Environmental Science 101. Chapter 9 Land Degradation

Transcription

1 Environmental Science 101 Chapter 9 Land Degradation

2 Big Picture: 1. Connections 2. Natural Resources 3. Natural Services (Process)

3 Asian Dust Clouds Start in Gobi Desert Can reach USA Natural Service China Huangsha, Korea Whangsa Japan Kosa

4 Other Connections Weather (Air) El Nino La Nina Ocean Currents

5 Soil Formation Dfn: Rocks particles, decaying plant and animal mater, water, air and microscopic organisms Basis for most life Soil Plants Animals 4 Main layers O horizon: sticks, leaves A horizon: topsoil, rich in organic matter B horizon: subsoil, rocks, sand, gravel C horizon: Base, Bedrock Bactria, Fungi, Earthworms, Small Insects Break down matter Water Cycle + N 2 and O 2

6 Ecosystems Dfn: One or more groups of organisms interacting among themselves and with nonliving mater and energy in a specific area Biodiversity variety of species and genetic material Important Functions 1. Natural Resources 2. Natural Processes 3 Feeding Levels 1. Producers 2. Consumers 3. Decomposers Food Chains/Webs

7 Ecosystem Succession Dfn: gradual change in the composition of an area Primary no soil, and slow process of soil formation ( years) Ex: Volcano, Deserts, Reclaimed Land Secondary Existing soil base, changes occur quickly when ecosystem is disturbed Ex: Abandoned Land, Forest Fires, Climate Change Old Theory: Predictable New Theory: Unpredictable *Some broad patterns

8 Climate vs Weather Climate Weather Atmospheric conditions in a region over long time periods ( years) Ex: Glaciers, Sea Level Rise, Droughts, Climate Change Atmospheric conditions in a region over short time periods (days) Ex: Severe Weather, Hurricane, Blizzards

9 Biomes or Climate Zones Distinct Climate Temperature Precipitation Dominant Vegetation Figure 9.2 and 9.3 *More Complex Only learn 4

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12 Forests Grasslands Mountains Deserts

13 Forests 30% Land Surface Old Growth vs Second Growth Planted Forest 3 Types Tropical Temperate Cold Natural Capital Natural Man made

14 Tropical Forests High H 2 O, Temp Diverse/Specialized (2% surface, 50%specieds) Arranged in Layers (Figure 9.10) Poor Soil Temperate Deciduous Forests Moderate H 2 O, Temp Varying Seasons Nutrient Rich Soils Cold Forest Coniferous, Boreal, Taigas Low H 2 O, Temp Long cold winters Short cool summers Low Diversity Poor Soils

15 Grasslands Seasonal Drought + Grazing + Fires Tropical (Savanna) Warm year round Wet/Dry Seasons o Africa Temperate (Prairie) Long cold winter Hot dry summer Windy/Dry Nutrient Rich o Midwest USA Cold (Artic Tundra) Winter Long, dark, frigid, windy, low H 2 O Summer 24 hr. sun, low H 2 O Poor soil, fragile Permafrost o Canada or Siberia

16 Dfn: highlands created by dramatic changes in altitude, slope, soil, vegetation within a small area 25% earth Climate Control 4 Billion People H 2 O Role in Biodiversity Mountains

17 Deserts Hot/Dry year round Rocky, Sand Dunes Low Biodiversity *Unique Species Fragile Uniformly Wetter Highly Variable Temp. (Day/Night) Slightly higher Biodiversity *Unique Species Fragile Cold winter, cool summers, low ppt Low Biodiversity *Unique Species Fragile

18 Summary of Biomes

19 Big Picture or Review? Ch. 1: Fig 1.23 Lecture Ch. 8: 60 80% land 50% H 2 O Large Ecological Footprints Unsustainable Resource Use Ch. 2: Carrying Capacity Ch. 1: 1.3 Earths 5 6 Earths (USA) Ch. 2: 1.3 Ecological Tipping Point Ch. 4 *Deforestation Desertification Soil Erosion Soil Salinization Overgrazing Land Degradation

20 Very Random 1. Does not discuss mountains in book 2. Figure and Book discussion d/n match 3. Too much off roading

21 Deforestation Removal of large expanses of forest Agriculture Mining Firewood Housing 50% 30% by % CO 2 Emissions CO 2 Sequestration Degraded Ecosystem Succession (Tropical Rainforest Savanna) 8000 threatened species (10%) Soil Erosion Temperate Forests National Forest System (40%)

22 Degradation and Fragmentation Roads Logging Clear cutting Selective cutting Strip cutting Erosion/Sedimentation Invasive Species

23 Tropical Rainforest Deforestation Causes Population Growth Poverty Firewood Building Materials Timber Harvest Cattle Mining Plantation Biofuels Logging Cattle Plantations

24 Palm Oil Plantations Indonesia 600% (since 1990) Plans to double the size 90% of Worlds Supply Expanding to: Congo, Madagascar etc. Congo = 2x size of Texas palm industrys role in deforestation and climate change.html

25 Forest Fires Surface Fire Beneficial Succession Prevent large fires Crown Fires Destructive Kill tree s, wildlife Erosion etc. Climate Change Freq/Severity Ecological Tipping Points

26 1 Solutions (3) Manage Forests Sustainable Selective Cutting Location Decrease Fragmentation Prescribed Burns or Natural Certification True Cost Pricing

27 2 Reducing Deforestation Population Growth (Ch. 2) Poverty Restoration (Wangari Maathai Kenya) Recycling Substitution

28 Costa Rica 80% land Sustainable industry More biodiversity USA 500,000 species Shifted subsidies Planted 14 million trees 2x forested land 3 Protecting Land Currently only 13% (5%) Reserves, Parks etc. Theory = 20% minimal needed Buffer Zones Developed World paying Less Developed to preserve UN = 564 biosphere reserves Biodiversity Hotspots (5%)

29 Desertification Dfn: Loss of soil moisture causing loss of productivity to produce vegetation Natural Cause (Drought) Human Overgrazing, Farming etc. 70% Land threatened Water shortages (3 Billion/40%) Climate Change Environmental Refugee (Ch. 2)

30 Overgrazing 42% of Rangelands Renewable vs Nonrenewable Soil Formation, Nutrient Cycling Erosion (water/wind) Compac on ( H 2 O absorption) Invasive Plants

31 Solutions to Desertification Alternative Resources (grazing, deforestation, mining etc.) Rotational Grazing Climate Change Restoration ($$$) ounce prevention, pound of cure Overgrazed 10 years later

32 Soil Erosion Review of Ch. 4 Natural Process (but slow) Humans Plowing, Deforestation Increases Rate Degradation (loss of fertility) Decreased Yields 17% Renewable vs Nonrenewable

33 Solutions to Soil Erosion Review Ch. 4 Soil Conservation Terracing, contour planting, strip cropping, windbreaks, conservation tillage Conservation Reserve Programs (USA) vs Ethanol Restoration

34 Soil Salinization Review Ch. 4 Caused by Irrigation (salts) 20% cropland 45% food Stunt growth, decrease yields % degraded (25% USA)

35 Solutions to Soil Salinization Review Ch. 4 Decrease Irrigation New Improved Methods Expensive

36 Mining Review Ch. 7 Surface (Open Pit, Strip, Mt Top) Soil Erosion Buries Forests/Streams (Tailings) Pollutes H 2 O

37 Solutions to Mining I think the authors forgot about it? Review Ch. 7

38 A look to the Future Goal = 20% preserved Ecological Restoration (4 Steps) Identify problem area Stop destructive activity Reintroduce species Protection from further harm Success Curtis Prairie WI Success BoababFarms Kenya