Causes of Landscape Pattern

Land Use

• Land Use: Human employment of the land- settlement, cultivation, pasture, rangeland, recreation, forestry, etc.

• Different from Land Cover: Physical state of the land, such as vegetation type, water, materials, crop types, urban.

US Geological Survey/NASA http://astroboy.gsfc.nasa.gov/earthasart/index.html

Garden City, KansasImage taken 9/25/2000

Center pivot irrigation systems create red circles of healthy vegetation in this image of croplands near Garden City, Kansas.   Garden City can be found on Landsat 7 WRS Path 30 Row 34, center: 37.48, -100.51.

From Corner and MacLean 1996; photograph by A. MacLean

From Corner and MacLean 1996; photograph by A. MacLean

From Corner and MacLean 1996; photograph by A. MacLean

How important is land use as a cause of landscape pattern?

• Human actions now major source of changes in the biosphere

Understanding these forces, and social drivers, critical importance

Understanding processes

  Modeling, prediction

  Management- response to change

Two sources of global environmental change        Industrial processes

        Land transformation

From Meyer and Turner 1994, Chap. 2

• Industrial processes      Energy, material flows, pollution, due to

production, consumption

• Land transformation Cover type conversion--and physical change,

e.g., forest clearing, plowing grassland,converting ag land to subdivision 

Land Use change that is not cover change-Land cover modification: change withincover type category, e.g.,

Beginning use of chemical fertilizer

From World Resources 2000-2001

• During most of history of human land use, modification concerns largely limited to impacts on soils and biota due to agriculture

Land transformation seen as good (“development”, “improvement”) until very recent times (still is somewhat)

•  Post-agricultural society did not mean land transformation lessened - It diversified and intensified (Why?) 

Population increase, economic globalization, technological capacity

Early writers dealing with land use issues and effects:

• George Perkins Marsh (mid-19th c.) documenting modification of land by human use.

• V. I. Vernadsky (Russian, early 20th c.) analyzed growing human impacts on major biogeochemical cycles.

Forest thinning, or change in composition

Consequences of land use intensification e.g.,:

 • Species loss, domestication, translocation

• Functional losses, e.g., - wetlands drainage

 

From Whitney 1994

US Geological Survey/NASA http://astroboy.gsfc.nasa.gov/earthasart/index.html

Florida EvergladesImage taken 2/5/2000

Spanning the southern tip of the Florida Peninsula and most of Florida Bay, Everglades National Park is the only subtropical preserve in North America. It contains both temperate and tropical plant communities, including sawgrass prairie, mangrove and cypress swamps, pinelands, and hardwood hammocks, as well as marine and estuarine environments. The park is known for its rich bird life, particularly large wading birds, such as the roseate spoonbill, wood stork, great blue heron, and a variety of egrets. It is also the only place in the world where alligators and crocodiles exist side by side.   The Everglades can be found on Landsat 7 WRS Path 15 Row 42, center: 26.00, -80.43.

• On one hand no part of the earth is “unmanaged”-

• Given definition of managed as under direct or indirect influence by humans – Land transformation– Industrial Processes

Yet land use change, or land transformation, is local in its immediate occurrence, often perceived and evaluated as single, small, events

• Effects often cumulative, from local to global scales

 • E.g., only after mid 20th c. did fossil fuel

combustion C release surpass that from land transformation - still a large part

• Global human demand likely to continue growing, and not linearly - increasing rate

Many of worlds most productive ag lands have been under continuous use, increasing productivity for centuries or longer, some failed

 • China, for 2000 yrs • Parts of Mideast, central America

• Europe

• What is improvement, what is degradation? Sustainability?       Not totally objective - colored by our

context

In N Am, some areas had fairly high populations around agricultural development

in Pre-European settlement times

From Corner and MacLean 1996; photograph by A. MacLean

From Sisk 1998, Chap. 2

From Sisk 1998, Chap. 2

From Sisk 1998, Chap. 2

From Sisk 1998, Chap. 2

Despite these changes --

• Have the luxury of standard of a high degree of “naturalness”.

 • E.g., compared to Europe, or China, or many other

areas.

Evaluating effects of land transformation and consequences important --

 

• Prediction of future consequences– Resources, functional capacity of ecosystem

processes– Value to future generations, other species

• Whatever our values or world view, scientific knowledge needed as base 

Historically, land cover study was in realm of physical and biological sciences

Land use study was done by social scientists • Agents of human land use and land cover change

are proximate sources of change- not ultimate causes or drivers – Biomass burning, fertilizer application, forest cutting,

plowing • Land use change research on effects, and

prediction due to agents, requires mix of social and physical, biological sciences

• Land use conversions are direct effects of agents of change

• Changes also produce secondary effects—trace gas and C emissions, biodiversity loss, soil erosion, albedo alteration (sun energy reflection/absorption)

From Sisk 1998, Chap. 4

From World Resources 2000-2001

Ultimate sources of change are driving human forces

 

• Drive proximate sources causing all effects

• Socio-economic and cultural attributes of humankind.

Land use change and prediction of effects - Important but difficult

• Global aggregation of changes does not always capture regional effects – E.g., in Italy and other parts of Europe, rural

land being abandoned, afforestation occurring

Much of the tropics, huge pressure on remaining undeveloped forest land for agricultural use

US Geological Survey/NASA http://astroboy.gsfc.nasa.gov/earthasart/index.html

Bolivian DeforestationImage taken 8/1/2000

Once a vast carpet of healthy vegetation and virgin forest, the Amazon rain forest is changing rapidly. This image of Bolivia shows dramatic deforestation in the Amazon Basin. Loggers have cut long paths into the forest, while ranchers have cleared large blocks for their herds. Fanning out from these clear-cut areas are settlements built in radial arrangements of fields and farms. Healthy vegetation appears bright red in this image.   This deforestation can be found on Landsat 7 WRS Path 230 Row 72, center: -17.35, -62.18.

Rate and direction of change can vary over space (different locations) as well as time

• Global trends and effects remain, but make prediction difficult – Danger of developing global

prescriptions that will not apply to all regions 

Also, can’t make global predictions from aggregated data of dissimilar regions 

– Danger of making predictions from assumption of linear trends 

– Need for prediction from models that consider interaction human and environmental variables, feedbacks through time

• Regional societal context important

• Character of local bio-physical environment

Additional complication is that land use/cover effects felt far removed from source 

• Acid rain, N deposition • Atmospheric deposition of chlorinated

compounds from pesticides• Mercury from coal burning• Groundwater and river basin flows

Demands also come from far removed origins

• Developed world demand for tropical timber, or general agricultural products

 

Global economy means environmental and social costs can be more easily exported, in space or time

 • E.g., pollution effects of certain processes,

deforestation• Exported in time by valuing costs and benefits so

that future generations will pay 

From Sisk 1998, Chap. 3