PARENT SESSION
Contributed Oral Session 87: Rare, Threatened, and Endangered Species: Flora; Habitat
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 522 A, Level 5, Palais des congrčs de Montréal

Does habitat loss at landscape level affect local density of Red Data Book and indicator species?

Paltto, Heidi^*,1, Björn, Nordén¹, Frank, Götmark¹, ¹ Göteborg University, Göteborg, Sweden

ABSTRACT- To be effective, nature conservation efforts should be focused on the conservation of species at high risk of extinction, but our knowledge of how these species respond to habitat fragmentation — a great threat to these species — is poor. We have surveyed indicator species according to the Swedish Woodland Key Habitat Inventory and nationally Red Data Book species of vascular plants, lichens, bryophytes and wood-living fungi in 22 temperate broadleaved forests in southern Sweden. In this project we tested 1) if Red Data Book or indicator species suffered from habitat loss, 2) if their responses to habitat loss were delayed and 3) at which spatial scales these processes were important. Tests of single organism groups included both Red Data book and indicator species. The amount of suitable habitat in the surrounding landscape was measured at two temporal scales — present-day and historic — and at two spatial scales. Multiple log-linear regression analyses were run to test a total of 13 variables characterizing landscape, abiotic and biotic features. The frequency of Red Data Book species was negatively affected by decreasing amounts of habitat in the landscape while the indicator species seemed to be unaffected. The frequencies of bryophytes and lichens were explained by the present-day amounts of habitat while vascular plants and wood-living fungi were explained by historic landscape data. The response to historic instead of present-day landscape can be interpreted either 1) as a time delay in their response to habitat loss (according to current theory) or 2) a result of prolonged substrate availability for wood-living fungi in changing forests. Red Data Book species, lichens and bryophytes responded to the amount of habitat at a coarse spatial scale (1-5 km) while vascular plants and wood-living fungi responded at a finer scale (0-1 km). Our study indicate that rare and specialized (red-listed) species are prone to local or regional extinction, but that this process is mediated by the different traits that characterizes different taxa.

Key words: Endangered species, Habitat fragmentation, Historic landscape, Plants