Sustaining Ecosystems Study Guide

An ecosystem is a community of living organisms (biotic components) interacting with non-living components (abiotic components) of their environment. These interactions create a dynamic system where everything is interconnected. For example, plants (producers) use sunlight, water, and CO2 to grow, providing food for herbivores (primary consumers). Carnivores (secondary consumers) then feed on herbivores. Decomposers break down dead organisms, returning nutrients to the soil for plants. This intricate web of relationships is known as interdependence. If one part of the ecosystem changes, it can have cascading effects on all other parts. For instance, a decrease in rainfall (abiotic factor) can lead to fewer plants, which in turn reduces the food supply for herbivores, potentially impacting carnivore populations.

Global biomes are large-scale ecosystems defined by their climate, vegetation, and animal life. Their distribution across the Earth's surface is primarily determined by latitude, which influences temperature and precipitation patterns. For example, tropical rainforests are found near the equator where temperatures are consistently high and rainfall is abundant, supporting dense, diverse vegetation. Deserts, conversely, are located in regions with very low precipitation, leading to sparse vegetation adapted to arid conditions. Tundra biomes are found at high latitudes, characterised by permafrost and low-growing plants due to cold temperatures and short growing seasons. Understanding biome distribution involves recognising the link between global climate patterns and the resulting types of ecosystems that can thrive in those conditions. This understanding helps us appreciate the diversity of life on Earth and the delicate balance within these interconnected systems.