Interest in the new philosophy of ecosystem management led the Forest Service to sponsor a study of past land use in the Lone Mountain/San Rafael Valley Ecosystem Project Area, part of the Sierra Vista Ranger District of Coronado National Forest in… See more
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We report here on the flora of the Sierra de los Ajos, Sonora, Mexico, based on collections made in 1992 and 1993. The known flora of this Sky Island range contains 376 species of vascular plants in 93 families. Based on our collections and the… See more
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The Apachian-Madrean region is a zone of confluence and geographic termini of species and floras from the north and the south. Lower and intermediate elevations support many taxa of tropical plants and animals that are at their northernmost limits.… See more
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Bi-National Conference September 19-23, 1994 Tucson, Arizona This conference brought together scientists and managers from government, universities, and private organizations to examine the biological diversity and management challenges of the… See more
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In southern Arizona and northern Sonora, the neotropical vine snake (Oxybelis aeneus) lives in temperate oak woodland, canyon riparian woodland, desert-grassland, and pine-oak woodland communities at 1160 to 1650 m elevation. Perennial plants in an… See more
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Resumen del Proyecto: El Buho Manchado Mexicano (Strix occidentalis lucida) se distribuye en Sonora bajo condiciones adecuadas en canadas y elevaciones medias en montanas, can bosques de pino, pino-encino y encino-pino. Actualmente, dentro del… See more
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Scenically spectacular, the Sierra Madre Occidental is challenging to researchers in ecology as well as in geology. Like mountain gradients elsewhere in tropical Mexico, it offers a variety of habitats and species. In this section we will introduce… See more
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The pine-oak woodlands of the Sierra Madre Occidental of Mexico extend for about 1100 km from the northern end ofthe Sonoran-Chihuahuan border southward to the region ofthe common borders of Zacatecas, Nayarit, and Jalisco. On the eastern side of… See more
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The Arizona hedgehog cactus, Echinocereus triglochidiatus var. arizonicus, was officially given Endangered status by the U.S. Fish and Wildlife Service under the Endangered Species Act of 1973 on October 25, 1979 (44 FR 61556). The taxon as… See more
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The Rio Yaqui drainage basin of northwestern Mexico comprises about 73,000 km of the most inaccessible and rugged terrain in western North America (Blásquez 1959). An average annual discharge of almost 2,800 ha2 makes the Rio Yaqui one of the major… See more
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On May 3, 1887, a major earthquake shook much of the southwest United States and Mexico, an area of nearly two million square kilometers. This seismic event, with an estimated magnitude of 7.2 (DuBois and Sbar, in press), caused 51 deaths in… See more
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Held in Tucson, Arizona. Foreward: The material offered in this symposium is both urgently needed and late in coming. Only in very recent years have scientists and managers begun to shift their perspective on riverine systems away from localized,… See more
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