high plant diversity and patchy distribution of
decaying logs a higher horizontal spatial variability
in detritus quality will be found than observed in
this plantation. When soil engineers are also present
horizontal spatial variability in community compo-
sition will increase, owing to their direct and indirect
effects on organic matter quantity and quality.
Nevertheless, horizontal spatial variability in
community composition is present, and this im-
plies that connectedness food webs can be
structured into compartments in which interac-
tions between species are localized. Compartmen-
talization might strongly influence food web
stability properties (Hall and Raffaelli 1997; butbacFigure 6.4A theoretical, horizontal spatially explicit connectedness food web of three trophic groups (1, microbes; 2,
microbivores; 3, predators) with 10 species (indicated with a letter). (a) Distribution of the 10 species (boxes) in
horizontal space, at a specific time. The length of the boxes indicates the amount of horizontal space (home range)
occupied by a species. (b) The potential connectedness food web showing ecologically possible feeding interactions
(lines) between the 10 species (boxes). (c) Three samples at different points in space (vertical grey arrows) result in three
local or actual food webs. The actual food web contains a subset of the species and feeding interactions of the
potentially possible food web. Adapted from Broseet al. (2005).
76 SPACE AND TIME