Variability in radial increment can predict an abrupt decrease in tree growth during forest decline: Tree-ring patterns of Abies alba Mill. in near-natural forests

2021 ◽  
Vol 479 ◽  
pp. 118579
Author(s):  
Rafał Podlaski
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Algirdas Augustaitis ◽  
Dalia Jasineviciene ◽  
Rasele Girgzdiene ◽  
Almantas Kliucius ◽  
Vitas Marozas

The present study aimed to detect sensitivity of beech trees (Fagus sylvaticaL.) to meteorological parameters and air pollution by acidifying species as well as to surface ozone outside their north-eastern distribution range. Data set since 1981 of Preila EMEP station enabled to establish that hot Summers, cold dormant, and dry and cold first-half of vegetation periods resulted in beech tree growth reduction. These meteorological parameters explained 57% variation in beech tree ring widths. Acidifying species had no significant effect on beech tree growth. Only ozone was among key factors contributing to beech stand productivity. Phytotoxic effect of this pollutant increased explanation rate of beech tree ring variation by 18%, that is, up to 75%. However, due to climate changes the warmer dormant periods alone are not the basis ensuring favourable conditions for beech tree growth. Increase in air temperature in June-August and decrease in precipitation amount in the first half of vegetation period should result in beech tree radial increment reduction. Despite the fact that phytotoxic effect of surface ozone should not increase due to stabilization in its concentration, it is rather problematic to expect better environmental conditions for beech tree growth at northern latitude of their pervasion.


2019 ◽  
Vol 49 (9) ◽  
pp. 1069-1077
Author(s):  
Rafał Podlaski

Crown traits and competition attributes have an important effect on tree radial increment. Relationships among these elements are modeled using the distributions of the crown characteristics in a given calendar year, but these patterns can differ over time. The suitability of the patterns during recovery and normal growth was investigated using silver fir, Abies alba Mill., in old-growth forests. Generalized additive models (GAMs) for silver fir in the older (OG, trees aged 136–300 years) and younger (YG, trees aged 45–135 years) generations were developed. To test the validity of these GAMs, field data sets representing silver fir recovery and normal growth were used. For silver fir in OG, crown transparency had the largest effect on tree growth, explaining more than 25% of the variance. For silver fir in YG, relative crown length had the largest effect on tree growth, explaining more than 15% of the variance. The absolute relative prediction errors, AREmin and AREmax, were less than 0.03 and 1.50 mm, respectively. The developed GAMs are suitable during recovery and normal growth, but the GAMs were fitted to a relatively small area, neglecting climatic gradients and different disturbance types. This type of investigation should be continued on a larger scale.


2015 ◽  
Vol 63 (1) ◽  
pp. 111-129 ◽  
Author(s):  
Maris Hordo ◽  
Vivika Kängsepp ◽  
Taavi Kannimäe ◽  
Priit Kask

AbstractLarch is widely used in tree-ring studies, while tree-ring width and signature years provide information on environmental changes with annual resolution. The aim of the study was to build tree-ring (TR), early- (EW) and latewood (LW) width chronologies by larch species (Hybrid, European, Russian, Japanese, Kuril), and to study the response of the radial increment of larches to weather at Järvselja forest stands by using correlation, redundancy analysis, and the pointer year method. The increment cores were collected from 233 trees in Järvselja larch stands during autumn 2014. The increment cores were collected from 24 stands and divided into five groups by larch species. High EPS values (≥ 0.887) for the larch species in all groups indicate that a sufficient number of trees was included in the chronologies to be representable. The results show that different species have a similar sensitivity to various weather variables. Among the factors influencing the size of radial growth of larches were the weather conditions prevailing in the autumn of the previous year and the spring of the current year. An overall RDA revealed that 63.9% of tree growth variation in larch species was explained by the considered weather variables (F = 4.925,p< 0.001). The pointer year analysis distinguished between several common extreme pointer years by larch species; it revealed a significant response to the winter temperature and the temperature in spring. However, these weather characteristics are very complex and the causes that can affect tree growth may vary from year to year.


