A5033957255- Geology and Paleoclimatology Research
- Tree-ring climate responses
- Fire effects on ecosystems
- Archaeology and ancient environmental studies
- Pleistocene-Era Hominins and Archaeology
- Rangeland and Wildlife Management
- Archaeology and Natural History
- Botany, Ecology, and Taxonomy Studies
- Geological formations and processes
- Plant Water Relations and Carbon Dynamics
- Aeolian processes and effects
- Isotope Analysis in Ecology
- Geomagnetism and Paleomagnetism Studies
- Landslides and related hazards
- Hydrology and Watershed Management Studies
- Yersinia bacterium, plague, ectoparasites research
- Forest Ecology and Biodiversity Studies
- Cryospheric studies and observations
- Climate variability and models
- Maritime and Coastal Archaeology
- Climate change and permafrost
- Ecology and biodiversity studies
- Groundwater and Isotope Geochemistry
- Water Quality and Resources Studies
- Geological and Geochemical Analysis
University of Nevada, Reno
2015-2024
Research Experiences for Undergraduates
2018
Georgia Southern University
2013
NOAA National Severe Storms Laboratory
2013
Desert Research Institute
2013
University of California, Berkeley
1998
SignificanceWe provide the first assessment of aboveground live tree biomass in a mixed conifer forest over late Holocene. The record, coupled with local Native oral history and fire scar records, shows that burning practices, along natural lightning-based regime, promoted long-term stability structure composition for at least 1 millennium California forest. This record demonstrates climate alone cannot account observed conditions. Instead, forests were also shaped by regime frequent fire,...
Abstract The Black Death (1347–1352 ce ) is the most renowned pandemic in human history, believed by many to have killed half of Europe’s population. However, despite advances ancient DNA research that conclusively identified pandemic’s causative agent (bacterium Yersinia pestis ), our knowledge remains limited, based primarily on qualitative remarks medieval written sources available for some areas Western Europe. Here, we remedy this situation applying a pioneering new approach, ‘big data...
Abstract Microscopic charcoal from varved Santa Barbara Basin sediments was used to reconstruct a 560-yr record (A.D. 1425 1985) of Ana fires. Comparison large (>3750 μm 2 ) with documented fire records in the Ranger District shows that high accumulations correspond fires (>20,000 ha) occurred during conditions. The reconstructed minimum 20 region study period. average time between no distinct change across three different land use periods: Chumash period, apparently characterized by...
We use macroscopic charcoal analysis to reconstruct fire history in sagebrush (Artemisia tridentata var. wyomingensis and A. tridentata), Newark Valley, Nevada. analyzed at continuous 1-cm intervals (~7–127 years), pollen 2- 10-cm (~70–263 years) a core spanning the last 5500 cal yr BP (calendar years before present). A peak historic period was associated with >1400-ha dated 1986 that burned watershed. reconstructed prehistoric by inferring fires from similar peaks were significantly greater...
This paper compares changes in vegetation structure and composition (using synthetic fossil pollen data) with proxy data for population levels (including settlements radiocarbon dates) over the course of last 10 millennia Tyrrhenian central Italy. These show generalised patterns clearance woodland response both to early agriculturalists urbanism, as well specific adoption tree crops variations stock grazing. The results provide a comprehensive understanding development anthropogenised...
Pollen and algae microfossils preserved in sediments from Pyramid Lake, Nevada, provide evidence for periods of persistent drought during the Holocene age. We analyzed one hundred nineteen 1-cm-thick samples pollen a set cores that span past 7630 years. The early middle Holocene, 7600 to 6300 cal yr B.P., was found be driest period, although it included short but intense wet phase. suggest Lake Tahoe below its rim most this greatly reducing volume depth Lake. Middle aridity eased between...
Abstract Knowledge of the direct role humans have had in changing landscape requires perspective historical and archaeological sources, as well climatic ecologic processes, when interpreting paleoecological records. People directly impact land at local scale use decisions are strongly influenced by sociopolitical priorities that change through time. A complete picture potential drivers past environmental must include a detailed integrated analysis evolving priorities, ecological processes....
Abstract. The California grassland is dominated by alien plant species. It generally assumed that the invasion of aliens began with initial introduction livestock Spanish missionaries in 1769. In this paper we present pollen evidence which indicates Erodium cicutarium , a Mediterranean annual, was well established Santa Barbara region several years before founding first mission at San Diego Historical shows it took nearly decade to develop base California. Disturbance therefore not necessary...
Abstract Pollen and algae from Owens Lake in eastern California provide evidence for a series of climatic oscillations late the last glaciation. Juniper woodland, which dominated Valley 16,200 to 15,500 cal yr B.P., suggests much wetter conditions than today. Although still cooler today, area then became fairly warm dry, with woodland being replaced by shrubs (mainly sagebrush) 13,100 B.P. Next, Chenopodiaceae (shadscale) increased, woody species declined, lake levels fell—all brief (ca....
The influence of Native American land-use practices on vegetation composition and structure has long been a subject significant debate. This is particularly true in portions the western United States where tribal hunter-gatherers did not use agriculture to meet subsistence other cultural needs. Climate viewed as dominant determinant change over time, but ethnographic anthropological evidence suggests that (particularly through fire) had landscape effects vegetation. However, it difficult...
Abstract. Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time the geological past. Existing global compilations not geographically comprehensive and do provide consistent metadata for all sites. Furthermore, age models provided these harmonised many based on older calibrations of radiocarbon ages. These issues limit use existing research into past regimes. Here, we present an expanded database records, accompanied by new recalibration...
Abstract Mono Lake sediments have recorded five major oscillations in the hydrologic balance between A.D. 1700 and 1941. These can be correlated with tree-ring-based Sierra Nevada snowpack. Comparison of a reconstruction Pacific Decadal Oscillation (PDO) index (D’Arrigo et al., 2001) coral-based Subtropical South sea-surface temperature (Linsley 2000) indicates high degree correlation two records during past 300 yr. This suggests that PDO has been pan-Pacific phenomena for at least few...
In marked contrast to California's landscape of urban sprawl, expansive agriculture, and wildlands altered by protectionist management systems, many landscapes in neighboring Baja California would still be recognizable the first European explorers. This book shows that vegetation present-day is remarkably similar observed 18th 19th centuries, historical fire grazing has done little alter region's resilient mediterranean-type shrublands forests.