scholarly journals Condition, protection and maintenance of age-old pedunculate oak trees in Feofania forest

2018 ◽  
Vol 29 (1) ◽  
pp. 36-41
Author(s):  
Yu. S. Prokopuk ◽  
Ya. I. Krylov

Large old trees are significant elements of forests, arboretums, botanical gardens and parks and perform a number of unique functions contributing to ecosystem integrity and biodiversity. At the same time human activities such as compaction of topsoil layers, deterioration of soil permeability and soil aeration drive the decline of large old trees. The human impact is also exacerbated by plants inevitable physiological age-specific changes. The presence of such old trees in urban environments brings great scientific promises enhancing a social, cultural and historical forest value, although these benefits increase responsibility for trees maintaining. Regarding old-growth trees historical, cultural, and environmental significance and their overall vulnerability, the individual-by-individual tree protection measures are required. Pedunculate oak (Quercus robur L.) is among the most widespread long-lived species in Europe, in particular in Ukraine. In Feofania (or Theophania) forest, that is an oak-hornbeam forest located in southern part in Kyiv, the age of the oldest oak trees reaches about 300 years. In this article, we aim to estimate vitality, overall condition, and recreational digression stages of pedunculate oak trees and to develop the recommendations to maintain and extend trees longevity in Feofania forest. We estimate the stages of recreational digression and vitality using an approach of Hensiruk et al. (1987) and Sanitary Regulations in forests of Ukraine (1995) respectively. The dendrochronological analysis is performed on core samples from sixteen age-old pedunculate oaks in order to determine their exact cambial age and to evaluate their growth rates. We use at least two cores per tree extracted at a height from 0.5 m to 1.3 m above ground level with an increment borer. The tree-ring widths are measured using AxioVision (Carl Zeiss) software to the nearest 0.01 mm. To identify false rings we employ stereomicroscope MBS-1. The individual tree-ring series are cross-dated, standardized and checked using the COFECHA program. Then we determine exact cambial age of oak trees as number of tree-rings in individual series. To estimate the age of trees with cores without pith we use a graphical method. The analyze is performed on 42 increment cores containing 7335 annual rings formed in the period from 1746 to 2016. Measured diameter of the age-old oaks ranges from 57.6 cm to 165.2 cm. The longest chronological series contains 271 years. The age of studied trees varies from 202 to 275 years averaging 175 years and radial growth ranges from 1.07±0.400 mm to 2.85±1.487 mm averaging 1.95±0.792 mm. In recent years the reduction of radial growth isn’t observed, although in a long time interval in five studied trees the rings width not exceeds the individual series average value. However, the growth rate reducing could not be regarded as critical for trees vitality because it is above 10 % of the average value yet. The evaluated mean increment coefficient is 5.13±1.482 years in cm that allows to estimate the age of dominant and codominant oaks in the association of Galeobdoloni luteae-Carpinetum in other forests. The estimated vitality is mostly of 6–7 points. Five oaks are in «satisfactory condition», nine oaks are «weakened», one oak is «very weakened» and one tree is «dying». «Weakened» trees are with mechanically damaged stem and are often suffered from leaves defoliation caused by Acrocercops brongniardella and Microsphaera alphitoides. Regarding wood samples maintenance, the «dying» oak stem is found rotted in its center. The recreational digression is at the stage 1–4. For eight oaks it is at the first stage, for four oaks at the second stage, for two oaks at the third stage and for two oaks at the fourth stage with 60 % destruction of the understorey. The number of age-old Q. robur trees is limited, thus measures to care could consider individual tree-specific features. Given trees vitality and stages of recreational digression, we develop the guidelines to preserve and extend trees longevity. We also propose to include four old-growth oaks in the list of monumental plants.

2017 ◽  
Vol 26 (2) ◽  
pp. eSC02 ◽  
Author(s):  
Mar Génova ◽  
Carlos Santana ◽  
Begoña Martínez

Aim and area of study: In the present paper we estimated the age of four monumental Pinus canariensis of Gran Canaria (Canary Islands, Spain) by means of tree-ring analysis. Many tree-ring series have been accurately studied and many missing rings have been determined.Material and methods: The trees were dead and the samples analysed were big disks. We measured numerous radii and crossdated the individual tree-ring series, paying particular attention to the existence and location of missing rings. We have distinguished between missing outer rings (MORs) and missing inner rings (MIRs) and analysed the possible causes of both.Main results: We determined an average of 8.8% total missing rings (MRs) for these long-lived trees, with a maximum of 96 MRs in a series of over 500. We have tried to establish a tree-ring chronology on Gran Canaria Island, also having the tree-ring series from Inagua site, but the long individual tree-ring series analysed do not crossdate between them. Research highlights: We consider the Canary pine a species hard to conducting dendroecological studies, especially if the samples come from managed old trees, in which a large amount of known and potentially unknown missing rings can hampered dating. Even knowing the difficulties involved in dendrochronological analyses of P. canariensis, we can confirm that it is a long-lived species, which can grow to over 500 years, and some of whose growth changes could be associated with certain historical and ecological events.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1002
Author(s):  
Rafael M. Navarro-Cerrillo ◽  
Antonio Gazol ◽  
Carlos Rodríguez-Vallejo ◽  
Rubén D. Manzanedo ◽  
Guillermo Palacios-Rodríguez ◽  
...  

