Effects of defoliation on growth, biomass allocation, and wood properties of Betula pendula clones grown at different nutrient levels

2002 ◽  
Vol 32 (3) ◽  
pp. 498-508 ◽  
Author(s):  
Seija Anttonen ◽  
Riikka Piispanen ◽  
Jari Ovaska ◽  
Pia Mutikainen ◽  
Pekka Saranpää ◽  
...  

Three-year old Betula pendula Roth clones were grown at two nutrient levels in a field experiment to investigate the responses and recovery in growth and wood properties to a range of defoliation levels (0–100%). No general threshold value of defoliation level for negative effects in growth was found, since the sensitivity of saplings to defoliation varied according to plant traits studied. However, responses were related to defoliation intensity. Saplings compensated for 25% defoliation in terms of height growth and number of current branches and were able to tolerate 50% defoliation without effects on diameter growth 1 year after the defoliation. Nutrient availability was significant only in determining how total biomass responded to defoliation. Fertilized saplings were able to tolerate 25% defoliation without reduction in total biomass, but nonfertilized saplings were not. The interaction between defoliation and fertilization disappeared in the second growing season after the defoliation. Saplings were not able to compensate for 75% defoliation in terms of total biomass or for 100% defoliation in terms of growth and branching even in 2 years' recovery time. In stemwood, complete defoliation reduced growth ring width and vessel diameter simultaneously and also induced a narrow zone of secondary xylem with defects. Our results suggest that defoliation level and recovery time played a crucial role in compensatory growth of birch saplings, while nutrient availability had a minor role.

2006 ◽  
Vol 36 (8) ◽  
pp. 2038-2046 ◽  
Author(s):  
Heidi J Renninger ◽  
Barbara L Gartner ◽  
Frederick C Meinzer

Little is known of wood properties in trees that were initially suppressed and subsequently released from suppression. The purpose of this study was to assess differences in growth ring width, specific conductivity (Ks), tracheid dimensions, moisture content, and wood density in suppressed Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees and trees released from suppression averaging 12–18 years of age. Growth ring width was 370% higher for Douglas-fir and 300% higher for western hemlock trees released from suppression, and Ks was 182% higher for Douglas-fir and 42% higher for western hemlock trees released from suppression. Earlywood width was approximately four times greater after release in both species, whereas the relative increase in latewood width was much greater in Douglas-fir. Tracheids were 25% wider and 11% longer in released Douglas-fir trees. In western hemlock, released trees had 19% wider tracheids that were approximately the same length as those in suppressed trees. Moisture content was 66% greater in released Douglas-fir and 41% greater in released western hemlock. Wood density decreased by 21% in Douglas-fir trees and by 11% in western hemlock trees released from suppression. However, wood density of released trees did not differ from average reported values, implying that wood from released trees may be suitable for many of its traditional applications.


2018 ◽  
Vol 46 (120) ◽  
Author(s):  
Joaquim Carlos Gonçalez ◽  
Nayara Santos ◽  
Francides Gomes da Silva Junior ◽  
Roberta Santos Souza ◽  
Marcella Hermida de Paula

1986 ◽  
Vol 16 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
K. C. Yang ◽  
C. A. Benson ◽  
J. K. Wong

The distribution and vertical variation of juvenile wood was studied in an 81-year-old dominant tree and an 83-year-old suppressed tree of Larixlaricina (Du Roi) K. Koch. Two criteria, growth ring width and tracheid length, were used to demarcate the boundary of juvenile wood. The width of juvenile wood, expressed in centimetres and the number of growth rings, decreased noticeably from the base to the top of the tree. The volume of juvenile wood decreased in a similar pattern. These decreasing trends had a strong negative correlation with the year of formation of cambial initials at a given tree level. The length of these cambial initials decreased with increasing age of formation of the cambial initials. In the juvenile wood zone, there was a positive linear regression between the growth ring number (age) and the tracheid length. The slopes of these regression lines at various tree levels increased as the age of the year of formation of the cambial initials increased. At a given tree level, the length of tracheids increased from the pith to a more uniform length near the bark. However, the number of years needed to attain a more uniform tracheid length decreased from the base to the top of the tree. These relationships suggest that the formation of juvenile wood is related to the year of formation of the cambial initials. Consequently, the juvenile wood is conical in shape, tapering towards the tree top.


IAWA Journal ◽  
2019 ◽  
Vol 40 (2) ◽  
pp. 276-287 ◽  
Author(s):  
Marcos González-Cásares ◽  
Marín Pompa-García ◽  
Alejandro Venegas-González

ABSTRACTOngoing climate change is expected to alter forests by affecting forest productivity, with implications for the ecological functions of these systems. Despite its great dendrochronological potential, little research has been conducted into the use of wood density as a proxy for determining sensitivity to climate variability in Mexico. The response of Abies durangensis Martínez, in terms of wood density and growth ring width, to monthly climatic values (mean temperature, accumulated precipitation and the drought index SPEI) was analyzed through correlation analysis. Abies durangensis presents a high response, in terms of radial growth, to climatic conditions. Tree-ring widths are more sensitive to hydroclimatic variables, whereas wood density values are more sensitive to temperature. In particular, mean (MeanD) and minimum (MND) wood density values are more sensitive to climate than maximum (MXD). We found very marked spatial variations that indicate that A. durangensis responds differently to drought conditions depending on the indices of density.


