Ecological Principles Part I PaCES/HIMB Summer Program in Environmental Science David A. Krupp, Ph.D PaCES/HIMB Summer Program in Environmental Science David A. Krupp, Ph.D

Topics to be Studied Define “ecology” and describe its scope Define essential terms Contrast biotic and abiotic factors Physiological limits and abiotic factors Biomes Population characteristics Population growth Define “ecology” and describe its scope Define essential terms Contrast biotic and abiotic factors Physiological limits and abiotic factors Biomes Population characteristics Population growth

Ecology Ecology = the study of the interaction of organisms with their environments. It involves understanding biotic and abiotic factors influencing the distribution and abundance of living things. The word "ecology" coined from Greek word "oikos", which means "house" or "place to live”. Ecology = the study of the interaction of organisms with their environments. It involves understanding biotic and abiotic factors influencing the distribution and abundance of living things. The word "ecology" coined from Greek word "oikos", which means "house" or "place to live”.

The Scope of Ecology Population growth Competition between species Symbiotic relationships Trophic (= feeding) relationships Origin of biological diversity Interaction with the physical environment Ecosystem change Human impacts on the environment Population growth Competition between species Symbiotic relationships Trophic (= feeding) relationships Origin of biological diversity Interaction with the physical environment Ecosystem change Human impacts on the environment

Some Important Terms Population A collection of individuals all belonging to the same species in a defined area and time Community A group of interacting populations in a defined area and time Population A collection of individuals all belonging to the same species in a defined area and time Community A group of interacting populations in a defined area and time

Some Important Terms Ecosystem A system composed of the biological community interacting with its surrounding abiotic environment Biosphere The entire portion of the Earth in which life occurs; all of the ecosystems of the Earth combined Ecosystem A system composed of the biological community interacting with its surrounding abiotic environment Biosphere The entire portion of the Earth in which life occurs; all of the ecosystems of the Earth combined

Biotic Factors Dispersal Behavior Species interactions Competition for common resources Predator-prey relationships Symbiotic associations Dispersal Behavior Species interactions Competition for common resources Predator-prey relationships Symbiotic associations

Abiotic Factors Temperature Water Light Salinity Wind Currents Substrate Temperature Water Light Salinity Wind Currents Substrate

environmental gradient Physiological Limits

zone of tolerance Physiological Limits

zones of intolerance Physiological Limits

optimum range Physiological Limits

zones of physiological stress Physiological Limits

Biomes Biomes = major types of ecological assemblages that occupy broad geographic regions of land or water Aquatic biomes: primarily influenced by depth (light) and temperature Terrestrial biomes: primarily influenced by temperature and balance between precipitation and evaporation Biomes = major types of ecological assemblages that occupy broad geographic regions of land or water Aquatic biomes: primarily influenced by depth (light) and temperature Terrestrial biomes: primarily influenced by temperature and balance between precipitation and evaporation

Aquatic Biomes: Lakes oligotrophic eutrophic

Aquatic Biomes: Wetlands

Aquatic Biomes: Streams and Rivers

Aquatic Biomes: Estuaries

Aquatic Biomes: Intertidal

Aquatic Biomes: Oceanic Pelagic Biome

Aquatic Biomes: Coral Reefs

Aquatic Biomes: Marine Benthic Zone

Terrestrial Biomes

Terrestrial Biomes: Tropical Forests

Terrestrial Biomes: Deserts

Terrestrial Biomes: Savanna

Terrestrial Biomes: Chaparral

Terrestrial Biomes: Temperate Grasslands

Terrestrial Biomes: Coniferous Forest

Terrestrial Biomes: Temperate Broadleaf Forest

Terrestrial Biomes: Tundra

Population Characteristics Size and density Dispersion Survivorship Population growth Population age structures Size and density Dispersion Survivorship Population growth Population age structures

Density Number of individuals per unit area, per volume or unit of habitat. 5 individuals/m 2 15 individuals/m 2

Dispersion Patterns Random

Dispersion Patterns Clumped

Dispersion Patterns Uniform

Generation Population Size Population Growth

Population Size Generation Exponential Population Growth

Population Growth Population Size (N) Population Size (N) Births Deaths Immigration Emigration

Population Growth  N/  t = B - D dN/dt = bN - mN dN/dt = (b - m)N = rN r = b - m b = per capita birth rate m = per capita mortality rate b = per capita birth rate m = per capita mortality rate dN/dt = instantaneous rate of population increase

Population Growth dN/dt = rN r = per capita rate of increase dN/dt = r max N r max = optimal per capita rate of increase Under Optimal Conditions

Effects of Different Intrinsic Growth Rates (r) r max = 1.0 r max = 0.5

Density-Dependent Growth: The Logistic Growth Model

Population Growth A Paramecium population in the lab

Population Growth A Daphnia population in the lab

Population Growth A sparrow in its natural habitat

Density-Dependent Factors limiting resources (e.g., food & shelter) territoriality production of toxic wastes infectious diseases predation stress and other intrinsic factors emigration limiting resources (e.g., food & shelter) territoriality production of toxic wastes infectious diseases predation stress and other intrinsic factors emigration

Density-Independent Factors severe storms and flooding sudden unpredictable severe cold spells earthquakes and volcanoes catastrophic meteorite impacts severe storms and flooding sudden unpredictable severe cold spells earthquakes and volcanoes catastrophic meteorite impacts