scholarly journals Evaluation of Thinning Efficiency in Pineries of Dry Forest Sites of the Kazakh Uplands

Author(s):  
Anastasiya Dancheva ◽  
◽  
Vladislav Pankratov ◽  

According to the current Forest Code of the Republic of Kazakhstan, in the forest plantations of specially protected natural areas, the main forestry measures aimed at the conservation and enhancement of the protective functions of forests are intermediate felling, that is, thinning. Pinus sylvestris L. is one of the main forest-forming species in Kazakhstan. Increasing the stability of forest plantations and the possibility of forming recreationally attractive landscapes through thinning is an urgent problem for plantations growing in arid conditions. The research purpose is to analyze the effectiveness of thinning of high intensity in dry pine forests of the Kazakh Uplands for a 70-year period, using dendrochronological methods. It was proved that in dense pine forests growing in dry conditions, there is an increase in radial growth in each subsequent 10-year period after thinning. It was found with statistical certainty that the greatest response to changes caused by thinning of high intensity was observed between 1949 and 1960. Analysis of indexed tree-ring chronologies using regional curves (indexed average tree-ring chronologies of pine) using a cubic spline function revealed differences in pine radial growth indices from the site where thinning of high intensity were carried out and from the control site (time periods: 1947–1955, 1961–1970, 1981–1990, and 1995–2015). The data obtained show a positive effect of thinning of high intensity on the radial growth of trees in the considered pine forests. In dense pine forests of dry growing conditions of the Kazakh Uplands it is recommended to make 1 or 2 cuttings with thinning intensity of 25–35 % at the age of 20–25 and 40–50, respectively, with subsequent increment thinning.

Author(s):  
Yanhua Zhang ◽  
Shengzuo Fang ◽  
Ye Tian ◽  
Linlin Wang ◽  
Yi Lv

AbstractPoplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.


2013 ◽  
Vol 22 (2) ◽  
pp. 36-42 ◽  
Author(s):  
D. K. Kharal ◽  
T. Fujiwara

Tree ring analysis is one of the most useful methods in volume and biomass estimation especially of the conifer trees. Ring width and ring density are important parameters in dendrochronological research. The present research was carried out with the aim of estimating the radial and volumetric growth of the Japanese Cypress trees (Chamaecyperis obstusa and C. pisifera). Destructive method was used while collecting the wood samples from the selected trees. Ring width and ring density were measured using soft X-ray densitometry method using micro-densitometer. Computer programme, developed by the Forestry and Forest Products Research Institute, Japan was used to analyze the ring with and ring density data. The average ring width of the Chamaecyparis spp. was found to be about 3.4 mm at the age of 30 years. However, two types of growth pattern were observed in the trees. Average radial growth was about 5% every year during the first 20 years of the tree age, whereas, the average radial growth was negative during the age of 20–30 years. Average density of the tree rings were increased by about 11% in each height of the trees starting from the ground. Similarly, the stem density decreased by about 3.4% annually along the radial direction from the pith.DOI: http://dx.doi.org/10.3126/banko.v22i2.9197Banko Janakari: A Journal of Forestry Information for NepalVol. 22, No. 2, 2012 November Page: 36-42 Uploaded date: 12/1/2013 


2007 ◽  
Vol 38 (2) ◽  
pp. 90-93 ◽  
Author(s):  
O. V. Sidorova ◽  
E. A. Vaganov ◽  
M. M. Naurzbaev ◽  
V. V. Shishov ◽  
M. K. Hughes

2021 ◽  
Author(s):  
David Montwé ◽  
Audrey Standish ◽  
Miriam Isaac-Renton ◽  
Jodi Axelson

&lt;p&gt;Increasing frequency of severe drought events under climate change is a major cause for concern for millions of hectares of forested land. One practical solution to improving forest resilience may be thinning. There may be several potential benefits, chief of which is that drought tolerance could be improved in the remaining trees due to lower competition for resources and increased precipitation throughfall. By improving resilience to drought, this may increase productivity of the remaining trees while lowering risks of mortality. Such potential benefits can effectively be quantified with data from statistically-sound, long-term field experiments, and tree rings provide a suitable avenue to compare treatments. We work with an experiment that applied different levels of tree retention to mature interior Douglas fir (&lt;em&gt;Pseudotsuga menziesii&lt;/em&gt; var. &lt;em&gt;glauca&lt;/em&gt;) in a dry ecosystem of western Canada. The treatments were applied in the winter of 2002/2003, coinciding with the aftermath of a severe natural drought event in 2002. We used tree-rings to quantify the extent to which thinning improves recovery and resilience of treated trees as compared to non-thinned controls. Tree-ring samples as well as height and diameter data were obtained from 83 trees from 8 treatment units of the randomized experimental design. Indicators for resilience to drought were calculated based on basal area increments. Thinning substantially increased basal area increments at the individual tree level, but more importantly, led to significantly higher recovery and resilience relative to the control. The results of this tree-ring analysis suggest that thinning may be a viable silvicultural intervention to counteract effects of severe drought events and to maintain tree cover.&lt;/p&gt;


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.


2018 ◽  
Vol 74 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Raquel Alfaro-Sánchez ◽  
J. Julio Camarero ◽  
Raúl Sánchez-Salguero ◽  
Valérie Trouet ◽  
Jorge de Las Heras

2018 ◽  
Vol 419-420 ◽  
pp. 197-205 ◽  
Author(s):  
Shawn M. McKenzie ◽  
Greg Slater ◽  
Sang-Tae Kim ◽  
Michael F.J. Pisaric ◽  
M. Altaf Arain

2019 ◽  
Vol 29 (2) ◽  
pp. 3-12
Author(s):  
S. Basnet ◽  
N. P. Gaire ◽  
P. K. Chhetri

This study presents the potential of a conifer species (Abies spectabilis D. Don) to reconstruct fire history by using dendro chronological technique along with thedendroclimatic response in Langtang National Park, Central Himalaya of Nepal. For the fire history reconstruction, altogether eight cross-sections samples from fire affected eight trees and another 20 tree-cores from 10 trees with visible fire scars were taken. In the case of dendroclimatic study, 24 healthy cores of A. spectabilis were selected from the 40 cores extracted from 19 trees. The standard dendro chronological methodology was used for sample preparation and analysis. A 199-year long ring-width chronology of A. spectabilis spanning from 1818 to 2016 AD was developed. In spite of visible fire burn in near bark-surface, no potential fire scars are seen in inner parts in the cross-section samples. However, 12 cores showed that three fire burns occurred simultaneously in the forest area in the years 1917−1918, 1969−1970 and 2009−2010, respectively. Tree-ring-based fire event-record is found to be concurrent to the local people's perceptions/experience about the past fire history in the area. Tree growth climate relationship showed sensitive responses to both growing and non-growing season’s temperature and precipitation variability. Summer temperature had positive influence on growth of the species. Precipitation of monsoon and autumn were found to have negative influence on radial growth whereas pre-monsoon precipitation had positive association with tree radial-growth. This preliminary assessment shows that there is a huge potential of tree-ring research for long-term fire history in the region and helps us to better understand the role of fire in the ecology and management in the Himalayan region. The study can also be replicated in other fire-affected areas of the Himalayan region by using fire sensitive species in the sampling.


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