CHAPTER 2

1. CHAPTER 2 LIFE ON LAND

2. Life on Land • Natural history: Study of how organisms in particular area are influenced by factors such as climate, soils, predators, competitors, and evolutionary history. • Daniel Janzen’s study case of Guannacaste tree (Enterolobium cyclocarpum) in CR (1981a.1981b) • Each tree produce average of 5000 fruit. • Most seeds remain on the floor under the trees • Large herbivorous animals feeding on fruits were hunted 10,000 years ago. • European introduce cattle which feed on those seeds, which eventually helped to disperse those trees. • His study help to understand the role of natural history on restoration of G tree and G National Park.

3. Fig. 2.2

4. Terrestrial Biomes • Biomes: divisions of the terrestrial environment with distinguish predominant plants and associated climate.( e.g. tropical forest, desert). • Soil: Complex mixture of living and nonliving material upon which most terrestrial life depends. • Soil form a medium in which organisms grow, and their activities in turn affect soil structure. • Soil vertical profile : • O horizon: organic, decomposed organics as result of bacteria, fungi, and soil animals. Merger gradually with A horizon. • A horizon: mixture of minerals material such clay, support high level of biological activities, rich in mineral nutrients. • B horizon: contains clay, humus and other materials transported from A. Distinct color and banding patterns. Occupied by the roots of plants, and gradually merge with C. • C horizon: deepest layer, weathered parent material, small fragments of particles (sand, silt, clay).

5. Fig. 2.3

6. Large-scale patterns of climatic variation • Uneven heating of earth’s spherical surface by the sun and tilt of earth axis will results predictable climate variation • The geographical distribution of terrestrial biomes corresponds closely to variation in climate, especially temperature and precipitations. • Pattern of atmospheric circulation and Coriolis effect.

7. Fig. 2.4

8. Fig. 2.5

9. Fig. 2.6

10. Climate Diagrams • Develop by Heinrich Walter (1985) • Tool used to explore the relationship between distribution of terrestrial vegetation and climate. • Scale of temperature and precipitation where scaled so 10 °C = 20 mm of precipitation. • Climate diagram for various cities (see fig 2.8 page 20)

11. Fig. 2.7

12. Biomes • Tropical Rain Forest • The more alive biomes • Illuminated by dim greenish light shining through a ceiling of leaves. • Availability of rain and warm and wet around the year. • Falls within the equator in three regions : • Southeast Asia, West Africa , and south and Central America. • Soil is nutrient-poor, acidic, thin, and low in organic matter. • Nutrients are tied up in living tissues than in soil. • Beneficiary partnership such as “Mycorrhizae” in which fungi associated with plant roots. • Rain forest could occur on volcano fertile soil, or along rivers. • Animal and plants diversities are immense. • Human influences on tropical rain forest has been devastated.

13. Fig. 2.10

14. Tropical Dry Forest • Life responds to the rhythms of annual solar cycle. • During dry season most trees are dormant, they flourish during the rainy season. • Occupy a substantial portion of the earth’s surface ( 10° and 25° latitude) (Cancer and Capricorn) • Climate is more seasonal than tropical forest (see fig 2.13). • More seasonal variations in temperature. • Soil is less acidic, and more richer in organic. • Soil is more vulnerable to erosion, particularly when disturbed by agriculture. • Plants are strongly influenced by physical factors. • Share many animal species with the rain forest and savanna • Animal may migrate during dry season. • Dry forest has been severely exploited more than tropical forest, by agriculture and cattle grazing.

15. Fig. 2.13

16. Fig. 2.14

17. Tropical Savanna • Tropical grassland dotted with scattered trees. • Believed ancient humans lived in it and scattered to other biomes. • Occur north and south of tropical dry forests within 10° to 20° of the equator. • Life cycles to rhythms of alternating dry and wet seasons, with intense lightening and often fires. • Fires help to maintains grassland as nutrients will be recycled. • Soil layers with low permeability resulting in maintaining plants. • Soil low permeability prevent trees as trees occur only where soils are well drained. • Biological activities take place near ground level. • Animals response to rainfall and food availability. • Human early use as hunting and gathering of food ground. • Human influence were seen as livestock ranching activities. • Drought and climate change have devastated most of it.

