Table 2. Sensitivity of the performance of a system to differences in reachability. Reachability Advantages       Disadvantages     High Access to distant information (Granovetter 1973)     Increased ability to respond to changes (see Aldrich 1999 and references therein)   Spread of contaminants over large distances Union of different social actors, e.g., government agencies and local users, to better match ecological and social boundaries (Schneider et al. 2003)   Increased spread of diseases such as HIV (Friedman et al. 1997) Enhanced possibilities of long-range interpatch dispersal (Urban and Keitt 2001)       Low Potential for the formation of coherent and efficient groups/clusters   Difficult recolonization (Keitt 1997, Nystrom and Folke 2001) Implications of disturbances such as, e.g., extinction of single species, do not extend beyond the local neighborhood in food webs (Krause et al. 2003)   Inaccessibility of distant information (Granovetter 1973)