Basic Ecology Four Levels of Investigation 1 Organism

Basic Ecology

Four Levels of Investigation 1. Organism 2. Population – An interbreeding group belonging to the same species 3. Community – All the populations of different species in an area 4. Ecosystem – The community and all non living factors of an area

Ecosystem examples: Aquariums Ponds Pastures Coral reefs Woodlots

Ecosystems: involve exchange of matter and energy between living and nonliving elements in a manner that sustains life - includes plants, animals, air, soil, and water

Living part of the ecosystem: biotic community – plants, animals, insects, etc. Nonliving part: abiotic (physical environment) – temperature, light, substrates, altitude, etc. - biotic and abiotic exchange energy and material

Ecosystems consist of several communities ex. : wetland communities - great blue herons, egrets, ducks, geese, etc. = bird community - dragonflies, mosquitoes, damselflies, spiders, etc. = insect community - cottonmouth, garter snake, water snake, copperhead, etc. = snake community

The Macrocosm and Microcosm

• • • Cosmos – Everything that exists anywhere Macro – Large Micro – Small Macrocosm – The universe without Microcosm – The universe within

Primary Abiotic Factors 1. Solar Energy 2. Water 3. Temperature 4. Wind

The Atmosphere

The Origins of the Atmosphere • Molten metals solidify within the frost line of the early solar system • They become planetary seeds, and continue to grow as gravitational attraction brings them together • As they approach planetary size the force of gravity causes a density distribution, with denser materials sinking and lighter ones rising • Volcanic activity begins to spew trapped gasses into the air – H 2 O, CO 2, CO, H 2 • Earth is only massive enough to keep heavier gasses, H 2 and He escape into space • Oxygen is never released in this manner, and had to arrive through biological processing

Atmospheric Composition

Parts of the Atmosphere

Atmospheric Purpose • It creates pressure which allows water to exist in liquid form • It absorbs and scatter light making daytime skies bright • Absorption allows them to protect from dangerous radiation • They cause wind and weather patterns • Interactions between atmospheric gasses and the solar wind can create a protective magneto sphere around planets with a strong magnetic field • Greenhouse gasses cause planetary temperatures to be warmer than they normally would be (H 2 O, CO 2, CH 4)

Greenhouse Gasses

Climate • Curvature of the earth induces temperature variation • Temperature patterns induce wind • Evaporation and condensation patterns cause rainfall

Wind Induction

Water

The Origins of Terrestrial Oceans • H 2 O was emitted by early volcanic activity. • The major abundance of water on earth is still a mystery. • Scientists speculate large amounts of water were brought to earth after it cooled by comets from the Kuiper Belt and Oort Cloud.

Water Ecosystems 1. Estuary: A freshwater stream or river merging with an ocean 2. Wetland: Inbetween an aquatic and terrestrial region where soil is saturated with water permanently or periodically 3. Intertidal zone: A wetland at the edge of an estuary or ocean which is sequentially covered by the tides 4. Pelagic Zone: Open ocean

Pelagic Regions • Photic Zone: Oceanic region where light penetrates • Aphotic Zone: Oceanic region where light does not penetrate sufficiently for photosynthesis • Benthic Zone: The ocean floor

Primary Ecosystems

Biomes – worldwide grouping of similar communities, commonly described by dominant vegetation

Temperate Grassland: - Big bluestem, Little bluestem, Grama grass - prairie chicken, western meadowlark, prairie dog, coyote

Temperate Deciduous Forest: - Oaks, Maples - ruffed grouse, black-capped chickadee, blue jay, white-tailed deer, fox squirrel, white-footed mouse

Desert: - Sagebrush, Creosote bush, Cacti - sage grouse, burrowing owl, roadrunner, desert bighorn sheep, desert jackrabbit

Tundra: - Sedges, Lichens, Cranberries - snowy owl, golden plover, caribou, musk ox, brown lemming

Boreal Forest: - Spruce, Firs - gray jay, moose, lynx, snowshoe hare

Mediterranean Scrub Forest : - Coffee-berry, Scrub oaks (fire-resistant) - California quail, anna’s hummingbird, mule deer, bobcat, brush rabbit

Density and Dispersion Patterns

Dispersion Patterns 1. Clumped: Often results from unequal distributions of resources 2. Uniform: Often results from interactions between individuals of a population 3. Random: Quite rare. Occurs in the tropics.

Idealized Growth Models Exponential Growth: G = r. N • G: Growth Rate • r: Intrinsic rate of increase – An organism’s maximum capacity to reproduce. It can be estimated by subtracting the death rate from the birth rate. • N: Population size

Population Limiting Factors • K = Carrying Capacity: the maximum population size that an environment can support

What causes non-ideality? • Declining birth rates • Rising death rates • Competition for limited resources

Boom and Bust Cycles The Lynx and the Hare

Thermodynamics

History • The study of energy • Arose from the need to increase the efficiency of steam engines • Fluidic theory of heat disproved by Boyle • 1824 Carnot publishes, “Reflections on the Motive Power of Fire. ” • The term, Thermodynamics, coined in 1849 by William Thomson (the Lord Kelvin). Sadi Carnot

The Laws 1. Conservation of Energy – The change in the internal energy of a closed thermodynamic system is equal to the sum of the amount of heat energy supplied to the system and the work done on the system 2. Entropy – The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value. 3. Absolute Zero Temperature – As a system asymptotically approaches absolute zero all processes virtually cease and the entropy of the system goes to a minimum value.

