Stadium Woods: A dendroecological analysis of an old-growth forest fragment on a university campus

On the Virginia Tech campus, adjacent to the football stadium is a 4.6-ha forest fragment that contains a population of unusually large white oak (Quercus alba L.) trees. We used dendroecology and sampled vegetation in fixed area plots to reconstruct the disturbance history of this forest fragment and compared the radial-growth averaging criteria and the boundary-line release criteria for identifying canopy disturbances. Structurally, the Stadium Woods has an inverse-J diameter distribution and trees present in all canopy strata. The oldest white oak had periods of asynchronous suppression and release indicating a closed canopy forest with periodic canopy disturbances. The boundary-line release criteria detect a broader range of growth releases, whereas the radial-growth averaging criteria are more specialized for capturing canopy gaps. Release events identified with the boundary-line release criteria lagged an average of 5.8 years behind those identified with the radial-growth averaging criteria because the boundary line release criteria identifies the year of maximum percent growth change, whereas the radial-growth averaging criteria identifies the first year with a detectable increase in radial growth. The Stadium Woods represents a unique collection of unusually large white oak trees growing in a heavily populated area and reveals the importance of long-term tree-ring chronologies stored within urban forest fragments.     

Comparative analysis of dendroecological methods used to assess disturbance events

The use of dendroecological methods to identify and describe disturbance histories has become quite common, and numerous techniques have been developed. These methods simultaneously use accurately dated and measured tree rings and objective criteria to identify release events; i. e., sustained increases in radial growth. The goals of this investigation were to perform a literature review to identify the various methods used to identify release events, critically compare the methods, and use an appropriate method to describe the disturbance history of a mixed mesophytic old-growth forest of Ohio, U. S. A. Application of 30 different methods resulted in substantial differentes in the number of disturbance events and the disturbance return interval. Analysis of individual growth segments revealed a large portion to be non-normally distributed. Furthermore, non-normality was especially high during identified disturbance events. We subsequently modified an existing disturbance identification method by changing the measure of central tendency from the mean to the median growth rate since medians are more robust estimators of central tendency than means. Application of this running median method (> 25 or 50 % increase in radial growth when medians of adjacent 10-yr growth segments are compared) to tree-ring series obtained from the study site led to the identification of numerous synchronous and asynchronous radial-growth increases among the individual tress. Based an the observed release patterns, we hypothesize that the disturbance regime of the old-growth stand is best categorized by gap-phase dynamics.     

burnr: Fire history analysis and graphics in R

We developed a new software package, burnr, for fire history analysis and plotting in the R statistical programming environment. It was developed for tree-ring fire-scar analysis, but is broadly applicable to other event analyses (e.g., avalanches, frost rings, or culturally modified trees). Our new package can read, write, and manipulate standard tree-ring fire history FHX files, produce fire—demography charts, calculate fire frequency and seasonality statistics, and run superposed epoch analysis (SEA). A key benefit of burnr is that it enables automation of analyses and plotting, especially for large data sets. The package also facilitates creative plotting, mapping, and analyses when combined with the thousands of packages available in R. In this paper, we describe the basic functionality of burnr and introduce users to fire history analyses in R.     

xRing—An R package to identify and measure tree-ring features using X-ray microdensity profiles

Climate influences tree-ring density and ring-density variables extracted from X-ray images have been widely used for climate reconstructions. The R package xRing was developed to identify and measure tree rings on X-ray microdensity profiles automatically. This package is available for free and it offers functions to visualize and calibrate X-ray images, to detect tree-ring borders and to identify earlywood-latewood transition using wood density variations at the inter- and the intra-ring scale. The most important functions are calibrateFilm, detectRings, correctRings, detectEwLw, and getDensity. Outputs of these functions are S3 objects, for which specific methods are provided, including plot and print. The non-linear relationship between optical density of the film and wood density is defined by the function calibrateFilm. The function detectRings detects tree rings using wood density profiles as input. This function uses the difference between local maximum and minimum values to identify tree-ring borders automatically. The correctRings function is used to call a Graphical User Interface (GUI) to visualize and to correct tree-ring borders manually. After correcting tree-ring borders, the detectEwLw function is used to compute earlywood and latewood widths by dividing rings according to relative intra-ring density changes. The getDensity function computes for each tree ring the minimum (maximum) density and the mean earlywood, latewood and whole-ring density. Finally, a list with dataframes with tree-ring width and density variables can be obtained using the function getRwls. One of the major advantages of xRing package is that requires little knowledge of R language, but at the same time it can be easily changed or adapted by experienced users.     

