A5053062871- Tree-ring climate responses
- Plant Water Relations and Carbon Dynamics
- Forest ecology and management
- Ecology and Vegetation Dynamics Studies
- Fire effects on ecosystems
- Geology and Paleoclimatology Research
- Climate variability and models
- Hydrology and Drought Analysis
- Hydrology and Watershed Management Studies
- Rangeland and Wildlife Management
- Atomic and Molecular Physics
- Hydrology and Sediment Transport Processes
- Advanced Chemical Physics Studies
- Forest Ecology and Biodiversity Studies
- Archaeology and ancient environmental studies
- Environmental and Cultural Studies in Latin America and Beyond
- Quantum, superfluid, helium dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Plant responses to elevated CO2
- Landslides and related hazards
- Remote Sensing and LiDAR Applications
- Climate change and permafrost
- Quantum Electrodynamics and Casimir Effect
- Chemical Reaction Mechanisms
- Cryospheric studies and observations
Louisiana Department of Natural Resources
2018-2025
University of Nevada, Reno
2016-2025
Ecological Society of America
2016
Sierra Nevada Corporation (United States)
2016
Dana-Farber/Harvard Cancer Center
2014
Harvard University
2014
Cooperative Institute for Research in Environmental Sciences
2013-2014
University of Colorado Boulder
2013-2014
Stanford University
2008
University of California, San Diego
1997-2000
Drought effects on carbon cycling The response of forest ecosystems to drought is increasingly important in the context a warming climate. Anderegg et al. studied tree-ring database 1338 sites from around globe. They found that forests exhibit “legacy effect” with 3 4 years' reduced growth following drought. During this postdrought delay, will be less able act as sink for carbon. Incorporating legacy into Earth system models provide more accurate predictions global cycle. Science , issue p. 528
The R package treeclim helps perform numerical calibration of proxy‐climate relationships, with an emphasis on tree‐ring chronologies. provides a unified, fast, and public‐domain compilation established methods while adding novel functionality not implemented in other software. includes static moving bootstrapped response correlation functions, seasonal analysis, test for spurious temporal changes relations, the evaluation reconstruction skills. stationary bootstrap method has been...
Climate in the North Pacific and American sectors has experienced interdecadal shifts during twentieth century. A network of recently developed tree-ring chronologies for Southern Baja California extends instrumental record reveals decadal-scale variability back to 1661. The decadal oscillation (PDO) is closely matched by dominant mode that provides a preliminary view multiannual climate fluctuations spanning past four centuries. reconstructed PDO index features prominent bidecadal...
One of the main elements dendrochronological standardization is removing biological trend, i.e. progressive decline ring width along a cross-sectional radius that caused by corresponding increase in stem size and tree age over time. The "conservative" option for this trend to fit modified negative exponential curve (or straight line with slope ≤ 0) ring-width measurements. This method based on assumption that, especially open-grown and/or shade-intolerant species, annual growth rate mature...
Abstract Productivity of old‐growth beech forests in the Mediterranean Basin was measured by average stem basal area increment (BAI) dominant trees at two mountain sites Italian Apennines. Both could be ascribed to stage, but they differed markedly with regard elevation (1000 vs. 1725 m a.s.l.), soil parent material (volcanic calcareous), mean tree age (less than 200 years 300 years), and stand structure (secondary primary forest). Drought quantified self‐calibrated Palmer Moisture Anomaly...
Significance Forest trees can live for hundreds to thousands of years, and they play a critical role in mitigating global warming by fixing approximately 15% anthropogenic CO 2 emissions annually wood formation. However, the environmental factors triggering formation onset springtime cellular mechanisms underlying this remain poorly understood, since forms beneath bark is difficult monitor. We report that Northern Hemisphere conifers driven primarily photoperiod mean annual temperature....
