The Response of Erica arborea L. Tree Growth to Climate Variability at the Afro-alpine Tropical Highlands of North Ethiopia

The important ecosystem services of the high altitude tropical afro-alpine Erica arborea L. forests are under increasing environmental and human pressure. The Erica treeline ecotone in the Ethiopian highlands forms a temperature-responsive vegetation boundary that is potentially affected by climate change. The cambium of 10 Erica arborea trees in Lib Amba Mountain and Ferrah Amba Mountain in the North Ethiopian highlands was marked in 2012, and corresponding tree disks were sampled after 498 days. Microphotographs of these cambial marks confirmed the formation of annual growth rings (0.76 ± 0.24 mm) with higher vessel density in earlywood and radially flattened fibers in the last layers of the latewood. In-continuum measurements of vessel size and density on microphotographs indicated the formation of inter-annual density fluctuations (IADFs) related to early rainfall in March-May. The same stem disks and 40 increment cores were used for detailed tree-ring analyses—a tree-ring chronology with 18 trees spanning from 1966 to 2014 could be derived. A significant (p < 0.1) positive correlation with minimum temperature in the growing season (August) and a negative correlation with minimum temperature in the spring season (March) were indicated as the most important climate factors regulating tree growth of Erica trees in the afro-alpine forest. The existence of annual tree rings and the proven potential for chronology building encourages further tree-ring analyses of Erica arborea in the afro-alpine tropical highlands in order to link it with climate variability and climate change.

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The impact of drought on tree growth in Mediterranean sites

10.5194/egusphere-egu21-8635 ◽

2021 ◽

Author(s):

Giovanna Battipaglia ◽

Francesco Niccoli ◽

Arturo Pacheco-Solana

Keyword(s):

Climate Change ◽

Tree Growth ◽

Sustainable Forest Management ◽

Climatic Factors ◽

Management Strategies ◽

Ring Width ◽

Limiting Factor ◽

Individual Tree ◽

Annual Growth Rings ◽

The Impact

Climate-induced forest mortality is a critical issue in the Mediterranean basin, with major consequences for the functioning of these key ecosystems. Indeed, in Mediterranean ecosystems, where water stress is already the most limiting factor for tree performance, climatic changes are expected to entail an increase in water deficit. In this context, annual growth rings can provide short- (e.g., years) and long-term (e.g., decades) information on how trees respond to drought events. With climate change, Pinus pinaster and Pinus pinea L. are expected to reduce their distribution range in the region, being displaced at low altitudes by more drought tolerant taxa such as sub Mediterranean Quercus spp.This study aims was to assess the physiological response of Pinus and Quercus species growing in the Vesuvio National park, located in Southern Italy and where an increase of temperature and drought events has been recorded in the recent years. Our preliminary results underlined the importance of temperature on the tree ring width of all the analyses species. The high temperatures can cause a change in the constant kinetics of the RuBisCo, leading to a consequent decrease in carboxylation rate and thus to a reduction in tree growth. On the other hand, also precipitation seemed to affect the growth of the sampled trees: indeed, in all the chronologies a reduction in growth was found after particular dry years: for example, the low rainfall in 1999 (455 mm/year) determined a drastic decline in growth in 2000 in all the species. In addition to the climatic factors, competition can also play an important role in the growth rate: dendrochronological analyzes have highlighted how stand specific properties (i.e. density, structure and composition) can influence individual tree responses to drought events. The knowledge of those researches should be integrated into sustainable forest management strategies to minimize the potential impacts of climate change on forest ecosystems.

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A 200-Year Perspective of Climate Variability and the Response of White Spruce in Interior Alaska

Climate Variability and Ecosystem Response in Long-Term Ecological Research Sites ◽

10.1093/oso/9780195150599.003.0024 ◽

2003 ◽

Author(s):

Glenn Patrick Juday ◽

Valerie Barber

Keyword(s):

