environmental relationships in tropical rainforests

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Environmental Relationships in Tropical Rainforests

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Environmental Relationships in Tropical Rainforests Slide 2 Climate: Tropical Wet (Af) High rainfall all year (>2 / month) Straddles Equator by 5 o - 10 o Windward mountain regions in tropics Consistently warm (all months > 18C/64.4F) Annual precipitation exceeds evaporation Daily temp range exceeds annual temp range Slide 3 Cook Islands, 2001 Slide 4 Costa Rica, June 2004 Slide 5 Slide 6 Fiji, 2004 Slide 7 Where: Straddles Equator by 5 o - 10 o. Northern South America, Central America, West and Central Equatorial Africa, SE Asia, NW Coastal Australia, Pacific Islands. Covers 6% of land surface (down from 14% prior to humanity). Vegetation: Tens of thousands of species. Highest density of species, tall trees, many canopy layers, evergreen, broadleaf trees, epiphytes, lianas (vines), climbers, stranglers, ferns. Fauna: More species than all other biomes combined, colorful insects, amphibians, reptiles, and birds, few large animals, high density of biomass and incredible species diversity. Soils: Laterite, thin and poor, most nutrients in vegetative litter because of leaching, biological processes, and rapid weathering. Red or orange soils. Threats: Among most threatened biomes. Logging and various types of deforestation, mining, cattle ranching, and development all contribute to an estimated loss of 214 acres a day (larger than New York City). OVERVIEW: TROPICAL RAINFOREST ENVIRONMENTS Slide 8 Tropical Rainforest Vegetation: Broadleaf Evergreen Deciduous vs. Evergreen Broadleaf vs. Needle-Leaf Cold Low Sunlight Drought Abundance of Water Cold Slide 9 Buttresses Epiphyte Lianas (Vines) Epiphyte Slide 10 Strangler Fig 3-Toed Sloth, Panama Clear-cut Tropical Deforestation Slash-and-Burn Agriculture Leaf-cutter Ants, Costa Rica Slide 11 Sugar Cane Field, Maui Tropical Soils: Laterization Laterite Soil, Fiji Ironically, tropical areas have poor soils. High temperatures and very high rainfall lead to the characteristically red soils of tropical areas. Most minerals are dissolved and leached away out of reach of plants. The remaining minerals (iron, aluminum, and manganese) are highly oxidized (rusted) and appear red. Only a very thin top layer of soil is rich. Slide 12 Summary: Tropical Rainforest Where: Straddles Equator by 5 o - 10 o. Northern South America, Central America, West and Central Equatorial Africa, SE Asia, NW Coastal Australia, Pacific Islands. Covers 6% of land surface (down from 14% prior to humanity). Vegetation: Tens of thousands of species; highest density of species, tall trees, many canopy layers, evergreen, broadleaf trees, epiphytes, lianas (vines), climbers, stranglers, ferns. Fauna: More species than all other biomes combined; colorful insects, amphibians, reptiles, and birds, few large animals, high density of biomass and incredible species diversity. Soil: Laterite; fairly thin and poor, most nutrients in vegetative litter because of leaching, biological processes, and rapid weathering. Threats: Among most threatened biomes; logging and various types of deforestation, mining, cattle ranching, and development all contribute to the loss of 214 acres a day (larger than New York City). Slide 13 =? Remember: Geographers Do Fieldwork! Slide 14 Global Rates of Rainforest Destruction (including deforestation) 2.4 acres (1 hectare) per second: equivalent to two U.S. football fields 149 acres (60 hectares) per minute 214,000 acres (86,000 hectares) per day: an area larger than New York City 78 million acres (31 million hectares) per year: an area larger than Poland Source: Myers, Norman. 1989. Deforestation Rates in Tropical Forests and Their Climatic Implications. Updated 1994.