Tree-Ring Talk

Ecology-centered tree-ring research at ForestGEO

Reliable projections of future carbon (C) dynamics are essential to resource management decision making under a changing climate. A hybrid-biometric modelling approach that combines tree-ring based stand reconstruction and the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to estimate past magnitude and inter-annual variation of ecosystem carbon stocks and fluxes including net primary production (NPP), net ecosystem production (NEP), and heterotrophic respiration (Rh) can be used to generate additional corroborative data that may reduce uncertainty in C flux estimates.

A hybrid biometric-modelling approach for estimating carbon stock and flux indicators from tree-ring data

Reliable projections of future carbon (C) dynamics are essential to resource management decision making under a changing climate. A hybrid-biometric modelling approach that combines tree-ring based stand reconstruction and the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to estimate past magnitude and inter-annual variation of ecosystem carbon stocks and fluxes including net primary production (NPP), net ecosystem production (NEP), and heterotrophic respiration (Rh) can be used to generate additional corroborative data that may reduce uncertainty in C flux estimates.

Contrasting impacts of climate warming on Himalayan hemlock (Tsuga dumosa) growth: seasonal and elevational variations

Ongoing climate change can have varying impacts on tree growth within the growing season and across their elevation ranges, with important implications for forest ecosystem functions and services. However, our knowledge of these effects on climate-sensitive Himalayan forests is still limited. Here, we explore the elevational changes in climatic factors driving long-term changes in the radial growth of Himalayan hemlock (Tsuga dumosa), including recent responses to unprecedented climate warming in the central Himalayas.

A 250-year perspective on high spring flows and climatic drivers in eastern boreal Canada from flood rings

Flood severity in eastern boreal Canada has increased in recent decades (1990–2020) and is likely to increase with projected climate change in the 21st century. The lack of instrumental hydroclimatic data makes the study of paleoenvironmental indicators necessary to identify historical trends and long-term hydroclimatic trajectories. However, in boreal environment where water is not a limiting factor to tree growth, using tree ring width as a single proxy might not allow to capture a complete spectrum of hydrological variability.

Linking carbon fluxes, tree-rings, and xylem anatomy to better understand the processes of carbon allocation to aboveground woody biomass under drought conditions

Carbon allocation to woody tissues is a key set of processes underlying biomass increment during a tree’s growing season. Existing research has rarely addressed this process from a long-term perspective and its interannual to decadal dynamics remain poorly constrained. This also limits our understanding of the sub-seasonal connections and dynamics between carbon uptake and stem growth under a warming climate.

At the crossroads: how tree-ring reconstructions can shape policy to protect vulnerable communities in the Colorado Basin

Tree-Ring Talks Seminar

Wednesday, October 4 at Noon, MST

 

Please join us for a presentation by Dr. George Rhee on "At the crossroads: how tree-ring-reconstructions can shape policy to protect vulnerable communities in the Colorado Basin" in Bannister 110 or via zoom.

 

Abstract

Single-year dating of Siberian Scythian kurgans with 14C spike

Abstract

Photosynthetic carbon isotope discrimination in trees: observations, predictions, and drivers

Abstract: Under elevated CO2, photosynthetic carbon isotope discrimination is expected to increase in response to photosynthesis stimulation driven by the growth of atmospheric CO2. While this response is widely documented in laboratory, field experiments and short-term observations, long-term proxies indicate that such response is not universally observed in forested ecosystems.

Impact of persistent droughts on forests in Mediterranean Chile

Global warming is concurrently associated with a rise in occurrences of drought episodes in numerous regions worldwide, with central Chile a sad example. This region is the only Mediterranean bioregion of South America, which is considered a biodiversity hotspot due to high endemism levels and high anthropic pressure. These ecosystems since 2010 have been impacted by a period of below-average rainfall, a so-called Mega Drought (MD), so their contribution to the regional carbon sink is at risk.

State-of-the-art radiocarbon measurements to study Earth's carbon cycle

The development of high-precision, rapid through-put radiocarbon dating for small samples via a compact accelerator mass spectrometer — the MIni CArbon DAting System (MICADAS) — has opened a wide variety of new possibilities for next generation radiocarbon studies. This talk will explain the basics of the instrumentation (which will be installed in the Laboratory of Tree-Ring Research in 2024) and explore a variety of examples of the ways in which it can be used to explore the carbon cycle and beyond.

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