Nineteenth Century ◽

North America ◽

Climate Variability ◽

Tree Ring ◽

Tree Growth ◽

White Spruce ◽

Boreal Region ◽

The North ◽

Interior Alaska ◽

Summer Temperatures

The two most important life functions that organisms carry out to persist in the environment are reproduction and growth. In this chapter we examine the role of climate and climate variability as controlling factors in the growth of one of the most important and productive of the North American boreal forest tree species, white spruce (Picea glauca [Moench] Voss). Because the relationship between climate and tree growth is so close, tree-ring properties have been used successfully for many years as a proxy to reconstruct past climates. Our recent reconstruction of nineteenth- century summer temperatures at Fairbanks based on white spruce tree-ring characteristics (Barber et al. in press) reveals a fundamental pattern of quasi-decadal climate variability. The values in this reconstruction of nineteenth-century Fairbanks summer temperatures are surprisingly warm compared to values in much of the published paleoclimatic literature for boreal North America. In this chapter we compare our temperature reconstructions with ring-width records in northern and south-central Alaska to see whether tree-growth signals in the nineteenth century in those regions are consistent with tree-ring characteristics in and near Bonanza Creek (BNZ) LTER (25 km southwest of Fairbanks) that suggest warm temperatures during the mid-nineteenth century. We also present a conceptual model of key limiting events in white spruce reproduction and compare it to a 39-year record of seed fall at BNZ. Finally, we derive a radial growth pattern index from white spruce at nine stands across Interior Alaska that matches recent major seed crop events in the BNZ monitoring period, and we identify dates after 1800 when major seed crops of white spruce, which are infrequent, may have been produced. The boreal region is characterized by a broad zone of forest with a continuous distribution across Eurasia and North America, amounting to about 17% of the earth’s land surface area (Bonan et al. 1992). The boreal region is often conceived of as a zone of relatively homogenous climate, but in fact a surprising diversity of climates are present. During the long days of summer, continental interior locations under persistent high-pressure systems experience hot weather that can promote extensive forest fires frequently exceeding 100 kilohectares (K ha). Summer daily maximum temperatures are cooled to a considerable degree in maritime portions of the boreal region affected by air masses that originate over the North Atlantic, North Pacific, or Arctic Oceans.

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Directional Variability in Response of Pinus koraiensis Radial Growth to Climate Change

Forests ◽

10.3390/f12121684 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1684

Author(s):

Yingjie Sun ◽

Mark Henderson ◽

Binhui Liu ◽

Hong Yan

Keyword(s):

Climate Change ◽

Tree Ring ◽

Tree Growth ◽

Radial Growth ◽

Maximum Temperature ◽

Pinus Koraiensis ◽

Climate Trends ◽

The Difference ◽

Individual Scale ◽

Individual Trees

Climate change affects forest ecosystems at a variety of scales, from the composition of landscapes to the growth of individual trees. Research across regions and tree species has produced contradictory findings on the effects of climate variables on radial growth. Here, we examine tree ring samples taken from four directions of a tree to determine whether there is directional variability in tree growth in relation to climate trends. The results showed directional differences in the temporal growth processes of Pinus koraiensis, with more commonalities between the west and north directions and between the east and south directions. The contemporaneous June maximum temperature was the main climate factor associated with the difference between the growth of tree rings toward the east or west. Annual tree ring growth toward the east was more affected by the year’s temperature while growth toward the south was more sensitive to the year’s precipitation. Our research demonstrates that diverse response of tree growth to climate may exist at intra-individual scale. This contributes to understanding the sensitivity of tree growth to climate change at differ scales.

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Using Tree Rings to Predict the Response of Tree Growth to Climate Change in the Continental United States during the Twenty-First Century

Earth Interactions ◽

10.1175/2010ei362.1 ◽

2010 ◽

Vol 14 (19) ◽

pp. 1-20 ◽

Cited By ~ 23

Author(s):

A. Park Williams ◽

Joel Michaelsen ◽

Steven W. Leavitt ◽

Christopher J. Still

Keyword(s):

Climate Change ◽

United States ◽

Tree Ring ◽

Tree Growth ◽

Ring Width ◽

First Century ◽

Annual Growth ◽

Climate Variations ◽

Tree Ring Data ◽

Twenty First Century

Abstract In the early 1900s, tree-ring scientists began analyzing the relative widths of annual growth rings preserved in the cross sections of trees to infer past climate variations. Now, many ring-width index (RWI) chronologies, each representing a specific site and species, are archived online within the International Tree-Ring Data Bank (ITRDB). Comparing annual tree-ring-width data from 1097 sites in the continental United States to climate data, the authors quantitatively evaluated how trees at each site have historically responded to interannual climate variations. For each site, they developed a climate-driven statistical growth equation that uses regional climate variables to model RWI values. The authors applied these growth models to predict how tree growth will respond to twenty-first-century climate change, considering four climate projections. Although caution should be taken when extrapolating past relationships with climate into the future, the authors observed several clear and interesting patterns in the growth projections that seem likely if warming continues. Most notably, the models project that productivity of dominant tree species in the southwestern United States will decrease substantially during this century, especially in warmer and drier areas. In the northwest, nonlinear growth relationships with temperature may lead to warming-induced declines in growth for many trees that historically responded positively to warmer temperatures. This work takes advantage of the unmatched temporal length and spatial breath of annual growth data available within the ITRDB and exemplifies the potential of this ever-growing archive of tree-ring data to serve in meta-analyses of large-scale forest ecology.

