Ecosystem Interactions

Biophysical Interactions in Ecosystems: Examples from the Great Barrier Reef and Hunter Valley Estuary Wetlands

• An ecosystem is made up of biotic organisms and their interaction with the abiotic environment.
• The Great Barrier Reef (GBR) and Hunter Valley Estuary Wetlands (HEW) have unique biophysical interactions that make each ecosystem diverse and integral for functioning.
• The dynamics of weather and climate determine the diversity, geographical distribution, and productivity of an ecosystem.
• The GBR lies within the tropical climate zone and is subjected to warm temperatures, dry and wet seasons, and low-pressure systems that can contribute to erosion, deposition, and impact biochemical cycles.
• In the HEW, temperature and rainfall determine the distribution of mangroves and salt marsh species, affecting the water table and freshwater proximity, and impacting photosynthesis processes.
• Geomorphic and hydrological processes, including earth movements, weathering, erosion, transport, and deposition, affect the diversity and functioning of an ecosystem.
• Rifting caused the Townsville and QLD troughs to join close to the edge of the Australian continent around 95 million years ago, determining the shape, location, and distribution of the reefs in the GBR.
• Weathering in the GBR produces limestone from calcium carbonate, leading to the formation of new landforms like coral cays, while coral browsers physically break apart coral, allowing for regeneration and relocation.
• Erosion from large waves and strong winds, usually associated with cyclones, breaks apart and moves large areas of corals called bommies, contributing to reef building and maintaining biodiversity.
• Biogeographical processes, such as succession and modification, operate in the HEW, enabling the functioning of the ecosystem.
• Succession in the HEW involves seagrasses establishing themselves, stabilizing the area, trapping other sediments, which encourages more seagrasses to grow and facilitates deposition and sediment development into mudflats.
• Salt marshes often develop in the salty soil behind the mangroves, contributing to high productivity and nutrient cycling in salt marsh areas with saltbush and insects.

Biophysical Interactions in Ecosystems: Examples from the Great Barrier Reef and Hunter Valley Estuary Wetlands

• An ecosystem is made up of biotic organisms and their interaction with the abiotic environment.
• The Great Barrier Reef (GBR) and Hunter Valley Estuary Wetlands (HEW) have unique biophysical interactions that make each ecosystem diverse and integral for functioning.
• The dynamics of weather and climate determine the diversity, geographical distribution, and productivity of an ecosystem.
• The GBR lies within the tropical climate zone and is subjected to warm temperatures, dry and wet seasons, and low-pressure systems that can contribute to erosion, deposition, and impact biochemical cycles.
• In the HEW, temperature and rainfall determine the distribution of mangroves and salt marsh species, affecting the water table and freshwater proximity, and impacting photosynthesis processes.
• Geomorphic and hydrological processes, including earth movements, weathering, erosion, transport, and deposition, affect the diversity and functioning of an ecosystem.
• Rifting caused the Townsville and QLD troughs to join close to the edge of the Australian continent around 95 million years ago, determining the shape, location, and distribution of the reefs in the GBR.
• Weathering in the GBR produces limestone from calcium carbonate, leading to the formation of new landforms like coral cays, while coral browsers physically break apart coral, allowing for regeneration and relocation.
• Erosion from large waves and strong winds, usually associated with cyclones, breaks apart and moves large areas of corals called bommies, contributing to reef building and maintaining biodiversity.
• Biogeographical processes, such as succession and modification, operate in the HEW, enabling the functioning of the ecosystem.
• Succession in the HEW involves seagrasses establishing themselves, stabilizing the area, trapping other sediments, which encourages more seagrasses to grow and facilitates deposition and sediment development into mudflats.
• Salt marshes often develop in the salty soil behind the mangroves, contributing to high productivity and nutrient cycling in salt marsh areas with saltbush and insects.