Water is the principal limiting resource for Californian Mediterranean-climate plants. The relationship between rainfall variation and the abundance and distribution of plant species was investigated at the Jasper Ridge Biological Preserve near Stanford University. Five years of rainfall data (1986-1990) were combined with a yearly census of plant species on a 100m transect to relate inter-annu...

Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of "nurse plants" an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of tw...

Increased livestock densities near artificial watering sites create disturbance gradients called piospheres. We studied responses of alien and native annual plants and native perennial plants within 9 piospheres in the Mojave Desert of North America. Absolute and proportional cover of alien annual plants increased with proximity to watering sites, whereas cover and species richness of native an...

Exotic annual grasses are a major challenge to successful restoration in temperate and Mediterranean climates. Experiments to restore abandoned agricultural fields from exotic grassland to coastal sage scrub habitat were conducted over two years in southern California, U.S.A. Grass control methods were tested in 5 m2 plots using soil and vegetation treatments seeded with a mix of natives. The t...

Biological soil crusts (BSCs) can improve the stability and health of native plant communities in arid ecosystems. However, it is unknown whether BSCs can also inhibit invasions of exotic vascular plants on stabilized reclaimed sand dunes. To answer this question, we conducted a greenhouse experiment to test the effects of cyanobacteria-dominated BSCs on 1) seed germination and biomass of an ex...

Carcass and meat quality of Thai native cattle, fattened for 2 years on Guinea grass (Panicum maxima) and Guinea grass-legume (Stylosanthes guianensis) pastures, were investigated in twelve 3-years old males. Groups had similar carcass quality except for kidney fat percentage (higher in cattle of the grass-legume group). This group also had a lighter meat (Longissimus dorsi, Infraspinatus) than...

Hawaiian lowland dry forests have been reduced by >90% since first human contact. Restoration has focused on protection from fire and ungulates, and removal of invasive grasses as ways to stimulate native forest regeneration. Despite these efforts, natural regeneration of native plants has been infrequent. To assess effects of previous restoration treatments on natural regeneration, we monitore...

Practices within the Conservation Reserve Program promote planting native grasses and forbs to improve habitat for northern bobwhite (Colinus virginianus) and other wildlife. However, native grasses often become dense and stands can be invaded by undesirable plant species that reduce habitat quality. We investigated three herbicides (clethodim, glyphosate, and imazapyr) at two rates to reduce n...

Exotic plant invasions are especially problematic because reestablishment of native perennial vegetation is rarely successful. It may be more appropriate to treat exotic plant infestations that still have some remaining native vegetation. We evaluated this restoration strategy by measuring the effects of spring burning, fall burning, fall applied imazapic, spring burning with fall applied imaza...

Endophytic fungi are plant symbionts living asymptomatically within plant tissues. Neotyphodium spp., which are asexual vertically transmitted systemic fungal endophytes of cool-season grasses, are predicted to be plant mutualists. These endophytes increase host plant resistance to environmental stresses and/or increase the production of alkaloid-based herbivore deterrents. The ubiquity of this...