Landforms are natural features on the Earth’s surface that both reflect and shape geophysical and ecological process. The result is a defining part of landscapes that so often impact on human perception and interactions with environment. Blascyznki (1997) defines landforms as, “specific geomorphic features on the surface of the Earth,...
The Altar Valley is an important working landscape that supports biodiversity and vulnerable species in Pima County, Arizona (Huckelberry 2000). This semi-desert grassland, alluvial valley and 713,807-acre watershed composed of 39 subbasins serves as an aquifer to a portion of southwestern Tucson. This region of Southern Arizona has been identified...
The existence, sources, distribution, circulation, and physicochemical nature of macroscale oceanic water bodies have long been a focus of oceanographic inquiry. Building on that work, this paper describes an objectively derived and globally comprehensive set of 37 distinct volumetric region units, called ecological marine units (EMUs). They are constructed on...
Reintroduction programs are increasingly being used to save animals from extinction and aid in their recovery. The California Condor (Gymnogyps californianus), one of the most endangered birds in the world, is a remarkable example of how reintroduction programs can help rapidly increase a species' population numbers and range following a...