The Galápagos Islands are known to have experienced significant drought during the Quaternary. The loss of mesophytic upland habitats has been suggested to underlie the relatively lower endemism of upland compared with lowland plant assemblages. A fossil pollen record spanning the last 26,000 years from an upland bog on Santa Cruz Island, revealed the persistent presence of highland pollen and ...

This study applies the observation of alignment between geographical watersheds and linguistic groupings to the Tibetan Plateau and the Himalayas. Tournadre (2014) estimates 220 Tibetic language varieties in 25 major groupings, sharing a common linguistic ancestry. Typological groupings can be readily identified through mapping human settlements to watersheds. For areas that have yet to be rese...

We study the watersheds in edge-weighted graphs. Contrarily to previous works, we define the watersheds following the intuitive idea of drops of water flowing on a topographic surface. We establish the consistency (with respect to characterizations of the catchment basins and dividing lines) of these watersheds, prove their optimality (in terms of minimum spanning forests) and derive a linear-t...

This study was conducted to determine if the Agricultural Policy/Environmental Extender (APEX) model could reasonably replicate the effects of silvicultural practices on streamflow and loading of sediments and nutrients. APEX was modified to enhance factors associated with forestry conditions such as rainfall interception by canopy, litter, subsurface flow, nutrient movement, and routing enrich...