Tree-ring-based disturbance reconstruction in interdisciplinary research: Current state and future directions

Disturbances play an important role in forest dynamics. The determination of long-term spatiotemporal characteristics of disturbance regimes is essential for understanding forest dynamics and its shifts under global changes. Tree rings are known to provide detailed insight into both temporal and spatial patterns of forest disturbance history. One of the most commonly used indirect tree-ring techniques for investigating past disturbances is growth release detection (GRD), i.e. the abrupt radial growth increase of trees as a reaction to improved light conditions after the death of a disturbed neighbouring canopy tree or trees. However, there are several issues which have not been addressed so far. Here, an overview of GRD and guide for researchers aiming to incorporate GRD into their research is provided, with focus on conventional running mean methods. The aim is to cover various issues of the GRD procedure such as sampling strategy and data quality, selection of appropriate methods and parameter settings, suggested analysis procedures as well as result presentation. Overall, the importance of GRD incorporation in multidisciplinary studies of forest dynamics is highlighted, as it offers a precise tool for gathering long-term information about past disturbances. Lastly, this paper also suggests several future challenges focused on possible utilization of GRD in mainstream ecology to answer long-standing global ecological questions and improve understanding of past processes in forest ecosystems.     

Refining the standardized growth change method for pointer year detection: Accounting for statistical bias and estimating the deflection period

Detecting pointer years in tree-ring data is a central aspect of dendroecology. Pointer years are usually represented by extraordinary secondary tree growth, which is often interpreted as a response to abnormal environmental conditions such as late-frosts or droughts. Objectively identifying pointer years in larger tree-ring networks and relating those to specific climatic conditions will allow for refining our understanding of how trees perform under extreme climate and consequently, under anticipated climate change. Recently, Buras et al. (2020) demonstrated that frequently used pointer-year detection methods were either too sensitive or insensitive for such large scale analyses. In their study, Buras et al. (2020) proposed a novel approach for detecting pointer years – the standardized growth change (SGC) method which outperformed other pointer-year detection methods in pseudopopulation trials. Yet, the authors concluded that SGC could be improved further to account for the inability to detect pointer years following successive growth decline. Under this framework, we here present a refined version of the SGC-method – the bias-adjusted standardized growth change method (BSGC). The methodological adjustment to the SGC approach comprises conflated probabilities derived from standardized growth changes with probabilities derived from a time-step specific global standardization of growth changes. In addition, BSGC allows for estimating the length of the deflection period, i.e. the period before extraordinary growth values have reached normal levels. Application of BSGC to simulated and measured tree-ring data indicated an improved performance in comparison to SGC which allows for the identification of pointer years following years of successive growth decline. Also, deflection period lengths were estimated well and revealed plausible results for an existing tree-ring data set. Based on these validations, BSGC can be considered a further refinement of pointer-year detection, allowing for a more accurate identification and consequently better understanding of the radial growth response of trees to extreme events.     

Calibrating the radial-growth averaging method for detecting releases in old-growth forests of coastal British Columbia,Canada

Dendroecological methods that use growth releases to reconstruct the history of canopy disturbances are most useful when calibrated for specific species in specific forest types. In this study, we calibrate the radial-growth averaging method to detect growth releases of western redcedar (Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and Pacific silver fir (Abies amabilis Dougl. ex J. Forbes) following fine-scale canopy disturbances in old-growth forests of coastal British Columbia, Canada. Our goal is to establish a version of the method that will capture the full range of growth increases that occur for the study species following natural, fine-scale canopy gaps, yet will account for the effects of climatic variability on radial growth and growth increases. We used traditional dendroclimatological techniques and the radial-growth averaging method to examine how climatic and regional-scale factors contributed to radial growth and growth increases. In addition, we did a sensitivity analysis, using both ring widths and basal area increments, to explore how varying the values of three parameters of the radial-growth averaging method (threshold, moving average, and window) influenced the proportion of trees that showed a release pattern following the formation of canopy gaps of known timing of origin. Although radial growth of western redcedar and western hemlock was significantly associated with climate, percent-growth change derived from residual chronologies rarely exceeded 25%, which defined our minimum threshold for a release. For the sensitivity analysis, two general trends were common to all three species: (1) as threshold increased, the proportion of trees that showed a release pattern decreased, particularly for western redcedar and (2) a higher proportion of trees showed a release pattern using a 10-year versus a 5-year window, particularly for thresholds <100%. The greatest proportion of trees showed a release pattern using a 25% threshold, 5-year moving average, and 10-year window for both ring widths and basal area increments. Overall, a higher proportion of trees showed a release pattern using basal area increments as opposed to ring widths. Therefore, basal area increments are better suited to assess releases in these old-growth stands that have large inter- and intra-species variability in tree size. By establishing these empirically-based criteria, we have achieved the first step towards quantifying attributes of growth releases of trees in the study stands, allowing future studies to capture the variability of past disturbance events and predict changes in forest structure and composition over time.     

