Within 1 yr of collection, 60% or more of false broomweed (Ericameria austrotexana M. C. Johnst.) seed germinated at continuous temperatures from 15 to 30C if light was provided for 8 h daily. Maximum radicle elongation and fresh weight of 14-day-old seedlings occurred at 25 and 30C. Alternating temperatures did not enhance germination, and germination was suppressed in the dark. Germination, time required for germination, and early seedling vigor were tolerant of CaCl2 and MgCl2 solutions at concentrations as high as 200 mM, but NaCl reduced germination at concentrations in excess of 100 mM. Germination was sensitive to polyethylene glycol solution osmotic potentials of 0.6 mPa or more. Reduced germination in salt solutions was attributed to an osmotic effect rather than a direct effect of ions. Other than an inability to germinate when soil water is limited, no narrow environmental requirements appear to restrict establishment of this undesirable rangeland shrub.

Community composition and ecosystem processes during succession may be driven partly by traits of plant species that attain dominance. Here, we addressed the hypothesis that Stipa pulcherrima, the dominant grass of abandoned continental grasslands, controls seedling recruitment of co-occurring species through chemical effects of its litter. Eight species with successful and unsuccessful recruitment under field conditions were selected (four familial pairs) to study experimentally the effects of leaf leachate under four temperature regimes. Since fungi developed in leachate-treated Petri dishes, in another experiment seeds were surface sterilized to remove confounding effects of fungi on recruitment. Leachate affected various stages of seedling recruitment: it significantly reduced seed germination (by 33–94%) and radicle elongation, and it delayed germination of seedlings of all species. In two families, species with unsuccessful field recruitment were more negatively affected than the successful ones. In a third family, the species with successful recruitment was more negatively affected, and in the fourth there were no differences. Similar germination responses after exclusion of fungi through seed-surface sterilization suggested that leachate was responsible for the observed effects on recruitment. Besides other traits and physical/microclimatic effects of accumulating litter, S. pulcherrima influences plant community dynamics and may potentially affect ecosystem processes through its secondary compounds.