1 Exam 4 BSC2011 Ecology can be studied physiologically or behaviorally Studied at many different levels or organization Example Characteristics that allow kangaroos to live in certain Interaction between species All species as well as nonliving things Example how does altering environment affect Kangaroo pop o Individual areas o Population o Community o Ecosystem Multiple ecosystems o Landscape o Biosphere Planet Ecology the study of factors influencing the distribution and abundance of organisms interaction between organisms and the environment what things determine which species live where The darker the shading the more kangaroos there are in that location Red kangaroos are mostly in semiarid and arid regions of the interior where precipitation is less variable from year to year This may look abiotic because of the precipitation however could be biotic because climate can influence pathogens diseases predators and food availability Biotic Factors Other factors than climate can influence abundance and distribution 2 o Pink line both removed from environment showed the greatest increase in seaweed growth o Blue line only sea urchins removed from environment o The slope of the line is due to the increasing algae growth which increases dramatically o Bottom red and green lines almost no seaweed growth when both species were present or where only limpets were removed from environment o This illustrates the community level of ecology or the interaction between species The results show that both species had some sort of influence on the seaweed distribution but sea urchins had a much greater effect than limpets in limiting seaweed distribution because removing urchins only had a greater increase in growth while removing limpets had little effect Amount of Solar energy is a major influence on climate Since solar energy influences the climate it influences the distribution of plants and animals as well since they are influenced by climate The more direct the sunlight the more constantly warm the climate is When the sun hits the earth at 90 degrees it covers more surface area as seen in the two bands at the north and south pole Climate can also be affected by regional local effects 3 o Seasonality o Large bodies of water o Mountain ranges Solar Radiation varies seasonally Earth orbiting around the sun on an axis global changes in the day length solar radiation and temperature Reason for seasonality because earth is not perpendicular but rather on an axis to the sun However since the equator gets a 90 degree angle all the time at any point in the axis it is always warm there Surface heating drives air circulation The sun drives the movement of the air warm air can hold more moisture than cold air lands heats up faster than water same goes for the air above them Warm air raises then cools and falls which result in rain In some places the warmer tropical seasons rainy days regularly Coastal regions are generally wetter than inland areas of the same latitude 4 Once the air rises and sinks it cant keep going up and down the whole time it has to also circulate move sideways as well The high temperatures in the tropics evaporate water from earth s surface and cause warm wet air masses to rise and flow towards poles The rising air masses release much of their water content creating abundant precipitation in tropical areas As earth rotates on its axis and near the equator moves faster than at the poles deflecting the winds from the vertical paths and creating more easterly and westerly flows Cooling trade winds blow from east to west in the tropics prevailing westerlies blow from west to east in temperate zones Effects of water on climate Is land is close to a large body of water o Water holds a lot of heat which makes it harder to cool down but harder to warm up as well o Therefore water acts as a buffer to prevent it from getting too hot or too cold since its takes a lot more energy time to heat or cool water down Rain shadows Air comes from off the ocean it cools then rises to form the cloud then is released as rain or snow The leeward side where the cloud is casting the shadow is much drier less precipitation that can usually lead to a desert Zones in the ocean 5 Benthic zone seafloor below surface waters of the coastal zone high in oxygen gas soft sediments invertebrate fish seaweed Coral reef formed largely from calcium carbonate skeletons or corals in the photic zone high levels of O2 fishes and algae Biomes Type of community you have in certain environments even though species might differ the environment is somewhat the same Major life zones characterized by vegetation type terrestrial biome or by the physical environment aquatic biomes 6 Based on annual averages could be consistent or have wet dry seasons 2 main factors that influence environment in different locations water temperature Tropical Rainforest Warm and rainy 200 400 cm all year round highly seasonal Tall trees complex community many different species Estuaries and subequatorial regions Highly layered trees emergent tress closed canopies canopy sub canopies shrubs and herbs Desert 30 degrees north or 30 degrees south from the equator Extremely dry precipitation low and variable Widely scattered plants snakes insects lizards rodents Temperate Broadleaf Forest Midlatitudes in the northern hemisphere 70 200 cm rainfall annually Distant vertical layers canopy strata of understory trees shrubs herbs Mammals birds insects Habitat that is inundated by water at least some of the time and that supports Lakes Wetland Standing bodies of water Light clarity decreases with depth plants adapted to water saturated soil Decrease in dissolved oxygen Most productive biome on earth Streams Rivers Have a current Downstream Tributaries River Headwaters rich in oxygen gas Diversity of fishes and invertebrates 7 Estuaries Transition area between river and sea seawater flows up the estuary channel during high tide then flows back down during a falling tide Grasses and algae Abiotic and Biotic factors influence density distribution size and age structure of a population Density number of individuals per unit area or volume of trees per km Dispersion pattern of spacing among individuals within boundaries of the population Mark Recapture Method Hector s Dolphins Method to describe population in terms of boundaries and size Population Group of individuals of a single species living in the same general area rely on the same resources influenced by
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