Ecology Notes

Ecología

  • Etimología:

    • Griego “oikos” = hogar

    • Griego “logos” = estudio

  • Ecología = Estudio de interacciones entre seres vivos y su ambiente

Ecological Studies

  • Ecological studies are conducted at many levels, from individuals to the entire planet.

Levels of Ecological Study

  • Ecology organismal

  • Ecology of populations

  • Ecology of communities

  • Ecology of ecosystems

  • Ecology of the landscape

  • Global ecology

Organism

  • Can be unicellular or multicellular

Organismal Ecology

  • What are the temperature tolerance limits of a common coqui?

  • How does a coqui choose its food?

Population

  • Population = Group of individuals of the same species that occupy the same geographic area in the same period of time

Population Ecology

  • What factors control the size of common coqui populations?

Community

  • Community = Set of populations of different species that inhabit the same place at a given time

Community Ecology (Synecology)

  • With what other species do common coquíes compete for resources?

  • What are the predators of common coquíes?

Ecosystem

  • Ecosystem = Community of organisms that inhabit an area at a given time and physical factors with which they interact

System Ecology

  • How do common coquíes influence the flow of energy and nutrient recycling in the tropical forests of Puerto Rico?

Landscape

  • Landscape = Mosaic of ecosystems interconnected by exchanges of energy, materials and organisms

Landscape Ecology

  • How large should a forest fragment be to support a stable population of common coquíes?

Biosphere

  • Biosphere = Sum of all ecosystems on the planet

Global Ecology

  • What impact will global warming have on the distribution of common coquíes?

Ecology as a Science

  • It is an interdisciplinary science that integrates all areas of biology and other sciences, especially geology, meteorology, geography, physics, chemistry and mathematics

Ecology vs. Environmentalism

  • Ecology versus ecologism (or environmentalism)

  • Interactions between living beings and their environment determine distribution (i.e., where it is) and abundance (i.e., number of individuals in a given area) of species

  • Biogeography = Study of past and present distribution of species

Distribution

  • Distribution of a species is influenced by:

    • Geographic barriers

    • Behavior (animals)

    • Existence of adequate environmental conditions

    • Interactions with other organisms

Distribution and Abundance Examples

  • Cattle egret (Bubulcus ibis) - showing spread over time

  • Africanized or killer bees

  • Eleutherodactylus coqui - native and introduced ranges

  • Kangaroos rojos (Macropus rufus)/km^2 (0–0.1, 0.1–1, 1–5, 5–10, 10–20, >20)

Habitat

  • Habitat = Specific place in which a species lives

  • There are two types of factors that determine the distribution of organisms:

    • Abiotic = Non-living components of the environment (e.g., water, soil, light, temperature, pH, salinity)

    • Biotic = Other organisms that share the habitat

Factors Limiting Distribution

  • Why is species X absent from an area?

    • Does dispersion capacity limit its distribution?

    • Does behaviour limit its distribution?

    • Do biotic factors (i.e., other species) limit their distribution?

    • Do abiotic factors limit their distribution?

      • Chemical factors: Water, oxygen, salinity, pH, nutrients, etc.

      • Physical factors: Temperature, light, soil structure, fire, humidity, etc.

Applied Ecology

  • Applied ecology = Use of ecological principles to solve problems of human interest (e.g., management of natural resources, restoration)

Natural Resources

  • Natural resources are those that are found in the environment (e.g., water, air, minerals, organisms)

  • They are grouped into two categories based on availability in time, rate of regeneration and rate of consumption:

    • Non-renewable

    • Renewable

Non-Renewable Resources

  • Non-renewable resources = Exist in finite quantities and have regeneration cycles well below extraction or exploitation rates

    • Examples: mineral deposits, fossil fuels, salt, sand

Renewable Resources

  • Renewable resources = Can be restored by natural processes since they have regeneration cycles above their extraction

    • Examples: forests, fish, water, soil

  • Time it takes to renew them varies

  • They are vulnerable to abuse

Philosophies of Natural Resource Use

  • There are three philosophies of use of natural resources:

    • Exploitation

    • Preservation

    • Sustainable use

Exploitation

  • Exploitation = Intensive and unregulated extraction of natural resources to maximize economic gain

    • Focused on human beings

Preservation

  • Preservation = Protection of natural resources from use by human beings via prohibitive laws

    • Centered on nature

Sustainable Use

  • Sustainable use = “Use that does not reduce future potential use or harm the long-term viability of the species used or other species and that is compatible with maintaining the long-term viability of the ecosystem that supports or depends on the species used” (IUCN 1994)