Lecture 4 - Ecosystem Essentials and Terrestrial Biomes Flashcards
(57 cards)
Define an ecosystem.
A biological community of interacting organisms and their physical environment; *biotic and abiotic *components are linked together through nutrient/matter cycles and energy flows.
List characteristics of an ecosystem.
- Holistic approach,
- somewhat self-contained,
- transitional zones called ecotones,
- each component has its own role,
- interconnected elements at various overlapping scales.
Define ecology.
The study of the relationships and interactions among groups of living things and their environments, at different scales.
HOW they Interact
How does ecology relate to other sciences?
is the Intersection of Earth science, biology, and geography.
Define biogeography.
The study of the distribution of plants and animals, the diverse spatial patterns they create, and the physical and biological processes, past and present, that produce Earth’s species richness.
WHERE they are
Define landscape ecology.
The study of how landscape structure affects the abundance and distribution of organisms.
Define landscape structure.
Composition (e.g., the amount of forest or wetland, the length of forest edge, or the density of roads) and configuration of landscape elements (e.g., juxtaposition of different landscape elements, and measures of habitat fragmentation).
What is the importance of landscape ecology?
A spatially integrated mosaic and an important concept for regional development or the study of habitat fragmentation.
Define ecological footprint.
The impact of a person or community on the environment, expressed as the amount of land required to sustain their use of natural resources.
Why is ecological footprint important?
One of the world’s leading measures of human demand on nature and a measure of nature’s capacity to meet the demands which humans place on our planet.
Define a system.
A network of relationships among parts, elements, or components that interact with and influence one another through the exchange of energy, matter, or information.
What is the difference between open and closed systems?
Open systems input and output energy and matter, while closed systems input energy and matter but only output energy, with matter cycling within the system.
Define biotic and abiotic systems.
Biotic refers to anything having to do with life, while abiotic refers to the nonliving parts of the environment.
What role does the sun play in ecosystems?
Solar energy drives most systems on Earth and enters the ecosystem energy flow by way of photosynthesis.
How much solar energy is fixed by photosynthesis?
Only 1% of solar energy reaching the Earth is ‘fixed’ by photosynthesis as carbohydrates in plants.
What does ‘fixed’ mean in the context of photosynthesis?
Chemically bound into plant tissue.
Define net photosynthesis.
The difference between photosynthetic production of carbohydrates and respiration loss of carbohydrates.
Define compensation point in plants.
The breakeven point where a plant needs a surplus of carbohydrates to grow, otherwise, the plant eliminates the leaf.
Define Net Primary Productivity.
The net photosynthesis for an entire ecosystem, the amount of stored chemical energy that an ecosystem generates (measured in fixed carbon per square metre per year).
What are biochemical cycles?
The recycling of gases and nutrient sedimentary materials.
What elements make up 90% of the Earth’s biomass?
Hydrogen, oxygen, and carbon.
List key nutrients for living organisms.
Nitrogen, calcium, potassium, magnesium, sulfur, and phosphorous.
Give examples of gaseous cycles.
Carbon, oxygen, and nitrogen.
Describe the carbon and oxygen cycles.
Carbon is fixed with oxygen as a by-product, while respiration and human activity release carbon into the atmosphere.
