Plant species with physical seed dormancy are common in mediterranean fire-prone ecosystems. Because fire breaks seed dormancy and enhances the recruitment of many species, this trait might be considered adaptive in fire-prone environments. However, to what extent the temperature thresholds that break physical seed dormancy have been shaped by fire (i.e., for post-fire recruitment) or by summer...

We synthesize recent results from lake-sediment studies of Holocene fire-climatevegetation interactions in Alaskan boreal ecosystems. At the millennial time scale, the most robust feature of these records is an increase in fire occurrence with the establishment of boreal forests dominated by Picea mariana: estimated mean fire-return intervals decreased from ≥300 yrs to as low as ∼80 yrs. This f...

Prior to Anglo-European settlement, fire was a major ecological process influencing the structure, composition and productivity of shortgrass prairie ecosystems on the Great Plains. However during the past 125 years, the frequency and extent of grassland fire has dramatically declined as a result of the systematic heavy grazing by large herds of domestic cattle and sheep which reduced the avail...

Cytosolic Ca2+ has been likened to a kind of cellular fire (Rasmussen et al., 1990). The metaphor is apt in an obvious way because it suggests that transient or localized elevations in cytosolic Ca2+-like a fire contained in a hearth-may be useful to plant cells for performing certain tasks, whereas uncontrolled or prolonged elevations in cytosolic Caz+-like a fire loose on the roof-are destruc...

Positive species interactions have the potential to strongly influence the structure and dynamics of ecological communities, yet surprisingly few studies have documented their general importance. We tested the hypothesis that the mutualistic association between fire ants and aphids enhances the impact of fire ants on the herbivorous and predaceous arthropod community of cotton. We found that th...

Fire is a globally distributed disturbance that impacts terrestrial ecosystems and has been proposed to be a global "herbivore." Fire, like herbivory, is a top-down driver that converts organic materials into inorganic products, alters community structure, and acts as an evolutionary agent. Though grazing and fire may have some comparable effects in grasslands, they do not have similar impacts ...

BACKGROUND AND AIMS Germination studies of species from fire-prone habitats are often focused on the role that fire plays in breaking dormancy. However, for some plant groups in these habitats, such as the genus Leucopogon (Ericaceae), dormancy of fresh seeds is not broken by fire cues. In the field, these same species display a flush of seedling emergence post-fire. Dormancy and germination me...

Risk and liability concerns regarding fire affect people's attitudes toward fire and have led to human-induced alterations of fire regimes. This has, in turn, contributed to brush encroachment and degradation of many grasslands and savannas. Efforts to successfully restore such degraded ecosystems at the landscape scale in regions of the United States with high proportions of private lands requ...

BACKGROUND AND AIMS Although it is well known that fire acts as a selective pressure shaping plant phenotypes, there are no quantitative estimates of the heritability of any trait related to plant persistence under recurrent fires, such as serotiny. In this study, the heritability of serotiny in Pinus halepensis is calculated, and an evaluation is made as to whether fire has left a selection si...