25 research outputs found
Cork-oak woodlands as key-habitats for biodiversity conservation in Mediterranean landscapes: a case study using rove and ground beetles (Coleoptera: Staphylinidae, Carabidae)
http://www.springerlink.com/content/552436w37r088v36/Land-use intensification in Mediterranean agro-forest systems became a pressure on biodiversity, concerning particularly the woodland sensitive species. In 2001, the effects of a land-use gradient from old-growth cork-oak forest to a homogeneous agricultural area were assessed using rove beetles as indicators in a Mediterranean landscape. The aim was to find which species were negatively affected by land-use intensification at the landscape level and whether they benefited from cork-oak patches occurring along the land-use gradient. A total of 3,196 rove beetles from 88 taxa were sampled from all landscape types. Agricultural area recorded significantly higher numbers of abundance and species richness in relation to the cork-oak mosaics, i.e. the old-growth forest and the managed agro-forest landscapes (montados). Moreover, 70% of rove beetle indicator
species common enough to be tested by IndVal displayed their highest indicator value for agriculture, showing a lower number of woodland indicators in comparison to ground beetles. Nevertheless, one rove beetle taxon was considered a specialist of closed woodland mosaics while no specialist ground beetle was found for that landscape typology. Some rare rove beetle species were also important in typifying diversity patterns of oldgrowth cork-oak forests. Hence, future management in Mediterranean landscapes should take into account not only indicator species common enough to be tested by IndVal, but also rare and endemic species. Considering the added value of cork-oak woodland cover for sensitive rove and ground beetle diversity, the strengthening of cork-oak woodland connectivity seems to be a crucial management that is required in agricultural Mediterranean landscapes.BIOASSESS project (Contract No. EVK4â1999-00280); Portuguese Foundation for Science and Technology (SFRH/BD/37976/2007)
An Integrated Population Model From Constant Effort Bird-Ringing Data
Data from annual bird-ringing programs, in which catch effort is standardized, are
routinely used to index abundance, productivity, and adult survival. Efficient models
have been developed for each. Such monitoring schemes, based on ringing across a
number of sites, are perhaps unique in providing this combination of demographic information
and make the data particularly amenable to an integrated approach to population
modeling. We develop a Bayesian approach and a deterministic population model
uniting abundance, productivity, and survival. The method is applied to sedge warbler
Acrocephalus schoenobaenus data from the British Trust for Ornithologyâs Constant Effort
Sites scheme. The possibility of âtransientâ birds needs to be incorporated within
this analysis. We demonstrate how current methodology can efficiently be extended
to use additional data from multiple within year recaptures when controlling for transience.
Supplemental materials for this article are available online