1. Ecology as a science and an academic discipline:a subject, objectives, structure and methods of modern ecology. Main ecological laws. Environment.Global environmental problems. Ecological systems, biogeochemical cycling of matter and energy in nature.

2.  Ecological systems represent recurring represent recurring groups of biological groups of biological communities that are communities that are found in similar found in similar physical environments physical environments and are influenced by and are influenced by similar dynamic similar dynamic ecological processes, ecological processes, such as fire or flooding. such as fire or flooding.

3.  Ecological systems (ecosystems) consist of all the living organisms in an area and their physical environment (soil, water, air). Ecosystems are influenced over time by the local climate, variations in the local landscape, disturbances such as fire and floods, and the organisms that inhabit them.

4. Components of Grasslands  Grassland ecosystems have both  biotic  abiotic components.  abiotic components.

5. Classification of biotic components  producers (grasses, shrubs and trees ) shrubs and trees )  consumers (grazing ungulates, birds ungulates, birds and insects) and insects)  decomposers (fungi, insects (fungi, insects and bacteria ) and bacteria )

6. Classification of plants  trees  shrubs  grasses  grass-like plants (sedges and rushes)  forbs (broad-leaved herbaceous plants)  cryptogams (mosses and lichens)

7. Trees  Trees can be either coniferous or deciduous.  Coniferous trees, including Douglas fir and ponderosa pine, have needle-like leaves and seeds borne in cones.  Coniferous trees, including Douglas fir and ponderosa pine, have needle-like leaves and seeds borne in cones.  Deciduous trees, such as trembling aspen, generally have broad, net-veined leaves and seeds that are produced from flowers.

8. Grasses  Grasses are herbaceous plants, which mean that they die back to ground level each year.  The flowers and seeds of grasses can vary greatly and are used to distinguish between different grass species.  The flowers and seeds of grasses can vary greatly and are used to distinguish between different grass species.

9. Grass-like plants  Sedges and rushes are similar to grasses in that they have slender, parallel-veined leaves, but their stems are unjointed and solid.  Sedges and rushes are similar to grasses in that they have slender, parallel-veined leaves, but their stems are unjointed and solid.

10. Forbs  Forbs are generally small plants that produce flowers. They flower at different times throughout the growing season

11. Hazardous Plants and Cryptogams  Plants that are either poisonous or injurious to livestock naturally exist in BC’s grasslands.  Plants that are either poisonous or injurious to livestock naturally exist in BC’s grasslands.  Cryptogams are rather complex and have both visible and microscopic components that grow over the surface of soils.  Cryptogams are rather complex and have both visible and microscopic components that grow over the surface of soils.

12. Cryptogams  The visible part includes lichens, mosses and liverworts, while the microscopic component is made up of algae, fungi and bacteria.  The visible part includes lichens, mosses and liverworts, while the microscopic component is made up of algae, fungi and bacteria.

13. Systems  Ecological systems (ecosystems) have many biogeochemical cycles operating as a part of the system, for example the water cycle, the carbon cycle, the nitrogen cycle.  All chemical elements occurring in organisms are part of biogeochemical cycles.

14. Biogeochemical cycle  Is a pathway by which a chemical element or molecule moves through both biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth. chemical elementmoleculebiospherelithosphereatmosphere hydrosphere Earthchemical elementmoleculebiospherelithosphereatmosphere hydrosphere Earth

15. Classification of systems Classification of systems  closed system  open system carboncarbon, nitrogen, oxygen, phosphorus, and sulfur—used in ecosystems by living organisms are a part of a closed system; nitrogenoxygenphosphorussulfur carbonnitrogenoxygenphosphorussulfur flow of energy in an ecosystem is an open system

16. Reservoirs  Chemicals are sometimes held for long periods of time in one place.  This place is called a reservoir.  example, as coal deposits that are storing carbon for a long period of time. coalcarboncoalcarbon

