Search results for "Wildfire"
showing 5 items of 25 documents
Conservation of Ptilostemon greuteri (Asteraceae), an endemic climate relict from Sicily (Italy): state of knowledge after the discovery of a second …
2022
Ptilostemon greuteri is one of the most endangered and poorly studied woody vascular plant species of the Mediterranean Basin, endemic to Sicily (Italy). Several peculiar traits confer to P. greuteri a character of uniqueness and an enigmatic attractiveness. In fact, at first glimpse the largest individuals of this species remind the most remarkable and peculiar cases of herbaceous genera (e.g., Echium, Senecio) turned woody on insular or insular-like mountain ecosystems. Following the discovery of a second population of this rare species, a project aiming at the study and conservation of P. greuteri was set up. We present here updated information on the distribution, conservation status, b…
Bayesian chronological analyses consistent with synchronous age of 12,835-12,735 Cal BP for Younger Dryas boundary on four continents
2015
The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature minerals and melt glass, nanodiamonds, carbon spherules, aciniform carbon, platinum, and osmium. Bayesian chronological modeling was applied to 354 dates from 23 stratigraphic sections in 12 countries on four continents to establish a modeled YDB age range for this event of 12,835-12,735 Cal B.P. at 95% probability. This range overlaps that of a peak in extraterrestrial platinum in the Greenland Ice Sheet …
Measurement report: Emission factors of NH3 and NHx for wildfires and agricultural fires in the United States
2023
During the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) study, the NASA DC-8 carried out in situ chemical measurements in smoke plumes emitted from wildfires and agricultural fires in the contiguous United States. The DC-8 payload included a modified proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) for the fast measurement of gaseous ammonia (NH3) and a high-resolution time-of-flight aerosol mass spectrometer (AMS) for the fast measurement of submicron particulate ammonium (NH4+). We herein report data collected in smoke plumes emitted from 6 wildfires in the Western United States, 2 prescribed grassland fires in the Central United …
Compound climate extreme events threaten migratory birds’ conservation in western U.S.
2022
In a warming world, more intense and frequent compound climate extreme events pose serious challenges to biodiversity and conservation on Earth as one of the 2030 United Nations’ sustainable development goals (SDGs): “Life On Land” (SDG 15). In summer 2020, concurrent swelling wildfires and a sudden cold snap in the western U.S. killed a massive number of migratory birds. In August 2020, the hot and humid weather in response to the wildfire radiation and the oceanic evaporation could result in killing heat stress for migratory birds along the coastal shoreline, particularly in California. The heat and smoke of wildfires forced the migratory birds to abandon such feeding grounds towards inla…
Effects of forest fires on flood frequency curves in a Mediterranean catchment
2005
The effect of land-use change on the flood frequency curve (FFC) in a natural catchment is analysed. To achieve this, a simple methodology for the derivation of FFCs in land-use change scenarios is proposed. The adopted methodology, using a stochastic model in Monte Carlo simulation of FFCs, was found to provide a useful framework for detecting changes in flood magnitudes in both pre- and post-fire conditions. In particular, the importance of the antecedent soil moisture condition in the determination of the flood frequency distribution was analysed. The analysis of FFCs for pre- and post-fire conditions shows an increase in the average value of Curve Number and a decrease in the catchment …