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The connection between resources and armed conflict: Darfur

Changes in precipitation 1900-2000

Drought in the northern part of Darfur has forced nomadic groups to immigrate southwards

in search of water and herding ground, which resulted in conflict with sedentary tribes.

Solutions to the violence in Darfur must consider the environmental factors behind the conflict.

Conflicts over resources are predicted to intensify. Reduced resource exploitation can

help mitigate these conflicts.

I'm only one person, what can I do?

What you eat can contribute to or help alleviate global climate change.

Fig 55.11

Energy is lost in each consumer: the 10% rule

Human impact:

As consumers

Use of agriculture in the U.S.About 1/2 of water and ~80% of agricultural land is used for raising animals.

Fossil Fuels:Producing beef consumes over 100 times more fossil fuel than producing potatoes.The typical American could save almost as much gas by going vegetarian as by not driving.

http://bicycleuniverse.info/transpo/beef.html

What you eat can contribute to or help alleviate global climate change.

Not all habitats are equal

How do stable ecosystems develop?

Primary Succession- the first organisms to colonize bare rock

Secondary Succession- recovery from a disturbance

Primary Succession- from non-living to living

Primary succession as this glacier retreats

Fig 54.22

Primary Successionafter glacier retreat,150-300 years

Fig 54.22

in Primary Succession biodiversity increases as resources become available

Fig 54.22

Primary Succession: each stage helps enable the next

Fig54.23

Secondary Succession: after a fire

Fig 54.21

Grassland biodiversity and biomass are increased by regular burns

Secondary Succession of a field(20 yrs)

Disturbances can increase resources, but disturb the interconnections between organisms

Human vs Natural Disturbances

Fig 56.21

Restoration Ecology- human involvement in recovering from a disturbance.

Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 – 1124

Looked at the results of 89 different ecological restorations.

Tbl 1: Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 - 1124

Types of Disturbances:Cessation of prescribed burning; Cultivation and cropping; Disturbance, excavation, or burial of Substrate; Eutrophication; Hydrological disruption; Invasion by non-native species; Logging of trees; Over-grazing; Removal of carnivores or herbivores; Soil contamination

Restoration action:Cessation of degrading action only (passive restoration); Extirpation of damaging species (including non-natives); Nutrient removal; Planting of forbs or grasses; Planting of trees; Reinstatement of burning; Reintroduction of herbivores or carnivores; Remodeling of topography; Soil amendments

Fig 1: Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 - 1124

(goods)

(nutrients and primary production)

(climate, water, etc)

Fig 1: Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 - 1124

Fig 1: Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 - 1124

Restoration recovered 86% of biodiversity and 80% of combined ecosystem services compared to non-disturbed systems.

Fig 1: Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 - 1124

What limits the success of restoration?

Not all habitats are equalFig 56.13

A third to a half of all old-growth species avoid younger (<30-year-old) regrowth.

What limits the success of restoration?

Invasive Species

Why are species going extinct?

"Global Biodiversity" Chapman & Hall, World Conservation Monitoring Centre, London, 1992

Fig 55.6

Invasive species can disrupt an ecosystem

The brown tree snake (Boiga irregularis)

• Its native in Australia and was introduced to Guam accidentally in the 1950’s

• Overall responsible for the extinction of 3 out of 4 seabirds; 9 out of 13 forest birds; 3-5 out 12 reptile species on the Island of Guam.

• This snake caused the extirpation or serious reduction of most of the island's 25 resident bird species on the main island of Guam.

Nile Perch (Lates niloticus)

• Introduced to Lake Victoria in 1954 to increase fish yield

• Caused extinction of 200+ endemic fish species through predation, and competition

• Fish caused indirect increased erosion on land, causing higher nutrient levels in the lake.

Water Hyacinth (Eichhornia crassipes)

• Introduced as ornamental plant around the world• Now in 50 countries on 5 continents including US• In California it replaced the native pennywort

(Hydrocotyle umbellata) which occupies a similar habitat, leading to a marked decrease in invertebrate communities

• Limits water transport, reduces oxygen and light levels in the water

How Many Invasive Species Are There in Texas?

67 terrestrial plants 12 aquatic/wetland plants 10 mammals 4 birds 7 fishes 11 insects 11 mollusks and crustaceans

Fig 1: Enhancement of Biodiversity and Ecosystem Services by Ecological Restoration: A Meta-AnalysisJ M Rey Benayas, A C Newton, A Diaz, J M BullockScience 28 August 2009: Vol. 325. no. 5944, pp. 1121 - 1124

What limits the success of restoration?

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