Native bird breeding in a chronosequence of revegetated sites.
Restoration of degraded landscapes through replantings of native vegetation has been proceeding in response to habitat loss and fragmentation and plummeting biodiversity. Little is known about whether the investments in ecological restoration have resulted in biodiversity benefits. We evaluated the potential of restored sites to support populations by assessing bird breeding activity. We surveyed 21 revegetated sites of various ages (9-111 years) in the box-ironbark region of Victoria, Australia. Sites differed in landscape context, patch features and in-site characteristics. The latter, including whether sites were grazed, amounts of fallen timber and numbers of remnant trees, were most important in affecting overall bird breeding activity. Patch-configuration (e.g., shape, area) was of secondary importance. Landscape context appeared to have little effect on bird breeding except for one species. While these results suggest that in-site habitat structure is the predominant driver, we caution against dismissing the importance of patch characteristics and landscape context for two reasons. First, the available sites covered a relatively small range of areas (<54 ha), and we could not provide a broad range of landscape-contextual contrasts given that we could only use existing plantings. Second, much of the breeding activity was by bird species known to be tolerant of smaller woodland areas or of the open countryside. We show that there is very little breeding activity in replantings by species that have declined dramatically in rank abundance between large 'reference' areas and fragmented landscapes. It seems likely that most replantings provide habitat configurations unsuited for dealing with declines of species most vulnerable to habitat loss and fragmentation.
Selwood
Katherine
K
Australian Centre for Biodiversity, School of Biological Sciences, Monash University, Melbourne 3800, Australia.
Mac Nally
Ralph
R
Thomson
James R
JR
D000818:Animals; D001717:Birds / Q000502:physiology*; D052918:Environmental Restoration and Remediation; D012098:Reproduction; D013045:Species Specificity; D014739:Victoria