Influence of climatic and edaphic factors on the distribution of Eragrostis lehmanniana Nees in Arizona, USA.

Aims to delineate areas where Lehmann lovegrass, Eragrostis lehmanniana, has been successfully established from sown seed, where mature plants have persisted for more than ten years, and where seed produced from mature plants has colonized new areas. Describes factors which have contributed to the spread of Lehmann lovegrass, and discusses relationships between soils and climate which may influence the long-term persistence of Lehmann lovegrass in Arizona, United States of America; Lehmann lovegrass (Eragrostis lehmanniana Nees) was introduced into Arizona, USA, from South Africa in 1932 and has since been sown throughout the south-western USA and Northern Mexico. The species is well adapted in south-eastern Arizona where it has been sown on over 69 115 ha and has spread by seed to an additional 76 040 ha. Where Lehmann lovegrass predominates and spreads, surface soils are sandy, summer rainfall is greater than or equal to 200 mm and winter temperatures rarely fall below 0 °C. Factors contribution to the spread of Lehmann lovegrass in south-eastern Arizona include fire, cattle grazing and drought.Keywords: Arizona; Cattle grazing; Climate; Colonization; Distribution; drought; Edaphic factors; Eragrostis lehmanniana; Fire; grasses; grazing; Lehmann lovegrass; lovegrass; plant invasion; Plant invasions; rainfall; Rangeland revegetation; seed; Seed germination; south africa; spread; United States of AmericaJournal of the Grassland Society of Southern Africa

Mineral assessment in Atriplex halimus L. and Atriplex nummularia L. in the arid region of Jordan

The foliage of Atriplex halimus contained higher levels (P < 0.05) of ash (28.03%) than that of Atriplex nummularia (23.11%). Spring growth of the two saltbushes contained less ash than the fall regrowth. The foliage of A. halimus contained higher levels of macro-minerals than A. nummularia plants except sodium. The two saltbushes contained higher levels of P, K and Mg during spring, but lower levels of Ca and Na compared to the growth of the fall season. Levels of Fe, Cu, Mn and Se present in the foliage of A. nummularia plants were higher than A. halimus. Clipping had no significant effect on ash content of saltbushes, but it affected the composition of the ash significantly. Clipping decreased the concentrations of Ca, P, Na, Mg and Fe in the foliage of clipped shrubs. The mineral composition of the two species of Atriplex appeared adequate to meet the requirements of sheep and goats grazing such types of forage.African Journal of Range & Forage Science 2003, 20(3): 247–25