Population Ecology and the Distribution of Organisms Paige, Erica, Sierra, Vanessa

Ecology Ecology: the study of the relations of organisms to one another and to their physical surroundings. The different types of ecology: Global ecology-regional exchange of energy and materials that influences the functioning and distribution of organisms across the biosphere Population-Analyzes factors that affect population size and how and why it changes through time Landscape-focuses on the factors controlling exchange of energy, material, and organisms across multiple ecosystems. Ecosystem -emphasizes energy flow and chemical cycling between organisms and the environment Community -Examines how interactions between species, such as predation and competition, affect community structure and organization. Organism -Concerned with how an organism's structure, physiology and behavior meet the challenges posed by its environment

Earth’s Climate Influences the Structure and Distribution of Terrestrial Biomes Factors that contribute to the different biomes: Seasons Bodies of water Air circulation

Different Biomes Biomes-any of the world's major ecosystems depending on vegetation for land biomes and physical environment for aquatic biomes 2 factors that make each biome different is temperature and rainfall Types of biomes: Tropical rainforest Savanna Desert Chaparral Tundra

The Exponential & Logistic Models Exponential: No carrying capacity and grow at rapid rate Logistic: Starts growing at exponential rate but will slow down. Has a carrying capacity

Interactions Between Organisms and the Environment Limit the Distribution of Species The distribution of species may be limited by Dispersal-movement of individuals or gametes away from their area of origin or of areas of high population density. biotic (living) factors- like other species (predator & prey) abiotic (physical) factors-temperature extremes, salinity and water availability Patterns of Dispersion

Population Density and Demography Population density- the number of individuals per unit area or volume- reflects the interplay of births, deaths, immigration, and emigration. Increase population: births and immigration. Decrease Population: deaths and emigration Demography-the study of the vital statistics of populations and how they change over time Types of graphs and charts that show/represent demography: Survivorship curves Life tables Reproductive tables

Survivorship Curve Type I- low death rates at the beginning years of life and then drops steeply as death rates increase at older age Type II- constant death rates throughout the organism's life Type III- high death rates among young and low death rates among the older that survive

Population Dynamics are Influenced Strongly by Life History Traits and Population Density Life history traits: evolutionary outcomes that are reflected in development, physiology and the behavior of organisms. Density-dependent changes in birth and death rates curb population increase through negative feedback. Density-dependent limiting factors: intraspecific competition for limited food or space increased predation disease intrinsic physiological factors Build up of toxic substances Metapopulation: a group of populations linked by immigration and emigration

Key Concepts Earth's climate influences the structure and distribution of terrestrial biomes Aquatic biomes are diverse and dynamic systems that cover most of the earth Interactions between organisms and the environment limit the distribution of species

Key Concepts Cont. Dynamic biological process influence population density, dispersion, and demographics The exponential and logistic models describe the growth of populations Population dynamics are influenced strongly by life history traits and population density

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BYE