Extensive redistribution of water, organic matter and nutrients occurs in many arid and semi-arid ecosystems due to high spatial connectivity and the strength of wind and water vectors. The ‘leakiness’ of these systems has been cited as an indicator of degradation. Attempts to limit or modify soil loss and redistribution is a component of many restoration strategies. There are surprisingly few data, however, about the extent to which reducing connectivity at the plot level results in increased resource retention or plant establishment, or how these effects might vary across the landscape. The objective of this study was to determine the extent to which reducing connectivity in plant interspaces can increase resource retention and plant establishment at plant and patch scales in three contrasting sites. Two sites are located on gravelly soils that are dominated by alluvial processes. One of these is on a geomorphically stable and the other on a geomorphically unstable surface. The third site is located on a sandy soil and is believed to be dominated by aeolian processes. Four paired treatment and control plots were established in late spring – early summer 2008 and evaluated in fall 2008 with digital photographs.
Results/Conclusions
The results showed significant reductions in bare ground at all three sites that were associated with increases in litter cover. The reductions were much greater at the aeolian site (26%) and the alluvial site on an geomorphically unstable surface (22%) than on at the geomorphically stable, lower productivity site (3%). These preliminary results illustrate the importance of testing hypotheses about the importance of connectivity across a broad variety of plant communities and geomorphic surfaces.
