Desert Plants, Volume 24, Number 1 (June 2008)
ABOUT THE COLLECTION
Desert Plants is a unique botanical journal published by The University of Arizona for Boyce Thompson Southwestern Arboretum. This journal is devoted to encouraging the appreciation of indigenous and adapted arid land plants. Desert Plants publishes a variety of manuscripts intended for amateur and professional desert plant enthusiasts. A few of the diverse topics covered include desert horticulture, landscape architecture, desert ecology, and history. First published in 1979, Desert Plants is currently published biannually with issues in June and December.
Digital access to this material is made possible by the College of Agriculture and Life Sciences, Boyce Thompson Southwestern Arboretum, and the University Libraries at the University of Arizona.
Contact Desert Plants at DesertPlants@cals.arizona.edu.
- Physiological and Stuctural Mechanisms of Niche Differentiation for Three Sky Island Oaks in Relation to Light and Temperature
- The Boyce Thompson Arboretum and the Boys of the CCC
- Vegetation of Grassy Remnants in the Las Vegas Valley, Southern Nevada
- Supporters and Underwriters
- The Canary Islands: Continents in Miniature, Lands of Myth
- Book Review
Vegetation of Grassy Remnants in the Las Vegas Valley, Southern NevadaThe approximately 1000-km² Las Vegas Valley contains a rich assemblage of unique plant communities in the eastern Mojave Desert. Yet, there is little published documentation of this vegetation as its destruction continues with proceeding urban development. Development has intensified after the 1998 Southern Nevada Public Land Management Act mandated the disposal of federal lands. We document plant communities at four unique grassy remnants, some of which have since been destroyed, in the southwestern Las Vegas Valley. Sample plots of 0.25 or 0.09 ha at each site contained washes (supporting catclaw [Acacia greggii] at three sites) and associated uplands. Native perennial grasses comprised 12% of plant species richness/100 m2 and 5% of total relative cover on average. A total of 8 native perennial grasses were detected at the four sites, with predominant species including fluff grass (Dasyochloa pulchella), purple three-awn (Aristida purpurea), big galleta (Pleuraphis rigida), red grama (Bouteloua trifida), and slim tridens (Tridens muticus). These communities appeared as grass-shrublands, rather than the widespread shrublands commonly described for the Mojave Desert. Of large shrubs at the three sites containing catclaw, catclaw density ranged from 52-124/ha, Mojave yucca (Yucca schidigera) from 8-32/ha, and creosote bush (Larrea tridentata) from 168-456/ha. We also obtained permission to salvage native plants from one site prior to land development. Overall survival of salvaged plants of eight species exceeded 76% after one year of greenhouse/outdoor storage. We suggest that while many opportunities have already been lost, collecting and documenting information on the rich vegetation of the Las Vegas Valley and salvaging native plants or seed for use in desert landscaping, parks and habitat improvement in protected areas would leave a future legacy of this ecologically unique region.
Physiological and Stuctural Mechanisms of Niche Differentiation for Three Sky Island Oaks in Relation to Light and TemperatureIn an effort to identify the influence of light and temperature on the physiology and leaf structural characteristics of three species of Quercus from Coahuila, Mexico, we measured a comprehensive suite of plant traits as functions of light and temperature intensity. We tested the hypotheses that 1) species' physiological responses to light and temperature were related to their distributions in their native habitats; and 2) that species' physiological responses corresponded to similar variation in leaf anatomical and morphological traits. Quercus sideroxyla was adapted to high elevation forest over stories as evidenced by its high photosynthetic rate, transpiration rate, relative water content (RWC), leaf density (LD), and thick palisade and spongy parenchyma. Quercus rugosa displayed typical characteristics of a forest understory species including a low photosynthetic rate and light saturation point, thick spongy parenchyma tissue and high RWC, leaf density, and leaf mass per unit area. Quercus laceyi was adapted to hot, dry sites based on its lower RWC and LD, intermediate photosynthetic rate, thick cuticle and upper epidermis, and low transpiration rates at high temperatures. Our results suggest that the physiological and structural adaptations of Mexican oaks to changing environmental conditions across resource gradients are key regulators of plant community structure.