Lecture 12 Lecture 12

Impacts of Land Use Change Impacts of Land Use Change

Impacts of LCLUC Pattern/Rates> Causes> Impacts> Prediction• Direct and Indirect impacts• Immediate and delayed impacts • Temporary and permanent impacts• Positive and negative impacts• Biophysical and societal impacts

• How to quantify the impacts?

Example Impacts

• Biogeochemical Cycles– Carbon – Nitrogen

• Air Quality– Smoke, – Industrial pollution

• Water Cycle – Water Quality – Soil Erosion,

Sedimentation– Water Availability

• Land Productivity – Degradation,

Salinization, Desertification, Infestations and Disease

– Enhancement, Increase

Example Impacts

• Biodiversity– Species loss, extinction,

increase– Habitat loss or

fragmentation (wetlands)– Invasive species

• Societal Impacts – Human health (malaria,

pollution) – Local economics and well

being– Transportation -

congestion, pollution– Culture, societal structure

and governance

• Climate Impacts – Emissions – Global – Albedo and

Temperature – Water Cycle –

Regional Evaporation, Precipitation

2003 Heat Wave – more than 40,000 Europeans died. While there were contingency plans for a variety of natural and man-made catastrophes, high temperatures had never been considered a major hazard.

Human Health

Haze from fires is thick over the Indonesian island of Borneo.

GHG gases

Precipitation is enhanced by the transpiration and evaporation over the Brazilian rain forest. Deforestation removes this vital source of water for the atmosphere.

Climate Regulation

Hydrology & Water Quality

Dark patches in the Elizabeth River are signs of algae blooms, which can pose a lethal threat to other living things in the water.

Human HealthLand cover change in much of the southwest U.S. has resulted in new disease vectors such as those borne by mosquitos (e.g West Nile Virus)

Biodiversity

Habitat fragmentation and loss

Soil Fertility Sediment loss, nutrient run-off, salinization

Suburban encroachment on farmland alters the cultural landscape. In this scene a farmstead (center left) has been leapfrogged by a suburban development that abuts a cornfield (lower right).

California is the most important agricultural state in America California is the most important agricultural state in America and produces 42% of its fruit and 43% of its vegetablesand produces 42% of its fruit and 43% of its vegetables. • By 1960, already three million acres of high quality Californian farmland was lost to urban areas. • One third of the prime agricultural land was gone by 1980. • Predictions for the year 2020 show that more than fourteen million acres of the southern state's highest quality farmland will have disappeared

U.S. Corn Boom Has Downside for Gulf

Effects of land use, soils, and Effects of land use, soils, and human populations on export of human populations on export of water, C, N, and P from the Mid-water, C, N, and P from the Mid-Atlantic coastal plainAtlantic coastal plain

Thomas R Fisher

Horn Point Laboratory

University of Maryland-CES

NASA LCLUC Science Team meeting, 20-22 Jan 2004

Goals • Reconstruct land use history in the Choptank basin over

the last 150 years using maps, aerial photos, and Landsat imagery.

• Model rates of N and P export associated with the land use change.

What’s the significance of this chart? What are the likely effects?

Environmental Impacts

1. Water Quality: Nutrient, sediment, and bacterial contamination are critical water quality problems. Pesticides and other organic contaminants are also a concern.

2. Soil Quality: Soil quality concerns center on maintenance of soil tilth by preserving and sequestering carbon in soils.

3. Air Quality: Ammonia and odorous emissions from activities connected with poultry production and the associated challenges that arise from increasingly complex urban-rural interface are air quality concerns within the watershed.

4. Loss of wetlands and wildlife habitat: Historical loss of wetlands in the Upper Choptank River sub-watershed is large compared to similar Maryland watersheds.

5. Ecosystem health of the Chesapeake Bay: Low dissolved oxygen, low water clarity, health of submerged aquatic vegetation, and populations of oysters, clams, and blue crabs dominate the list of ecosystem health concerns.

Synthesis Land cover history controlled population growth

in the basin Agricultural conversion complete by 1800 Limited population density for 150 years (feedback) Service economy after 1950 increased density

Land cover change from 1665 to 2000 probably doubled losses of N and P from land to water

Small effect which would not have decreased water quality

However, land use intensity is the real driver of poor water quality (2-10x as much effect as land cover change)

Application of fertilizers to crop lands Human population density (waste disposal)

Land Use Change Around Protected Areas and Consequences for Biodiversity

P.I.: Andrew Hansen

Funding: NASA Land Cover Land Use Change Program

Greater Yellowstone

Conifer

Herb;Seed/sap

Urban

AgricultureHardwood

Fire, logging

Succession, encroachment

CRP

Land Cover/Use Change in GYE: 1975-1995

-17%

+348%

-9%

+4%

-46%

MxCon+90%

Mxhw-24%

Burned +4968%

GYE Rural Residential

Development

National Park ServiceOther federal landsCounty boundaries

Low HighCounties without home

density data

Home density

Bozeman

Rexburg

Pocatello

Idaho Falls

Billings

Jackson

Rural Homes

Population has increased 55% 1975-1995

Rural homes increased 108% 1975-99

Data SourceCounty tax assessor records validated

against aerial photographs

Site Total Area (km2)

Total % Converted

% Unprotected Lands Converted

% Remaining Habitat Found Outside Reserves

GYE 95,363 11 37 20

GYE: Loss of Wildland Habitats

Species Abundance/Hotspots Methods

Obtain data from field surveys of species abundances.

Develop statistical relationship with biophysical and land use predictors.

Use statistical relationship to extrapolate species abundance over the landscape.

Analyze spatial distribution of species abundance to prioritize conservation.

Predicted Bird

Hotspots

National Park ServiceOther federal landsCounty boundariesBiodiversity hotspotsunclassified

Bozeman

Rexburg

Pocatello

Idaho Falls

Billings

Jackson

Places where bird species richness and abundance are <60% of maximum

Hotspots cover 6.4% of area

Bozeman

Rexburg

Pocatello

Idaho Falls

Billings

Jackson

National Park ServiceOther federal landsCounty boundariesBiodiversity hotspotsBiodiversity modeling mask

Low HighCounties without home

density data

Home density

Bird Hotspots and Rural

Homes

% of hotspots on: Private land: 41%National Parks: 12.3%Hotspots overlap with:

•Rural homes

•Conifer expansion

•High fire risk

Avian richness > 60% of maximumGreater Yellowstone Area boundaryCounty boundariesYellowstone National Park

Low HighCurrent Home Density

Greater Yellowstone Area boundaryCounty boundariesYellowstone National Park

Predicted Rural Homes > 1, and Avian Richness > 60% of Maximum

Current Housing Density < Exurban,Predicted Housing Density > Exurban,and Avian Richness > 60% of Max.

Areas predicted to have high avian richness are also the same areas receiving the most pressure

from human land use: rural homes were disproportionately located close to avian hotspots.

Within areas of high avian biodiversity, those places that are currently undeveloped but have high future development potential should be considered high

priorities for future conservation efforts.

Criteria for Regional Management

• In Greater Yellowstone, low elevation population source habitats for birds have been converted to population sink areas due to rural home development.

• Consequently subpopulations in Yellowstone National Park are at increased risk of extinction.

• A major conclusion is that the viability of nature reserves can best be ensured by managing them in the context of the surrounding region.

Homework

• Reading and discussion – Hansen et al. (2005) – Effects of exurban

development on biodiversity patterns, mechanisms, and research needs, Ecological Applications

Source: Hansen et al., 2005

Tot

al #

of

spec

ies

dete

cted

Explain the curvilinear response