2.3 Flashcards
Explain the pathways of solar radiation as it passes through the atmosphere.
Solar radiation enters the Earth’s atmosphere and can either be reflected back into space, absorbed by the atmosphere, or reach the Earth’s surface. The absorbed solar radiation heats the atmosphere and surface, leading to the emission of infrared radiation. Some of this infrared radiation is trapped by greenhouse gases, causing the greenhouse effect.
Explain the pathways of energy through the ecosystem – conversions, transfers, transformations, efficiencies, and losses.
Energy flows through an ecosystem in a series of steps. It starts with primary producers (plants) converting solar energy into chemical energy through photosynthesis. This energy is then transferred to primary consumers (herbivores) when they consume the plants. Energy is further transferred to secondary consumers (carnivores) when they eat primary consumers. Energy transformations occur at each trophic level. Efficiency decreases at higher trophic levels due to energy loss in the form of heat and waste.
Define and explain productivity – gross and net.
Productivity refers to the rate at which energy or biomass is produced in an ecosystem. Gross productivity is the total energy or biomass produced through photosynthesis or assimilation. Net productivity is the energy or biomass available for the next trophic level after accounting for the energy used by primary producers in respiration.
Equations for NPP and GPP
Net primary productivity: NPP= GPP (gross) - R (respiration). Expressed as gm-2y-1
Gross primary productivity: Total primary productivity.
Secondary productivity (assimilation) is the total biomass consumed by primary consumers.
Net secondary productivity: NSP = GSP - R (respiration)
Gross secondary productivity: GSP = Food eaten - fecal loss (g/J m-2y-1)
Explain the link between net primary and net secondary productivity of a system and maximum sustainable yield.
Net primary productivity (NPP) determines the maximum amount of energy available for consumption by herbivores and decomposers in an ecosystem. Net secondary productivity (NSP) is the energy available for consumption by tertiary consumers. Maximum sustainable yield is the harvest level that allows the system’s NPP to remain constant. NSP cannot exceed NPP because it depends on the energy available at the primary producer level.
Describe the differences between energy flow and nutrient cycling.
Energy flow refers to the transfer and transformation of energy through trophic levels in an ecosystem. It is unidirectional and involves the transfer of energy from one organism to another. Nutrient cycling, on the other hand, involves the recycling of nutrients within an ecosystem. Nutrients are taken up by organisms, released through decomposition, and reused by other organisms. Nutrient cycling is cyclical and essential for maintaining nutrient availability in the ecosystem.
Explain how matter may transfer and transform in ecosystems.
Matter, such as nutrients, is taken up by organisms from the environment, incorporated into their bodies, and released back into the ecosystem through excretion and decomposition. This allows for the recycling and reuse of matter within the ecosystem.
Explain how energy may transfer and transform in ecosystems.
Energy is transferred between organisms through feeding relationships in trophic levels. It is transformed as organisms perform life processes and is eventually lost as heat.
Demonstrate how the carbon and nitrogen cycles illustrate stores and flows of matter.
In the carbon cycle, carbon is stored in various forms, including the atmosphere (as carbon dioxide), organisms (as organic matter), and fossil fuels. Carbon flows through the cycle via processes like photosynthesis, respiration, decomposition, and combustion, which transfer carbon between different reservoirs. Similarly, the nitrogen cycle involves the storage of nitrogen in the atmosphere, soil, and organisms. Nitrogen flows through the cycle via processes such as nitrogen fixation, nitrification, assimilation, and denitrification.
Outline the different stores and flows in the carbo cycle.
In the carbon cycle, stores include the atmosphere, plants, animals, soil, and oceans. Flows occur through processes like photosynthesis, respiration, decomposition, and combustion.
Outline the different stores and flows in the nitrogen cycle.
In the nitrogen cycle, stores include the atmosphere, soil, plants, animals, and bacteria. Flows occur through processes such as nitrogen fixation, nitrification, assimilation, and denitrification.
Discuss the impacts of human activity on energy flows and the carbon and nitrogen cycles.
Human activities, such as burning fossil fuels and deforestation, release additional carbon dioxide into the atmosphere, contributing to the greenhouse effect and climate change. Nitrogen is also impacted through the excessive use of fertilizers, which can lead to nitrogen runoff, eutrophication, and disruptions in natural nitrogen cycling. These activities alter energy flows and disturb the balance of carbon and nitrogen cycles in ecosystems.
Sustainable yield:
Sustainable yield is the amount of biomass that can be extracted without reducing natural capital of an ecosystem.
Natural capital are natural resources that can be economically exploited.
The Carbon Cycle:
1: All living things are made of carbon.
Biological activity makes carbon constantly transferred through different forms and locations.
2: This is known as the carbon cycle.
The cycle of matter in the carbon cycle is the following:
3: Plants absorb carbon through photosynthesis.
4: Animals eat plants and carbon is transferred into their bodies. Animals also release carbon through respiration.
5: Decomposers (such as the shitake mushroom) break carbon down into organic matter when plants and animals die.
6: Over millions of years, Carbon is packed under intense pressure to create fossils.
7:Fossils are excavated and combusted in order to extract energy.
8: through combustion carbon gets released into the atmosphere
What is the nitrogen cycle
The nitrogen cycle shows the movement of nitrogen around the biosphere.
The biosphere is the worldwide sum of ecosystems (the area where anything is alive).
Nitrogen is important for life because it is the building blocks of living things (DNA).
However, animals and humans cannot inhale nitrogen, meaning it has to be converted into usable nitrogen.
