Weibull, H. 2000. Bryophytes on boulders diversity, habitat preferences and conservation aspects. Doctor’s dissertation. ISSN 1401-6230, ISBN 91-576-5893-5 The influence of different overstorey tree species on the floristic composition of bryophytes growing on boulders was studied in two deciduous forests. Covering tree species and amount of litter were the factors explaining most of the variat...

To treat the problem of growing protoplanetary disc solids across the meter barrier, we consider a very simplified two-component coagulation-fragmentation model that consists of macroscopic boulders and smaller dust grains, the latter being the result of catastrophic collisions between the boulders. Boulders in turn increase their radii by sweeping up the dust fragments. An analytical solution ...

[1] Large boulders are prominent features in many geomorphic systems and are frequently targeted for cosmogenic exposure dating. Presently, there are little data or theory predicting exposure age, erosion rate, and mobilization frequency of boulders in environments such as channels, talus slopes, or moraines. Here we explore the potential for cosmogenic isotope analysis to constrain the transpo...

[1] Boulder morphology reflects both lithology and climate and is dictated by the combined effects of erosion, transport, and weathering. At present, morphologic information at the boulder scale is underutilized as a recorder of environmental processes, partly because of the lack of a systematic quantitative parameter set for reporting and comparing data sets. We develop such a parameter set, i...

The initial stages of planet formation in circumstellar gas discs proceed via dust grains that collide and build up larger and larger bodies1. How this process continues from metre-sized boulders to kilometre-scale planetesimals is a major unsolved problem2: boulders stick together poorly3, and spiral into the protostar in a few hundred orbits due to a head wind from the slower rotating gas4. G...

An April–May 2000 ‘‘Coon Creek Fire’’ burned f 37.5 km of the Sierra Ancha Mountains, 32.3 km miles north of Globe, AZ—including 25 sandstone and 19 diorite boulders surveyed in 1989 and resurveyed after the burn, after the summer 2000 monsoon season, and after the winter 2001 season. When viewed from the perspective of cumulative eroded area, both sandstone and diorite displayed bimodal patter...