C4.2 Transfers of Energy and Matter
In most ecosystems, this is the principal external energy source that sustains producers.
What is sunlight?
This property of natural ecosystems is shown when an ecosystem continues over a long period without collapsing into a completely different state.
What is stability?
These two greenhouse gases are named in the syllabus as the main anthropogenic atmospheric increases driving climate change.
What are carbon dioxide and methane?
This term means the variety of life in all its forms, levels and combinations, including ecosystem, species and genetic diversity.
What is biodiversity?
This term describes an interacting group of organisms of the same species living in the same area.
What is a population?
These organisms use external energy sources to synthesize carbon compounds from simple inorganic substances.
What are autotrophs?
These four requirements help ecosystems remain stable: energy supply, nutrient recycling, genetic diversity, and climatic variables staying within these.
What are tolerance levels?
Loss of reflective snow and ice increases absorption of solar radiation, making warming worse. This is an example of this type of cycle.
What is a positive feedback cycle / loop?
Human population growth, over-exploitation, urbanisation, deforestation, pollution, invasive species and global transport are all causes of this current biological crisis.
What is the biodiversity crisis?
This sampling method is used to estimate population size for sessile organisms, such as plants or barnacles.
What is random quadrat sampling?
In food chains and food webs, arrows show the direction of transfer of this, along with biomass.
What is energy? / What is chemical energy?
In the Amazon rainforest, large-scale deforestation may push the ecosystem past this kind of threshold, after which stability may be lost.
What is a tipping point?
In the Antarctic, early breakout of landfast ice may cause this species to lose breeding grounds.
What is the emperor penguin?
Conservation of species in their natural habitats, such as protected reserves, is known by this Latin phrase.
What is in situ conservation?
This term describes the maximum population size that an environment can sustainably support, given limiting resources.
What is carrying capacity?
This process explains why energy availability decreases at each trophic level, as chemical energy is converted and lost as heat.
What is cellular respiration?
These species have a disproportionately large effect on community structure, so removing them can risk ecosystem collapse.
What are keystone species?
Warmer surface water can reduce this ocean process, lowering nutrient supply, primary production, and energy flow through marine food chains.
What is nutrient upwelling?
Zoos, botanic gardens, seed banks and tissue banks are examples of this conservation approach, carried out away from a species’ natural habitat.
What is ex situ conservation?
This population-estimation method involves catching organisms, marking them, releasing them, and later catching another sample.
What is capture-mark-release-recapture?
An ecosystem acts as this when photosynthesis exceeds respiration, causing a net uptake of carbon dioxide.
What is a carbon sink?
This process restores natural ecosystem processes by methods such as reintroducing apex predators, reconnecting habitats, and reducing human management.
What is rewilding?
Increased carbon dioxide causes ocean acidification and reduced calcification, while higher water temperatures cause bleaching, threatening collapse of these ecosystems.
What are coral reef ecosystems?
This conservation programme prioritises species that are both evolutionarily distinct and globally endangered.
What is EDGE of Existence?
Using the Lincoln index, 40 animals are first captured and marked. Later, 50 are captured, of which 10 are marked. This is the estimated population size.
What is 200?