18. Fig. 2.16

19. Desert • Landscape sculptured by wind and water scarcity in general. • Drought and treacherous floods, heat and better cold often go hand in hand. • Life is not luxuriant, organisms adapted to water shortage and extreme temperatures (low & High). • Occupy 20% of the land surface of the earth. • Two bands of deserts ring the globe, one 30°N and 30°S latitudes. These bands corresponds to where dry subtropical air descends. • Environmental conditions varies from one desert to another (rain, temp, evaporation, plants transpiration). • Soil is low in organic and classified as lithosols, which means stone or minerals soil. Soil may cumulate salts, and forming calcium carbonate –rich hardpan horizon (Caliche) • Desert animals can effect soil properties (burrows, leaves under shrubs). • Plant cover is rare, and plants are adaptive to drought through leaves or dormancy. • Desert cultures flourished, because of human activities deserts have expanded in expense of other biomes.

20. Fig. 2.19

21. Temperate woodland and shrubland • Location above the tropic of Cancer and Capricorn between about 30° and 40° latitude, most extensive in the Mediterranean sea and North America. • Climate is cool and moist during fall, winter and spring. Summer in most regions is hot and dry, causing frequent fire. • Soil is low to moderate fertility and fragile. • Organisms show adaptations to drought and adapted mutualistic relationship with microbes to fix atmospheric nitrogen. Decomposition is slow during dry summer. • Fire-resistance plants and resprout rapidly. • Animals (vertebrate and invertebrate) are highly diverse. • Human impacted it by clearing trees and shrubs and used it for agriculture. • Most of temperate and woodlands and shrubs are destroyed and converted to various human land activities.

22. Fig. 2.22

23. Temperate Grassland • Largest biomes in North America and Eurasia. • Receive between 300 and 1,000 mm of rain. However, may experience occasional drought that extend to several years. • Grass height varies from 5 cm to 200 cm with great species varieties. Supported once huge herds of herbivores. • Maximum precipitations during summer, with growing height in summer. Cold winter and hot summer. • Soil is drive from wide varieties of parent materials. Contain large quantities of organic matter and fertile. • Dominated by herbaceous vegetation. Trees and shrubs are often limited to margins of streams and rivers. • Animals of intermediate size generally had one of two lifestyles (borrowing and fleet). • First human populated it were nomadic hunters. Next came nomadic herders. Then came farmers. • Produce the most fertile farms and fed much of the world. • Lost its fertility through human usage 35-40%.

24. Fig. 2.25

25. Temperate Forest • Found between 30° and 55° latitude, with majority lies between 40° and 50°. • Forests may be coniferous or deciduous, with temperatures are not extremes with precipitation averages of 650-3,000 mm. • Few deciduous trees are restricted to streamside. • Soil are usually fertile, with the most fertile develop under deciduous forests. Soil is neutral to slightly acidic and rich of organic and inorganic nutrients. • Have lower diversity than tropical forest, it is vertically stratified. • Animals uses all levels, with small to medium animals presents. • Organic materials are stored on the floor, with microscopic and invertebrates used to recycle those nutrients. • Large cities where build on temperate forests, first forests were removed and agriculture were practiced. • Most deciduous trees were cut to support lumber and wood industries.

26. Fig. 2.28

27. Boreal Forest or Taiga • Covers over 11% of the earth’s land area, and confined to Northern Hemisphere. • Extend between 50° and 65° N latitude. • Winter is long (>6 months), with moderate precipitation ranging from 200 to 600 mm. • Low rate of evaporation and brief drought if any. • Soil of low fertility, thin and acidic, with low decomposition rate. Nutrients are tide up in a thick layer of plant litter. In extreme boreal forest the subsoil is permanently frozen. • Plant roots are shallow with mycorrhizal fungi. • Dominantly green, and home of many animals including migratory birds and big animals like bears. • Early caveman live in boreal forest. • Human invasion is relatively light, however forest becomes intense lately as lumber being cut.

28. Fig. 2.31

29. Tundra • Covering the land north of the Arctic circle. • Climate is typically cold and dry, less temperature than boreal forests. Winter is less severe and summer are shorter. • Precipitation varies from less than 200 to a little over 600 mm, as exceed evaporation. • Soil loaded with accumulated organic matter. • Freezing and thawing of surface soil and action of water and gravity produce “Solifluction” where soil moves slowly down slopes and bringing stones to the surface forming a net of polygonal pattern (see fig. 2.35). • Dominated by perennial herbaceous plants (grass, sedges, mosses and lichens). • Support substantial numbers of large native mammals. • Human is limited, however recently increased

30. Fig. 2.34

31. Mountains • May consist of several biomes due to altitude variations. • Mountains built by geological process such as volcanoes or earth’s crust movement . North to South in America, and East to West in Asia and Europe, and isolated in Africa and Australia. • Climate is different according to latitude • Soil changes with elevation, soil is well drained, effected by wind and erosion. • Vegetation is influenced by altitude. • Human influenced mountains by exploitations and grazing.

32. Fig. 2.35

33. Fig. 2.37

34. Fig. 2.38