Ecology and Organisms PDF

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Bio 141, Textbook: Biological Science chapter 49, Teacher: Eladio Abreu...

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49: Ecology - Ecology: the study of how organisms interact with each other and their environment - Understanding the distribution and abundance of organisms - Researchers work at five levels: organisms, populations, communities, ecosystems, and biosphere - Conservation biology: the effort to study, preserve, and restore threatened genetic diversity in population, species diversity in communities and ecosystem function Each Type - Organismal Ecology - The morphological, physiological and behavioral adaptation that allow individuals to live in a particular area - How individuals interact with their physical surroundings and with other organisms - Population Ecology - Population: a group of individuals of the same species that live in the same area at a time - Focus on how the number and distribution of individuals in populations change over time - Community Ecology - Community: population of different species that interact with each other within an area - Focuses on the nature of the interactions between species and their consequences - Concentrate on predation, parasitism, competition, and natural disturbances and disasters - Ecosystem Ecology - Ecosystem: consists of all the organisms in a particular region along with nonliving components (abiotic) - Study how nutrients and energy move among organisms and through the surrounding atmosphere and soil or water - Global Ecology - Biosphere: thin zone surrounding the Earth where all life exists - Try to quantify the effects of human impacts on the biosphere 49.2: What Determines the Distribution and Abundance of Organisms - Biogeography: the study of how organisms are distributed geographically - Abiotic Factors - No one species can survive the full array of environmental conditions present on earth - Temperature has an impact on the physiology of organisms because organisms can’t control their own temperatures - Due to fitness trade-offs - Organisms are adapted to a limited set of abiotic conditions - Niche: range of conditions that a species can tolerate and the range of resources it can use - Biotic Factors - The ability of a species to persist in a given area is limited by biotic factors - interactions with other organisms - Competition - niches that a species could occupy is actually smaller due to competition - The distribution of organisms is determined not only by present conditions but also events in the past - The abiotic and biotic factors that influence the distribution of organisms are dynamic and change

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over time - Mountains rise and fall, islands and lakes disappear, continental drift, plate tectonics, climate change (sea level rise) - Dispersal: the movement of individuals from their place of origin to the location where they live and breed as adults - Exotic species: one that is not native - Can become an invasive species - competes successfully with native species Biotic and abiotic factors interact to determine the distribution and abundance of organisms - Factors that occured in the past and in the present - The range of particular species depends on the capacity to survive climatic conditions, the ability to find food and avoid being eaten, and the ability to disperse

49.3: Climate Patterns - Species are adapted to the abiotic conditions present where they live - The climate and weather - Most organisms are found near the equator rather than the poles because it gets the most sunlight → most energy absorbed -

Seasons - regular, annual fluctuations in temperature and precipitation - Occurs because of earth's tilt Climate patterns are dictated by global heating patterns, air circulation cells, and seasonality - Due to the presence of mountain ranges and proximity to an ocean - Mountains → the movement of air -

Oceans → water has a high specific heat - absorb heat from the atmosphere

49.4: Types of Terrestrial Biomes - Biomes: regions characterized by distinct abiotic characteristics and dominant types of vegetation - Forests, deserts, grasslands, and tundra - Each terrestrial biome is associated with a specific set of abiotic conditions determined by climate - Temperature, moisture, sunlight, and wind - Temperature and moisture are most important in determining plant distribution and abundance - The nature of a terrestrial biome that develops is governed by: - Average annual temperature and precipitation - Annual variation in temperature and precipitation - Net Primary Productivity (NPP): the total amount of biomass generated by the fixation of carbon per year minus the amount that is oxidized during cellular respiration - Biomass: total mass of organisms - Represents the organic matter that is available as food for other organisms - Aboveground Biomass: total mass of living plants (excluding roots) - Six terrestrial biomes: arctic tundra, boreal forest, temperate forest, temperate grassland, subtropical desert, and tropical wet forest - Humans are impacting the earth's biomes in majorly significant ways - Biologists use four tools to make predictions about the earth

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Simulation studies, observational studies, historical studies, and experiments

49.5: Types of Aquatic Biomes - 70 percent of earth's surface is covered in water - Abiotic factors that distinguish streams from oceans: salinity, water depth, water flow, nutrient availability - Salinity - Water is an excellent solvent - when it rains the water picks up solutes in streams which lead into the oceans - Water evaporated from the ocean but the solutes stay - high concentration - Proportion of solutes dissolved in water determines its salinity - Grams of solute per kilogram of water - Ocean is extremely saline - the salt - Water depth - Water absorbs and scatters light - wavelengths available to organisms changes with depth - Light availability has a major effect on productivity - Water flow - Water has a physical force - can literally sweep organisms away - Can be harmful to downstream organisms - Nutrient Availability - The scarcity of nutrients limits growth rates in photosynthetic organisms that provide food for other species - Water flow can carry nutrients to come areas - Coastal runoff, ocean upwelling, lake turnover - Humans often treat aquatic biomes as unlimited resources, causing both direct and indirect changes to their physical, chemical, and biotic properties...