Unit 2: Ecology Chapter 2: Principals of Ecology

Ecology the study of interactions that take place between organisms and their environment Ecological Research – includes descriptive and quantitative techniques

Biosphere portion of the Earth that supports living things extends from high in the atmosphere to the bottom of the ocean diverse group of organisms in a wide range of climates living things – are affected by physical (non-living) things and other living things

The non-living environment – Abiotic Factors - Abiotic Factors – non- living parts of an organism’s environment Examples – air currents, moisture, light, and soil included in ecology because they are parts of an organisms life

The living environment – Biotic Factors Biotic Factors – all the living organisms that inhabit an environment Example – Fish Tank- other fish, plants, food? All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection Single individual only tells part of the story

Levels of Organization levels of the living world Population – group of organisms – all of the same species, which interbreed and live in the same area at the same time –sharing resources depends on how far apart organisms live –members may compete for food, water, mates, or other resources –competition increases when supplies are short

Biological Community made up of interacting populations in a certain area at a certain time change in one population may cause changes in other populations some changes minor, some extreme

Ecosystem made of interacting populations in a biological community and the communities abiotic factors both biotic and abiotic factors

Organisms Habitat – the place where an organism lives most of its life Niche – all strategies and adaptations a species uses in its environment –Foods –Shelter –Survival –Reproduction –2 species can not exist for long together if they share a niche

Survival Relationships Predator – type of consumer Organisms that eat other plants and animals Prey – the animals that predators eat Symbiosis – close and permanent relationship between organisms of two different species “symbiosis” – living together

3 types of symbiosis 1. Mutualism 2. Commensalism 3. Parasitism

1. Mutualism symbiotic relationship where both species benefit Ex- ants and acacia trees, ants protect the tree, and the tree provides nectar and a home

2. Commensalism symbiotic relationship in which one species benefits and the other is neither harmed nor benefited Ex – small mosses growing on large tree, moss benefits, tree is neither helped nor harmed

3. Parasitism symbiotic relationship where one species derives benefit at the expense of another species (host) Ex - tapeworms live in their hosts, causing harm if not death

Nutrition and Energy Flow How organisms obtain food –Ultimate source of energy for life = SUN –Plants use sun’s energy to manufacture food – photosynthesis

Autotrophs the producers an organism that uses light energy or energy stored in chemical compounds to make energy- rich compounds plants, green algae

Consumers depend on autotrophs for food –obtain nutrients by eating other organisms –Ex – cat eats a bird Heterotroph – an organism that can not make its own food and feeds on other organisms

Herbivore a heterotroph that feeds on only plants

Carnivore a heterotroph that feeds on other hetertrophs

Scavengers a heterotroph that does not kill for food, but rather feeds on animals that are already dead

Omnivores a heterotroph that feeds on both plants and animals

Decomposers break down complex compounds from dead and decaying plants and animals into simpler molecules that can easily be absorbed

The Flow of Matter and Energy Matter - carbon, nitrogen, and other elements that flow through ecosystems is recycled Cycle Matter – some trapped energy is transferred from one level to the next and the rest is lost to the environment

Food Chains pathway for matter and energy nutrients and energy are transferred from: Autotrophs  Heterotrophs  Decomposers Ex- Berries  mice  black bear The final energy is only a portion of what was available at the first level A portion is given off as heat at each level

Trophic Levels – feeding step Ecological Pyramid – show how energy flows through a system –Base = autotrophs = 1 st level –Higher levels = one on top of the other Pyramid of Energy – shows the energy decreases as the level increases

Pyramid of Energy Consumers 0.1% Consumers 1% Consumers 10% Producers 100%

Pyramid of Numbers Shows that population size decreases as the levels increases Fox(1) Birds(25) Grasshoppers(250) Grasses(3000

Biomass the total weight of living matter at each trophic level 1 Kg of Human Tissue 10 Kgs of beef 100 kg of grain

Matter cycled, but not replenished from the sun, like energy moves through and is part of every level constantly recycled, but never lost

The Water Cycle - life on earth continually depends on water water is cycled through stages water evaporates from lakes, ponds, and oceans and becomes water vapor in the air Condensation occurs – where water vapor in the air condenses on something – like on your soda can Water vapor condenses on dust in the air and forms clouds. It eventually will form drops that form as precipitation (rain) Plants pull water from the ground and lose water through their leaves (transpiration) Animal breath out water in their breath Perspiration and urination also return water

The Carbon Cycle Carbon – framework for proteins, carbohydrates, fats, and others Molecule of life During photosynthesis – carbon converted from carbon dioxide to energy-rich carbon molecules energy-rich carbon molecules used by organisms for food and energy When organisms used these molecules for energy, carbon is released back into the air Carbon cycles again

The Nitrogen Cycle - bacteria convert nitrogen in the air to a more suitable form in the soil plants use the nitrogen in the soil to make important molecules and proteins Herbivores eat the plants and convert the nitrogen into nitrogen-containing animal proteins Nitrogen is converted into proteins in the form of muscle cells, blood cells, enzymes and urine When an animal urinates or dies the nitrogen returns to the soil

The Phosphorus Cycle cycles in two ways 1. plants obtain phosphorus from the soil –Animals eat the plants –animals dies and phosphorus is returned to the soil 2. Phosphorus is washed into water –incorporated into rock –millions of years later – rock is exposed - rock erodes and phosphorus again becomes part of the system