Human Density and Land Use: Variation among Biomes

Spatial Distribution of Humans

Top 400 urban areas. Population density North America 2000.

Population density in 1994.

Spatial Distribution of Humans

The human footprint based on population density, land transformation access, electrical infrastructure. Sanderson et al. 2002

Socioeconomic Drivers

Hypotheses? • • • •

Environmental Correlates with Human Density

Sub-Saharan Africa. Balmford et al. 2001.

R2 = .64

R2 = .30

Great Britain. Evans and Gaston 2005

R2 = .32

Mexico. Vazquez and Gaston 2005

Global. Small and Cohen 2004

Environmental Correlates with Human Land Use

Soil Fertility

Agriculture

Human Density and Species Richness

NPP, vertebrate richness, and human density in sub-Saharan Africa. Balmford et al. 2001.

Past

Present

Natural Resource Constraints •Agricultural suitability

•Water

•Climate

•Timber

•Minerals

Transportation •Rivers

•Coast

•Railroads

•Highways

Natural Amenities •Scenery

•Wilderness

•Public lands

•Outdoor recreation

What Factors Drive of Land Use?

Huston, M. A. 2005. The three phases of land-use change: implications for biodiversity. Ecological Applications 15:1864–1878.

Past

Present

Natural Resource Constraints •Agricultural suitability

•Water

•Climate

•Timber

•Minerals

“Dirt is destiny”

What Factors Drive of Land Use?

Past

Present

Natural Resource Constraints •Agricultural suitability

•Water

•Climate

•Timber

•minerals

Transportation •Rivers

•Coast

•Railroads

•Highways

Natural Amenities •Scenery

•Wilderness

•Public lands

•Outdoor recreation

What Factors Drive of Land Use?

Past

Present

Natural Amenities •Scenery

•Wilderness

•Public lands

•Outdoor recreation

“Desperately seeking nature”

What Factors Drive of Land Use?

Patty (Hernandez) Gude

Table 4. The structure of the hypothesized models of growth in rural residential development from 1970 to 1999 was determined via exploratory analysis.

Hypothesis Description Model Structure

H1 Natural Resources Agriculture

H2 Transportation and Services Road Density + Travel Time to Hospital + Town Zone + (Town*Travel Time to National Park) + (Town*Education Attainment)

H3 Natural Amenities Distance to Water + Previously Isolated + (Isolation*Travel Time to National Parks)

H4 Encroaching Development Past RRD per section + Past RRD within 20 sections + Enc20*Enc20

H5 Combined Models All possible combinations of H1, H2, H3, and H4

What Factors Drive of Land Use?

Methods: Statistical Analysis of Competing Models

• Exploratory analyses to identify best covariates per category.

• Generalized linear models, ranked by AIC.

• Exclude ¼ of private lands for model validation.

• Control for spatial autocorrelation.

What Factors Drive of Land Use?

Model selection results. "k" is the number of estimated parameters per

model.

Model Structure k Delta AIC

Inf + Nat + Enc + Aga 14 0

Inf + Nat + Enc 13 88

Inf + Nat + Ag 11 425

Inf + Nat 10 459

Inf + Enc + Ag 11 1805

Inf + Enc 10 1825

Nat + Enc + Ag 9 2444

Nat + Enc 8 2459

Inf + Ag 8 3136

Inf 7 3156

Nat + Ag 6 3254

Nat 5 3275

Ag + Enc 6 4424

Enc 5 4425

Ag 3 6858

Ag = (H1) natural resource constraints; Inf = (H2) transportation

infrastructure and services; Nat = (H3) natural amenities; Enc =

(H4) encroaching development. a AIC weight equals 1 for the most inclusive model and 0 for the

remaining models; AIC value = -83765.

Gude et al. 2006

What Factors Drive of Land Use?

Conclusion: Current land use patterns reflect integration of agricultural suitability, transportation, natural amenities, and past development.

Implications:

• The old model of economy vs environment does not hold.

• Natural amenities contributes to growth, hence conservation likely has economic benefits.

• Airports, schools, etc. are important also

• Counties can better predict and shape future growth with this knowledge.

What Factors Drive of Land Use?

Anthropogenic Biomes of the World Ellis and Ramankutty 2008

Ellis and Ramankutty 2008

Land Use Change Across Traditional Biomes

What can we learn about drivers of human settlement and land use from comparison of land use change among biomes?

What can we learn about drivers of human settlement and land use from comparison of land use change among biomes?

Balmford, A., J. L. Moore, T. Brooks, N. Burgess, L. A. Hansen, P. Williams, and C. Rahbek. 2001. Conservation conflicts across Africa. Science 291:2616–2619. Ellis, E.C. and N. Ramankutty 2008. Putting people in the map: anthropogenic biomes of the world. Front Ecol Environ 2008; 6(8): 439–447. Gude, P.H., A.J. Hansen, R. Rasker, B. Maxwell. 2006. Rate and drivers of rural residential development in the Greater Yellowstone. Landscape and Urban Planning 77:131-151. Evans, K. L., and K. J. Gaston. 2005. People, energy and avian species richness. Global Ecology and Biogeography 14:187–196. Sanderdon, E., M. Jaiteh, M.A. Levey, K. Redford, A.V. Wannebo, G. Woolmer. 2002. The Human Footprint and the Last of the Wild: BioScience, 52(10):891-904. 2002. Small, C. and J.E. Cohen. 2004. Continental physiolography, climate, and the global distribution of human population. Current Anthropology 2: 269-277. Vázquez, L. B., and K. J. Gaston. 2006. People and mammals in Mexico: conservation conflicts at a national scale. Biodiversity and Conservation 15: 2397–2414. Huston, M. A. 2005. The three phases of land-use change: implications for biodiversity. Ecological Applications 15:1864–1878.

Literature Cited