parasitism

COMMENSALISM • Clown fish and sea anemones • One species is benefit, the other species neither harmed nor get benefit.

MUTUALISM • Mutualism refers to the relationship of two organisms where both benefit from the association. The example below is a lichen growing on the trunk of a mangrove tree. The lichen consists of a fungus and an algae growing together. The fungus gets food from the photosynthesising algae and the algae gets a place to live.

PARASITISM

ECTOPARASITE

ENDOPARASITE

• The association in the parasite host relationship is one in which one organism benefits from the relationship and the other is disadvantaged..

DISCUSSION • In groups, discuss about saprophytism, prey-predator relationships and competition. • What do you understand about dynamic equilibrium? Discuss…