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Introducción al estudio de Ecología PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Ecología es el estudio científico de las interacciones entre los organismos y su ambiente • Estas interacciones determinan la distribución de los organismos y su abundancia Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • La ecología tiene una larga historia como una ciencia descriptiva • Y es también una rigurosa ciencia experimental Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Eventos que ocurren en tiempos ecológicos afectan la vida a escalas de tiempo evolutivo Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Los Organismos y el Ambiente • El ambiente de cualquier organismo incluye: – Componentes Abióticos – Componentes Bióticos • Todos los organismos que son parte de un ambiente constituyen su biota • Los componentes ambientales afectan la distribución y abundancia de los organismos Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-2 Kangaroos/km2 > 20 10–20 5–10 1–5 0.1–1 < 0.1 Limits of distribution Tasmania • Los ecólogos usan sus observaciones y experimentos para proponer explicaciones para la distribución y abundancia de las especies Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • La ecología organísmica estudia cómo la estructura de un organismo, su fisiología, y (en los animales) su comportamiento, se ajustan a cambios ambientales Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecología organísmica • La ecología de poblaciones se enfoca en los factores que afectan la cantidad de individuos de una especie que viven en la misma área Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-3b Ecología de Poblaciones • La ecología de comunidades estudia el conjunto de especies que interaccionan en una comunidad Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-3c Ecología de comunidades • La ecología de los ecosistemas hace énfasis en el flujo de energía y los ciclos químicos entre los componentes bióticos y abióticos Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecología de ecosistema • La ecología del paisaje estudia los ordenamientos de los ecosistemas en una región geográfica Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-3e Ecología del paisaje • La biosfera es el ecosistema global, la suma de todos los ecosistemas del planeta Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecology and Environmental Issues • Ecology provides the scientific understanding underlying environmental issues • Rachel Carson is credited with starting the modern environmental movement Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • La mayoría de los ecólogos sigue el principio de precaución respecto de los temas ambientales • Este establece que los humanos debieran sentirse afectados por cómo sus acciones afectan a su vez al ambiente Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 50.2: Interactions between organisms and the environment limit the distribution of species • Ecologists have long recognized global and regional patterns of distribution of organisms within the biosphere • Many naturalists began to identify broad patterns of distribution by naming biogeographic realms Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-5 Palearctic Nearctic Tropic of Cancer (23.5°N) Oriental Ethiopian Equator Neotropical (23.5°S) Tropic of Capricorn Australian • Biogeography is a good starting point for understanding what limits geographic distribution of species Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-6 Species absent because Yes Area inaccessible or insufficient time Dispersal limits distribution? No Behavior limits distribution? Yes No Habitat selection Biotic factors (other species) limit distribution? Yes Predation, parasitism, Chemical competition, disease factors Water Oxygen Abiotic factors Salinity No limit pH distribution? Soil nutrients, etc. Temperature Physical Light factors Soil structure Fire Moisture, etc. Dispersal and Distribution • Dispersal is movement of individuals away from centers of high population density or from their area of origin • Dispersal contributes to global distribution of organisms Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Natural Range Expansions • Natural range expansions show the influence of dispersal on distribution Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-7 New areas occupied Year 1996 1989 1974 Species Transplants • Species transplants include organisms that are intentionally or accidentally relocated from their original distribution • Species transplants can disrupt the communities or ecosystems to which they have been introduced Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Behavior and Habitat Selection • Some organisms do not occupy all of their potential range • Species distribution may be limited by habitat selection behavior Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biotic Factors • Biotic factors that affect the distribution of organisms may include: – Interactions with other species – Predation – Competition Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-8 100 Sea urchin Seaweed cover (%) 80 Both limpets and urchins removed Only urchins removed 60 Limpet 40 Only limpets removed Control (both urchins and limpets present) 20 0 August 1982 February 1983 August 1983 February 1984 Abiotic Factors • Abiotic factors affecting distribution of organisms: – Temperature – Water – Sunlight – Wind – Rocks and soil Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Temperature • Environmental temperature is an important factor in distribution of organisms because of its effects on biological processes Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Water • Water availability in habitats is another important factor in species distribution Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sunlight • Light intensity and quality affects photosynthesis • Light is also important to development and behavior of organisms sensitive to photoperiod Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Wind • Wind amplifies effects of temperature by increasing heat loss from evaporation and convection • Wind can change morphology of plants Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Rocks and Soil • Many characteristics of soil limit distribution of plants and thus the animals that feed upon them: – Physical structure – pH – Mineral composition Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Climate • Four major abiotic components of climate: temperature, water, sunlight, and wind • Climate is the prevailing weather in an area • Macroclimate consists of