AN AREA OF INCREDIBLE BIOLOGICAL DIVERSITY



            Though humans have always left their mark on the Highlands, the capability to massively alter landscapes has come to the borderlands only very recently on an ecological timescale. The dramatic effects of large-scale human intervention have irrevocably changed the course of natural history in the Atascosa Highlands, making it essential to document the ecology of the region now. This will provide a baseline for future generations who can use the data gathered today to chart the consequences of this unprecedented era of industrialization and climate change on the ecology of the sky islands.

            In 1943 writer Natt Dodge referred to the Chiricahua mountains of Southern Arizona as a “mountain island in a desert sea.” This became the origin of a new understanding of the isolated ranges of Southern Arizona and Northern Sonora as “sky islands.” This term refers to a series of mountain ranges which connect the Sierra Madre Occidental of Mexico with the Rocky Mountains of the U.S. and Canada, sitting at the confluence of the Sonoran and Chihuahuan deserts. These mountains bridge political boundaries and act as essential migratory routes for species unaware of the arbitrarily defined borders dividing their habitat. Sky islands of the region can rise thousands of feet from their scorching desert bases to cool, wet forests of Douglas Fir (Pseudotsuga menziesii) and Pine (Pinus spp.). The radical geologic, climactic, and topographical variations make the sky island region one of the most biodiverse places on the planet.





I. Juniperus arizonica (Arizona Juniper)
II. Noccaea fendleri (Alpine Pennycress)
III. Quercus hypoleucoides (Silverleaf Oak)
IV. Lobelia laxiflora (Sierra Madre Lobelia)
V. Agave palmeri (Palmer's Agave)
VI. Carex chihuahuensis (Chihuahuan Sedge)
VII. Choisya dumosa var. Mollis (Mexican Orange)
VIII. Mimosa dysocarpa (Velvetpod Mimosa)
IX. Asclepias linaria (Pineleaf Milkweed)


Mark