Show description

Temporal uncoupling can therefore mask the expression of other potential constraints. The hypothesis about matches and mismatches of life-cycle events of potentially interacting species was first formulated by Cushing (1975). g. Bloch and Ritter, 1977, in the concept ‘ungleichzeitigkeit’). , 2006; Snow and Snow, 1972). , 2007). , 1977). In one of the few studies to quantify the source of forbidden links, Jordano et al. (2003) found that 51% of forbidden links in a Mediterranean plant–animal mutualistic network were due to phenological uncoupling, 24% were due to size mismatches and 6% were due to physiological/biochemical constraints (with 19% of possible links left unexplained).

2005a) is not so clearly evident within a single sampling 20 JENS M. OLESEN ET AL. , 2010): that is a temporal gradient in foodweb structure in responses to long-term eutrophication. Data from food-web nodes from 11 other contemporary lake sites are also shown on this MRT model, which indicates declines in plant abundance and changes in fish community associated with eutrophication: that is a spatial gradient of eutrophication. , 2010). PVI ¼ percentage volume infested, a measure of the density of rooted plants per unit volume which is an indicator of regime shift as the lake loses its plants and switches into a turbid phytoplankton-dominated state.

In addition, borders that are obvious to researchers, for example a forest edge or a coastline, may be porous or non-existent to certain animals, and vice versa. Habitat borders, which despite being ubiquitous natural phenomena, have received surprisingly little research attention in the ecological network literature. For example what is the relationship between penetrability of a habitat border and various traits of a species? Most network studies are made within a given study plot that has been selected because of its assumed homogenous character.