Topic 13 Ecology - Class Note

Ecology study of how organisms react with the environment depending on biotic and abiotic factors Biotic factors animals, plants, fungi. protists Abiotic factors temperature, sunlight, wakr, soil These in kractions dekrmine. 1. geographic distribution of species (ex migration) abundance & diversity of organisms 2- 3 evolutionary processes Exspeciation, speciation, adaptive radiation) movement of energy materials. in living ecosystems (ex: nutrient recycling, primary 4. producers) s successional development of ecosystems (ex: a fire causing colonization of new. species) There are different levels of studying ecology organismal ecology, population ecology, community ecology (interactions between species: symbiasis, predation, etc), ecosystem ecology (nitrogen cycle in the environment), landscape ecology, and global ecology. Climate is the most important cause for the distribution of organisms; it's determined by light, wind, temperature, & precipitation. These factors influence wind currents and wakr currents. Solar energy causes variations and creates gradients of those factors. Wind can create ocean currents will cause the Eastern coasts to be warmer and the Western coast to be cooler Different types of ecosystems are called biomes (tropical rainforest, temperate rainforest, desert, tundra, taiga, grassland, savanna). They're classified based on their vegetation and in their physical properties they differ in temperature, precipitation, soil nutrient composition, and seasonal variation. Aquatic biomes are characterized by climate, salinity, etc and they're vertically and horizontally stratified. -The photic zone contains enough light for photosynthesis - The benthic zone is the ballam surface of the lake/ocean -The Pelagic zone, whose fish swim -The Limnetic zone is part of the photic zone & is farther away from the shore. Meromictic lakes are deep lakes that don't mix! There's no oxygen at the bellom and these lakes present thermoclines which are vertical temperature gradients. Holomictic lakes experience turnovers in the water which moves oxygenated surface wakr to the bottom and nutrient-rich bottom water rises to the top. Upwelling in oceans is caused by strong winds that move surface water & bring up nutrient-rich bottom waky causing an explosion in population sizes of dinoflagellates and other primary producers. Species distribution depends on their evolutionary history, abiotic factors, biotic factors Changing ecosystems alkus habits which increases speciation (ecological Changing ecosystems allers habitats which increases speciation (ecological Speciation): different populations adapt to different environments & they may live together in sympatry or allopatry. Species richness depends on it more speciation events occur or if more extinchon events occur 3 hypotheses to explain a latitudinal gradient in species richness: more solar energy around the tropics leads to higher productivity, less variation in temperature, longer growing seasons. - less seasonal changes around the tropics leads to niche specialization: a lot of competition will lead to smaller niches that will cause specialization (because Inkase competition will reduce the fitness of individuals that I use the same resources) Individuals will now be better able to exploit resources kads to resource partitioning (using specific resources) and ultimately increase diversity. Glaciation events in the ice age caused tempera regions to undergo many changes whereas tropical regions have remained stable tun-distributed, reduced. extinction rak tropics. breaker land mass in the Northern hemisphere may also explain the uneven distribution. of species. Organisms can be classified on how specialized they are generalists (use wide variety of resources), and specialists (use narrow range of resources) Acclimatization refers to reversible, short-term physiological adjustments due to environmental stress, it occurs during the organism's lik time, not across generations. If there's an increase seen in any acclimatized trait across generations then its adaptation (acclimation & acclimatization; these are 2 different tarms!). Species dispersal has limitations regarding bialic factors, abiatic factors, and the species own limitations such as its ability to adapt, etc. Interspecific interactions: