The timing of fireworks-caused wildfire ignitions during the 4th of July holiday season.

Although anthropogenic climate change is causing increased wildfire activity in the United States (US), humans are also an important ignition source. Humans cause a surge in wildfire ignitions every 4th of July (Independence Day in the US) through the use of fireworks. We examine the 4th of July peak in fireworks-caused wildfire ignitions and show that their spatial distribution varies but has been heavily concentrated in the west and north central US and predominantly on tribal lands.

The DiSCPersal model: A simple model for the small-scale atmospheric transport of spheroidal carbonaceous particles (SCPs).

Spheroidal carbonaceous particles (SCPs) are atmospherically mobile by-products of anthropogenic, high-temperature fossil fuel combustion. Since they are preserved in many geologic archives across the globe, SCPs have been identified as a potential marker for the onset of the Anthropocene. Our ability to reliably model the atmospheric dispersal of SCPs remains limited to coarse spatial scales (i.

Beringia and the peopling of the Western Hemisphere.

Did Beringian environments represent an to humans until less than 15 000 years ago or was access to the Americas controlled by the spatial-temporal distribution of North American ice sheets? Beringian environments varied with respect to climate and biota, especially in the two major areas of exposed continental shelf. The East Siberian Arctic Shelf ('Great Arctic Plain' (GAP)) supported a dry steppe-tundra biome inhabited by a diverse large-mammal community, while the southern Bering-Chukchi Platform ('Bering Land Bridge' (BLB)) supported mesic tundra and probably a lower large-mammal biomass. A human population with west Eurasian roots occupied the GAP before the Last Glacial Maximum (LGM) and may have accessed mid-latitude North America via an interior ice-free corridor.

Phytolith-occluded carbon in leaves of Dendrocalamus Ronganensis influenced by drought during growing season.

Being an important carbon (C) sink, phytolith-occluded carbon (PhytOC) has been investigated in various soil-plant systems. However, the effects of environmental factors (i.e.

Electron probe microanalysis of the elemental composition of phytoliths from woody bamboo species.

Electron probe microanalysis (EPMA) is promising for accurately determining elemental components in micro-areas of individual phytolith particles, interpreting compositional features and formation mechanisms of phytoliths in plants, identifying archeological and sedimental phytolith. However, the EPMA method of analyzing mounted slide phytoliths has not well been defined. In this study, we attempted different EPMA methods to determine the elemental compositions of phytoliths in mounted slides.