bio - ecosystems + material cycles (9)

• Population refers to all the organisms of a particular species that live in a habitat.
• Community refers to all the populations of different species that live together in a habitat.
• Biotic factors are living factors of the environment.
• Abiotic factors are non-living factors of the environment.
• Ecosystem is the interaction of a community of living organisms with the non-living parts of their environment.
• Animals need territory, food, water and mates.
• Plants need light, space, water (mineral ions) and soil.
• Organisms compete for resources such as territory, food, water and mates.
• Interdependence means all species depend on other species in some way, for example, in food chains.
• Microorganisms require water to grow, so removing water can prevent them from growing.
• Gamma radiation can be used to destroy microorganisms.
• Biotic factors are living factors that affect other organisms or the ecosystem, examples for animals include predation, competition for resources/habitat, amount of disease, availability of food.
• Abiotic factors are chemical and physical factors that can affect organisms, examples include light intensity, moisture level, pH, temperature, wind intensity/direction, CO2 concentration, mineral content.
• Quadrats are small square frames that have been subdivided into lots of smaller squares, used to sample a habitat and estimate size of population.
• Food chains start with a producer (photosynthetic organism), then it’s a primary consumer (there would be multiple but only 1 is shown), then a secondary consumer (some type of predator), then a tertiary consumer.
• Trophic levels are the different levels of a food chain from producer to tertiary, level 1 uses photosynthesis to produce its food and is always a producer, level 2 are herbivores (primary consumers), level 3 are carnivores (secondary consumers), level 4 are carnivores (tertiary consumers).
• Decomposers are bacteria and fungi, they decompose the dead plant and animal matter in the environment, allowing them to recycle nutrients from animals and plants back into the ground so they can be used again by producers.
• Pyramids of Biomass show the biomass of each trophic level in a food chain, the total mass of each organism decreases the further in each level because most of the biomass and energy is either lost or used and only 10% gets transferred each time.
• Calculating efficiency of biomass transfer is done by dividing the biomass of the top trophic level by the biomass of the bottom trophic level.
• Carbon is split into five stores: the air, fossil fuels, soil, in plants (locked up in biological molecules), and animals.
• Carbon and water cycles involve energy from the sun causing water to evaporate, which condenses in the air to form clouds, falls back down to earth in the form of rain, seeps into soil, flows into rivers, or is absorbed by plants, and then the cycle starts again.
• Preserving food involves preventing decomposition from taking place, for example, by storing food in a fridge or freezer, or by storing food in airtight containers to prevent microorganisms from contaminating.
• Decay, also known as rotting, is the process by which dead organic matter is broken down into simpler organic/inorganic substances such as carbon dioxide, water, simple sugars, and minerals, and it is essential for the recycling of elements throughout an ecosystem.
• Factors that affect the rate of decomposition include oxygen availability, temperature, and water content.
• Factors affecting food security include rising populations, diet changes as countries become wealthier, new pests and pathogens that can kill crops or livestock, environmental changes such as climate change, agricultural inputs that can be expensive, and conflicts such as wars that can disrupt the production and transportation of food.
• Photosynthesis is the process by which plants take in carbon dioxide and produce glucose and oxygen, and this carbon can be passed out to the atmosphere by respiration or to animals that eat the plants.
• Compost is a mixture of decayed organic material that is used to fertilize and improve the soil, commonly prepared by leaving dead plant waste in ideal conditions until it is mostly decomposed, and then it can be spread across soil where it provides nutrients for the plants.
• Decomposition is carried out by detritivores (small animals like worms and woodlice that feed on dead organic matter) and decomposers (microorganisms, such as bacteria and fungi).
• Pollution harms organisms (directly/indirectly) and often changes ecosystems and reduces biodiversity.
• Biodiversity refers to the variety of different species on earth, or within an ecosystem.
• Individuals can contribute to protecting biodiversity by recycling, reducing waste in landfills, and protecting the environment.
• Humans clear out the natural ecosystem and produce lots of waste individually (bins + flushing toilet) and collectively (production of things we buy).
• Biomass transferred to next level/ biomass that was available at the previous level x 100
• Eutrophication starts with fertilisers, nitrates and phosphates are washed into river/lake systems, leading to an increased nutrients concentration in the water.
• 200,000 of the pollinators are bees and more than half of new medical drugs are derived from living organisms.
• Governments can set quotas for how much CO2 can be released by businesses, set laws prohibiting/requiring certain things or paying businesses to carry out processes.
• Reducing the impact of harmful but necessary things like farming can involve having field margins (strip around the field where anything can grow) and hedgerow acts as a border, providing extra habitats and food sources for a wider range of species to survive.
• Eutrophication is a process that happens in a water body with too many nutrients.
• Important functions of biodiversity include making the ecosystem stable as there are so many other relationships if one fails there are more to rely on.
• The nutrients in the water are food for algae, which reproduce quickly to form a thick green bloom in the water.