Abstract Aim To identify the dominant spatial patterns of Fagus sylvatica radial growth in Eastern Alps, and to understand their relationships climate variation bioclimatic gradients. Location Fourteen beech stands growing between 200 1500 m a.s.l. Italy, Slovenia Austria. Methods At each site, trees were sampled using increment borers or by taking discs from felled trees. Cores processed measuring crossdating ring width. Ring width series standardized, averaged, prewhitened obtain site...
Question: Which are the structural attributes and history of old-growth Fagus forest in Mediterranean montane environments? What processes underlying their organization? Are these forests stable time how does spatial scale affect our assessment stability? How do compare to other temperate deciduous forests? Location: 1600-1850 m a.s.l., near tree line, central Apennines, Italy. Methods: An was studied following historical, dendroecological approaches. History cover changes analysed using...
Abstract Fire regimes in North American forests are diverse and modern fire records often too short to capture important patterns, trends, feedbacks, drivers of variability. Tree‐ring scars provide valuable perspectives on regimes, including centuries‐long year, season, frequency, severity, size. Here, we introduce the newly compiled tree‐ring fire‐scar network (NAFSN), which contains 2562 sites, >37,000 fire‐scarred trees, covers large parts America. We investigate NAFSN terms geography,...
Historical information on forest growth is essential to evaluate and understand change in managed unmanaged forests. Two ground-truth nondestructive sources of interannual interdecadal changes are (a) repeated timber inventories (b) tree-ring chronologies. I present here a case study how those two types data can complement benefit each other. At the Gus Pearson Research Natural Area, ponderosa pine stand near Flagstaff (Arizona, USA), were by U.S. Forest Service from 1920 1990. The analysis...
Geostatistics provides tools to model, estimate, map, and eventually predict spatial patterns of tree size growth. Variogram models kriged maps were used study dependence stem diameter (DBH), basal area (BA), 10-year periodic increment (BAI) in an old-growth forest stand. Temporal variation was evaluated by fitting stochastic at intervals, from 1920 1990. The a naturally seeded stand southwestern ponderosa pine (Pinusponderosa Dougl. ex Laws. var. scopulorum) where total BA density have...
Ongoing changes in disturbance regimes are predicted to cause acute ecosystem structure and function coming decades, but many aspects of these predictions uncertain.A key challenge is improve the predictability post-disturbance biogeochemical trajectories at level.Both ecologists paleoecologists have generated complementary datasets about (type, severity, frequency) response (net primary productivity, nutrient cycling) spanning decadal multi-millennial timescales.Here, we take first steps...
Abstract When site factors reduce growth rates, tree lifespan tends to increase. This study investigates processes leading such inverse relationship in F agus sylvatica stands distributed along two elevation gradients, with an emphasis on climatic response, suppression periods, and trends. Dendrochronological records from old‐growth beech populations sampled at different elevations within bioclimatic regions ( A lps vs. pennines), were used investigate that control lifespan. Differences...
Future seasonal dynamics of wood formation in hyperarid environments are still unclear. Although temperature-driven extension the growing season and increased forest productivity expected for boreal temperate biomes under global warming, a similar trend remains questionable water-limited regions. We monitored cambial activity montane stand ponderosa pine (Pinus ponderosa) from Mojave Desert 2 consecutive years (2015-2016) showing opposite-sign anomalies between warm- cold-season...
ABSTRACT With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts tree growth, vitality, and survival. How individual species will react to increased drought is therefore a key research question address for carbon accounting the development of climate change mitigation strategies. Recent tree‐ring studies have shown that trees at higher latitudes benefit from warmer temperatures, yet this likely highly species‐dependent...
Paleorecords provide information on past environmental variability, and help define ecological reference conditions by means of changes in their characteristics (accumulation rate, geochemical composition, density, etc.). A measure temporal dissimilarity, which has traditionally been used dendrochronology is called "mean sensitivity," only focuses first-order time-series lags. In this paper mean sensitivity was extended to all possible lags derive a function (MSF). The MSF equivalent...