EXAM 1

What is Ecology?

What it's not:

Hierarchy of Ecology

"Political Tree Huggers"

Environmental Science= mixture of ecology, economy, society

  1. Population
  1. Community
  1. Organism
  1. Ecosystem
  1. Biosphere

Approaches to Ecology

Ecological inferences

Metapopulation

Scale = in space and time

Scope = the extent to finding may be applicable to other studies

Models

Field Experiments

Natural Observation

Physical Environment

Anthropological Disturbances

Invasive species

Air pollution

Development

Habitat Fragmentation

Sources of Environmental Variation

Disturbances

Evolution History

Biotic Features

Dispersal

Abiotic Features

Global Climate Patterns

Climate

Factors that Control Climate

Extreme conditions > Averages as they determine mortality

Timing of changes in physical environment

Climate = avg conditions at a given location, long-term description of weather

Weather is day-to-day while Climate is long-term

Water Bodies = water has higher heat capacity so it takes longer to heat up

Latitude = the closer to equator, the more hot b/c of direction of sunlight

Altitude and Temperature= the closer to the poles, the more cold b/c of less heating being able to contain

Altitude and Precipitation = mountain ranges can separate regions of precipitation

Seasonality = orbit and tilt of earth determines the rate of seasonality

Wind Direction/Pressure = temperature determines low and high wind pressure

Warmer winds = Low pressure

The more away wind is from the earth, the greater chance of precipitation as it cools to become rain or snow

Hemispheres have more pressure than equator (Hadley Cell)

Windward = wind goes uphill, more susceptible to rain

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Biomes

Tropical Seasonal Forests and Savannas

Desert

Tropical Rainforest

Temperate Grasslands

Temperate Shrubland and Woodlands

Temperate Deciduous Forests

Temperate Evergreen Forests

Boreal Forests

Tundra

Aquatic Environments

Thermal Stratification

Light Attenuation

Types of aquatic systems

Lentic = Lakes

Marine = Oceans

Lotic = Streams

Metalimnion/Thermcoline = transition temperature of water

Hypolimnion = cold, bottom water

Epilimnion = warm, surface water

Dimictic Lake = lake that has 2 mixing events per year (winter and summer)

Littoral Zone = ground near photic zone with rooted plants

Aphotic Zone = bottom water with least sunlight

Photic Zone = surface water with most sunlight

Oceans

Common with lakes: Different Light Attenuation zones

Different from Lakes: Oceans have tides from gravitational pull from moon

Enough salt to create coral reefs and tidal zones

Evolution and Ecology

Ecology influences evolution by ecological interactions changing gene frequency

4 Mechanisms that drive evolution

Evolution = change in gene frequency in a population over time

Mutation

Gene Flow

Natural Selection

Genetic Drift

Rapid Evolution = Invasive species and selective harvesting

Adaptations to Heat

Modifications of energy balance in plants

REDUCED HEAT LOSS = pubescence on plants, boundary layer

CONTROL EVAPOTRANSPIRATION = stomates, drought deciduousness

SOLAR RADIATION INPUT = control solar radiation input

Modifications of energy balance by animals

Ectotherms

Endotherms

Adjust their body temp by moving environments

Main regulation = moving to different areas

Dealing with freezing temperatures

Antifreeze

Freeze tolerance

Supercooling

Relatively high metabolic rates

Deal with cold by:

Tolerate narrow range of body temperature, but greater geographic range

Deal with heat by:

Increasing heat production

Limiting heat loss

Limiting heat gain

Increasing heat dissipation

Adaptations to Water

Water moves from high to low pressure

Water movement in plants

Water moves upwards in a plant

Follows a difference in pressure where there is high pressure in its roots

Adaptation to Dry biomes

Closed stomates during day

Waxy cuticle

Root:Shoot ratio, More root = more water area and reduced evaporation

Dormancy/ephemerals

Water storage

Aquatic Animals Adaptation

Salt or Water concentration influences movement of both

Saltwater = hypoosmotic fish = high water, low solute

Freshwater = hyperosmotic = low water, high solute

Terrestrial Animal Adaptation

Thick, impermeable surfaces

Noctural

Water from different sources = oxidative metabolism