2002 ◽  
Vol 32 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Barbara L Gartner ◽  
Eric M North ◽  
G R Johnson ◽  
Ryan Singleton

It would be valuable economically to know what are the biological triggers for formation of mature wood (currently of high value) and (or) what maintains production of juvenile wood (currently of low value), to develop silvicultural regimes that control the relative production of the two types of wood. Foresters commonly assume the bole of softwoods produces juvenile wood within the crown and mature wood below. We tested that assumption by comparing growth ring areas and widths and wood density components of the outer three growth rings in disks sampled from different vertical positions of 34-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. The 18 trees were sampled from one site and had a wide range of heights to live crown. Most of the variance (63–93%) in wood characteristics (growth ring area: total, earlywood, latewood; growth ring width: total, earlywood, latewood; latewood proportion: by area, width; and ring density: total, earlywood, latewood) was due to within-tree differences (related to age of the disk). Stepwise regression analysis gave us equations to estimate wood characteristics, after which we analyzed the residuals with a linear model that included whether a disk was within or below the crown (defined as the lowest node on the stem with less than three live branches). After adjusting for tree and disk position, only 2–10% of the residual variation was associated with whether the disk was in or out of the live crown. There were no statistically significant differences at p = 0.05 between a given disk (by node number) in versus out of the crown for any of the factors studied. Moreover, the wood density characteristics were not statistically significant at p = 0.30. This research suggests that there was no effect of the crown position on the transition from juvenile to mature wood as judged by wood density. Therefore, we found no evidence to support the concept that tree spacing and live-branch pruning have a significant effect on the cambial age of transition from juvenile to mature wood in Douglas-fir trees of this age.


1996 ◽  
Vol 46 (2) ◽  
pp. 176-185 ◽  
Author(s):  
Jean-Frederic Terral ◽  
Genevieve Arnold-Simard

Morphometric analyses show quantitative differences in anatomical characters of wood and charcoal between wild and cultivated olive. Samples from modern olive wood in eastern Spain (Levante) provide five distinctive anatomical criteria: growth width ring, vessel surface, number of vessels per group, vessel density, and vulnerability ratio. Multivariate analysis shows that growth ring width and number of vessels per group are both significant criteria for discriminating between wild and cultivated olive. Moreover, bioclimatic environments of wild olive (thermomediterranean and mesomediterranean stages) are distinguished by vessel density. Ancient olive charcoal from archaeological sites at Valencia and Alicante implies increasing aridification from the Cardial Neolithic to the Roman Period. This pattern may reflect the onset of a Mediterranean climate and human deforestation. Charcoal from cultivated specimens of early Neolithic age shows that the olive tree is the earliest cultivated temperate fruit.


IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 309-318 ◽  
Author(s):  
Ingrid de Kort

A comparison was made of diameter growth and wood structure in 26 trees of Douglas fir of different vitality cJasses in a decJining, c. 50- years old stand in De Peel (southeastern Netherlands). Ring width patterns agree cJosely but not perfectly with vitality cJasses as estimated by external appearance of the crown. The 'diseased' vitality cJasses all show growth reductions over the last 20 to 30 years. In the most diseased cJass no wood had been formed at all at the stern base over the last 4 to 10 years. The onset of growth reduction may be connected with the effect of air pollution in the last 40 to 50 years. The most striking result was the inverse relationship between growth rate in the first 10 to 15 years of growth, and growth rate in the last decades: all trees which are healthy at present showed slow radial growth when young, and all diseased to dead trees exhibited fast growth in their youth.


2018 ◽  
Vol 46 (118) ◽  
Author(s):  
Joaquim Carlos Gonçalez ◽  
Nayara Santos ◽  
Francides Gomes da Silva Junior ◽  
Roberta Santos Souza ◽  
Marcella Hermida de Paula

BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 386-399 ◽  
Author(s):  
Mehran Roonia ◽  
Mohammad-Ali Hossein ◽  
Seyed-Ehsan Alavi-Tabar ◽  
Ajang Tajdini ◽  
Ahmad Jahan-Latibari ◽  
...  

In this study, variation in acoustic properties of Arizona cypress wood was monitored from pith to bark as affected by tapering of the growth ring width. Specific modulus of elasticity, acoustic coefficient, damping, and acoustic conversion efficiency were calculated. It was shown that the outer parts of the stem, close to the bark containing narrower growth rings, exhibited lower damping due to internal friction and higher sound radiation. Our finding theoretically justified the luthier craftsmen’s traditional preference toward timbers with narrow growth rings to make sounding boards in musical instruments.


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