Dendrochronologia最新文献

Foresters and scientists worldwide rely on the use of increment borers to collect wood cores from living trees for dendrochronology and a range of other applications. While there are many different types of increment borers, 4–5 mm diameter manual borers are most frequently used. Although these standard-size devices have a long history with well-established protocols, a range of newer analyses require the collection of larger diameter cores from living trees. To meet these needs, researchers worldwide have developed an array of techniques to collect these types of samples but little information is available comparing approaches and synthesizing options. Here, we summarize work testing several different commonly employed techniques for excising larger width (∼10 mm diameter) cores from living trees, comparing strengths and weaknesses of each approach. In addition to informing the selection of methods and equipment for researchers collecting larger diameter cores, this information may also provide new ideas for exploring core collection options beyond traditional increment borers.

Climate change in eastern North America is likely to impact the abundance and distribution of the region’s tree species. However, determining the degree to which species will be impacted by altered climates is challenging. Dendrochronology research aimed at understanding relationships between climate and annual ring-width is one way of understanding how climate change may impact forest communities. Oak (Quercus spp.) and hickory (Carya spp.) are two foundational groups of trees likely to undergo changes in abundance and distribution due to climate change. The goal of this study was to compare the radial growth climate sensitivity of three common and co-occurring hickory species (Carya glabra, Carya ovata, and Carya tomentosa) to ecologically similar Quercus montana in southeast Ohio. Also, this study compared conspecific radial-growth climate responses between canopy and subcanopy trees to assess the impacts of climate and drought on subcanopy forest layers. All four species in the forest canopy demonstrated significant positive relationships to growing season precipitation, significant negative relationships with growing season temperature, and significant positive relationships with growing season site water balance. Subcanopy chronologies for all four species demonstrated weaker growth responses to climate, with only Carya glabra demonstrating significant growth relationships with May precipitation and site water balance. Additionally, the increased drought resistance of subcanopy trees provided some evidence of the forest overstory buffering the impacts of climate variability on understory trees. Overall, ontogenetic differences in tree sensitivity to climate variability and drought show that climate change likely has the potential to influence the forest understory, but the degree to which systems are impacted may be highly species-specific.

Pinus sabiniana (grey pine) is a common associate of Quercus douglasii (blue oak) in the iconic, ecologically-rich, and economically-relevant Mediterranean woodland savannah of California, USA. While there are dozens of Q. douglasii sites in the International Tree-Ring Data Bank, P. sabiniana was conspicuously absent, and little is known about its growth patterns or water relations. Here, we introduce a new tree-ring chronology of P. sabiniana collected in central California and assess climatic drivers of annual and sub-annual growth. Specifically, we examine earlywood, latewood, and total annual ring widths and analyse their relationships with variables related to water supply (precipitation, soil moisture) and water demand (air temperature, potential evaporation rate). Annual and earlywood widths had nearly identical responses to climate, likely because annual widths mostly consisted of earlywood (mean: 88 %). In both cases, growth was strongly and positively associated with water supply and negatively associated with water demand. Soil moisture was, by far, the strongest and most temporally-consistent correlate of P. sabiniana growth: correlations between soil moisture and annual growth were >0.8 for five contiguous 3-month seasons. Other variables were significant, in part, because of their influence on soil moisture. The association between latewood growth and climate was qualitatively similar but weaker and, with the exception of soil moisture, more seasonally localised (precipitation was relevant in winter and early spring and water demand variables were relevant in summer, somewhat later in the season than for total ring width and earlywood). Further, P. sabiniana growth was nearly always more sensitive to soil moisture than growth of either co-located Q. douglasii or P. ponderosa (ponderosa pine) at a neighbouring site, suggesting that it may act as a particularly sensitive harbinger of drought stress in this ecosystem.

Warmer and drier climate is among the main factors of the declining processes reported and expected for the future in the Mediterranean forest ecosystems. Pinus pinea is one the main Mediterranean conifers and its largest populations are in SW Spain, providing multifunctional services. The sensitivity of this species to drought is known, but the potentiality of its productivity to decline in SW Spain has not been yet assessed. We modeled P. pinea growth with climate covariates and a large set of tree ring chronologies from the beginning of the 20th century to the 2010s. Then we forecast annual increments over the period 2030–2100 using regionalized estimates of a global change model in three scenarios of greenhouse gas concentration. The climatic conditions between winter and mid spring were the most significant for the model. The climate predictions indicated an increase of potential water stress, and our forecasts described downturn trends of the annual growth, more accentuated in the scenario with the highest emissions and temperatures. These are the first long-term forecasts of growth of P. pinea in SW Spain. Our model cannot be directly applied at higher latitudes, where previous studies have shown differences in climate-growth relationships, but provides a benchmark for research and forestry of the potential climate-driven decrease of productivity of the P. pinea populations in the Southern Iberian Peninsula.

In a recent communication, Jetschke et al. (2023) compared various pointer-year detection methods against the recently published (bias-adjusted) standardized growth change method (SGC and BSGC, Buras et al., 2020, 2022). Based on their comparative evaluation, Jetschke et al. (2023) pointed out specific weaknesses of the (B)SGC methods. In this short communication, I reveal their analyses to be erroneous and consequently their conclusions to be based on false grounds.