Systematic forest networks of health monitoring have been established to follow changes in tree vigor and mortality. These networks often lack long-term growth data, but they could be complemented with tree ring data, since both defoliation and radial growth are proxies of changes in tree vigor. For instance, a severe water shortage should reduce growth and increase tree defoliation in drought-prone areas. However, the effects of climatic stress and drought on growth and defoliation could also depend on tree age. To address these issues, we compared growth and defoliation data with recent climate variability and drought severity in Abies pinsapo old and young trees sampled in Southern Spain, where a systematic health network (Andalucía Permanent Plot Network) was established. Our aims were: (i) to assess the growth sensitivity of old and young A. pinsapo trees and (ii) to test if relative changes in radial growth were related with recent defoliation, for instance, after severe droughts. We also computed the resilience indices to quantify how old and young trees recovered growth after recent droughts. Wet-cool conditions during the prior autumn and the current early summer improved the growth of old trees, whereas late-spring wet conditions enhanced the growth of young trees. Old trees were more sensitive to wet and sunny conditions in the early summer than young trees. Old and young trees were more responsive to the Standardized Precipitation-Evapotranspiration Index drought index of June–July and July–August calculated at short (one–three months) and mid (three–six months) time scales, respectively. Old trees presented a higher resistance to a severe drought in 1995 than young trees. A positive association was found between stand defoliation and relative growth. Combining monitoring and tree ring networks is useful for the detection of early warning signals of dieback in similar drought-prone forests.


2014 ◽  
Vol 41 (1) ◽  
pp. 92-103 ◽  
Author(s):  
Kristina Sohar ◽  
Samuli Helama ◽  
Alar Läänelaid ◽  
Juha Raisio ◽  
Heikki Tuomenvirta

Abstract We investigated the decline of a pedunculate oak (Quercus robur L.) forest growing on shallow soil at the northern distributional limit of the species in southern Finland, using the dendroclimatic approach. About 200-year-old trees in three vigour classes — healthy, declining and dead — were sampled in 2008. Annual tree-ring, earlywood and latewood widths were measured and chronologies were established. The tree-ring data were correlated with monthly and seasonal climate data. Radial increment of oaks was positively related to the June and July precipitations. This was expressed especially in total ring width and latewood width, whereas the earlywood was more influenced by the warmer winter and spring. Furthermore, the correlation between the current year earlywood width and the preceding year latewood width was higher than between the earlywood and latewood of the same year. The analyses showed that the dead oaks and part of the declining oaks had ceased growing during 2005–2007 after a decadelong summer drought series. This indicates a time lag in the oak dieback. The radial growth of the declining and the dead oaks had dropped already since the 1990s, while the healthy oaks had better longterm growth and higher adaptive capacity to climate variation.


2021 ◽  
Author(s):  
Saša Kostić ◽  
Wolfgang Wagner ◽  
Tom Levanič ◽  
Tzvetan Zlatanov ◽  
Ernest Goršić ◽  
...  

<p>New technologies, such as satellites and sensors, provide a wealth of new information about all ecosystems. In dendrochronological studies, all drought-related factors are of great importance for a more comprehensive understanding of associations between radial growth and water loss. Soil moisture directly reflects the wetness of immediate root surroundings, which is vital to the water uptake by trees. Owing to the advances in satellite observation systems and sensors, soil moisture (SM) can be remotely measured, opening new window in dendrochronological research.</p><p>Using the pedunculate oak (Quercus robur L.) lowland SE Europe forests dataset, which count 23 stands and more than 300 tree ring width (TRW) series, we observed reliable associations between satellite-based SM and TRW. Specifically, we observed different TRW−SM patterns based on the precipitation regime. SM in the hottest months (July and August) boosted radial growth, whereas opposite results were noted in the wettest spring months oaks that growing in wetter stands. Unlike oaks from drier and wetter stands that exhibited strong response to SM, those growing on moderately wet (optimal) stands are less sensitive to SM, making these stands optimal oak surroundings.</p><p>On the other hand, by applying a Generalized Additive Mixed Model (GAMM), we noted moderate−weak interactions between TRW series and smoothed SM timescales, with stronger deviations in extreme dry/wet years. Based on the TRW sensitivity to SM findings, which were interpreted via Pearson’s correlation technique and GAMM modeling, strong relations can be inferred, and SM can be labelled as reliable pedunculate oak driver.</p><p><strong>Keywords:</strong> Forestry, Remote sensing, Dendrochronology, Soil moisture, Pedunculate oak, GAMM</p><p><strong>Acknowledgments:</strong> This research was supported by the Science Fund of the Republic of Serbia, PROMIS, #6066697, TreeVita.</p><p><strong>Note:</strong> This contribution is a summary of a study by Kostić S, Wagner W, Orlović S, Levanič T, Zlatanov T, Goršić E, Kesić L, Matović B, Tsvetanov N, Stojanović DB. Different tree-ring width sensitivities to satellite-based soil moisture from drier, moderate and wetter pedunculate oak (Quercus robur L.) stands across a southeastern distribution margin (In press)</p>


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 585
Author(s):  
Omid Fathizadeh ◽  
Seyed Mohammad Moein Sadeghi ◽  
Iman Pazhouhan ◽  
Sajad Ghanbari ◽  
Pedram Attarod ◽  
...  

