Symposium 1 (PT 2). Tree rings from national forest inventories: a timely opportunity to assess tree growth across space and through time
My Session Status
Tree-ring time series provide long-term, annually resolved information on the growth of individual trees. However, public tree-ring archives contain a considerable portion of data collected from trees that have been selected with specific research questions in mind (e.g., for climate reconstruction). This makes these archives a biased representation of the sensitivity of forest ecosystems to ongoing climate variation (e.g. temperature, precipitation), including non-stationarity (i.e., global warming and associated changes to Earth’s climate). Many public collections also lack the tree and forest information needed to quantify forest-level growth, making it very difficult to scale-up tree-level information to ecosystem estimates of biomass accumulation and carbon sequestration. National forest inventories (NFIs), by comparison, are systematic observatories of forest ecosystems designed specifically for large-scale inference. Yet, this spatial information comes at relatively low temporal (e.g. decadal) resolution and hampers the investigation of forest responses to annual climate variability as well as seasonal and climate extremes. When tree-ring data are collected in NFIs (or other statistically designed) forest plot networks, multiple influences on tree growth can be captured in an unbiased and representative way—not just climate, but also competition, disturbance processes, and other environmental factors (atmospheric CO2 concentration, N deposition)—which is critical to parse their effects and understand how they may interact. A systematic effort to sample tree rings in NFIs can yield unprecedented temporal and spatial resolution of the drivers of forest and carbon dynamics. This symposium aims to showcase the latest work on the development and applications of tree rings collected from NFIs and forest plot networks. Applications of NFI tree-ring data may include retrospective analyses of spatial variations in productivity and climate sensitivity, efforts to improve carbon accounting, examinations of climate change impacts, and assessments of mitigation potential critical for Earth’s habitability.
Sub Sessions
Mexico has a forest cover of 660,400 km2, representing 34% of its territory. Due to deforestation and land-use change, Mexico has lost 32,200 km2 over the last 25 years, representing 1.9% of its territory. Mexican forests are now additionally threatened by climate change. Currently, there is no assessment of the impact of current and future climatic changes on forest productivity to develop mitigation and adaptation plans in the forestry sector. Most growth studies in Mexico focus on clima...
As northern latitudes experience rapid winter warming, there is an urgent need to assess the effect of varying winter conditions on tree growth and forest carbon sequestration potential. We examined tree growth responses to variability in cold-season (November-April) frequency of freeze days (FFD) over 1951-2018 using tree-ring data from 35,217 trees and 57 species at 4,375 sites distributed across Canada. We found that annual radial growth responses to FFD varied by species, with some com...
Montane forests of Central Europe are experiencing faster changes in climate than the average trends. It is still unclear how these natural forests, and especially saplings, have responded to recent modifications in growth conditions. We took advantage of the REMOTE forests network to look at the changes in juvenile growth rates of Norway spruce and European beech, two economically important tree species in Europe. This network includes ring-widths series of more than 19,000 spruces and 14...
The objective of this study is to identify and estimate the impact of the change in climate on the annual growths of the three main forest species from Romanian forests: Norway spruce, European beech, and sessile oak. We have used more than 6500 increment cores of the National Forest Inventory in combination with the Romanian homogenized climatic data. To ensure more than 30 observations per time step, we have used quinquennials rather than years. Using a longitudinal autoregressive mixed ...
Our understanding of climate change impacts on boreal forest net primary productivity (NPP) largely rely on terrestrial biosphere models (TBMs). TBMs characterize forest NPP through predictions of plant carbon fluxes and allocation from climatic data, physiological parameters and process logic. TBMs’ outcomes may be highly variable, a major source of uncertainty being the formulation of ecophysiological processes and their parameterization. In our study, we compared patterns of growth resp...