Energy Production: Primary production, Gross primary production, Net primary production

The term ecosystem was first used by Tansley (1935) to refer to all the components of an ecological system, biotic and abiotic, that influence the flow of energy and elements. The ecosystem concept integrates ecology with other disciplines such as geochemistry, hydrology, and atmospheric science. Primary production is the chemical energy generated by autotrophs during…

Honey & Antibiotic Properties: Manuka & Ulmo

Historically, honey has been used by humans to treat a variety of ailments through topical application, but only recently have the antiseptic and antibacterial properties of honey been chemically explained. Hydrogen peroxide is formed in a slow-release manner by the enzyme glucose oxidase present in honey. It becomes active only when honey is diluted, requires…

Mutualism and Commensalism

Positive interactions occur when neither species is harmed and the benefits of the interaction are greater than the costs for at least one species. Facilitation is a synonym for positive interactions. Mutualism: Mutually beneficial interaction between individuals of two species (+/+). Commensalism: Individuals of one species benefit, while individuals of the other species do not…

Ecology: Population Distribution and Abundance

Distribution: Geographic area where individuals of a species occur. Abundance: Number of individuals in a given area. Ecologists try to understand what factors determine the distribution and abundance of species. Populations are dynamic—distribution and abundance can change over time and space. ***Understanding the factors that influence these dynamics helps us manage populations for harvest or…

Life History: Diversity, Reproduction, K vs. R species, Tradeoffs

An organism’s life history is a record of events relating to its growth, development, reproduction, and survival. Life history characteristics include: Age and size at sexual maturity. Amount and timing of reproduction. Survival and mortality rates. Life History Diversity Individuals within a species show variation in life history traits due to genetic variation or environmental…

Evolution & Ecology: Natural selection, Gene flow, Speciation, Drift

Humans have a large impact on the environment—pollution, land use change, climate change, etc. We are just beginning to realize that we also cause evolutionary change, and the consequences of this. Ecology and evolution are strongly interconnected. What Is Evolution? Evolution can be viewed as genetic change over time or as a process of descent…

Coping with Environmental Variation: Temperature and Water

The physical environment influences an organism’s ecological success in two ways: Availability of energy and resources—impacts growth and reproduction. Extreme conditions can exceed tolerance limits and impact survival. Energy supply can influence an organism’s ability to tolerate environmental extremes. The actual geographic distribution of a species is often lower than potential distribution due to other…

Forms of Sexual Contraception & Types of Abortion

Contraception Combination Pill: Birth control pills that contain a combination of estrogen and progestin (progesterone) (21 days on, 7 placebo) The pill works by preventing ovulation; keeps estrogen high inhibits LSH and no ovulation; high progesterone inhibits LH . Keep endometrium lining thick and prevents sperms from effectively travelling Failure Rate: percentage of women who…