scholarly journals The onset of xylogenesis in Smith fir is not related to outer bark thickness

2019 ◽  
Vol 106 (10) ◽  
pp. 1386-1391
Author(s):  
Xiaoxia Li ◽  
Sergio Rossi ◽  
Eryuan Liang
Keyword(s):  
Bark Thickness ◽  
Outer Bark

Bark in Woody Plants: Understanding the Diversity of a Multifunctional Structure

2019 ◽  
Vol 59 (3) ◽  
pp. 535-547 ◽  
Author(s):  
Julieta A Rosell
Keyword(s):  
Woody Plants ◽  
Fire Regime ◽  
Soluble Sugars ◽  
Plant Performance ◽  
Functional Ecology ◽  
Bark Thickness ◽  
Outer Bark ◽  
Plant Parts ◽  
Selective Forces ◽  
Plant Ecological

Abstract Most biological structures carry out multiple functions. Focusing on only one function to make adaptive inferences overlooks that manifold selection pressures and tradeoffs shape the characteristics of a multifunctional structure. Focusing on single functions can only lead to a partial picture of the causes underlying diversity and the evolutionary origin of the structure in question. I illustrate this discussion using bark as a study case. Bark comprises all the tissues surrounding the xylem in woody plants. Broadly, bark includes an inner and mostly living region and an outer, dead one. Of all plant structures, bark has the most complex anatomical structure and ontogenetic origin involving two (and often three) different meristems. Traditionally, the wide diversity in bark traits, mainly bark thickness, has been interpreted as the result of the selective pressures imposed by fire regime. However, recent research has shown that explanations based on fire regime cannot account for salient patterns of bark variation globally including the very strong inner bark thickness–stem diameter scaling, which is likely due to metabolic needs, and the very high intracommunity variation in total, inner, and outer bark thickness, and in inner:outer proportions. Moreover, explanations based on fire disregard that in addition to fire protection, bark carries out several other crucial functions for plants including translocation of photosynthates; storage of starch, soluble sugars, water, and other compounds; protection from herbivores, pathogens, and high temperatures; wound closure, as well as mechanical support, photosynthesis, and likely being involved in xylem embolism repair. All these functions are crucial for plant performance and are involved in synergistic (e.g., storage of water and insulation) and trade-off relationships (e.g., protection from fire vs photosynthetic activity). Focusing on only one of these functions, protection from fire has provided an incomplete picture of the selective forces shaping bark diversity and has severely hindered our incipient understanding of the functional ecology of this crucial region of woody stems. Applying a multifunctional perspective to the study of bark will allow us to address why we observe such high intracommunity variation in bark traits, why some bark trait combinations are ontogenetically impossible or penalized by selection, how bark is coordinated functionally with other plant parts, and as a result, to understand how bark contributes to the vast diversity of plant ecological strategies across the globe.

scholarly journals Variation in Bark Allocation and Rugosity Across Seven Co-occurring Southeastern US Tree Species

2021 ◽  
Vol 4 ◽  
Author(s):  
Timothy M. Shearman ◽  
J. Morgan Varner
Keyword(s):  
Tree Species ◽  
Fire Behavior ◽  
Height Growth ◽  
Bark Thickness ◽  
Pinus Echinata ◽  
Outer Bark ◽  
Mixed Effect ◽  
Southeastern Us ◽  
Rate Measure ◽  
Quercus Marilandica

Bark is a complex multifunctional structure of woody plants that varies widely among species. Thick bark is a primary trait that can protect trees from heat generated in surface fires. Outer bark on species that allocate resources to thick bark also tends to be rugose, with bark being thickest at the ridges and thinnest in the furrows. Tree diameter or wood diameter is often used as a predictor for bark thickness but little attention has been made on other factors that might affect bark development and allocation. Here we test multiple mixed effect models to evaluate additional factors (height growth rate, measure height) that correlate with bark allocation and present a method to quantify bark rugosity. We focused on seven co-occurring native tree species in the Tallahatchie Experimental Forest in north Mississippi. Approximately ten saplings of Carya tomentosa, Nyssa sylvatica, Prunus serotina, Pinus echinata, Pinus taeda, Quercus marilandica, and Quercus falcata were destructively sampled for stem analyses. Outer bark thickness (OBT) ranged from 0.01 to 0.77 cm with the thickest maximum outer bark occurring on P. taeda (0.77 cm) and the thinnest maximum outer bark occurring on P. serotina (0.17 cm). Our outer bark allocation models suggest that some individuals with rapid height growth allocate less to outer bark in C. tomentosa, N. sylvatica, P. taeda, and P. serotina, but not for P. echinata or either oak species. All species except for C. tomentosa and N. sylvatica showed evidence for outer bark taper, allocating more outer bark at the base of the bole. Inner bark also was tapered in Carya and the oaks. Bark rugosity varied among species from 0.00 (very smooth) to 0.17 (very rugose) with P. Serotina and C. tomentosa having the smoothest bark. OBT was the best fixed effect for all species. Aside from providing data for several important yet understudied species, our rugosity measures offer promise for incorporating into fluid dynamics fire behavior models.