Understanding the complex dynamics of past tree growth-climate interactions is essential for predicting forest ecosystem responses to current climate change. Here, we explore the climate drivers of long-term growth dynamics in 400-year-old Pinus ponderosa trees at Sunset Crater Volcano in northern Arizona, including recent responses to unprecedented warming. To evaluate multiple climate factors potentially limiting montane trees on porous lava at 2450 m elevation, we employed several tree-ring proxies, including total ring width (TRW), earlywood width (EWW), latewood width (LWW), earlywood minimum density (minD), and latewood maximum density (maxD). We used static and moving correlations to assess how variations in previous and current year temperatures, precipitation, Standardised Precipitation-Evapotranspiration Index (SPEI), El Niño 3.4, and Pacific Decadal Oscillation (PDO) indices impact overall growth and density and their seasonal pattern. Our analyses revealed a seasonal shift in climate drivers, from the positive influence of winter and spring precipitation on EWW and minD to the negative effect of high summer temperatures and drought on LWW and maxD. This supports the hypothesis that tree growth in semi-arid regions results from a complex interplay between soil water content and evaporative forcing. Diminished precipitation and increased temperatures reduced EWW (constituting ∼60 % of total TRW), notably in the years 1925–1950 and 1990–2010, while the most favorable periods for growth were during cooler, wetter years 1900–1925 and 1960–1980, resulting in large EWW with low minD. During the warmer and drier years of 1930–1960 and 1990–2016, warmer Pacific waters, indicated by positive PDO and El Niño 3.4 indices, promoted wider earlywood with larger lumen size and thus lower minD, likely due to increased moisture and reduced spring drought. There was no marked growth decline in the last three warmest decades due to relatively stable precipitation. However, since the 1980s, climate drivers have shifted from winter and spring to summer, possibly contributing to extremely low growth years and fire events in the region due to summer heatwaves and droughts. These findings contribute to a better understanding of the complex relationship between climate change and tree growth dynamics in vulnerable semi-arid mountain forests.

In recent decades, xylem anatomical traits have become increasingly important in dendrochronological research, as they offer the unique opportunity to assess eco-physiological drivers of tree growth at intra-annual resolution. However, standard protocols for generating such data are still missing, leading to methodological uncertainty, and complicating data exchange among laboratories. Here, we compare protocols for high-quality permanent slide preparation in dendroanatomy and address the effects of paraffin embedding vs. non-embedding approaches. Tests are conducted on both gymnosperm and angiosperm wood types of widely distributed European tree species, considering cell wall thickness (CWT), mean lumen area (MLA), and hydraulic diameter (Dh). Results indicate that non-embedding does not significantly alter the qualitative and quantitative characteristics of permanent slides compared to embedded samples. Whereas the mean chronologies of MLA and Dh and their non-embedded counterparts share substantial high-frequency variance, the CWT chronologies reveal slightly larger discrepancies at inter-annual scale. However, methodological differences do not exceed 11.1 % for any parameter. While these results show high similarity between the two approaches, we recommend adopting the non-embedding procedure, since it saves resources and therefore allows to produce larger datasets. Regardless of the protocol used to build wood anatomical datasets, assembling large-scale networks of wood anatomical data could transform our understanding of forest responses to global changes.

This paper evaluates the dendrochronological potential of Prosopis nigra in the subtropical xerophytic forests of northeastern Argentina, an area of the Espinal forest particularly poor in dendrochronological records. Our study is based on tree-ring analyses of 23 cross sections providing a high-quality chronology (Rbar = 0.24 and EPS = 0.92). The mean annual radial increment recorded was 2.38 ± 1.51 mm. The inter-annual variability in the tree rings indicates that water availability from the previous winter to the current summer growing season is the major forcing on tree growth. Above-average rainfall and SPEI from July to February favored radial growth. Our results show for the first time the strong influence of both ENSO 3.4 and subtropical Atlantic SST variations, mediated by changes in local precipitation, on the growth of P. nigra in the Espinal. We concluded that P. nigra has great dendrochronological and dendroclimatological potential, since its rings are visible after careful polishing of the samples, and its inter-annual variations in radial growth are related to regional climate variability. These results can help improve our knowledge of the vulnerability of xerophytic forests to climate change in northeastern Argentina. In addition, this dendroclimatological study provides new proxy climate records for the Pampean grasslands, one of the most important food producing regions in the world.

As climate change intensifies, trees face heightened drought risks, impacting future forest composition. This study compares the climate sensitivity and resilience of black pine (Pinus nigra) across its north-south distribution range, guiding adaptive forest management amidst changing environmental conditions. Tree-ring cores from 211 P. nigra trees across seven sites in northern distribution (Slovenia) and three different sites in southern distribution range (Western Turkey), including the subspecies P. nigra subsp. nigra and P. nigra subsp. pallasiana, were analyzed. We investigated climate-growth dynamics, evaluating temperature and precipitation correlations with tree-ring width indices, and analyzed resilience indices. Leveraging remote sensing data, disparities in surface reflectance and photosynthetic activity were assessed. Our findings reveal distinct climate-growth patterns between southern and northern P. nigra populations, with precipitation predominantly shaping growth in the south and both precipitation and temperature influencing growth in the north. Given the site-specific conditions of each population, resilience indices further suggest that P. nigra subsp. pallasiana exhibits stronger drought tolerance. Sites in the northern range show the lowest resistance due to precipitation limitation. Temperature-limited sites demonstrate the highest resilience, indicating potential long-term effects of drought on tree growth. Our findings enhance our understanding of the climate-growth responses and resilience mechanisms in two subpopulations of Pinus nigra in Southern Europe.