ecology 103g

determine health of an ecosystem based on its trophic pyramid

(also trophic pyramid, energy pyramid, or sometimes food pyramid) is a graphical representation designed to show the biomass or bio productivity at each trophic level in a given ecosystem.

Example of a survivorship curve

1.high age-specific survival probability in early and middle life, followed by a rapid decline in survival in later life. 2.curves are an intermediate between Types I and III, where roughly constant mortality rate/survival probability is experienced regardless of age 3.curves, the greatest mortality (lowest age-specific survival) is experienced early in life, with relatively low rates of death (high probability of survival) for those surviving this bottleneck

Parasitism

A relationship between two species in which one species (the parasite) nourishes itself to the disadvantage of the other species (the host)

Mutualism

A relationship where both species benefit from the relationship

Commensalism

A relationship where one species obtains food or shelter from the other species. Does not harm or help the other species

Survivorship curve definition

A survivorship curve is a graph showing the number or proportion of individuals surviving to each age for a given species or group (e.g. males or females). Survivorship curves can be constructed for a given cohort (a group of individuals of roughly the same age) based on a life table.

Trophic level 1

Green plants form the first trophic leve

understand the process of succession and be able to distinguish between primary and secondary types

Primary succession is the colonization of living organisms into an area that was not previously colonized by any living things. An example of this would be succession after a glacier recedes or after a new island forms from oceanic volcanoes.

explain the concept of bioaccumulation

The accumulation of a substance, such as a toxic chemical, in various tissues of a living organism

understand how survivorship curves relate to mortality rates

There are three types of survivorship curves: Type 1, 2 and 3. Mortality rates are a part of type 1 and 3.

how energy flows from one trophic level to another

Trophic levels are the feeding position in a food chain such as primary producers, herbivore, primary carnivore, etc

Example of a community

a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community

Definition of a community

a group of people living in the same place or having a particular characteristic in common

Example of secondary succession

include areas which have been cleared of existing vegetation (such as after tree-felling in a woodland) and destructive events such as fires.

Symbiosis

is a close relationship between two or more different species.

criteria that are necessary for a forest to be considered old growth

is a forest that has attained great age without significant disturbance and thereby exhibits unique ecological features and might be classified as a climax community

give an example of how you determine if competition is occurring and how it affects community structure

is a form of competition in which individuals of different species compete for the same resource in an ecosystem (e.g. food or living space or natural recourse)

Food chain

is a linear sequence of links in a food web starting from "producer" species (such as grass or trees) and ending at apex predator species (like grizzly bears or killer whales

Gause's Competitive Exclusion Principle

is a proposition that states that two species competing for the same resource cannot coexist at constant population values, if other ecological factors remain constant. When one species has even the slightest advantage or edge over another then the one with the advantage will dominate in the long term. One of the two competitors will always overcome the other, leading to either the extinction of this competitor or an evolutionary or behavioral shift toward a different ecological niche. The principle has been paraphrased into the maxim

Primary succession

is the colonization of living organisms into an area that was not previously colonized by any living things. An example of this would be succession after a glacier recedes or after a new island forms from oceanic volcanoes.

Food web

is the natural interconnection of food chains and generally a graphical representation (usually an image) of what-eats-what in an ecological community

Secondary succession

is the regeneration of the living community after a major disturbance. For example, after a forest is clear-cut the trees are removed but some small plants, the soil, and soil organisms remain. The forest will slowly regenerate.

Example of primary succession

the formation of new islands, on new volcanic rock, and on land formed from glacial retreats

Mortality rates

the number of deaths in a given area or period, or from a particular cause

Trophic level 2

the producers. Herbivores form the second trophic level

Trophic level 3

while carnivores form the third and even the fourth trophic levels