LTER cross-site team studies land fragmentation

Network News Fall 2010, Vol. 23 No. 2
Site News

A team of researchers recently completed a cross-site research initiative that examined land fragmentation across the cities and metropolitan areas associated with five Long Term Ecological Research (LTER) sites:

  • Central Arizona-Phoenix (Phoenix, Arizona)
  • Sevilleta (Albuquerque, New Mexico)
  • Jornada Basin (Las Cruces, New Mexico)
  • Short Grass Steppe (Fort Collins, Colorado)
  • Konza Prairie (Manhattan, Kansas)

Land fragmentation refers to discontinuous, low-density development at the urban fringes typical of suburbanization, exurbanization, sprawl, and leap-frog development. Such fragmentation has negative consequences for socio-ecological systems because it disconnects wildlife habitats, destroys migration corridors, increases costs of providing public services, and increases transportation distances (e.g. from home to work or other service locations).

Funded through a 2008 Social Science LTER Supplement, the study involved a host of faculty, post-doctoral, staff, and student researchers at the five sites: Central Arizona-Phoenix (Abigail York, Christopher Boone, Milan Shrestha, and Sainan Zhang); Jornada (Barbara Nolen, John Wright and Rhonda Skaggs); Konza Prairie (John Harrington and Tom Prebyl); Sevilleta (Amaris Swann and Mike Agar); and Short Grass Steppe (Michael Antolin).

The research team focused on understanding both the patterns and the drivers of land fragmentation. Using a revised classification of the National Land Cover Data for all five sites, they examined land fragmentation trends from 1992 to 2001. They found that residential development had increased land fragmentation on the fringes or peripheries at all research sites. Their analyses revealed three general fragmentation patterns:

  • Riparian: fragmentation along rivers (Las Cruces and Albuquerque)
  • Polycentric: suburbanization and exurbanization in disaggregated cities (Manhattan and Fort Collins)
  • Monocentric: rapid urban growth in a  concentric ring pattern (Phoenix)

By gathering local expert opinions and reviewing existing literature on the subject, the team identified five relevant drivers of land fragmentation across the five sites:

  • Availability of water
  • Population dynamics
  • Transportation
  • Topography
  • Institutions

A rich analysis of these drivers for each city using historical data revealed the importance of legacies of land use decision making. For example, rail corridors continue to influence observed patterns of urban growth in many of the cities.

Additional results from this research will be published in an upcoming issue of Urban Ecosystems, and detailed analyses from specific sites are in preparation. The land fragmentation research also feeds into the work of an Urban Long Term Research Area Exploratory (ULTRA-Ex) grant that focuses on open space and ecosystem services in the Albuquerque, Las Cruces, and Phoenix areas. Many of the researchers listed above have reconvened to undertake the ULTRA-Ex research.