This study examined the spatial variability of throughfall (Tf) and its implications for sampling throughfall during the leafless period of oak trees. To do this, we measured Tf under five single Brant’s oak trees (Quercus brantii var. Persica), in the Zagros region of Iran, spanning a six-month-long study period. Overall, the Tf amounted to 85.7% of gross rainfall. The spatial coefficient of variation (CV) for rainstorm total Tf volumes was 25%, on average, and it decreased as the magnitude of rainfall increased. During the leafless period, Tf was spatially autocorrelated over distances of 1 to 3.5 m, indicating the benefits of sampling with relatively elongated troughs. Our findings highlight the great variability of Tf under the canopies of Brant’s oaks during their leafless period. We may also conclude that the 29 Tf collectors used in the present study were sufficient to robustly estimate tree-scale Tf values within a 10% error of the mean at the 95% confidence level. Given that a ±10% uncertainty in Tf is associated with a ±100% uncertainty in interception loss, this underscores the challenges in its measurement at the individual tree level in the leafless season. These results are valuable for determining the number and placement of Tf collectors, and their expected level of confidence, when measuring tree-level Tf of scattered oak trees and those in forest stands.


2012 ◽  
Vol 56 (1) ◽  
pp. 5-15
Author(s):  
Mauri Timonen ◽  
Kari Mielikäinen ◽  
Samuli Helama

Abstract Tree-ring data is commonly used in forest science and dendrochronology. As the collected datasets represent restricted populations of theoretical infinite sample size, an interesting question deals with the sample selection that is carried out during the fieldwork and through the data analyses. This paper considers the latter issue, by statistically examining a recently completed Scots pine dataset of timberline tree-rings from Lapland (northern Finland). Following the detrending of individual ring-width series, the composition of the data was restricted using a pre-determined criteria of linear correlativity between the individual sample series and the master chronology (Rmaster). This procedure reduced both the number of sites and the sample size (i.e. the number of individual tree-ring series) and altered the tree-ring statistics of the remaining subset of the data in a systematic fashion. It was seen that the first-order autocorrelation, mean sensitivity and standard deviation all ascended with the uplifted Rmaster criterion. Conspicuously, such filtering also reduced the correlation between the resulting tree-ring chronology and climate parameter. The results indicated that the screening of the data will alter the chronology statistics in a way that may be artificially generated, irrelative to the predetermined sample selection criteria. We remain to assume that the most fundamental selection of data is attained through the cross-dating process.


Author(s):  
I.A. Petrov ◽  
◽  
A.S. Shushpanov ◽  
S.T. Im ◽  
A.S. Golyukov ◽  
...  

The study considers the climatic response of fir (Abies sibirica Ledeb.) radial increment in the zones of dark coniferous decline on the northern spurs of the Eastern Sayan Mountains. Radial increment of 203 fir trees was analyzed. The measurement of the tree ring width and the development of tree-ring chronologies were carried out according to the generally recognized dendrochronological methods. The individual tree-ring chronologies obtained were divided into two groups according to the characteristics of the vital state of trees and radial increment trends over the past decades. It was found that significant differences in radial increment were observed after the drought in 1999. Comparison of the radial increment indices with the SPEI showed that the depression in radial increment coincide with a decrease in the level of atmospheric moisture and an increase in the sensitivity of trees to atmospheric droughts. Atmospheric drought, which caused a decrease in radial increment, also preceded an increase in fir mortality and an outbreak of Polygraphus proximus Blandford.


2017 ◽  
Vol 168 (3) ◽  
pp. 127-133
Author(s):  
Matthew Parkan

Airborne LiDAR data: relevance of visual interpretation for forestry Airborne LiDAR surveys are particularly well adapted to map, study and manage large forest extents. Products derived from this technology are increasingly used by managers to establish a general diagnosis of the condition of forests. Less common is the use of these products to conduct detailed analyses on small areas; for example creating detailed reference maps like inventories or timber marking to support field operations. In this context, the use of direct visual interpretation is interesting, because it is much easier to implement than automatic algorithms and allows a quick and reliable identification of zonal (e.g. forest edge, deciduous/persistent ratio), structural (stratification) and point (e.g. tree/stem position and height) features. This article examines three important points which determine the relevance of visual interpretation: acquisition parameters, interactive representation and identification of forest characteristics. It is shown that the use of thematic color maps within interactive 3D point cloud and/or cross-sections makes it possible to establish (for all strata) detailed and accurate maps of a parcel at the individual tree scale.


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