Plant and animal abodes lecture 4

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NAU Lecture 4 on Plant and animal abodes

NAU Lecture 4 on Plant and animal abodes

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  • 1. Environmental Science A Study of Interrelationships Thirteenth Edition Enger & Smith Chapter 6 Kinds of Ecosystems and Communities Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 2. Kinds of Ecosystems and Communities
  • 3. 6.1 Succession  Succession is a series of regular, predictable changes in community structure over time. • Activities of organisms change their surroundings • Make the environment suitable for other kinds of organisms.
  • 4. 6.1 Succession  A climax community • relatively stable, long-lasting community that is the result of succession. • Traditionally, kind of climax community determined by climate.
  • 5. 6.1 Succession  Primary succession begins with a total lack of organisms and bare mineral surfaces or water.
  • 6. 6.1 Succession  Secondary succession begins with the disturbance of an existing ecosystem. • It is much more commonly observed • generally proceeds more rapidly than primary succession.
  • 7. Terrestrial Primary Succession  1. Pioneer stages  2. Intermediate stages  3. Climax community
  • 8. Pioneer Stage • A pioneer community is a collection of organisms able to colonize bare rock (e.g., lichens). – Lichens help break down rock and accumulate debris, helping to form a thin soil layer. – The soil layer begins to support small forms of life.
  • 9. Intermediate Stage  Lichen community replaced by annual plants.  Annuals replaced by perennial community (grasses).  Perennial community replaced by shrubs.  Shrubs replaced by shade-intolerant trees.  Shade-intolerant trees replaced by shade-tolerant trees.
  • 10. Climax community  Stable, complex, climax community eventually reached.  Process of succession can stop at any point  The general trend in succession is toward increasing complexity and more efficient use of matter and energy.
  • 11. Primary Succession Primary succession on land
  • 12. Primary Succession Primary succession from a pond to a wet meadow.
  • 13. Secondary Succession  Secondary succession • when an existing community is disturbed or destroyed but much of the soil and some of the organisms remain. • Because the soil and nutrients remain, this process can advance more rapidly than primary succession. • Plants and organisms that survive, grow quickly and reestablish themselves.
  • 14. Secondary Succession • Nearby undamaged communities can serve as sources of seeds and animals. • The new climax community is likely to resemble the destroyed community.
  • 15. Secondary Succession Secondary succession on land
  • 16. Modern Concepts of Succession and Climax  As settlers changed “original” ecosystems to agriculture, climax communities were destroyed. • Many farms were abandoned, and land began to return to its “original” condition.  Ecologists began to recognize there was not a fixed, pre-determined community for each part of the world. • The only thing differentiating a climax community from any other successional community is its time scale.
  • 17. Discussion  http://www.youtube.com/watch?v=AQQupOYonRo
  • 18. 6.2 Biomes Are Determined by Climate  Biomes are terrestrial climax communities with wide geographic distributions. • Determination of a biome – climate
  • 19. Biomes: Major Types of Terrestrial Climax Communities Biomes of the world
  • 20. Biomes: Major Types of Terrestrial Climax Communities  Primary non-biological factors that impact the kinds of climax communities: • Temperature • Patterns of precipitation – Total – Form – Seasonal distribution
  • 21. The Effect of Elevation on Climate and Vegetation • Temperature is warmest near the equator and cooler toward the poles. • As altitude increases, average temperature decreases.
  • 22. The Effect of Elevation on Climate and Vegetation Relationship between height above sea level, latitude, and vegetation.
  • 23. 6.3 Major Biomes of the World: Desert  Deserts • less than 25 cm annual precipitation. • Unevenly distributed throughout the year.  Windy  Large daily temperature fluctuations.  There are many species, but they are present in low numbers.  Many species exhibit specialized adaptations to climate • ability to conserve water.
  • 24. Desert
  • 25. Temperate Grassland  Temperate grasslands, also known as prairies or steppes • 25-75 cm of annual precipitation. • Fire is an important force in preventing the invasion of trees • releasing nutrients from dead plants to the soil  Grasses 60-90% of vegetation  The primary consumers are large herds of migratory grazing mammals. – Many insect species are also common.
