Effect of stand density on radial growth of branches of Scots pine in southern and central Finland

1999 ◽  
Vol 29 (8) ◽  
pp. 1216-1224 ◽  
Author(s):  
Harri Mäkinen

Branch growth dynamics in Scots pine (Pinus sylvestris L.) were studied in 19 thinning experiments in southern and central Finland. Data were collected from 229 trees growing on sites of different fertility with different stand density, age, and canopy position. Radial increments were measured from discs from the base of the thickest branch on every fifth living whorl. Branch growth declined gradually from the upper part of the crown towards the crown base. Near the crown base, the effect of stand density was most apparent and branches remained alive without forming annual rings. After the thinnings, branch growth did not increase, but wider spacing delayed the reduction in branch growth and increased branch longevity. Correlation of branch increment between trees was greater in the upper whorls than in the lower crown. Correlation of the radial increment between whorls of different ages was greater between whorls near each other than between whorls from the upper and lower crown. Variation of the annual increments was similar in the stem and branches. A model was developed for predicting branch increment at different heights in the crown. The best independent variables for indicating branch increment were stem radial increment, height/diameter ratio, and branch age.

Author(s):  
Vida Stravinskienė ◽  
Regina Erlickytė-Marčiukaitienė

Investigation of Scots pine annual radial increment was carried out in the surroundings of one of the largest pollution sources in Lithuania – the cement plant “Akmenes cementas”. The main objective of the investigation was to analyse possible impact of climatic and anthropogenic factors on the radial growth of Scots pine (Pinus sylvestris L.) stands growing in the local impact zone of the plant. Investigation has shown that in peat‐bog sites active vegetation period temperature higher than the long‐term average influences the formation of radial increment positively (r = 0.22–0.34; p < 0.05), and July precipitation higher than the long‐term average causes the reduction of radial increment (r = ‐0.25; p < 0.05) of the investigated pines. Analysis of the relation between pine radial increment and plant emissions has shown that the strongest correlations are in the closest vicinity of the plant (r = -0.63; p < 0.05). Weaker, but statistically significant relations were found between radial increment of pines growing at a distance of 5–10 km from the plant and plant emissions (r = -0.49; p < 0.05), and for the most distant pine correlations became insignificant (p > 0.05). Linear regression results have shown that changes of the radial increment of pine stands closest to the plant are the biggest and they decrease with distance from the plant. Santrauka Paprastosios pušies (Pinus sylvestris L.) metinio radialiojo prieaugio pokyčių tyrimai buvo atliekami cemento gamyklos „Akmenės cementas“ aplinkoje. Pagrindinis šio tyrimo tikslas – nustatyti galimą klimato ir antropogeninių veiksnių įtaką paprastosios pušies (Pinus sylvestris L.) medynų radialiajam prieaugiui gamyklos aplinkoje. Nustatyta, kad gamyklos aplinkoje augančiuose raistašilio (Carico–sphagnosa) miško tipo pušynuose teigiamos įtakos pušų radialiojo prieaugio formavimuisi turi aukštesnė nei vidutinė daugiametė aktyviosios vegetacijos oro temperatūra (r = 0,22–0,34; p < 0,05), o didesnis nei vidutinis daugiametis liepos mėnesio kritulių kiekis lemia radialiojo prieaugio mažėjimą (r = –0,25; p < 0,05). Nagrinėjant pušų radialiojo prieaugio sąsają su gamyklos teršalų kiekiu, stipriausias koreliacinis priklausomumas nustatytas artimiausioje gamyklos aplinkoje (iki 5 km) (r = –0,63; p < 0,05). Silpnesnis, tačiau statistiškai patikimas priklausomumas nustatytas tarp vidutiniu atstumu nuo gamyklos (5–10 km) augančių pušų prieaugio ir gamyklos teršalų kiekio. Toliausiai nuo gamyklos (per 10–20 km) augančių pušų radialiojo prieaugio sąsaja su bendruoju ir pavienių teršalų kiekiu yra statistiškai nepatikima (p > 0,05). Iš tiesinės regresinės analizės rezultatų akivaizdu, kad pušynų artimiausioje gamyklos aplinkoje metinio radialiojo prieaugio pokyčiai yra didžiausi, o tolstant nuo gamyklos mažėja. Резюме Исследования годового радиального прироста сосны обыкновенной (Pinus sylvestris L.) были проведены в окрестностях цементного завода „Акмянес цементас“. Главная цель исследования – определить возможное влияние климатических и антропогенных факторов на изменение радиального прироста сосны обыкновенной (Pinus sylvestris L.), произрастающей в окрестностях цементного завода. Исследования показали, что на формирование радиального прироста сосен, растущих в сосновых древостоях леса типа Carico-sphagnosa, позитивное влияние оказывает температура воздуха, превышающая среднюю многолетнюю температуру воздуха активной вегетации (r = 0.22–0.34; p < 0.05), а количество осадков в июле, превышающее среднее многолетнее количество, способствует уменьшению радиального прироста (r = –0.25; p < 0.05). Корреляционный анализ зависимости радиального прироста сосен от эмиссии завода показал сильнейшую связь (r = –0.63; p < 0.05) на расстоянии до 5 км от завода. На расстоянии 5–10 км от завода корреляционная связь уменьшается, а при дальнейшем удалении от завода статистически не доказана. Результаты линейной регрессии показали, что наибольшие изменения радиального прироста сосен происходят на расстоянии до 5 км от завода, а с увеличением расстояния от завода они уменьшаются.


