Plant and animal abodes lecture 4


Published on

NAU Lecture 4 on Plant and animal abodes

Published in: Education, Technology
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Plant and animal abodes lecture 4

  1. 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. 2. Kinds of Ecosystems and Communities
  3. 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. 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. 5. 6.1 Succession  Primary succession begins with a total lack of organisms and bare mineral surfaces or water.
  6. 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. 7. Terrestrial Primary Succession  1. Pioneer stages  2. Intermediate stages  3. Climax community
  8. 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. 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. 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. 11. Primary Succession Primary succession on land
  12. 12. Primary Succession Primary succession from a pond to a wet meadow.
  13. 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. 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. 15. Secondary Succession Secondary succession on land
  16. 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. 17. Discussion 
  18. 18. 6.2 Biomes Are Determined by Climate  Biomes are terrestrial climax communities with wide geographic distributions. • Determination of a biome – climate
  19. 19. Biomes: Major Types of Terrestrial Climax Communities Biomes of the world
  20. 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. 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. 22. The Effect of Elevation on Climate and Vegetation Relationship between height above sea level, latitude, and vegetation.
  23. 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. 24. Desert
  25. 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. 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. 27. Temperate Grassland
  28. 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. 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. 30. Savanna
  31. 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. 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. 33. Mediterranean Shrubland (Chaparral)
  34. 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. 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. 36. Tropical Dry Forest
  37. 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. 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. 39. Tropical Rainforest
  40. 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. 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. 42. Temperate Deciduous Forest
  43. 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. 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. 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. 46. Temperate Rainforest
  47. 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. 48. Northern Coniferous Forest, or Boreal Forest  Birds are migratory  Mammals: deer, moose, wolves, mice, snowshoe hares
  49. 49. Taiga, Northern Coniferous Forest, or Boreal Forest
  50. 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. 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. 52. Tundra
  53. 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. 54. Tundra vs Desert  Similarities: • 25 cm annual precipitation • Windy • Few people occupy  Differences: • Temperature • Type of plants and animals
  55. 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. 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. 57. Estuaries Human impact: Estuaries are affected by: fertilizers animal wastes pesticides sewage Settlements housing marinas
  58. 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. 59. Freshwater Ecosystems Lake ecosystem
  60. 60. APA style citations    
  61. 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. 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.