Week Three Flashcards
What are the three main factors that influence the distribution and abundance of individual species?
- Abiotic Conditions: Set the physical limits to where a species can live based on tolerance to temperature, wind speeds, soil etc.
These define what researchers call a fundamental niche
- Biotic interactions: Ranging from competition and herbivory to mutualism dictate the realized niche or actual area occupied by a species - an area always smaller than the fundamental niche.
- Life history traits: Adaptations that influence how individuals allocate energy either to growth and maintenance or reproduction.
What is evolution?
Constant change due to natural selection, genetic drift, gene flow, and mutation. Traits change so fundamental niches realized niches, and life history traits can change.
What are disturbance?
Historical events that influence the composition of biological community. In ecology, a disturbance is defined as an event that removes biomass.
What is wilderness?
A natural environment that has not been significantly modified by human activity. Todays research states that there is no such thing.
Do all species living in a particular community have the same fundamental niches?
No, they live in the same place because their fundamental niches overlap but at any location, some species may be at the very limits of their tolerance.
What is habitat fragmentation?
Types of human development that are converting large, continous regions of forest, grassland, or desert habitat into geographically isolated fragments (road construction, subordination)
What is a keystone species?
A species that has a disproportionately large impact on a community relative to its numbers. Example -> Wolves in Yellowstone
Explain the traditional farming method called zai?
- Digging deep pits in degraded soil during dry season, added live stock droppings and compostables
- The compost attracted termites which built tunnels and loosened the soil.
- The funnel-like pits helped trap and hold moisture from the rain season giving new plants a chance to establish themselves.
What are extremophiles?
organisms that are able to live in extreme conditions
What is the energy budget?
Time/energy spent acquiring one resource cannot be spent acquiring another. This trade-off can be growing more leaves for more sunlight versus larger roots to hold more food.
What are the different areas in which energy can be allocated?
Metabolism
Growth
Movement
Reproduction
Defense
How do both biotic and abiotic factors limit distribution?
Abiotic: Pond temperature and Ph level
Biotic: Predators keeping them out of the pond.
What is the ecological niche?
he position of a species within an ecosystem, describing both the range of conditions necessary for survival. These include both abiotic and biotic factors.
What is a fundamental niche?
A fundamental niche is the abiotic conditions that help us identify where an organism potentially lives. Example: Temperature, water sources, light availability, elevation
The niche is not where on earth a species is found but what is needed for a species to survive.
What is the realized niche?
Where could a species actually live and actually survive given all the biotic interactions.
