Lesson 13: Land Use and Land Degradation

Amy DurayEVPP 490 003

March 24, 2010

Aerial View of logging operations in SumatraPhoto by: Dieter Hoffman (rspb-images.com)

Expansion of desert in Minqin ChinaPhoto by: NY Times(2006)

Land DegradationA. Definition- “a substantial decrease in either or both of an area’s biological productivity or

usefulness to humans due to human activities” (Johnson and Lewis 2007)B. Forms of land degradation (UNEP 2007)

– soil erosion– nutrient depletion– water scarcity– salinity– disruption of biological cycles– land pollution– desertification– deforestation

C. Origin (Johnson and Lewis 2007)(1) an ancient problem beginning with the human discovery of fire.(2) after the discovery of fire, humans would carve an ever increasing path of land

alternation, with the Industrial revolution (technology) serving as the catalyst for massive habitat alteration

D. General DPSIR Model

Drivers

• Natural Forces:– Changes in rainfall patterns– Changes in storm event patterns

• Human Forces:– Population growth – Land use development– Economic growth

Pressures

• Expanding agriculture– Overgrazing– Overcultivation– Improper irrigation

• Forestry as an industry– Demand for forest products– Poor forestry techniques

State-and-Trends

• Reduced land productivity• Increased Soil degradation• Increasing desertification• Increasing Soil erosion• Increases in soil salinity• Increasing destruction of primary forest

Asian Forest Conversion (1990-2005)Nation 1990 2000 2005China 16.8 19.0 21.2Japan 68.4 68.2 68.2North Korea 68.1 56.6 51.4South Korea 64.5 63.8 63.5Mongolia 7.3 6.8 6.5Brunei Darussalam 59.4 54.6 52.8Cambodia 73.3 65.4 59.2Indonesia 64.3 54.0 48.8Lao PDR 75.0 71.6 69.9Malaysia 68.1 65.7 63.6Myanmar 59.6 52.5 49.0Philippines 35.5 26.7 24.0Singapore 3.4 3.4 3.4Thailand 31.2 29.0 28.4Timor-Leste 65.0 57.4 53.7Viet Nam 28.8 36.0 39.7United States 32.6 33.0 33.1

Source: Millennium Development Goals Indicators from Development Indicators Unit, Statistics Division, United Nations (statistics@un.org). Accessed 21 March 2009.

Asian Desertification

Impacts• Loss of vegetation or forestry cover• Loss of land biodiversity - more biodiverse forests are being

cut down for the growing and ever demanding forestry industry

• Habitat destruction-quality habitats of animals is being removed at alarming rates altering reproduction and migration patterns of animals

• Declines in crop production• Increases in poverty from decreased productivity of land• Water pollution and sedimentation (Gisladottir and Stocking

2005)

Responses• Global Level: Formation of International conventions and

organizations– UNCCD: UN Convention to Combat Desertification– WSSD at Johannesburg

• National Level:– Monitoring and Assessments– Establishment of land policies within countries of land degradation

problems• Local Level – Conservation Practices:

– Restoration of fertilized land through composting– Restoration of sand dunes with planting– Reforestation of forest

China• Key issues: Loss of Arable Land, Loss of Forest Land, Desertification, Land

Pollution• Drivers: Population Growth• Pressures: Conversion to agriculture “Grain-for-Green” Policy, Economic

expansion• State-and-Trends:

– Increased levels of soil erosion and salinization which has lead to desertification of lands in China (Xin et. al. 2009)

– Pollution is now a serious problem in China and includes: heavy metal pollution, chemical fertilizer and pesticide pollution, radioactive pollution, pathogen pollution (Xin et al. 2009).

• Impacts: – Vegetation and soil loss– Poverty and migration

• Responses:– Ministry of Agriculture soil testing and degradation abatement programs– Strategic Environmental Assessment rules– Revision of “Green-for-Grain” policy to reverse improper agricultural practices

China Desertification• http://www.nytimes.com/slideshow/2006/06/07/world/200

60608_DESERT_SLIDESHOW_4.html• Drivers: Population Growth, climate• Pressures: Overextraction of surface waters, impoundment

of surface waters• Responses: Water diversions from the Yellow river, limiting

water extractions, increasing dependence on groundwater wells, covering crops to reduce evapotranspiration

• Read the entire story: “A Sea of Sand Is Threatening China's Heart” NY Times: http://www.nytimes.com/2006/06/08/world/asia/08desert.html?pagewanted=1&_r=3

Mongolia• Key Issues: Deforestation and Desertification• Drivers: Population growth and Economic Expansion (esp. in neighboring China),

Natural processes and climatic forces (wind and rainfall and climate change)• Pressures: Demand for exported timber, increasing concentration of livestock

animals, increasing extractions of water for irrigation, increasing foraging activities in forested lands

• State-and-Trends:– Decreasing forest cover, changing forest compositions, encroaching desert areas

• Impacts:– Increasing fires as a result of increased human activities in forests, compacting of soils,

removal of vegetation, loss of soil suitable for agriculture• Responses:

– Forest management plans, logging taxes, reinstatement of traditional livestock practices and nomadic lifestyles

Southeast Asia - Deforestation• Drivers

– Increasing human populations– Global economic trade– In some areas, corruption and incapacity of government agencies responsible for

oversight

• Pressures– Expansion of demand for palm oil has led to conversion of tropical forests for plantation– Illegal and legal hardwood trade from forests

• State-and-Trends: Indonesian forest loss has is reported at 2.8 million hectares a year, the worst in the world, UN found that lowland habitats of Sumatra and Borneo were worst and by 2022 it is predicted the forests will be wiped out (Telapak and EIA 2007).

• Impacts (Telapak and EIA 2007).– critically endangering habitat of the orangutan and other native plants and animals– increasing human vulnerability to natural hazards such as flooding and landslides – loss of traditional livelihoods.

• Responses:– Government prosecution of illegal activities

Philippines – Mangrove deforestation• Drivers: Population growth• Pressures:

– Increasing aquaculture with 95% of the brackishwater ponds in 1952-1987 being derived from mangroves (PCAFNRRD 1991).

– Increasing use of mangroves for firewood and housing materials (Primavera and Esteban 2008)

• State-and-Trends:– 1900’s mangroves covered 450,000 ha in the Philippines including the major city, Manila,

(‘may” and “nila”) literally meaning there are mangroves there (Primavera and Esteban 2008).

– 1994-1995 mangroves declined to 120,000 ha (Primavera 2000).

• Impacts: – Increased human vulnerability, esp. to tidal surges and flooding– Decreased habitat for food fish species, and decreasing harvests causing food stress

• Responses:– Restriction of aquacultural pond size– 1976 National Mangrove Committee (NMC) formed– Replanting