The Laws - simplified 1. Conservation of Energy – The stuff is always there: you can’t get stuff from nothing, and stuff can’t disappear. 2. Entropy – The universe is lazy: stuff always take the path of least resistance. Entropy is a measurement of the chaos of the stuff. 3. Absolute Zero – Heat is actually movement of the stuff. If stuff is completely cold, it’s not moving at all.

Implications • Disorder is Natural • Order is unnatural – specified complexity is extremely rare. • Many processes are irreversible – Can’t burn something twice – Eggs shatter, but they don’t reassemble • The universe is running down • Processes are always losing energy

Dealing with Entopy • Entropy is one of the most important scientific understandings of the behavior of matter. • It has serious implications in philosophy as well. – Entropy makes rivers crooked – People do what is easiest to do • Ancient people described this as the law of disintegration or decay. It was often represented by a serpent eating its tail. – Ezekiel’s valley of dry bones – Mummification is a defense against it – Gold wasso admired for its resistance to decay

Wisdom Schools and Entropy • The Gods and the Fates • Greek Tragedy – Man can’t win because he doesn’t know what’s coming.

Their Solution 1. No day is like any other; you can’t know the details of tomorrow. 2. Despite that, there is a pattern: Everything moves. 3. Does it move in every way? No: everything is going down. 4. Since everything is going down, why didn’t everything end a long time ago? 5. Something is working the other way. – The sun goes down each year, but it comes back. 6. Though we can’t know the specifics of tomorrow, we can learn its patterns.

How Modern Science Uses Entropy • We use equations to model the future. – If we can describe the trajectory of a cannon ball with an equation, we know its future in that case. – The more repeatable the results, the more confident we are in our model. • We understand that we have to put thought directed work into matter to order it for our purposes. – Example: We don’t wait around for a football stadium to organize itself, we cause it to happen by putting work into the environment. – Example: Even though there is a chance that dust will fall on a table in the attic in a perfect checkerboard pattern, we know it won’t. • Many times we don’t know the specifics of one particular thing, but we know it for a group of them very well: statistics. – Example: the behavior of a fan at a football game as opposed to the entire stadium. – Example: radioactive decay - the behavior of one atom as opposed to billions of them in an object. – Implication: Stereotypes exist because they are mostly correct.

Energy Flow

The Origin of Energy • All energy ultimately comes from mass • E = mc 2 • The Big Bang • As far as we are concerned, from an ecological standpoint, almost all energy important to life comes from the sun. • A small portion comes from deep oceanic thermal vents.

The Direction of Energy • Energy is not recycled in ecosystems. • It must be imported from the sun. • Implication of the 2 nd Law: – When energy is converted some is always lost as heat. – Recall, this also means, ultimately, that the universe is running down. – Ecosystems have limits placed on them due to loss of energy.

Purpose of Energy in Organisms • Entropy (ie chaos) is always breaking organisms down. • The only way to counteract this trend is with energy applied in very specific ways. • Organisms use energy in several ways: – builds cells, tissues, and organs (growth) – thermoregulation – digestion – muscle activity

Trophic Structures • Sacrifice: The Law of Life • Trophic – Of, or relating to nutrition. • Everywhere along this chain energy is lost.

Plants are Producers – First trophic level Photosynthesis starts the energy flow Energy assimilated in photosynthesis = Gross Primary Productivity (GPP) Plants use energy for maintenance needs The leftover energy is stored as organic matter in green plants = Net Primary Productivity (NPP)

Primary consumers – Second trophic level Herbivores (ex. : mouse, grasshopper, caterpillar, deer) - eat plants and obtain NPP energy - some energy is used for maintenance, growth, or reproduction - some energy is passed out of the body as waste - some is lost as heat

Secondary consumers – Third trophic level Carnivores and omnivores; predators (ex. : snake, frog, coyote, etc. ) - eat primary consumers - energy is used for maintenance, growth, or reproduction -some energy is passed out of the body as waste - some energy is lost as heat

Tertiary consumers – Fourth trophic level Carnivores; top predator (ex. : hawk, wolf, bear, etc. ) - eat secondary consumers - energy is used for maintenance, growth, or reproduction - some energy is passed out of the body as waste - energy lost as heat

Decomposers – fungi and bacteria - break down organic molecules from the ecosystem to obtain energy - some is lost as heat

Limits • Between each level energy is lost • This puts limits on the possible levels an ecosystem can have • Consuming meat is simply less efficient than consuming plants

Matter Cycling

The Origins of Matter • The first Law informs us that matter and energy are related: we may think of matter as frozen energy. • The most prevalent elements in the universe: – Hydrogen 98% – Helium 2% – Others (fraction of a percent) • The Stars are Matter Mill Houses

The Supernova – Stellar Alchemy • Nearly all the matter present on earth came from super nova remnants

Earth – A Closed System • Matter, essentially, does not enter or leave the earth • A miniscule amount enters from meteors. • Matter must be recycled by ecosystems. • Chemicals are cycled between organic matter and abiotic reservoirs.

Water Cycling

The Carbon Cycle

The Nitrogen Cycle

The Phosphorus Cycle

Finis