1999 ◽  
Vol 29 (5) ◽  
pp. 585-594 ◽  
Author(s):  
Harri Mäkinen

Branch development of Scots pine (Pinus sylvestris L.) was studied in 19 thinning experiments in southern and central Finland. Data were collected from 229 trees on sites of different fertility with different stand density, age, and canopy position. Stem sections that included the thickest branch or knot of the whorl were sawn out from the whorls below the lowest living and dead whorl. The stem sections were dissected and the years of birth, suppression, death, and occlusion of the branches were determined. Diameter growth of the branches continued for a longer time in older trees. Branch growth was also prolonged by rapid radial growth of the stem. On average, branches died 7 years after their growth cessation. The number of years that branches stayed alive after growth cessation was independent of the tree or stand characteristics. After the death of a branch, more than 40 years elapsed before the branch was occluded. Large branch diameter and rapid radial growth of the stem increased the width of the loose knot zone in the stem. The results showed that there are limited possibilities of using delayed thinnings to reduce the knottiness of timber, and artificial pruning is needed to produce timber of high quality.


1999 ◽  
Vol 54 (7-8) ◽  
pp. 526-533 ◽  
Author(s):  
Katri Ots ◽  
Jtiri Rauk

Abstract Relationships of the width of annual rings of 75-85-year old Pinns sylvestris L. and Picea abies (L.) Karst, with average monthly temperature, amount of precipitation and a complex climatic indicator developed on their basis was studied against the background of pollution load in the zone influenced by a cement plant and in a control area. Multiple regression analysis (equations with two and three independent variables) showed a significant correlation between precipitation and temperatures with increment, especially for pine: however, the prediction capability of the models is modest, describing usually 35-40% of the variation in radial increment. The calculations suggest that precipitation amounts are more important and temperature parameters less important and can be replaced by one another in the models. A direct correlation with the pollution load can be observed: at probability (P) near zero the coefficients for precipitation were the highest (0.45-0.51) in the area strongly affected by the cement plant and the lowest (0.31 -0.35) in the weakly affected and control areas. In case of spruce shortage of air humidity during summer months was important for increment, especially so in the heavily polluted area.


