Transcript Document
Welcome to Ecology! Chapter 3 IN PEARSON book “The trouble with ecology is that you never know where to start because every thing affects everything else.” – Robert Heinlein “Farmer in the Sky” Biological Sciences Ecology Physical Sciences Earth Sciences “As an area of scientific study, ecology incorporates the hypotheticodeductive approach, using observations and experiments to test hypothetical explanations of ecological phenomena… ecologists face extraordinary challenges in their research because of the complexity of their questions, the diversity of their subjects and the large expanse of time and space over which studies must be conducted. Ecological questions from a continuum with those from other areas of biology, including genetics, evolution, physiology and behavior, as well as those from other sciences, such as chemistry, physics, geology and meteorology. “ Brainstorm session What does “bio” mean? What does “eco” mean? What do you think we are going to study in ecology? What were some examples of ecology concepts in the movie: The Future of Food? Ecology CO O 2 Ecology is the study of the relationships between organisms and their physical and biotic environment: “Organisms respond to their environments and can also change their environments, producing and ever changing, dynamic biosphere”. – pg 65 Nutrients 2 Learning Goals for this Unit • Recognizing the various levels of ecological organization • Explain matter and energy’s interdependence in nature. • Understanding how organisms get the energy the need to survive; looking at food chains and food webs • Describing how nutrient availability relates to the primary productivity • Understanding a producers means of obtaining energy through photosynthesis • Explaining how ATP is useful in cells Ecological Levels of Organization Living organisms can be studied at different levels of complexity. From least to most complex, these levels are (in an ecological context): Biosphere Biome Ecosystem Individual Population Community Community Population Ecosystem Biome Biosphere Individual Biosphere Ecosystems Communities Populations Organisms First Level: •Organism: A living thing. 8 Second Level: • Population: A group of organisms, all of the SAME SPECIES 9 Third Level: •Community: Made up of different species living in the same place at the same time. 10 Fourth Level: • Ecosystem: Made up of different species AND the abiotic factors of that habitat 11 Fifth Level •Biome: A group of ecosystems that share similar climates and types of organisms. (biomes share similar climates – “B before C”) Sixth Level: The Biosphere The biosphere is the region within which all living things are found on Earth. It is the narrow belt around the Earth extending from the bottom of the oceans to the upper atmosphere. What level of Organization? Population 14 What level of Organization? A community is a naturally occurring group of organisms living together as an ecological entity; the biological part of the ecosystem. A nudibranch snail feeding on rock encrusting organisms What level of organization? Organism What level of Organization? Ecosystem 17 Components of an Ecosystem An ecosystem encompasses the physical environment and the community. Physical environment Community Ecosystem Abiotic factors Biotic factors competitors, symbionts, predators, parasites, pathogens Physical environment Community atmosphere, soil, water, wind speed wind direction, current velocity Ecosystems Light intensity varies Fast flowing water habitat Still water habitat An ecosystem includes: all of the organisms (the community) … and their physical environment. There are many different sorts of ecosystems from natural to artificial, and they range in size from large to small. Rock habitat Flow rate varies Stream bank habitat Rainfall level varies What level of Organization? Population 21 A Hierarchy of Interactions • Ecology can be divided into four increasingly comprehensive levels Organismal ecology Population ecology Community ecology Ecosystem ecology Hierarchy of Interactions: Organismal Ecology Is concerned with the evolutionary adaptations that enable individual organisms to meet the challenges posed by their abiotic environments Figure 18.4a Population Ecology Is concerned with populations, groups of individuals of the same species living in the same area Concentrates mainly on factors that affect population density and growth Figure 18.4b Community Ecology Is concerned with communities, assemblages of populations of different species Focuses on how interactions between species affect community structure and organization Figure 18.4c Ecosystem Ecology Is concerned with ecosystems, which include all the abiotic factors in addition to the community of species in a certain area Focuses on energy flow and the cycling of chemicals among the various abiotic and biotic factors Figure 18.4d Ecology vs. Environmental Science • The science of ecology can provide understanding behind some environmental problems or concerns BUT does not involve the decision making process on solving those problems. • Doesn’t include: politics, economics, and ethical views to environmental problems • Example: Global climate change • ECOLOGY INVOLVED: how animals change to adapt to different changes in climate • OTHER FACTORS: How have humans influenced this change in climate and what can we do to slow change? Two environmental components when studying ecology: • ABIOTIC FACTORS: • BIOTIC FACTORS: Abiotic or Biotic? Biotic 30 Abiotic or Biotic? Abiotic 31 Abiotic or Biotic? Abiotic 32 Abiotic factors to consider: Sunlight • Solar energy powers nearly all ecosystems Water • • Aquatic organisms face problems with water vs salt ions balance Terrestrial organisms main water problem is dessication Wind • Organisms such as plants depend on wind to disperse pollen and seeds (or nutrients blown to them). Temperature • It’s effect on an organisms metabolism Environments The physical environment refers to the physical surroundings of any organism, including: the medium, e.g. water substrate, e.g. soil climatic (atmospheric) conditions light … and other physical properties. What is the connection between abiotic factors and distribution of species (biotic)? • Range of tolerance • Every organism/population thrives in an optimal range of abiotic factors • Outside of this range, less numbers of the organism Figure 18.8 Lower limit of tolerance Few organisms Abundance of organisms Few organisms No organisms Population size No organisms Upper limit of tolerance Zone of Zone of intolerance physiological stress Low Optimum range Temperature Zone of Zone of physiological stress intolerance High When do you use energy? ENERGY, PRODUCERS, AND CONSUMERS Primary Producers plants, certain bacteria, & algae Where do Primary Producers get their energy? • PHOTOSYNTHESIS • CHEMOSYNTHESIS • Discovered 35 yrs ago when investigating volcanic vents in total darkness.