Plant Disease ◽  
1997 ◽  
Vol 81 (9) ◽  
pp. 1053-1056 ◽  
Author(s):  
R. S. Hunt ◽  
F. G. Peet

The spread rate of tomentosus root disease, caused by Inonotus tomentosus, was investigated by a new technique employing temporal differences in the initiation of the reduced annual radial increment between pairs of diseased trees. Pairs of infected trees (stumps) located on the periphery of disease centers were selected in each of six widely separated spruce (Picea spp.) stands in British Columbia. Distances between 12 pairs of stumps were measured, and disks were collected from each stump. Similarly, disks from four additional pairs were collected from trees in a younger stand. Uninfected control disks were collected for all sites. Tree-ring measurements were determined for all disk samples and the year in which the reduction of the annual increment attributable to I. tomentosus began was determined for infected trees. The difference between initiation years for pairs of infected trees divided into the distance between them produced an average annual spread rate of 20 cm/yr. This rate will be used in developing a model for the disease.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 163
Author(s):  
Jan Světlík ◽  
Jan Krejza ◽  
Pavel Bednář

Tree growth depends on many factors such as microsite conditions, vitality, and variations in climate and genetics. It is generally accepted that higher growth indicates both an economic benefit and better vitality of any tree. Here we use a modified approach of evaluating tree social area to study mutual tree competition based on the orientation and shape of trees social area. The investigation was performed in nine Norway spruce stands in the Czech Republic. The objective of this study performed from 2008 to 2012 was to quantify relative tree radial increments with respect to the lowest and highest competition found in specific sectors of tree social area (AS). Specific groups of trees (tree classes) were evaluated according to their classes (dominant, co-dominant and sub-dominant) and their composition status in ninety-degree sectors of AS using established classifying rules. The results showed that a spatially-available area (AA) is an inappropriate parameter for predicting tree growth, whereas AS provided robust explanatory power to predict relative radial growth. Tree size was observed as an important indicator of relative radial increments. A significantly positive correlation was found for a radial increment of sub-dominant trees with the lowest competition from western directions; whereas a negative correlation was observed when the lowest competition was observed from eastern directions. For dominant trees, there was an evident growth reaction only when more than 50% of the AS was oriented towards one of the cardinal points. Individual differences in the orientation of tree AS may be important parameters with regard to competition and its spatial variability within an area surrounding a particular tree and deserve more detailed attention in tree growth models and practice.


Author(s):  
Paolo Cherubini ◽  
Giovanna Battipaglia ◽  
John L. Innes

Abstract Purpose of Review Society is concerned about the long-term condition of the forests. Although a clear definition of forest health is still missing, to evaluate forest health, monitoring efforts in the past 40 years have concentrated on the assessment of tree vitality, trying to estimate tree photosynthesis rates and productivity. Used in monitoring forest decline in Central Europe since the 1980s, crown foliage transparency has been commonly believed to be the best indicator of tree condition in relation to air pollution, although annual variations appear more closely related to water stress. Although crown transparency is not a good indicator of tree photosynthesis rates, defoliation is still one of the most used indicators of tree vitality. Tree rings have been often used as indicators of past productivity. However, long-term tree growth trends are difficult to interpret because of sampling bias, and ring width patterns do not provide any information about tree physiological processes. Recent Findings In the past two decades, tree-ring stable isotopes have been used not only to reconstruct the impact of past climatic events, such as drought, but also in the study of forest decline induced by air pollution episodes, and other natural disturbances and environmental stress, such as pest outbreaks and wildfires. They have proven to be useful tools for understanding physiological processes and tree response to such stress factors. Summary Tree-ring stable isotopes integrate crown transpiration rates and photosynthesis rates and may enhance our understanding of tree vitality. They are promising indicators of tree vitality. We call for the use of tree-ring stable isotopes in future monitoring programmes.


2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.


2021 ◽  
Author(s):  
Milagros Rodriguez-Caton ◽  
Laia Andreu-Hayles ◽  
Mariano S Morales ◽  
Valérie Daux ◽  
Duncan A Christie ◽  
...  