  • 26. Temperate Grassland  Human impact on grassland: • Most of the moist grasslands of the world have been converted to agriculture. • Most of the drier grasslands have been converted to the raising of domesticated grazers – sheep, cattle, and goats. • Little undisturbed grassland is left – fragments that remain need to be preserved as refuges for the grassland species
  • 27. Temperate Grassland
  • 28. Savanna  Savannas • tropical parts of Africa, South America, and Australia.  Extensive grasslands spotted with occasional patches of trees.  They receive 50-150 cm annual precipitation, unevenly distributed throughout year.  Predominant Mammals • Grazers  Fire is a common feature.
  • 29. Savanna  Human impact: • Savannas have been heavily impacted by agriculture. – Farming – Livestock in drier areas • In Africa, there are extensive areas set aside as parks and natural areas – ecotourism is an important source of income.
  • 30. Savanna
  • 31. Mediterranean Shrublands (Chaparral)  Mediterranean shrublands • located near oceans and are dominated by shrubby plants.  Their climate features wet, cool winters and hot, dry summers. • 40-100 cm annual precipitation. • Fire common feature  Vegetation is dominated by woody shrubs adapted to hot, dry summers.  Insects, birds, reptiles, mammals
  • 32. Mediterranean Shrublands (Chaparral)  Human impact: • Very little undisturbed Mediterranean shrubland still exists. • Agriculture is common, often with the aid of irrigation. • Major cities are located in this biome.
  • 33. Mediterranean Shrubland (Chaparral)
  • 34. Tropical Dry Forest  The tropical dry forest • heavily influenced by seasonal rainfall. • Annual precipitation ranges from 50-200 cm.  Many exhibit a monsoon climate with highly seasonal rainfall.  Plants have developed special adaptations to survive drought.
  • 35. Tropical Dry Forest  Human impact: • Many of these forests occur in areas of very high human population. (India) • Harvesting of wood for fuel and building materials has heavily affected these forests. • Many of the forests have been converted to farming or the grazing of animals.
  • 36. Tropical Dry Forest
  • 37. Tropical Rainforest  Tropical rainforests • located near the equator where temperature is relatively warm and constant. – 200+ cm annual rainfall, and some receive in excess of 500 cm.  Tropical rainforests have a multi-layered canopy.  They also host a very high diversity of species. • More species in tropical rainforests than in the rest of the world
  • 38. Tropical Rainforest  Human impact • Tropical rainforests are under intense pressure from logging and agriculture. • Many of the countries where tropical rainforests occur are poor and seek to obtain jobs and money by exploiting this resource. • Forestry can be a sustainable activity, but in many cases it is not.
  • 39. Tropical Rainforest
  • 40. Temperate Deciduous Forest  Temperate deciduous forests • 75-100 cm annual precipitation, evenly distributed throughout the year. • Mild winters and a long growing season (6 months).  Trees typically lose their leaves during the winter and replace them the following spring. • Specific species: maples, birch, oaks  Insects, migrant birds, small mammals, and foxes, coyotes
  • 41. Temperate Deciduous Forest  Human impact: • Much has been cleared for farming. • Much of the current forest is subjected to periodic logging. • Major population centers of eastern North America and Europe are in areas that were originally temperate deciduous forest.
  • 42. Temperate Deciduous Forest
  • 43. Temperate Rainforest  West winds bring moist air to the coast. • air is forced over the mountains, cools, and rain or snow is produced. • at least 130 cm of rain a year, many receive 300 cm  The cool climate slows evaporation, things are generally damp. • All trees are covered with mosses, ferns  Lush growth of plants • Sitka spruce, Douglas fir • Old growth forests have trees 800 years old.
  • 44. Temperate Rainforest  Insects, as well as insect and fruit eating birds  Slugs are common on the forest floor.  Elk, black tail deer, bears, beavers, and owls are common.  Several species of salmon migrate seasonally up the streams and rivers to spawn.
