27 research outputs found
Potential range of impact of an ecological trap network: the case of timber stacks and the Rosalia longicorn
Although the negative impact of timber stacks on populations of saproxylic beetles is a well-known phenomenon, there is
relatively little data concerning the scale of this impact and its spatial aspect. Beech timber stored in the vicinity of the forest
can act as an ecological trap for the Rosalia longicorn (Rosalia alpina), so in this study we have attempted to determine the
spatial range of the impact of a network of timber stacks. Timber stacks in the species’ range in the study area were listed
and monitored during the adult emergence period in 2014–2016. Based on published data relating to the species’ dispersal
capabilities, buffers of four radii (500, 1000, 1600, 3000 m) were delineated around the stacks and the calculated ranges of
potential impact. The results show that the percentage of currently known localities of the Rosalia longicorn impacted by
stacks varies from 19.7 to 81.6%, depending on the assumed impact radius. The percentage of forest influenced by timber
stacks was 77% for the largest-radius buffer. The overall impact of the ecological trap network is accelerated by fragmentation
of the impact-free area. It was also found that forests situated close to the timber stacks where the Rosalia longicorn was
recorded were older and more homogeneous in age and species composition than those around stacks where the species was
absent. Such results suggest that timber stacks act as an ecological trap in the source area of the local population