IncrementR: Analysing height growth of trees and shrubs in R

Dendrochronology mostly deals with secondary (radial) growth and attention to primary (height) growth has so far been limited. However, tree-ring widths might not adequately represent stem volume increments, net primary productivity and the size of the tree stem carbon sink. The main reason for the prevailing focus on radial growth is that establishing height growth chronologies requires time-consuming and destructive methods. However, for certain ecological applications, less laboriously acquired data on height growth averaged over several successive years are satisfactory. Here we present an R package that contains a set of tools for the analysis of height growth. The tools have been developed for input data of tree-ring widths extracted from series of successive stem height levels. Tree-ring widths ideally represent four directions in each cross section to capture potential changes in stem eccentricity between various height levels. The main computed parameters provided by the package include height growth along the stem, changes of stem eccentricity and stem taper. Accurate determination of average height growth depends on the correct estimation of the number of tree rings at different stem height levels, which might be complicated by missing rings in off-pith cores. The presented package therefore also contains functions implementing common procedures for the estimation of the number of missing tree rings near to the pith. Most outputs can be visualized graphically. The package is useful for estimating height growth in ecological and dendrogeomorphological studies, especially in situations where both primary and secondary growth is influenced by different environmental factors. It is also useful for analysing tree-ring chronologies assembled using serial sectioning, which typically applies to shrubs.     

DendroSync: An R package to unravel synchrony patterns in tree-ring networks

Spatial synchrony refers to the presence of a common signal for a time-varying characteristic that, in dendrosciences, is shared among tree-ring chronologies from a particular area. Analysis and interpretation of synchrony patterns in tree-ring networks is currently limited by: (i) the requirement for flexible modelling of complex correlations and heteroscedastic errors and (ii) the availability of ready-to-use open software to fulfil this task. We present an R package (DendroSync) that facilitates estimating and plotting synchrony patterns for pre-defined groups. The package has been devised to work with traits derived from tree rings (e.g. ring-width), but other data types are also suitable. It combines variance-covariance mixed modelling with functions that quantify the degree to which tree-ring chronologies contain a common signal over a fixed time period. It also estimates temporal changes in synchrony using a moving window algorithm. The functionality and usage of DendroSync are illustrated using a simple example.     

An organismal view of dendrochronology

An organism is the most basic unit of independent life. The tree-ring record is defined by organismal processes. Dendrochronology contributes to investigations far removed from organismal biology, e.g., archeology, climatology, disturbance ecology, etc. The increasing integration of dendrochronology into a diverse research community suggests an opportunity for a brief review of the organismal basis of tree rings.Trees are dynamic, competitive, and opportunistic organisms with diverse strategies for survival. As with all green plants, trees capture the energy in sunlight to make and break chemical bonds with the elements essential for life. These essential elements are taken from the atmosphere, water, and soil. The long tree-ring series of special interest to dendrochronology result from long-lived trees containing relatively little decayed wood. Both of those features result from organismal biology. While the tree-ring record tells us many things about local, regional, and even global environmental history, tree rings are first a record of tree survival.     

dendroTools: R package for studying linear and nonlinear responses between tree-rings and daily environmental data

We introduce in this paper the dendroTools R package for studying the statistical relationships between tree-ring parameters and daily environmental data. The core function of the package is daily_response(), which works by sliding a moving window through daily environmental data and calculating statistical metrics with one or more tree ring proxies. Possible metrics are correlation coefficient, coefficient of determination and adjusted coefficient of determination. In addition to linear regression, it is possible to use a nonlinear artificial neural network with the Bayesian regularization training algorithm (brnn). dendroTools provides the opportunity to use daily climate data and robust nonlinear functions for the analysis of climate-growth relationships. Models should thus be better adapted to the real (continuous) growth of trees and should gain in predictive capabilities. The dendroTools R package is freely available in the CRAN repository. The functionality of the package is demonstrated on two examples, one using a mean vessel area (MVA) chronology and one a traditional tree-ring width (TRW).     