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Contrasted effects of climate change on low-altitude relict Pinus uncinata stands in the Northern French Alps

Euro-Mediterranean Journal for Environmental Integration ◽

10.1007/s41207-021-00280-5 ◽

2021 ◽

Vol 6 (3) ◽

Author(s):

Christophe Corona ◽

Markus Stoffel ◽

Jérôme Lopez Saez

Keyword(s):

Climate Change ◽

Tree Ring ◽

Tree Growth ◽

Soil Water Potential ◽

Soil Conditions ◽

Growth Responses ◽

Cold Air ◽

French Alps ◽

Pinus Uncinata ◽

Low Altitude

AbstractThis paper reports on climate-induced growth changes in relict, low-altitude mountain pines (Pinus uncinata Mill. ex. Mirb.) from two refugia with cold microclimates located in the Northern French Alps. The P. uncinata stands analyzed grow at the lower bound of their ecological limit and are thus thought to be sensitive indicators of ongoing climate change. Using dendroecological approaches, we compare tree-ring growth at two closely spaced low-altitude stands in the Chartreuse massif (French Alps): La Plagne and Cirque de Bresson. La Plagne is a N-NW-exposed, ventilated slope with cold air circulating in the scree during summer, and the presence of sporadic permafrost as well as ground overcooling, whereas Cirque de Bresson is located on a small, S-exposed fan with sporadic avalanche activity. At both sites, growth responses of P. uncinata to changes in twentieth and twenty-first centuries temperature and precipitation conditions were investigated by means of moving correlation analyses. At Cirque de Bresson, a significant and rapid decline in tree-ring widths has been observed since the early 1990s. We attribute this decline to (i) increasing air temperatures at the beginning of the growing season (May–June) as well as to (ii) a decrease in soil water potential. At La Plagne, we do not detect any significant trend between the higher summer temperatures and tree growth, presumably as a result of the circulation of cold air in the scree slope, which is thought to maintain fresh and humid soil conditions and therefore favor tree growth. These forest stands provide prime examples on how dendroecology can contribute to the study of the dynamics and local variability of tree growth and climate change in relict forest populations with high ecological and conservation values.

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A national tree-ring data repository for Canadian forests (CFS-TRenD): structure, synthesis, and applications

Environmental Reviews ◽

10.1139/er-2020-0099 ◽

2021 ◽

Author(s):

Martin P. Girardin ◽

Xiao Jing Guo ◽

Juha Metsaranta ◽

David Gervais ◽

Elizabeth Campbell ◽

...

Keyword(s):

Tree Ring ◽

Populus Tremuloides ◽

Tree Growth ◽

Annual Growth ◽

Data Repository ◽

Individual Tree ◽

Drought Sensitivity ◽

Tree Ring Data ◽

Annual Growth Rings ◽

New Research

Understanding the magnitude and cause of variation in tree growth and forest productivity is central to sustainable forest management. Measurements of annual growth rings allow assessments of individual tree, tree population and forest ecosystem vulnerabilities to drought stress or other changing forest disturbance regimes (insects, diseases, fire), which can be used to identify areas at greatest risk of forest losses. Given a heightened demand for tree-ring data, we consolidated and synthesized tree-ring studies and datasets gathered over the past 30 years in Canada by scientists with the Canadian Forest Service and research partners. We incorporated these datasets into a data repository that currently contains tree-ring measurements from 40,206 tree samples from 4,594 sites and 62 tree species from all Canadian provinces and territories. Through our synthesis, we demonstrate the value of such large ensembles of tree-ring data for identifying patterns in tree growth over large spatial scales by mapping pan-Canadian drought sensitivity. Overall, we found high coherence in the samples analysed; low coherence was generally limited to data- poor regions and species. Drought sensitivity was widespread across species and regions: 34% of sampled trees displayed a significant positive relationship between annual growth increment and summer soil moisture index. Dependence upon water availability in species Picea mariana, Pinus banksiana, Pinus contorta, and Pseudotsuga menziesii was more strongly expressed in the warmest regions of the species’ range; for species Picea glauca and Populus tremuloides, drought sensitivity was stronger in the driest regions. This unprecedented consolidation and synthesis of tree-ring data will enable new research initiatives (e.g., meta-analyses) aimed at improved understanding of the drivers, patterns, and implications of changes in tree growth, as well as facilitating new research collaborations in earth and environmental sciences. Amongst other things, there is a need for expanding the spatial distribution of sites across Canada’s northern regions, increasing the number of samples collected from older stands and angiosperm species, and integrate datasets from studies that evaluate the effects of silvicultural experiments, including provenance and progeny trials, on tree growth.

