Reproductive Strategies, Species Transplants

SBI4U – Grade 12 AP Biology – Ecology Test Population Population Size = (Birth Rate + Immigration) – (Death Rate + Emigration) ÷ (n) 100 Reproductive Strategies Sea turtles large offspring , low survival rate Mammals small offspring, parental involvement high survival rate **density dependent Intraspecific Factors (within a species) – diseases**, human intervention, pests* and competition** for: food, shelter, mates Interspecific Factors – competition**, human intervention & predators** Ecosystems Niche a species has a number of variables that affect it and it affects a 3D space that includes all variables the species requires and affect Herbivore – animals that eat vegetation Carnivore – animals that eat other animals Omnivore – animals that eat both vegetation and other animals Symbiotic relationships – two species living together Mutualism (both benefit) Parasitism ( 1 benefits as the other loses) Commensalism (one benefits as the other is unaffected) Food Chains, Food Webs and Food Pyramids Biotic Factors Factors that affect the distribution of organisms include Interactions with other species Competition Predators Dispersal Movement of individuals away from centers of high population density or from their area of origin Contributes to global distribution of organisms Species transplants Organisms that are intentionally or accidentally relocated from their original distribution Disrupt the communities or ecosystems to which they have been introduced Endemic species —> local Transplanted species —> from another area Invasive —> if it spreads without predator Behavior and Habitat Selection Some organisms do not occupy all of their potential range Species distribution may be limited by habitat selection behavior Habitats Lakes Oligotrophic LakesNutrient-poor and generally oxygen-rich Eutrophic Lakes nutrient-rich and frequently oxygen-depleted if covered in ice in the winter The shallow, well-lit littoral zone is home to floating and rooted aquatic plants. Wetlands A habitat that is covered by water most of the time and that supports plants adapted to water-saturated soil Can develop in shallow basins, along flooded river banks, or on the coasts of large lake and seas Streams and Rivers Physical characteristic is current Estuaries A transition area between river and sea Nutrient rich and highly productive Intertidal Zones Periodically submerged and exposed by the tides Challenged by variations in temperature and salinity and by mechanical forces of wave action Oceanic Pelagic Zone A vast kingdom of open blue water, constantly mixed by wind-driven oceanic currents Covers approximately 70% of Earth’s Surface Coral Reefs Formed from the calcium carbonate skeletons of corals Phylum cnidaria Require a solid substrate for attachment Water can act like a temperature regulator in coral ecosystems Marine Benthic Zone Consists of the seafloor below the surface waters of the coastal, or neritic, zone and the offshore pelagic zone Organisms in the abyssal, zone are adapted to continuous cold and extremely high water pressure Terrestrial Ecosystems The ecotone is the area of integration between terrestrial biomes Canopy – the top layer of a forest, and it can have many layers Tropical Forests Tropical rainforests Rainfall is relatively constant Tropical dry forests Precipitation is highly seasonal Vertically layered and competition for light is intense Desert Precipitation- low and high variable May be hot or cold Desert plants Adapted for heat and drought tolerance, water storage, and reduced leaf surface area Savanna Precipitation and temperature are seasonal Chaparral Climate Highly seasonally Cool and rainy winters and hot dry summers Dominated by shrubs, small trees, grasses, and herbs Adapted to fire and drought Animals that look for food have to search in distinctive way Temperate Grassland Found on many continents Climate Winters are cold and dry Summers are wet and hot Dominated plants, grasses and shrubs Adapted to droughts and fire Northern Coniferous Forest Extends across North America and Eurasia Largest terrestrial biome on Earth Climate Winters are cold and long Summers may be hot Pointed shape of conifers prevents too much snow from accumulating and breaking their branches Temperate Broadleaf Forest Climate Winters are cool Summers are hot and humid Major precipitation falls year round as rain and snow Vertical layers dominated by deciduous trees in the Northern Hemisphere and ever green eucalyptus in Australia Mammals hibernate in the winter, Northern Hemisphere Tundra Expansive areas of the Arctic Alpine tundra exists on high mountaintops at all latitudes Low levels of oxygen Climate Winters are long and cold Summers are relatively cool Precipitation varies Permafrost – permanently frozen layer of soil, prevents water infiltration Vegetation is herbaceous and supports birds, grazers and their predators