Abstract Tree growth is generally considered to be temperature-limited at upper elevation treelines. Yet, climate factors controlling tree growth at semiarid treelines are poorly understood. We explored the influence of climate on stem growth and stable isotopes for Polyepis tarapacana, the world’s highest elevation tree-species found only in the South American Altiplano. We developed tree-ring width index (RWI), oxygen (δ18O) and carbon (δ13C) chronologies for the last 60 years at four P. tarapacana stands located above 4,400 meters in elevation, along a 500-km latitude-aridity gradient. Total annual precipitation decreased from 300 to 200 mm from the northern to the southern sites. We used RWI as a proxy of wood formation (carbon sink) and isotopic tree-ring signatures as proxies of leaf-level gas exchange processes (carbon source). We found distinct climatic conditions regulating carbon-sink processes along the gradient. Current-growing season temperature regulated RWI at wetter-northern sites, while prior-growing season precipitation determined RWI at arid-southern sites. This suggests that the relative importance of temperature to precipitation in regulating tree growth is driven by site-water availability. In contrast, warm and dry growing-seasons resulted in enriched tree-ring δ13C and δ18O at all study sites, suggesting that similar climate conditions control carbon-source processes. Site-level δ13C and δ18O chronologies were significantly and positively related at all sites, with the strongest relationships among the southern-drier stands. This indicates an overall regulation of intercellular carbon dioxide via stomatal conductance for the entire P. tarapacana network, with greater stomatal control when aridity increases. The manuscript also highlights a coupling and decoupling of physiological processes at leaf level versus wood formation depending on their respectively uniform and distinct sensitivity to climate. This study contributes to better understand and predict the response of high-elevation Polylepis woodlands to rapid climate changes and projected drying in the Altiplano.


2021 ◽  
Author(s):  
Pieter Zuidema ◽  
Flurin Babst ◽  
Peter Groenendijk ◽  
Valerie Trouet

&lt;p&gt;Tropical and subtropical ecosystems are primarily responsible for the large inter-annual variability (IAV) in the global carbon land sink. The response of tropical vegetation productivity to climatic variation likely drives this IAV, but the climate sensitivity of key productivity components are poorly understood. Tree-ring analysis can help fill this knowledge gap by estimating IAV in woody biomass growth, the major carbon accumulation process in tropical vegetation.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Here, we evaluate the climate responses of woody biomass growth throughout the global tropics. Using an unprecedented compilation of tropical tree-ring data, we test hypotheses that (1) precipitation (P) and maximum temperature (T&lt;sub&gt;max&lt;/sub&gt;) have opposite and additive effects on annual tree growth, (2) these climate responses amplify with increasing aridity and (3) wet-season climate is a more important driver of growth than dry-season climate.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;We established a network of 347 tree-ring width chronologies compiled from (sub-)tropical latitudes, representing 99 tree species on five continents and obtained from contributors (n=112) and the International Tree-Ring Data Bank (ITRDB; n=235). Our network is climatologically representative for 66% of the pantropical land area with woody vegetation.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;To test hypotheses we re-developed standardized ring-width index (RWI) chronologies and assessed climate responses using SOM cluster analysis (monthly P and T&lt;sub&gt;max&lt;/sub&gt;) and multiple regression analysis (seasonal P and T&lt;sub&gt;max&lt;/sub&gt;). Our results were consistent with hypothesis 1: effects of monthly or seasonal P and T&lt;sub&gt;max&lt;/sub&gt; on tree growth were indeed additive and opposite, suggesting water availability to be the primary driver of tropical tree growth. In accordance with hypothesis 2, these climate responses were stronger at sites with lower mean annual precipitation or a larger annual water deficit. However, our results contrast those expected under hypothesis 3. Three of the four clusters show a dominant role of dry-season climate on annual tree growth and regression analyses confirmed this strong dry-season role.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The strong dry-season effect on tropical tree growth seemingly contrasts the general notion that tropical vegetation productivity peaks during the wet season but is consistent with studies showing that climatologically benign dry seasons increase reserve storage and xylem growth. We posit that dry-season climate constrains the magnitude of woody biomass growth that takes place during the following wet season, and thus contributes to IAV in tree growth.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;By providing field-based insights on climate sensitivity of tropical vegetation productivity, our study contributes to the major task in Earth system science of quantifying, understanding, and predicting the IAV of the carbon land sink.&lt;/p&gt;


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