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Recent Consequences of Climate Change Have Affected Tree Growth in Distinct Nothofagus Macrocarpa (DC.) FM Vaz & Rodr Age Classes in Central Chile

Forests ◽

10.3390/f10080653 ◽

2019 ◽

Vol 10 (8) ◽

pp. 653 ◽

Cited By ~ 2

Author(s):

Alejandro Venegas-González ◽

Fidel A. Roig ◽

Karen Peña-Rojas ◽

Martín A. Hadad ◽

Isabella Aguilera-Betti ◽

...

Keyword(s):

Climate Change ◽

Climate Variability ◽

Tree Growth ◽

Principal Component ◽

Mediterranean Forests ◽

Age Classes ◽

Spring Precipitation ◽

Growth Trend ◽

Central Chile ◽

Precipitation Decrease

Forests play an important role in water and carbon cycles in semiarid regions such as the Mediterranean ecosystems. Previous research in the Chilean Mediterranean forests revealed a break point in 1980 in regional tree-ring chronologies linked to climate change. However, it is still unclear which populations and age classes are more affected by recent increases in drought conditions. In this study, we investigated the influence of recent variations in precipitation, temperature, and CO2 concentrations on tree growth of various populations and age classes of Nothofagus macrocarpa trees in Central Chile. We sampled 10 populations from five sites of N. macrocarpa through its whole geographic distribution in both Coastal and Andes ranges. We used standard dendrochronological methods to (i) group populations using principal component analysis, (ii) separate age classes (young, mature, and old trees), (iii) evaluate linear growth trends based on the basal area increment (BAI), and (iv) analyze the link between BAI and atmospheric changes using linear mixed-effects models. Results showed that young trees are more sensitive to climate variability. Regarding population grouping, we observed that all population clusters were sensitive to winter-spring precipitation, but only the Andes and Coastal populations were negatively correlated with temperature. The results of CO2 fertilization analyses were controversial and unclear. Since young trees from all population clusters reacted positively in the phase with an increase of atmospheric CO2 between 1980 and 2014, this behavior was not translated into growth for the last 15 years (2000–2014). However, it should be noted that the young trees of the highest elevation populations did not have a negative growth trend, so it seems that CO2 counteracted the negative effect of recent regional climate change (increase in temperature and precipitation decrease) in these population trees. Further studies are needed to assess the effects of climate variability over other ecological and physiological processes.

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Retrospective Analysis of Tree Decline Based on Intrinsic Water-Use Efficiency in Semi-Arid Areas of North China

Atmosphere ◽

10.3390/atmos11060577 ◽

2020 ◽

Vol 11 (6) ◽

pp. 577

Author(s):

Weiwei Lu ◽

Xinxiao Yu ◽

Guodong Jia

Keyword(s):

