Ecology

• Producers are the energy gateway.
• Worldwide agriculture could feed many more people if humans ate only plant materials.
• Mycorrhizal fungi can help plants access nutrients in the soil.
• Ecology is the scientific study of interactions between organisms (biotic) and interactions between organisms and the environment (abiotic).
• Ecology is a quantitative discipline including observation and experimentation.
• Ecologists study ecology at various levels of organisation: Global Ecology, Biosphere, Biomes, Ecosystem, Community, Population, Organism.
• An ecosystem is the community of organisms in an area (biotic) plus the physical factors (abiotic).
• Ecosystems vary in size from very small to very big.
• A habitat is a place/environment within an ecosystem where an organism lives.
• A niche is the role and position a species has in its environment; A species' niche includes all of its interactions with the biotic and abiotic factors of its environment.
• Biotic factors in an ecosystem include herbivory, predation, and competition.
• Abiotic factors in an ecosystem include climatic factors (temperature, sunlight, precipitation, wind etc.), physical factors such as rock, soil, and chemical factors.
• Organisms affect their environment (abiotic) factors and ecosystems can be defined as aquatic or terrestrial.
• Aquatic ecosystems include freshwater (lentic and lotic), marine (saline), and wetlands.
• Coral reefs are formed from the calcium carbonate skeletons of corals (cnidarians).
• Shallow reef-building corals live in the photic zone in warm (about 20 – 30  C), clear water; corals live at depths of 200 – 1,500 m.
• Some energy goes to decomposers at each level in an ecosystem: plants, herbivores, carnivores, and so on.
• Production Efficiency is the fraction of energy stored in food that is not used for respiration.
• Trophic Efficiency is the percentage of production transferred from one trophic level to the next.
• Only 10% of available energy consumed is incorporated into biomass.
• On average 10% of energy entering a trophic level is transferred to the next trophic level.
• Approximately 0.1% of chemical energy fixed by photosynthesis reaches a tertiary consumer.
• A pyramid of net production represents the loss of energy with each transfer in a food chain.
• Trophic structure is the feeding relationships between organisms in a community.
• Food chains link trophic levels from primary producer to top carnivore.
• Each food chain in a food web is normally only a few links long.
• Decomposition connects all trophic levels.
• Decomposers are consumers that get energy from Detritus.
• Prokaryotes and Fungi are important detritivores.
• In a grazing food chain, the producers and consumers cycle energy from living plants, with only 10% of energy passed up through the chain and the rest passed out into the atmosphere as heat from respiration and decomposition.
• In a detrital food chain, pathways through which energy and materials transfer from dead organic matter (non-living remains of plants and animals) to consumers.
• Detritus food chains are the dominant pathway of energy and matter flow in many ecosystems, including forests and wetlands.
• Eating meat is an inefficient way of tapping photosynthetic production.
• Coral reefs require high oxygen concentrations and a solid substrate for attachment.
• Complex interactions and intense competition occur in coral ecosystems, involving coral animals and associated symbiotic dinoflagellates, as well as many brightly coloured fish and invertebrates.
• Examples of aquatic ecosystems include rock pools and hydrothermal vents.
• Rock pools are shallow pools of water found in rocky areas, often with a variety of biotic factors and abiotic factors.
• Hydrothermal vents are deep-sea vents of volcanic origin on mid-oceanic ridges, surrounded by unique chemoautotrophic prokaryotes, as well as echinoderms and arthropods.
• Ecological energetics is the quantitative study of the flow of energy through ecological systems.
• Ecologists study the transformation of energy and matter in ecosystems.