17. Carbon cycle Carbon cycle

18.  Carbon cycle: Carbon is one of the most important elements that sustain life on earth. Carbon dioxide and methane gases (compounds of carbon) in the earth's atmosphere has a substantial effect on earth's heat balance. It absorbs infrared radiation and hence may contribute to global warming and climate change. Carbon cycleCarbon dioxidemethaneglobal warmingclimate change Carbon cycleCarbon dioxidemethaneglobal warmingclimate change

19. Nitrogen cycle

20.  The nitrogen cycle represents one of the most important nutrient cycles found in ecosystems.Nitrogen is a required nutrient for all living organisms to produce a number of complex organic molecules like amino acids, the building blocks of proteins. NitrogenmoleculesNitrogenmolecules

21. Water cycleWater cycle Water cycle Water cycle

22.  Hydrological cycle: This is some times called the water cycle. Water is the most important chemical of life for all living organisms on earth. Water in the atmosphere is usually in form of vapor but condenses to liquid water and can solidify when temperatures are 0 0 C to form ice.

23. Oxygen cycleOxygen cycle Oxygen cycle Oxygen cycle

24. Oxygen cycle:  The oxygen cycle describes the movement of oxygen within and between its three main reservoirs: the atmosphere, the biosphere, and the lithosphere. The main driving factor of the oxygen cycle is photosynthesis and because of this, oxygen and carbon cycles are usually linked and the two cycles are collectively called oxygen-carbon cycle. photosynthesis oxygen photosynthesis oxygen

25. Energy flow in ecosystems

26. What is an ecosystem?  System = regularly interacting and interdependent components forming a unified whole  Ecosystem = an ecological system; = a community and its physical environment treated together as a functional system

27. OR, MORE SIMPLY  an ecosystem is composed of the organisms and physical environment of a specified area.  SIZE: micro to MACRO

28. THE RULES OF ECOLOGY  F. A. BAZZAZ: 1. Everything is connected to everything else. 2. Everything must go somewhere. 3. There is no such thing as a free lunch.

29. Attributes of Ecosystems  Order  Development  Metabolism (energy flow)  Material cycles  Response to the environment  Porous boundaries

30. ENERGY FLOW IN ECOSYSTEMS  All organisms require energy, for growth, maintenance, reproduction, locomotion, etc.  Hence, for all organisms there must be: A source of energy

31. Types of energy  heat energy  mechanical energy (+ gravitational energy,etc.)  chemical energy = energy stored in molecular bonds

32. Transformations of energy  How is solar energy converted to chemical energy?  How does this process influence life as we see it on earth?  The transformations of energy from solar radiation to chemical energy

33. An ecosystem has abiotic and biotic components:  ABIOTIC components:  Solar energy provides practically all the energy for ecosystems.  Inorganic substances, e.g., sulfur, boron, tend to cycle through ecosystems.  Organic compounds, such as proteins, carbohydrates, lipids.

34. Autotrophs  Autotrophs (=self-nourishing) are called primary producers.  Photoautotrophs fix energy from the sun and store it in complex organic compounds  (= green plants, algae, some bacteria) photoautotrophs simple inorganic compounds complex organic compounds light

35. Chemoautotrophs (chemosynthesizers) are bacteria that oxidize reduced inorganic substances (typically sulfur and ammonia compounds) and produce complex organic compounds. chemoautotrophs reduced inorganic compounds complex organic compounds oxygen

36. Chemosynthesis near hydrothermal vents

37. Other chemoautotrophs: Nitrifying bacteria in the soil under our feet!

38. Heterotrophs  Heterotrophs (=other-nourishing) cannot produce their own food directly from sunlight+ inorganic compounds. They require energy previously stored in complex molecules. heterotrophs simple inorganic compounds complex organic compounds (this may include several steps, with several different types of organisms) heat

39.  Heterotrophs can be grouped as:  consumers  decomposers

40.  Consumers feed on organisms or particulate organic matter.  Decomposers utilize complex compounds in dead protoplasm.  Bacteria and fungi are the main groups of decomposers.  Bacteria are the main feeders on animal material.  Fungi feed primarily on plants, although bacteria also are important in some plant decomposition processes.