Age-dependent responses of tree-ring growth and intra-annual density fluctuations of Pinus pinaster to Mediterranean climate

Dendrochronology generally assumes that climate–growth relationships are age independent once the biological growth trend has been removed. However, tree physiology, namely, photosynthetic capacity and hydraulic conductivity changes with age. We tested whether the radial-growth response to climate and the intra-annual density fluctuations (IADFs) of Pinus pinaster Ait. varied with age. Trees were sampled in Pinhal de Leiria (Portugal), and were divided in two age classes: young (<65 years old) and old (>115 years old). Earlywood and tree-ring width of young P. pinaster trees were more sensitive to climate influence while the response of latewood width to climate was stronger in old trees. Young trees start the growing season earlier, thus a time window delay occurs between young and old trees during which wood cells of young trees integrate environmental signals. Young trees usually have a longer growing season and respond faster to climate conditions, thus young P. pinaster trees presented a higher frequency of IADFs compared with old trees. Most of the IADFs were located in latewood and were positively correlated to autumn precipitation. The radial-growth response of P. pinaster to climate and the IADFs frequency were age dependent. The use of trees with different age to create a tree-ring chronology for climate studies can increase the resolution of climatic signals. Age-dependent responses to climate can also give important clues to predict how young and old trees react to climate change.     

Responses of tree-ring growth and crop yield to drought indices in the Shanxi province,North China

In this paper, we analyze the relationships among the tree-ring chronology, meteorological drought (precipitation), agricultural drought (Palmer Drought Severity Index PDSI), hydrological drought (runoff), and agricultural data in the Shanxi province of North China. Correlation analyses indicate that the tree-ring chronology is significantly correlated with all of the drought indices during the main growing season from March to July. Sign test analyses further indicate that the tree-ring chronology shows variation similar to that of the drought indices in both high and low frequencies. Comparisons of the years with narrow tree rings to the severe droughts reflected in all three indices from 1957 to 2008 reveal that the radial growth of the trees in the study region can accurately record the severe drought for which all three indices were in agreement (1972, 1999, 2000, and 2001). Comparisons with the dryness/wetness index indicate that tree-ring growth can properly record the severe droughts in the history. Correlation analyses among agricultural data, tree-ring chronology, and drought indices indicate that the per-unit yield of summer crops is relatively well correlated with the agricultural drought, as indicated by the PDSI. The PDSI is the climatic factor that significantly influences both tree growth and per-unit yield of summer crops in the study region. These results indicate that the PDSI and tree-ring chronology have the potential to be used to monitor and predict the yield of summer crops. Tree-ring chronology is an important tool for drought research and for wider applications in agricultural and hydrological research.     

MtreeRing: An R package with graphical user interface for automatic measurement of tree ring widths using image processing techniques

Accurate measurements of ring-width series are essential for dendrochronological analyses. We present an R package MtreeRing for ring-width measurements on scanned digital images. A morphological alternate sequential filter is used for noise reduction in the original image. Ring boundaries are determined by the steepest negative slopes in the light reflectance of latewood-earlywood transitions. To automatically identify tree rings, the package provides three alternative methods (watershed-based segmentation, Canny edge detector, and a linear detection algorithm), each with advantages and disadvantages and suited to different wood anatomical features. The user can also manually mark tree rings on species with complex anatomical structures. The arcs of inner-rings and angles of successive inclined ring boundaries are used to correct ring-width series. Differences in ring-width measurements between MtreeRing and WinDENDRO in a given coniferous species (Larix gmelinii) were assessed, and no significant difference between programs was found. Furthermore, the package provides an R-based web application which was developed using the Shiny framework. This beginner-friendly application allows viewing and interacting with tree ring images. It requires no programming experience and can run on either a local computer or a remote server.     