Climate Change ◽

Tree Ring ◽

Tree Growth ◽

North China ◽

Isotope Composition ◽

Ring Width ◽

Carbon Isotope Composition ◽

Tree Decline ◽

Tree Ring Width

Long-term tree growth is significantly affected by climate change, which have become a global concern. Tree-ring width and isotopic information can show how trees respond to climate change on a long-term scale and reveal some phenomena of tree decline or death. In this study, we used isotopic techniques and investigated annual changes in carbon isotope composition and tree-ring width of Populus simonii Carr. in Zhangbei, as well as trends in tree-ring carbon discrimination (Δ13C) and iWUE in normal, mildly declining and severely declining trees, in order to make a retrospective analysis and further understand the process of tree decline. We found that there were significant differences (p < 0.01 **) in δ13C, Δ13C, ci and iWUE at different decline stages, meaning that the δ13C and iWUE could be new indicators of tree health. The iWUE of all groups increased significantly, while the growth rate of declined P. simonii was much higher than that of normal growth P. simonii. According to the analysis, there may be a threshold of iWUE for healthy trees, which once the threshold value is exceeded, it indicates that trees are resistant to adversity and their growth is under stress. Similarly, the changing trend of BAI supports our conclusion with its changes showed that tree growth became slower and slower as degradation progressed. iWUE inferred from tree-ring stable carbon isotope composition is a strong modulator of adaptation capacity in response to environmental stressors under climate change. Elevated annual temperatures and increased groundwater depth are all contributing to the decline of P. simonii in north China.

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Climate change and tree growth in the Khakass-Minusinsk Depression (South Siberia) impacted by large water reservoirs

Scientific Reports ◽

10.1038/s41598-021-93745-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

D. F. Zhirnova ◽

L. V. Belokopytova ◽

D. M. Meko ◽

E. A. Babushkina ◽

E. A. Vaganov

Keyword(s):

Climate Change ◽

Tree Ring ◽

Tree Growth ◽

Ring Width ◽

Warm Season ◽

Plant Performance ◽

Climatic Data ◽

Water Reservoirs ◽

Local Climate ◽

South Siberia

AbstractRegional and local climate change depends on continentality, orography, and human activities. In particular, local climate modification by water reservoirs can reach far from shore and downstream. Among the possible ecological consequences are shifts in plant performance. Tree-ring width of affected trees can potentially be used as proxies for reservoir impact. Correlation analysis and t-tests were applied to climatic data and tree-ring chronologies of Pinus sylvestris L. and Larix sibirica Ledeb. from moisture-deficit habitats in the intermontane Khakass-Minusinsk Depression, to assess modification of climate and tree growth by the Krasnoyarsk and Sayano-Shushenskoe Reservoirs on the Yenisei River. Abrupt significant cooling in May–August and warming in September-March occurred after the launch of the turbines in dams, more pronounced near the Sayano-Shushenskoe dam (up to – 0.5 °C in summer and to + 3.5 °C in winter) than near the Krasnoyarsk Reservoir headwaters (– 0.3 °C and + 1.4 °C). Significant lengthening of the warm season was also found for temperature thresholds 0–8 °C. Shifts of seasonality and intensity occurred in climatic responses of all tree-ring chronologies after development of water reservoirs. Patterns of these shifts, however, depended on species-specific sensitivity to climatic modification, distance from reservoirs, and physiographic regions. Mitigation of climate continentality and extremes by reservoirs appears to have offset possible negative effects of warming on tree growth.

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Late Holocene forest dynamics, volcanism, and climate change at Whitewing Mountain and San Joaquin Ridge, Mono County, Sierra Nevada, CA, USA

Quaternary Research ◽

10.1016/j.yqres.2006.05.001 ◽

2006 ◽

Vol 66 (2) ◽

pp. 273-287 ◽

Cited By ~ 40

Author(s):

Constance I. Millar ◽

John C. King ◽

Robert D. Westfall ◽

Harry A. Alden ◽

Diane L. Delany

Keyword(s):

Climate Change ◽

Sierra Nevada ◽

Tree Ring ◽

Forest Dynamics ◽

Minimum Temperature ◽

Late Holocene ◽

Wood Anatomy ◽

Late Summer ◽

Annual Minimum Temperature ◽

Show Evidence

AbstractDeadwood tree stems scattered above treeline on tephra-covered slopes of Whitewing Mtn (3051 m) and San Joaquin Ridge (3122 m) show evidence of being killed in an eruption from adjacent Glass Creek Vent, Inyo Craters. Using tree-ring methods, we dated deadwood to AD 815–1350 and infer from death dates that the eruption occurred in late summer AD 1350. Based on wood anatomy, we identified deadwood species as Pinus albicaulis, P. monticola, P. lambertiana, P. contorta, P. jeffreyi, and Tsuga mertensiana. Only P. albicaulis grows at these elevations currently; P. lambertiana is not locally native. Using contemporary distributions of the species, we modeled paleoclimate during the time of sympatry to be significantly warmer (+3.2°C annual minimum temperature) and slightly drier (−24 mm annual precipitation) than present, resembling values projected for California in the next 70–100 yr.

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