2019 ◽  
Vol 61 (2) ◽  
pp. 112-122
Author(s):  
Marta Górska ◽  
Edward Roszyk

Abstract The aim of this study was to examine Scots pine (Pinus sylvestris L.) xylem changes caused by heavy metal pollution. Annual rings width, number of tracheids in radial rows and the length of tracheids in the wood from trees growing on post-flotation tailings have been measured. Dimensions of tracheids have been examined separately for early- and latewood of each radial increment. The most demonstrable changes are observed in the tracheids length, which appears to be shorter in the xylem from the industrial area than in the control samples. In the wood from the polluted site, the variability of length of tracheids is increased. Microscopic observations revealed numerous deformations in the xylem tissue and deviations from the standard cell arrangement. Circumferential deformations occurring in the wood structure may indicate the increasing spring frost vulnerability of these trees.


2017 ◽  
Vol 10 (5) ◽  
pp. 476-487 ◽  
Author(s):  
A. V. Demina ◽  
L. V. Belokopytova ◽  
S. G. Andreev ◽  
T. V. Kostyakova ◽  
E. A. Babushkina

Author(s):  
O. S. Zheleznova ◽  
S. A. Tobratov

This paper is devoted to the patterns of radial growth of Scots pine (Pinus sylvestris L.) in various topoecological conditions of the Meshchera lowland (Ryazan region, the East European plain). The generalized tree-ring chronologies are constructed for 16 habitats differing in features of a relief of a day surface and a bedrock surface. Despite the relatively low-contrast relief of Meshchera, the average radial pine increment within the study area differs by 2.5 times (1.53.9 mm per year). The correlation and cluster analyses revealed that the key factor influencing the width of annual tree rings of pine is the amount of the available soil moisture. Its surplus (in wetlands) and deficiency (in conditions of sandy outliers) negatively affects the radial pine increment. It is established that in the waterlogged habitats positive correlation of the radial pine increment with temperature and negative with precipitation of autumn of the previous year is observed. The positive correlation of the radial increment with precipitation of autumn, May and with winter temperature is typical for a pine from arid habitats. The negative relationship between the pines growth and amount of precipitation and river discharge may occur with a lag of 14 years in conditions of wetlands. The positive relationship of the radial pine increment with the integral parameters of the current years moisture is more significant in conditions of relatively high hydrodynamics (for example, in conditions of sandy outliers).


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 627
Author(s):  
Mathias Steckel ◽  
W. Keith Moser ◽  
Miren del Río ◽  
Hans Pretzsch

A higher frequency of increasingly severe droughts highlights the need for short-term measures to adapt existing forests to climate change. The maintenance of reduced stand densities has been proposed as a promising silvicultural tool for mitigating drought stress. However, the relationship between stand density and tree drought susceptibility remains poorly understood, especially across ecological gradients. Here, we analysed the effect of reduced stand density on tree growth and growth sensitivity, as well as on short-term drought responses (resistance, recovery, and resilience) of Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea (Matt.) Liebl.), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson). Tree ring series from 409 trees, growing in stands of varying stand density, were analysed at sites with different water availability. For all species, mean tree growth was significantly higher under low compared with maximum stand density. Mean tree growth sensitivity of Scots pine was significantly higher under low compared with moderate and maximum stand density, while growth sensitivity of ponderosa pine peaked under maximum stand density. Recovery and resilience of Scots pine, as well as recovery of sessile oak and ponderosa pine, decreased with increasing stand density. In contrast, resistance and resilience of ponderosa pine significantly increased with increasing stand density. Higher site water availability was associated with significantly reduced drought response indices of Scots pine and sessile oak in general, except for resistance of oak. In ponderosa pine, higher site water availability significantly lessened recovery. Higher site water availability significantly moderated the positive effect of reduced stand density on drought responses. Stand age had a significantly positive effect on the resistance of Scots pine and a negative effect on recovery of sessile oak. We discuss potential causes for the observed response patterns, derive implications for adaptive forest management, and make recommendations for further research in this field.


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