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Full-Text Articles in Life Sciences
Potential For Kochia Prostrata And Perennial Grasses For Rangeland Rehabilitation Efforts In Jordan, Raed Al-Tabini, D. Bailey, B. Waldron, J. Libbin, M. Al-Oun, K. Al-Khlidi
Potential For Kochia Prostrata And Perennial Grasses For Rangeland Rehabilitation Efforts In Jordan, Raed Al-Tabini, D. Bailey, B. Waldron, J. Libbin, M. Al-Oun, K. Al-Khlidi
Raed Al-Tabini
Six varieties of forage kochia [Kochia prostrata (L.) Shad.], two Atriplex shrubs native to cold deserts in the western United States, and four drought-tolerant perennial grass varieties were seeded and evaluated under arid rangeland conditions in Jordan. Varieties were seeded in December 2007 and evaluated in August 2008 and June 2009 for frequency and height at two sites in arid rangeland areas of southern and northern Jordan. Conditions were very dry with the southern site (Qurain) receiving 110 mm and 73 mm of annual precipitation, and the northern site (Tal Rimah) receiving 58 and 43 mm during the winters of …
Does Niche Divergence Accompany Allopatric Divergence In Aphelocoma Jays As Predicted Under Ecological Speciation?: Insights From Tests With Niche Models, John Mccormack, Amanda Zellmer, L. Knowles
Does Niche Divergence Accompany Allopatric Divergence In Aphelocoma Jays As Predicted Under Ecological Speciation?: Insights From Tests With Niche Models, John Mccormack, Amanda Zellmer, L. Knowles
John E. McCormack
The role of ecology in the origin of species has been the subject of long-standing interest to evolutionary biologists. New sources of spatially explicit ecological data allow for large-scale tests of whether speciation is associated with niche divergence or whether closely related species tend to be similar ecologically (niche conservatism). Because of the confounding effects of spatial autocorrelation of environmental variables, we generate null expectations for niche divergence for both an ecological-niche modeling and a multivariate approach to address the question: do allopatrically distributed taxa occupy similar niches? In a classic system for the study of niche evolution—the Aphelocoma jays—we …
Small-Scale Divergence In Egg Color Along An Elevation Gradient In The Mexican Jay (Aphelocoma Ultramarina): A Condition-Dependent Response?, John Mccormack, Elena Berg
Small-Scale Divergence In Egg Color Along An Elevation Gradient In The Mexican Jay (Aphelocoma Ultramarina): A Condition-Dependent Response?, John Mccormack, Elena Berg
John E. McCormack
The functional significance of bird egg color and patterning is a continuing subject of interest and debate. Extreme polymorphism in eggshell appearance is often thought to be maintained by frequency-dependent selection operating within populations. However, variation could also be explained by small-scale differentiation combined with limited migration. Here, we report the existence of extreme variation in egg color in a population of Mexican Jays (Aphelocoma ultramarina) inhabiting a steep elevation and habitat gradient within a single mountain range, the Sierra del Carmen of Coahuila, Mexico. We quantified egg color of 143 eggs from 54 nests throughout the mountain range, using …