Biol 301 1nd Edition Lecture 2 Outline of Last Lecture I. Population growth equationsII. Basic Ecological TerminologyIII. Approaches to studying EcologyIV. Other important basic informationOutline of Current Lecture I. Distribution of populationsII. Population characteristicsIII. Quantifying IndividualsIV. Dispersal LimitationsCurrent Lecture1) Distributions of populations –A. Spatial structure: the pattern of density and spacing of individuals in a population.B. Fundamental niche: the range of abiotic conditions (e.g., temperature, humidity, salinity)under which a species can persist.- Competitors, predators, and pathogens may prevent a population from persisting in an area.- Everywhere that it is possible for an individual to surviveC. Realized niche: the range of abiotic and biotic conditions under which a species can persist.- Where the species actually do exist, not just where they can, but where they doD. Geographic range: a measure of the total area covered by a population (e.g., temperature and drought define the range of sugar maple).E. Ecological niche modeling: the process of determining the suitable habitat conditions fora species.F. Ecological envelope: the range of ecological conditions that are predicted to be suitable for a species (differs from the realized niche, which describes conditions in which a species currently exists).- Predicting the potential geographic range of a species is difficult when only a few individuals exist; researchers can use historic distributions of species.2) Population Characteristics – A. Geographic range – where does the species occur?These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Endemic: species that live in a single, often isolated, location. Tortoises, - Cosmopolitan: species with very large geographic ranges that can span several continents.B. Abundance: the total number of individuals in a population that exist within a defined area (e.g., total number of lizards on a mountain).- The total abundance of a populations provides a measure of whether a population is thriving or on the brink of extinctionC. Density: in a population, the number of individuals per unit area or volume; calculated by dividing abundance by area.D. Dispersion: the spacing of individuals with respect to one another within the geographic range of a population.E. Clustered dispersion: when individuals are aggregated in discrete groups (e.g., social groups or clustering around resources).F. Evenly spaced dispersion: when each individual maintains a uniform distance between itself and its neighbors (e.g., defended territories, croplands).G. Random dispersion: when the position of each individual is independent of other individuals; not common due to non-random environmental heterogeneity.H. Dispersal: the movement of individuals from one area to another3) Quantifying Individuals – A. Census: counting every individual in a population.B. Area- and volume-based surveys: surveys that define the boundaries of an area or volume and then count all of the individuals in the space.C. Line-transect surveys: surveys that count the number of individuals observed as one moves along a line.- This data can be converted into area estimates of a population.D. Mark-recapture survey: a method of population estimation in which researchers capture and mark a subset of a population from an area, return it to the area, and capture a second sample of the population after time has passed.- Population size is estimated by assuming that:-E. Lifetime dispersal distance: the average distance an individual moves from where it was born to where it reproduces.4) Dispersal limitationA. Dispersal limitation: the absence of a population from suitable habitat because of barriers to dispersal.- Barriers often include large expanses of inhospitable habitat that an organism cannotcross (e.g., oceans, deserts).- Occasionally, organisms cross these barriers, such as the many species of plants and animals that colonized the Hawaiian Islands.- Humans have created barriers for dispersal (e.g., roads, forest clearings) and have assisted in the dispersal of many species.B. Habitat corridor: a strip of favorable habitat located between two large patches of habitat that facilitates dispersal (e.g., a narrow band of trees that connects