Longleaf pine cone–radial growth relationships in the southeastern U.S.A.

Longleaf pine (Pinus palustris Mill.) cones have been counted annually by the United States Forest Service (USFS) at eleven locations throughout the species’ range since 1958. These data have been useful for understanding spatiotemporal patterns in longleaf pine cone production, and are beneficial in timing regeneration efforts. Variations in annual mast (i.e. seed crop) are known to influence ring widths in numerous tree species, yet this relationship is poorly understood for longleaf pine. This research examines the relationship between longleaf pine cone data and tree-ring growth from trees sampled in the multi-decadal USFS cone-crop study. We examined cone–radial growth relationships using individual tree-ring data and proprietary cone data for each tree from six sites in four locations in the southeastern USA. We found that longleaf pine cones were correlated with basal area increment growth (BAI) over the three-year cone-development cycle. Low BAI years were more frequently associated with above-average cone crop and BAI during years that coincided with the largest cone-crop class (bumper, > 100 cones per tree) were statistically less than any other cone class. We prepared linear models that predicted radial growth using PDSI and cones as predictors, and found that including cones in the models did not improve adjusted R² values. We conclude that while cone production is inversely related to radial growth, the combination of infrequent bumper years and the concentration of cone production by a few trees per stand, creates an environment where radial-growth chronologies assembled from longleaf pine for dendroclimatic purposes are unlikely to be significantly influenced by reproductive strain.     

Pointer years revisited: Does one method fit all? A clarifying discussion

The identification of pointer years is central in tree-ring studies, for example, for crossdating or describing growth responses of trees to extreme events. Various methods exist to define pointer years. To these methods, a presumably new method was recently added, i.e. the standardized growth change (SGC) method (Buras et al., 2020; 2022), which was claimed by the authors to outperform existing methods. In this Communication, we perform a concise method review and compare the SGC method with existing pointer year detection methods using simulated tree-ring data that contain diverse signal patterns. We not only provide evidence that the SGC method has already been proposed in 1994, but furthermore show that each method for pointer year detection, including SGC, has its own strengths and weaknesses. Given that each method highlights different aspects of extraordinary growth, we repeat our conclusion from Jetschke et al. (2019), namely that no method can be substituted by others completely, and thus be claimed as being ‘best’. As applies to all methods for pointer year detection, SGC is a complementary but certainly powerful method. We request the dendro-community to provide clear explanations in future studies on how the term pointer year was used to prevent unnecessary confusion and misunderstanding.     

BAI BAI bias – An evaluation of uncertainties in calculating basal area increments from cores

Basal area increment (BAI) is increasingly used in tree-ring based studies as it provides a direct measure of wood production and thus allows for the interpretation of growth trends. BAIs from increment cores are generally calculated while assuming circular growth patterns. However, observation of stem discs shows that many ring shapes are characterized by some form of eccentricity, not only characterized by deviations from circular ring shapes but also by piths not being centrally located. This observation poses to the question with what accuracy BAIs are calculated from increment cores. To quantify the estimation bias in BAI, we have developed a method that mimics eccentric tree growth by simulation. Various aspects of eccentricity are incorporated to created ‘stem discs’ with realistic appearances. Since BAI time series for our simulated discs are known, we can evaluate the accuracy of BAI calculation methods from cores. The ‘coring’ is simulated by taking cores at the thickest and thinnest sides of the simulated discs, whereby the number of cores is varied from one to four. In our simulations, we choose two calculation methods, namely the traditional circular approach and one that is based on the assumption of elliptical growth shapes. We find that bias in calculated BAI values is highly influenced by the number of cores taken, with a dramatic decrease from one to four cores. Furthermore, trend patterns in BAI series might be misleading in case of highly eccentric growth patterns. Based on these findings, we discuss the consequences for the interpretation of existing literature, where BAI analyses are based on one or two cores (along with the assumption of circular ring shapes). Such consequences are, however, difficult to quantify since we have no eccentricity statistics of tree growth within a forest stand. Therefore, we do not know the randomness of eccentricity within a stand, and thus to what extent chronology building (i.e. averaging BAI estimates over multiple trees) may reduce estimation bias. To lower BAI bias, we recommend to base BAI calculations on as many cores as possible. For individual trees with high levels of eccentricity, taking four increment cores seems necessary to reasonably estimate their basal area increments.     

