A person travels by car from one city to another with dif-ferent constant speeds between pairs of cities. She drivesfor 30.0 min at 80.0 km/h, 12.0 min at 100 km/h, and45.0 min at 40.0 km/h and spends 15.0 min eating lunch and buying gas. (a) Determine the average speed for thetrip. (b) Determine the distance between the initial andfinal cities along the route.
2/29 – Energy and Ecosystems NPP = GPP – R o Net Primary Productivity = Gross Primary Productivity – Respiratory o NPP – the stored energy in an organism. o GPP – all of the energy that an organism takes in. o R – the energy that is wasted/not used or stored. Chemical energy gained from other organisms decreases as it travels up the food chain; organisms in higher trophic levels receive less energy from the food they consume than organisms in lower trophic levels. o There’s an enormous loss at each trophic level. The unequal distribution of resources helps create biodiversity. Energy use is inefficient and most of the energy is lost, but nutrients are cycled. Nutrients can travel between ecosystems. Species deal with global change in different ways: o Migration o Evolutionary adaptation o Phenology or behavioral shifts in lifetime o Extinction 3/2 – Island Biogeography Biogeography – study of where species are found. Theory of Island Biogeography – predicts island species richness (number of species). The predicted number of species is where immigration and extinction are equal. Large vs Small islands: o Large islands can hold a lot of species (high immigration rate) and have more resources and habitats, which create less competition (low extinction rate). o Small islands can only hold a few species (low immigration rate) and have less resources and habitats, which creates competition (high extinction rate). Near vs Far islands: o Islands closer to the mainland tend to have more gene flow (high immigration rate), which helps replace the species that have gone extinct (low extinction). o Islands further from the mainland have very little gene flow (low immigration rate); therefore, the species that have gone extinct are not able to be replaced (high extinction rate). Types of islands: o Oceanic – formed from a volcanic eruption in the ocean. Pants, bird, and insects are normally native o Continental – broke off of a large piece of land. Land mammals, reptiles, amphibians, and freshwater fish are normally native. The organisms’ ability to travel onto the island dictates which animals are native to each type of island. Species on small distant islands are more likely to go extinct because they tend to be endemic (only live in one place). Words to Know Biogeochemical Cycle Global Warming Primary Producer/Autotroph Biogeography Gross Primary Productivity (GPP) Secondary Consumer Biomagnification Habitat Islands Species Diversity Biomass Net Primary Species Richness Continental Island Productivity (NPP) Tertiary Consumer Decomposer Oceanic Island Theory of Island Endemic Phenology Biogeography Food Chain Physiology Top-Down Control Food Webs Primary Consumer Watershed Global Nitrogen Cycle