title: Comment on "Roadless space of the conterminous United States".
abstract: Watts et al. (Reports, 6 May 2007, p. 736) introduced a metric of landscape pattern called roadless volume (RV). However, as with most previous metrics, RV does not explicitly address ecological processes. We demonstrate that RV can produce results inconsistent with the notion of landscape connectivity and contend that more ecologically relevant metrics are available.
authors.affiliation: Road Ecology Center, University of California, One Shields Avenue, Davis, CA 95616, USA. girvetz@u.washington.edu
authors.forename: Evan H
authors.initials: EH
authors.lastname: Girvetz
authors.forename: Jochen A G
authors.initials: JA
authors.lastname: Jaeger
authors.forename: James H
authors.initials: JH
authors.lastname: Thorne