Ecology and Environment

• Ecology is the study of the abundance of plants, animals, bacteria, fungus and other organisms as well as their distribution and environmental interactions with each other.
• The environment consists of all the biotic and abiotic components that surround an organism.
• The cowbird egg usually hatches earlier and the larger newborn cowbird may monopolize the food resources.
• Cowbirds lay eggs in the nests of other smaller birds and therefore do not have to expend energy building their own nest.
• Biotic or living parts of the environment include plants, animals and other organisms.
• Abiotic or non-living parts of the environment include physical and chemical parts such as temperature, light, water, nutrients or concrete.
• Ecologists focus their research on one of four categories: organism, population, community, and ecosystem.
• A habitat is a specific set of biotic and abiotic characteristics in which individuals of a species thrive.
• An ecological niche is a task an organism plays in the habitat.
• Succession is the process of successive change in species composition over time in an ecosystem.
• Primary succession occurs where no living species were previously found.
• Secondary succession occurs when patches of a community are distributed by fire, flood or logging.
• Population is a group of individuals of the same species living in the same geographical area, and usually able to breed together.
• Density is the number of individuals per unit area or volume represented by Dp.
• Dispersion is the pattern of spacing among individuals within the boundaries of the population.
• Density is the result of an interplay between processes that add individuals to a population and those that remove individuals.
• Environmental and social factors influence spacing of individuals in a population.
• There are three major population dispersion factors: nearly uniform, random, and clumped.
• A uniform dispersion is one in which individuals are evenly distributed and may be influenced by social interactions such as territoriality.
• In a random dispersion, the position of each individual is independent of other individuals.
• In a clumped dispersion, individuals aggregate in patches and this dispersion may be influenced by resource availability and behavior.
• Transect sampling, quadrat sampling, and mark-recapture sampling are techniques used to estimate a population and calculate a population density.
• Endoparasites live inside the body of their host.
• Commensalism is a symbiotic relationship in which one organism benefits and the other is not affected.
• Fundamental niche is the biological characteristics of the organism and the set of resources individuals in the population are theoretically capable of using under ideal conditions.
• Macroparasites are larger organisms, such as tapeworms, fleas, and lice.
• Realized niche is the biological characteristics of the organism and the resources individuals in a population actually use under the prevailing environmental conditions.
• Exploitative Competition involves consumption of shared resources by individuals of different species, where consumption by one limits the resource availability to the other species.
• Predation is an interspecific interaction by which population density of one species (predator) increases while population density of other species (prey) declines.
• Interference Competition involves aggression between individuals of different species who actually fight over the same resource(s).
• Social parasites manipulate the social behavior of another species so that they can complete their life cycle.
• Parasitism is a symbiotic relationship in which one organism benefits at the expense of another organism which is usually harmed.
• Ectoparasites live and feed on the outside surface of their host.
• Mutualism is a symbiotic relationship in which both species benefit.
• Microparasites are microscopic in size with rapid reproduction rate, causing diseases such as malaria.
• Lion's niche includes what it eats, what eats it, the way it reproduces, the temperature range it tolerates, its habitat, behavioral responses, and all other factors that can describe its pattern of living.
• Symbiosis is a relationship between individuals of two different species where at least one of the two species benefits.
• Equilibrial Life History, also called K-selection, is found in populations near their carrying capacity and populations living in relatively stable environments.
• Human population dynamics show that the human population was 300,000 in 0 C.E., 1000 C.E. had a population of 10,000,000, 1800 C.E. had a population of 1,000,000,000, and 1927 C.E. had a population of 2,000,000,000.
• An organism’s ecological characteristics, including use of and interaction with abiotic and biotic resources within its environment, describes a pattern of living.