41. The Laws of Thermodynamics  Energy flow is a one-directional process.  sun---> heat (longer wavelengths)  FIRST LAW of THERMODYNAMICS:  Energy can be converted from one form to another, but cannot be created or destroyed.

42.  SECOND LAW of THERMODYNAMICS  Transformations of energy always result in some loss or dissipation of energy  or  In energy exchanges in a closed system, the potential energy of the final state will be less than that of the initial state  or  Entropy tends to increase (entropy = amount of unavailable energy in a system)  or  Systems will tend to go from ordered states to disordered states (to maintain order, energy must be added to the system, to compensate for the loss of energy)

43. Examples  Internal combustion engines in cars are 25% efficient in converting chemical energy to kinetic energy; the rest is not used or is lost as heat.  My house, particularly my girls' rooms, goes from a complex, ordered state to a simpler, disordered state.

44. Energy flow  Simplistically: heat Producers Consumers Decomposers heat

45.  It is useful to distinguish different types of organisms within these major groups, particularly within the consumer group. Consumers

46. Terminology of trophic levels  We can further separate the TROPHIC LEVELS, particularly the Consumers:  Producers (Plants, algae, cyanobacteria; some chemotrophs)--capture energy, produce complex organic compounds

47. More trophic levels:  Detritivores--invertebrates that feed on organic wastes and dead organisms (detritus) from all trophic levels  Decomposers--bacteria and fungi that break down dead material into inorganic materials

48. Alternate Terminology  Producers = plants etc. that capture energy from the sun  Herbivores = plant-eaters  Carnivores = animal-eaters  Omnivores--eat both animals and plants

49.  Together, these groups make up a FOOD CHAIN  E.g., grass, rabbit, eagle CarnivoreHerbivoreProducer

50. Carnivores  Carnivores can be further divided into groups:  quaternary carnivore (top)  tertiary carnivore  secondary carnivore  primary carnivore  The last carnivore in a chain, which is not usually eaten by any other carnivore, is often referred to as the top carnivore.

51. Food chains

52. Problems  Too simplistic  No detritivores  Chains too long

53.  Rarely are things as simple as grass, rabbit, hawk, or indeed any simple linear sequence of organisms.  More typically, there are multiple interactions, so that we end up with a FOOD WEB.

55. Energy transfers among trophic levels  How much energy is passed from one trophic level to the next?  How efficient are such transfers?

56.  Biomass--the dry mass of organic material in the organism(s).  (the mass of water is not usually included, since water content is variable and contains no usable energy)  Standing crop--the amount of biomass present at any point in time.

57. Primary productivity  Primary productivity is the rate of energy capture by producers.  = the amount of new biomass of producers, per unit time and space

58.  Gross primary production (GPP)  = total amount of energy captured  Net primary production (NPP)  = GPP - respiration  Net primary production is thus the amount of energy stored by the producers and potentially available to consumers and decomposers.

59.  Secondary productivity is the rate of production of new biomass by consumers, i.e., the rate at which consumers convert organic material into new biomass of consumers.  Note that secondary production simply involves the repackaging of energy previously captured by producers--no additional energy is introduced into the food chain.

60. Ecological pyramids  The standing crop, productivity, number of organisms, etc. of an ecosystem can be conveniently depicted using “pyramids”, where the size of each compartment represents the amount of the item in each trophic level of a food chain. producers herbivores carnivores

61. Pyramid of energy  A pyramid of energy depicts the energy flow, or productivity, of each trophic level.  Due to the Laws of Thermodynamics, each higher level must be smaller than lower levels, due to loss of some energy as heat (via respiration) within each level.

62. Pyramid of numbers  A pyramid of numbers indicates the number of individuals in each trophic level.  Since the size of individuals may vary widely and may not indicate the productivity of that individual, pyramids of numbers say little or nothing about the amount of energy moving through the ecosystem.