patterns on the global, regional, and local level • Microclimate consists of very fine patterns, such as those encountered by the community of organisms underneath a fallen log Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Global Climate Patterns • Global climate patterns are determined largely by solar energy and the planet’s movement in space Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Sunlight intensity plays a major part in determining the Earth’s climate patterns Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-10a North Pole 60°N Low angle of incoming sunlight 30°N Tropic of Cancer Sunlight directly overhead at equinoxes 0° (equator) Tropic of Capricorn 30°S Low angle of incoming sunlight 60°S South Pole Atmosphere • Seasonal variations of light and temperature increase steadily toward the poles Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-10b 60°N 30°N June solstice: Northern Hemisphere tilts toward sun; summer begins in Northern Hemisphere; winter begins in Southern Hemisphere. 0° (equator) March equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight and 12 hours of darkness. 30°S Constant tilt of 23.5° September equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight and 12 hours of darkness. December solstice: Northern Hemisphere tilts away from sun; winter begins in Northern Hemisphere; summer begins in Southern Hemisphere. • Global air circulation and wind patterns play major roles in determining climate patterns Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-10c 60°N 30°N Descending dry air absorbs moisture 0° (equator) 30°S 60°S .5° 30° 23 Arid zone Ascending moist air releases moisture 0° Tropics Descending dry air absorbs moisture 23.5° 30 ° Arid zone LE 50-10d Westerlies Arctic Circle 60°N 30°N Northeast trades Doldrums Southeast trades 0° (equator) 30°S Westerlies 60°S Antarctic Circle Regional, Local, and Seasonal Effects on Climate • Various features of the landscape contribute to local variations in climate • Seasonal variation also influences climate Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bodies of Water • Oceans and their currents and large lakes moderate the climate of nearby terrestrial environments Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Mountains • Mountains have a significant effect on – The amount of sunlight reaching an area – Local temperature – Rainfall Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-12 Wind direction East Pacific Ocean Coast Range Sierra Nevada Seasonality • The angle of the sun leads to many seasonal changes in local environments • Lakes are sensitive to seasonal temperature change and experience seasonal turnover Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 0 4 8 Spring Winter O2 (mg/L) 12 8 16 2° 4° 4° 4° 4°C 24 O2 concentration 0° 4° 4° Lake depth (m) Lake depth (m) LE 50-13 O2 (mg/L) 0 4 8 12 8 16 24 4° 4° 4° 4°C High (>8 mg/L) Medium (4–8 mg/L) O2 (mg/L) 0 4 8 12 8 4° 22° 20° 18° 8° 6° 5° 4°C 4° 4° 4° 4°C 16 24 4° Autumn Thermocline Summer Lake depth (m) Lake depth (m) Low (<4 mg/L) O2 (mg/L) 0 8 16 24 4 8 12 Microclimate • Microclimate is determined by fine-scale differences in abiotic factors Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Long-Term Climate Change • One way to predict future global climate change is to study previous changes Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-14 Current range Predicted range Overlap 4.5°C warming over next century 6.5°C warming over next century Concept 50.3: Abiotic and biotic factors influence the structure and dynamics of aquatic biomes • Varying combinations of biotic and abiotic factors determine the nature of biomes • Biomes are the major ecological associations that occupy broad geographic regions of land or water Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Aquatic biomes account for the largest part of the biosphere in terms of area • They can contain fresh water or salt water • Oceans cover about 75% of Earth’s surface and have an enormous impact on the biosphere Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-15 30°N Tropic of Cancer Equator Tropic of Capricorn Continental shelf 30°S Key Lakes Rivers Estuaries Coral reefs Oceanic pelagic zone Intertidal zone Abyssal zone (below oceanic pelagic zone) • Many aquatic biomes are stratified into zones or layers defined by light penetration, temperature, and depth Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-16a Littoral zone Limnetic zone Photic zone Benthic zone Zonation in a lake Pelagic zone Aphotic zone LE 50-16b Intertidal zone Neritic zone 0 Oceanic zone Photic zone 200 m Continental shelf Pelagic zone Benthic zone 2,500–6,000 m Abyssal zone (deepest regions of ocean floor) Marine zonation Aphotic zone • Major aquatic biomes: – Lakes – Wetlands – Streams and rivers – Estuaries – Intertidal zones – Oceanic pelagic biome – Coral reefs – Marine benthic zone Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Video: Clownfish and Anemone Video: Coral Reef Video: Flapping Geese Video: Hydrothermal Vent Video: Shark Eating a Seal Video: Tubeworms Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 50.4: Climate largely determines the distribution and structure of terrestrial biomes • Climate is very important in determining why terrestrial biomes are found in certain areas Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Climate and Terrestrial Biomes • Climate has a great impact on the distribution of organisms, as seen on a climograph Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LE 50-18 Desert Temperate grassland Tropical forest Annual mean temperature (°C) 30 Temperate broadleaf forest 15 Coniferous forest 0 Arctic and alpine tundra –15 100 200 300 Annual mean precipitation (cm) 400 LE 50-19 30°N Tropic of Cancer Equator Tropic of Capricorn 30°S Key Tropical forest Savanna Desert Chaparral Temperate grassland Temperate broadleaf forest Coniferous forest Tundra High mountains Polar ice General Features of Terrestrial Biomes • Terrestrial biomes are often named for major physical or climatic factors and for vegetation • Stratification is a key feature of terrestrial biomes • Terrestrial biomes usually grade into each other, without sharp boundaries • The area of intergradation, called an ecotone, may be wide or narrow Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Major terrestrial biomes: – Tropical forest – Desert – Savanna – Chaparral – Temperate grassland – Coniferous forest – Temperate broadleaf forest – Tundra Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Video: Swans Taking Flight Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings