Christopher H. Baisan

Christopher H. Baisan
The University of Arizona | UA · Laboratory of Tree-Ring Research

About

88
Publications
19,549
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3,335
Citations
Additional affiliations
June 1987 - present
The University of Arizona
Position
  • Sr Research Specialist
June 1987 - present
The University of Arizona
Position
  • Sr Research Specialist

Publications

Publications (88)
Article
Full-text available
Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree‐ring fire scars provide valuable perspectives on fire regimes, including centuries‐long records of fire year, season, frequency, severity, and size. Here, we introduce the...
Article
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Every year, millions of hectares burn across Siberia, driven by a combination of warming temperatures, regional drought and human-caused ignitions. Dendrochronology provides a long-term context to evaluate recent trends in fire activity and interpret the relative influence of humans and climate drivers on fire regimes. We developed a 400-year recor...
Article
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A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-21647-w
Article
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Context Montane grasslands and forest-grassland ecotones are unique and dynamic components of many landscapes, but the processes that regulate their dynamics are difficult to observe over ecologically relevant time spans. Objectives We aimed to demonstrate the efficacy of using grassland-forest ecotone trees to reconstruct spatial and temporal pro...
Article
E xcursions in the carbon-14 (14 C) record measured in tree rings are attributed to various high energy but short-lived cosmic effects 1-7. Wang et al. 8 proposed a new event at 3372-3371 BCE based on a single set of annual 14 C data measured on a floating tree rings from a buried specimen of Chinese wingnut (Pterocarya stenoptera). Here we attempt...
Article
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Annually resolved radiocarbon ( ¹⁴ C) measurements on tree rings led to the discovery of abrupt variations in ¹⁴ C production attributed to large solar flares. We present new results of annual and subannual ¹⁴ C fluctuations in tree rings from a middle-latitude sequoia (California) and a high-latitude pine (Finland), analyzed for the period 1030–10...
Article
Conifer mortality rates are increasing in western North America, but the physiological mechanisms underlying this trend are not well understood. We examined tree‐ring based radial growth along with stable carbon and oxygen isotope composition (d13C and δ18O, respectively) of dying and surviving conifers at eight old‐growth forest sites across a str...
Article
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The iconic Plaza Tree of Pueblo Bonito is widely believed to have been a majestic pine standing in the west courtyard of the monumental great house during the peak of the Chaco Phenomenon (AD 850–1140). The ponderosa pine ( Pinus ponderosa ) log was discovered in 1924, and since then, it has been included in “birth” and “life” narratives of Pueblo...
Preprint
Excursions in the carbon-14 record measured in tree rings are attributed to various high energy but short-lived cosmic effects. So far, rapid changes at 774-775 CE, 993-994 CE and 660 BCE have been convincingly interpreted as due to rapid changes in solar cosmic-ray flux, usually accredited with reproduction of the events in trees at different loca...
Article
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Unraveling the effects of climate and land use on historical fire regimes provides important insights into broader human–fire–climate dynamics, which are necessary for ecologically based forest management. We developed a spatial human land‐use model for Navajo Nation forests across which we sampled a network of tree‐ring fire history sites to refle...
Article
The Spanish Colonial Mission San Xavier del Bac near Tucson, Arizona has been studied extensively for its contribution to the origin and development of Tucson as an urban center. While the general timeline of construction is understood from historical documentation, suggestions of timber reuse from earlier structures (Fontana, 2015) have not been s...
Article
Forty-one fire-scarred samples from two new Cedrus atlantica sites in the Ouled-Yaâgoub Forest were collected and combined with the two previous sites from the Chelia Forest reported in Slimani et al. (2014) to develop a regional analysis of fire history in the Aurès Mountains, northern Algeria. Prior to 1850, cedar forests were characterized by hi...
Article
Two floating, ring-width chronologies predate the long bristlecone pine (Pinus longaeva) absolutely-dated, ring-width chronology from the Methuselah Walk (MWK) site in the White Mountains of California. The two non-overlapping floating chronologies were derived from samples that crossdate internally but are temporally unconnected to each other and...
Article
Two radiocarbon ( ¹⁴ C) excursions are caused by an increase of incoming cosmic rays on a short time scale found in the Late Holocene (AD 774–775 and AD 993–994), which are widely explained as due to extreme solar proton events (SPE). In addition, a larger event has also been reported at 5480 BC (Miyake et al. 2017a), which is attributed to a speci...
Poster
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Insights of the history of domestication of Sycamore figs in the Mediterranean Bassin, culturally and religiously important trees asexually propagated by humans, using next generation sequencing.
Article
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Dendroecology is the science that dates tree rings to their exact calendar year of formation to study processes that influence forest ecology (e.g., Speer 2010 [1], Amoroso et al., 2017 [2]). Reconstruction of past fire regimes is a core application of dendroecology, linking fire history to population dynamics and climate effects on tree growth and...
Article
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We performed a new series of measurements on samples that were part of early measurements on radiocarbon ( ¹⁴ C) dating made in 1948–1949. Our results show generally good agreement to the data published in 1949–1951, despite vast changes in technology, with only two exceptions where there was a discrepancy in the original studies. Our new measureme...
Article
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Radiocarbon content in tree rings can be an excellent proxy of the past incoming cosmic ray intensities to Earth. Although such past cosmic ray variations have been studied by measurements of 14C contents in tree rings with ≥ 10-y time resolution for the Holocene, there are few annual 14C data. There is a little understanding about annual 14C varia...
Article
This illustrated glossary presents a selection of essential terms and people in the study of dendrochronology,in Arabic and English. It is intended to make accessible an array of related literature to Arabic readers, inhopes that the application of tree-ring research will be more widely applied to archaeological studies,especially in Egypt.
Article
Full-text available
Two radiocarbon excursions (AD 774?775 and AD 993?994) occurred due to an increase of incoming cosmic rays on a short timescale. The most plausible cause of these events is considered to be extreme solar proton events (SPE). It is possible that there are other annual 14 C excursions in the past that have yet to be confirmed. In order to detect more...
Article
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In ponderosa pine and mixed conifer ecosystems of the Southwestern US, regional-scale climate tends to synchronize fire years among study sites and increase fire extent or severity within a forest. At landscape scales (1-100km2), fire frequency and severity may also be influenced by local-scale differences in elevation and aspect, including fire ba...
Article
AimThe purpose of this study was to examine the influence of moisture and fire on historical ponderosa pine (Pinus ponderosa Dougl. ex Laws.) age structure patterns.LocationWe used a natural experiment created over time by the unique desert island geography of southern Arizona.Methods We sampled tree establishment dates in two sites on Rincon Peak...
Article
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Fire history researchers employ various forms of search-based sampling to target specimens that contain visible evidence of well preserved fire scars. Targeted sampling is considered to be the most efficient way to increase the completeness and length of the fire-scar record, but the accuracy of this method for estimating landscape-scale fire frequ...
Article
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The past fire regime of European black pine (Pinus nigra Arn.) forests in Valia Kalda in Greece was investigated by standard dendrochronology methods. The sampled trees contained a record of fires from the early 14th Century through the late 19th Century with the last fire recorded in 1891. Evidence of non-lethal surface fires over the past seven c...
Conference Paper
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Background/Question/Methods Montane grasslands are widely distributed across the western United States, including the southern and central Rocky Mountains, but little is understood about their historic fire regimes. These ecosystems provide habitat for numerous species of flora and fauna, while benefiting local economies through livestock grazing...
Article
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We used tree-ring and alluvial sediment methods to reconstruct past fire regimes for a mixed conifer forest within a 1 km2 drainage basin which was severely burned by a wildfire near Durango, Colorado. Post-fire debris flow events incised the valley-filling alluvial sediments in the lower basin, and created exposures of fire-related of deposits of...
Article
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Fire scars are used widely to reconstruct historical fire regime parameters in forests around the world. Because fire scars provide incomplete records of past fire occurrence at discrete points in space, inferences must be made to reconstruct fire frequency and extent across landscapes using spatial networks of fire-scar samples. Assessing the rela...
Article
Despite the extensive network of moisture-sensitive tree-ring chronologies in western North America, relatively few are long enough to document climatic variability before and during the Medieval Climate Anomaly (MCA) ca. AD 800-1300. We developed a 2300-yr tree-ring chronology extending to 323 BC utilizing live and remnant Douglas-fir (Pseudotsuga...
Article
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Bigcone Douglas-fir (Pseudotsuga macrocarpa [Vasey] Mayr) is a long-lived, fire-adapted conifer that is endemic to the Transverse Ranges of southern California. At the lower and middle reaches of its elevational distribution, isolated stands of bigcone Douglas-fir are surrounded by extensive stands of chaparral. Our dendrochronology investigations...
Article
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Giant sequoias (Sequoiadendron giganteum [Lindl.] J. Buchholz) preserve a detailed history of fire within their annual rings. We developed a 3000 year chronology of fire events in one of the largest extant groves of ancient giant sequoias, the Giant Forest, by sampling and tree-ring dating fire scars and other fire-related indicators from 52 trees...