  • 45. Temperate Rainforest  Human Impact • Because of the rich resource of trees, at least half of the original temperate rainforest has been logged. • Some patches have been protected because they are home to endangered northern spotted owls and the marbled murrelet, a seabird.
  • 46. Temperate Rainforest
  • 47. Northern Coniferous Forest, or Boreal Forest  An evergreen coniferous forest known as the northern coniferous forest, or boreal forest. • 25-100 cm precipitation annually.  It features short, cool summers and long winters with abundant snowfall. • The climate is humid because of the great deal of spring snowmelt  The trees are adapted to winter conditions: • Needle-shaped leaves prevent water loss. • Flexible branches
  • 48. Northern Coniferous Forest, or Boreal Forest  Birds are migratory  Mammals: deer, moose, wolves, mice, snowshoe hares
  • 49. Taiga, Northern Coniferous Forest, or Boreal Forest
  • 50. Tundra  North of the taiga is the tundra, • an extremely cold region that lacks trees and has a permanently frozen subsurface soil.  The tundra receives less than 25 cm annual precipitation. • short, wet summer.  Plants are usually less than 20 cm tall. • Grasses and lichens  Insects, waterfowl, Caribou, artic foxes
  • 51. Tundra  Human impact: • Because of the very short growing season, damage to this kind of ecosystem is slow to heal • so the land must be handled with great care.
  • 52. Tundra
  • 53. Grassland vs Savanna  Similarities: • • • • Fire Predominant plant: grasses Primary consumers: grazers Both have been impacted by agriculture  Differences: • Precipitation: 25-75 cm in grassland; 50-150 in savanna • Savanna: heavy rainfall followed by drought
  • 54. Tundra vs Desert  Similarities: • 25 cm annual precipitation • Windy • Few people occupy  Differences: • Temperature • Type of plants and animals
  • 55. 6.4 Major Aquatic Ecosystems  Aquatic ecosystems are shaped by key environmental factors: • • • • • The ability of the sun’s rays to penetrate the water Depth of the water The nature of the bottom substrate The water temperature The amount of dissolved salts – Marine ecosystems have a high dissolved salt content.
  • 56. Marine Ecosystems  Estuaries consist of shallow, partially enclosed areas where freshwater enters the ocean. • “Where the rivers meet the sea”  Organisms are specially adapted to varying levels of salinity from tides and river flow.  Extremely productive ecosystems because areas are shallow, warm, and nutrient-rich. • important nursery sites for fish and crustaceans.
  • 57. Estuaries Human impact: Estuaries are affected by: fertilizers animal wastes pesticides sewage Settlements housing marinas
  • 58. Freshwater Ecosystems  Freshwater ecosystems may be divided into two broad categories: • Stationary water (lakes, ponds, and reservoirs) • Running water (streams and rivers)  Human impacts  Agricultural runoff, sewage, sediment, and trash all find their way into streams and lakes.
  • 59. Freshwater Ecosystems Lake ecosystem
  • 60. APA style citations  https://owl.english.purdue.edu/owl/resource/560/02/  https://owl.english.purdue.edu/owl/resource/560/03/  https://owl.english.purdue.edu/owl/resource/560/06/  https://owl.english.purdue.edu/owl/resource/560/10/
  • 61. Summary  Ecosystems change as one kind of organism replaces another in a process called succession.  The climax community is a relatively stable stage.  Major regional terrestrial climax communities are called biomes.  Primary determiners of the kinds of biomes that develop are temperature and yearly rainfall distribution.
  • 62. Summary  Major biomes are desert, temperate grassland, savanna, Mediterranean shrublands, tropical dry forest, tropical rainforest, temperate deciduous forest, temperate rain forest, taiga, and tundra.  Aquatic ecosystems can be divided into marine (saltwater) and freshwater ecosystems.  The shore substrate determines the mixture of organisms that can live there.  Lakes have a structure similar to that of the ocean, but with different species.