14. Intro to Ecology and Population Ecology Flashcards
Define Ecology
study of
- relationship between organisms
- physical environment (abiotic)
- living environment (biotic)
Describe what each level in the hierarchy studies
Organism Level
- How do form, physiology, and behaviour lead to survival?
- Understanding population adaptations made through evolution, and modifications of structure and function that best suit the organism for its way of life in its environment
-Survivial and Reproduction: the unit of natural selection
Population Level
- Focus on Life processes such as births and deaths, immigration and emigration, influenced by:
- the physical environment
- evolutionary processes
- interactions with other populations
-Population dynamics: the unit of evolution
Community Level
- Community structure
- Community interactions + its consequences
- Interaction among populations
Ecosystem Level
- Dynamics in an ecosystem in terms of energy and materials
- Focus on movement of energy and materials in an ecosystem
-Energy flux and cycling of nutrients
Differentiate between biotic and abiotic components in the environment and recognize them as environmental challenges
Abiotic
- non-living (e.g. temp, sunlight, soil, minerals, metals, gases…)
Biotic
- all living (e.g. cells, organisms) and dead organic matter (fossil fuel, moss)
Define population, range and spacing
Population
- group of individuals of the same species in one given place at the same time
Population range
based on
1. habitat availability (abiotic, biotic needs)
2. presence of predators, competitors, parasites
3. range expansion and contraction due to comp, human activity, global cooling or warming
Population spacing
1. Uniform spacing : due to behavioural interactions, resource comp.
2. Random spacing: little to no interaction; not common in nature
3. Clumped spacing: uneven distribution of resources determines where populations live; social behaviour; common in nature
Identify the environmental limits to population growth
- Resource availability (e.g. water, nitrogen in soil)
- Density-independent effects (e.g. cold winters, volcanic eruptions, droughts, storms)
- Density-dependent effects
i. competition for resources;
ii. increased pollution due to wastes;
iii. disease spread is more rapid - Population cycles
i. Food for prey fluctuates in availability
ii. Predator numbers fluctuate
Provide an example of how a population may adapt to meet environmental challenges
- Giraffes and their necks (through natural selection
- adaptation to the animal’s natural habitat to reach leaves
Define demography and the role of life tables
(Geographic Distribution; pop. density; Dispersion; Growth Rate and; Age Structure)
Study of births, deaths, income, or the incidence of disease to summarize probability of survival and reproduction throughout lifetime
Describe how life table data shows probability of survivorship and reproduction throughout the lifetime of a cohort
Relate how environmental resources favour different reproductive strategies under conditions of ample limiting resources, and when resources are limiting
Explain exponential growth (J-curves) and why populations can’t grow exponentially forever (S-curves)
J- curves : exponential growth represents a population/ individual growth rate
- stays the same regardless of population size, making the population grow faster and faster as it gets larger
S-curves : logistic growth represents a population/ individual growth rate
- gets smaller and smaller as population size approaches a maximum imposed by limited resources in the environment, known as the carrying capacity (K)
Define carrying capacity
the maximum number of individuals that the environment can support indefinitely
Differentiate between the factors that regulate populations as density independent or density dependent. Describe current human population growth and be able to interpret population pyramids to determine the future population size