Article
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Spatial and temporal patterns of fire history are affected by factors such as topography, vegetation, and climate. It is unclear, however, how these factors influenced fire history patterns in small isolated forests, such as that found on Rincon Peak, a “sky island” mountain range in southern Arizona, USA. We reconstructed the fire history of Rinco...
Article
Full-text available
Bigcone Douglas-fir (Pseudotsuga macrocarpa [Vasey] Mayr) is a long-lived, fire-adapted conifer that is endemic to the Transverse Ranges of southern California. At the lower and middle reaches of its elevational distribution, isolated stands of bigcone Douglas-fir are surrounded by extensive stands of chaparral. Our dendrochronology investigations...
Article
Anthropogenic climate change is projected to exacerbate midlatitude aridity. Here, we analyze newly developed multi-century tree-ring records for a long-term perspective on drought in Tunisia and Algeria. We use a new set of 13 Cedrus atlantica and Pinus halepensis chronologies with a strong signal for warm-season drought (May-August) to generate a...
Article
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Primary methods for reconstructing paleofire occurrence include development of charcoal concentrations from radiocarbon-dated sediments (Whitlock and Anderson 2003) and dendrochronological dating of fire scars from live or dead trees (Swetnam and Baisan 1996). Seldom are these two methods combined at individual study sites to compare the interpreta...
Article
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1] New tree-ring records of ring-width from remnant preserved wood are analyzed to extend the record of reconstructed annual flows of the Colorado River at Lee Ferry into the Medieval Climate Anomaly, when epic droughts are hypothesized from other paleoclimatic evidence to have affected various parts of western North America. The most extreme low-f...
Article
Seasonal δ13 C changes observed in tree rings offer the potential of reconstructing environmental conditions at finer than annual resolution. In the American Southwest, an opportunity to better expose environmental influences on tree-ring δ13 C at seasonal scales is fortuitously afforded by the presence of a time marker within rings. The strong win...
Article
A time series of annual flow of the Sacramento River, California, is reconstructed to A.D. 869 from tree rings for a long-term perspective on hydrologic drought. Reconstructions derived by principal components regression of flow on time-varying subsets of tree-ring chronologies account for 64 to 81 percent of the flow variance in the 1906 to 1977 c...
Article
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The variability of the North American Monsoon System (NAMS) is important to the precipitation climatology of Mexico and the southwestern United States. Tree-ring studies have been widely applied to climatic reconstruction in western North America, but as yet, have not addressed the NAMS. One reason is the need for highly resolved seasonal dendrocli...
Article
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In southwestern North America, large-scale climate patterns appear to exert control on moisture availability, fire occurrence, and tree demography, raising the compelling possibility of regional synchronization of forest dynamics. Such regional signals may be obscured, however, by local, site-specific factors, such as disturbance history and land u...
Article
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Patterning in fire regimes occurs at multiple spatiotemporal scales owing to differences in scaling of local and regional influences. Local fire occurrence and behavior may be controlled largely by site factors, while regional climate and changes in human land use can synchronize fire timing across large areas. We examined historical patterns in fi...
Article
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In this paper we evaluate the associations between elevation and fire frequency and interannual climatic variability and fire occurrence at the regional scale. We reconstruct fire chronologies in a large set of stands over a broad range of elevations. Although we do not specifically evaluate human effects on past fire regimes, we identify and discu...
Article
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Four centuries of land use history were compared to fire regime characteristics along a use-intensity gradient. Changes in intensity and type of utilization varied directly with changes in fire regime characteristics near population centers, while remote areas shows little effect. Changes in fire frequency and fore-climate relationships during some...
Article
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Fire-scar chronologies from a network of 63 sites in the southwestern United States are listed and described. These data characterize the natural range and variability of fire regimes from low elevation pine forests to higher elevation mixed-conifer forests since AD 1700. A general pattern of increasing length of intervals between low intensity sur...
Article
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California Department. of Forestry and Fire Protection Mountain Home State Forest P.O. Box 417, Springville, CA 93265 Contract No. 8CA17025 June 21, 1994
Conference Paper
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Fire-scarred logs, snags, and trees were sampled within an oak-pine woodland and adjacent conifer-dominated gallery forest in Rhyolite Canyon, Chiricahua National Monument. Dendrochronological analysis of these firescarred samples documents a fire regime characterized by episodic surface fires that occurred at intervals of 1 to 38 years. The mean f...