US EPA

3292038 

Journal Article 

Effects of exurban development on biodiversity: Patterns, mechanisms, and research needs 

Hansen, AJ; Knight, RL; Marzluff, JM; Powell, S; Brown, K; Gude, PH; Jones, A 

2005 

Yes 

Ecological Applications
ISSN: 1051-0761
EISSN: 1939-5582 

WILEY 

HOBOKEN 

15 

6 

1893-1905 

WOS:000233858900005 

Low-density rural home development is the fastest-growing
form of land use in the United States since 1950. This ""exurban"" development (similar to 6-25
homes/km(2)) includes urban fringe development (UFD) on the periphery of cities and rural
residential development (RRD) in rural areas attractive in natural amenities. This paper
synthesizes current knowledge on the effects of UFD and RRD. We present two case studies and
examine the patterns of biodiversity response and the ecological mechanisms that may underlie
these responses. We found that many native species have reduced survival and reproduction near
homes, and native species richness often drops with increased exurban densities. Exotic species,
some human-adapted native species, and species from early successional stages often increase with
exurban development. These relationships are sometimes nonlinear, with sharp thresholds in
biodiversity response. These effects may be manifest for several decades following exurban
development, so that biodiversity is likely still responding to the wave of exurban expansion
that has occurred since 1950. The location of exurban development is often nonrandom relative to
biodiversity because both are influenced by biophysical factors. Consequently, the effects on
biodiversity may be disproportionately large relative to the area of exurban development. RRD is
more likely than UFD to occur near public lands; hence it may have a larger influence on nature
reserves and wilderness species. The ecological mechanisms that may underlie these responses
involve alteration of habitat, ecological processes, biotic interactions, and increased human
disturbance. Research on the patterns and mechanisms of biodiversity remains underdeveloped, and
comparative and experimental studies are needed. Knowledge resulting from such studies will
increase our ability to understand, manage, and mitigate negative impacts on biodiversity. 

biodiversity; biotic interactions; ecological mechanisms; fire; habitat fragmentation; landscape management; land cover; land use; rural residential development; urban fringe development; weeds 

87th Annual Meeting of the Ecological-Society-of-America 

Tucson, AZ