Automated 3D tree-ring detection and measurement from X-ray computed tomography

Tree ring analysis is essential to reveal the environmental information encoded in the wood structure. It provides quantitative data on the anatomical structure which can be used, for example, to measure the impact of the fluctuating environment on the tree growth, to support global vegetation models and for the dendrochronological analysis of archaeological wooden artefacts. Currently, several imaging-based methods for tree-ring detection and tree-ring feature estimation exist. However, despite advances in computer vision and edge recognition algorithms, detection of tree-rings is mostly limited to two-dimensional (2D) datasets and performed manually in some cases. This paper describes a new approach to estimate the three-dimensional (3D) structure of tree rings and their width automatically from X-ray computed tomography data. This approach relies on a modified Canny edge detection algorithm, which is capable of detecting fully connected tree-ring edges throughout the image stack. Our results show that this approach performs well on six tree species having conifer, ring-porous and diffuse-porous ring boundary structures. In our study, image denoising proved to be a critical step to achieve accurate results. A major advantage of this procedure is that it requires very little to no user interaction rendering it a reproducible procedure for tree-ring width measurements. As it also provides 3D representations of the ring edges, it also may be used in the future for the inspection of anatomical features.     

The spatio-temporal pattern of historical disturbances of an evergreen broadleaved forest in East China: a dendroecological analysis

Evergreen broadleaved forests (EBLF), the zonal forest ecosystem of the subtropical zone in east China, have been degraded from recent anthropogenic disturbance. Understanding the role of past disturbances in EBLFs would be helpful to the restoration of degraded EBLFs. We used dendroecological techniques to reconstruct the disturbance history of a secondary EBLF dominated by Schima superba and Castanopsis carlesii in Tiantong National Forest Park (29°48′N, 121°47′E), Zhejiang Province, East China. The disturbances were inferred from tree-ring growth release and long-term establishment patterns obtained from 91 overstory trees. The initial growth rates of these trees were compared to trees originating in the understory to evaluate the intensity of past disturbances. The spatial distribution patterns of disturbances were portrayed with tree mapping. The results revealed that there were five disturbances, averaging one disturbance per decade over the past half century. The first disturbance event was probably most intense given that most canopy trees established at that time and displayed high initial growth rates. The timing of the second disturbance event coincided with the documented selective logging. The last three disturbances, having lower tree growth responses and a clumped spatial distribution of gap creation, were probably the result of recurring typhoons. The first two disturbances led to tree regeneration and secondary succession, represented mainly by long-lived deciduous trees in the forest. The subsequent disturbances facilitated the stand development process, creating a complex three-dimensional structure from a pre-existing single-age cohort. This study suggests that EBLFs affected by large disturbances can recover in a few decades and the frequent gap disturbances probably facilitate its process in the early successional stages.     

A CSR classification of tree life history strategies and implications for ice storm damage

Differences in life history strategy influence the ecological roles of plant species, including their susceptibility to disturbance events. According to Grime's CSR model, plants exhibit three primary strategies, which reflect tradeoffs between stress and disturbance. Here we classify eastern North American tree species into life history strategies on the basis of the CSR model. Then, using data on ice storm damage to trees, we investigate how the level of damage varied among the different CSR categories. We used tree damage data for almost 2000 individual trees representing 30 species collected during two ice storms in the Appalachian Mountains. We augmented the study with ice damage data gleaned from nine published ice‐storm studies containing over 30 000 individuals representing 22 species. The trees we identified as stress‐tolerators (S) consistently sustained less damage than the other species. This finding matches the stress‐tolerant strategy: damage‐resistance is imperative for the persistence of trees that exhibit slow growth, low reproductive capacity and long lifespan. Our analyses also suggest that competitors (C) suffer widespread damage, particularly branch breakage, but experience low mortality. This pattern likely reflects features of the competitive strategy, such as wood strength and canopy form, which preclude resistance to damage but facilitate rapid recovery. The ice damage datasets did not contain trees that we classified as ruderals (R). Competitive ruderals (C‐R) and stress‐tolerant ruderals (S‐R), however, sustained heavy damage and high mortality, consistent with low investment in tree defense and a prioritization of reproduction. Our analyses suggest the usefulness of the CSR model for interpreting forest dynamics and understanding the implications of tree life‐history strategies for forest disturbance responses.