The abundance of Coleoptera, Diptera and Collembola on different species of fungi was investigated in relation to the size and abundance of fungal resources at different spatial scales; i.e., the size of the fungal fruiting body, the quality of resource in terms of number of conspecific sporophores growing within a radius of 50 cm, crowding of the clumps of fruiting bodies, and the quality of resource within a plot (20 m × 30 m). Multiple linear regression analyses showed that the influential spatial scale varied among the arthropod orders. The amount of resource at the scale of a clump made a significant contribution to the abundance of Coleoptera, and the fruiting body size significantly affected the abundance of Diptera on each fungal species. Collembolan abundance was significantly affected by the crowding of the clumps of fruiting bodies and the number of fruiting bodies per plot. These results suggest that the spatial distribution of fungal fruiting bodies may determine whether they are selected by arthropods visited.
This study investigates the influence of microhabitat on the presence of several species of fungivorous beetles in basidiocarps of Fomes fomentarius (L.) Kickx. All dead basidiocarps of F. fomentarius from fragments of forest in an agricultural landscape in Norway were sampled and dissected, and their content of Cis jacquemarti Mellié, 1848/C. alter (Silvferberg, 1991) (did not distinguish between individuals of these two species), C. bidentatus (Olivier, 1790), C. lineatocribratus Mellié, 1848, Ennearthron cornutum (Gyllenhal, 1827) (Ciidae) and Dorcatoma dresdensis Herbst, 1792 (Anobiidae) were identified. Multiple logistic regression models revealed that these species responded differently to the microhabitat variables. The incidence of these beetles was associated with the size (volume), position (height above ground) and moisture content of the basidiocarps. The analyses also indicated possible interspecific interactions between some of the beetles. The presence of some of the species mainly in basidiocarps at particular stages of degradation indicates a successional pattern of occurrence of these species. Together these results indicate that basidiocarps of F. fomentarius are a heterogeneous resource for fungivorous beetles. This has implications for conservation: To preserve the diversity of fungivores, sufficient dead wood has to be left in forests to assure an adequate supply of F. fomentarius basidiocarps of different quality.
I analyzed data from 1870 vascular floras from regions within North America to assess whether the determinants of native and alien diversity vary as a function of spatial grain. Moving window multiple regression revealed that richness of both native and alien species exhibit the expected species-area relationship, latitudinal gradient, elevation gradient, and year of publication effect. However, the strength of these factors varied between native and alien species, and as a function of scale. Alien diversity was more predictable than native diversity, and is more strongly related to elevation and latitude. For both groups, the latitudinal gradient is most pronounced at broad grains, and the elevational gradient is most pronounced at fine grains.