An anatomical study of epicormic bud strand structure in Eucalyptus cladocalyx (Myrtaceae)

2000 ◽  
Vol 48 (2) ◽  
pp. 233 ◽  
Author(s):  
G. E. Burrows
Keyword(s):  
Transverse Section ◽  
Secondary Xylem ◽  
Large Diameter ◽  
Anatomical Study ◽  
Leaf Primordia ◽  
Bark Thickness ◽  
Outer Bark ◽  
Epicormic Shoots ◽  
Vascular Connections ◽  
Do So

Epicormic bud strands in Eucalyptus cladocalyx F.Muell. extended from the pith to the outer bark. In large-diameter stems (30 cm diameter, 2 cm bark thickness) the epicormic bud strands had their greatest anatomical complexity at the level of the vascular cambium. At this level the epicormic bud strand was about 3 mm wide × 5 mm high in transverse section and within it were 22–40 radially arranged strips of cells of meristematic appearance embedded in a mainly parenchymatous matrix. Well-developed buds with leaf primordia and vascular connections were never observed in intact trees, although when stimulated each meristem strip could produce numerous bud primordia. Toward the bark surface the epicormic bud strands became progressively simpler in structure. On the stem surface, the position of the epicormic bud strand was shown by a number of adjacent small protrusions which appeared to have no meristematic potential. From the outer secondary xylem to the pith the bud strand usually became slightly smaller in diameter and its cells, although nucleated, had thick lignified walls and the meristem strips were much reduced or were not present. In most previously investigated angiosperm tree genera epicormic shoots develop from suppressed buds embedded in the bark. Eucalyptus appears to be unique in that suppressed buds are not present in the bark and that each epicormic bud strand has the potential to form numerous bud primordia when stimulated to do so.

scholarly journals A large database supports the use of simple models of post-fire tree mortality for thick-barked conifers, with less support for other species

Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
C. Alina Cansler ◽  
Sharon M. Hood ◽  
Phillip J. van Mantgem ◽  
J. Morgan Varner
Keyword(s):  
Tree Mortality ◽  
Characteristic Curve ◽  
Small Diameter ◽  
Fire Effects ◽  
Tree Level ◽  
Clear Understanding ◽  
Bark Thickness ◽  
Mortality Models ◽  
Species Specific ◽  
Stem Mortality

Abstract Background Predictive models of post-fire tree and stem mortality are vital for management planning and understanding fire effects. Post-fire tree and stem mortality have been traditionally modeled as a simple empirical function of tree defenses (e.g., bark thickness) and fire injury (e.g., crown scorch). We used the Fire and Tree Mortality database (FTM)—which includes observations of tree mortality in obligate seeders and stem mortality in basal resprouting species from across the USA—to evaluate the accuracy of post-fire mortality models used in the First Order Fire Effects Model (FOFEM) software system. The basic model in FOFEM, the Ryan and Amman (R-A) model, uses bark thickness and percentage of crown volume scorched to predict post-fire mortality and can be applied to any species for which bark thickness can be calculated (184 species-level coefficients are included in the program). FOFEM (v6.7) also includes 38 species-specific tree mortality models (26 for gymnosperms, 12 for angiosperms), with unique predictors and coefficients. We assessed accuracy of the R-A model for 44 tree species and accuracy of 24 species-specific models for 13 species, using data from 93 438 tree-level observations and 351 fires that occurred from 1981 to 2016. Results For each model, we calculated performance statistics and provided an assessment of the representativeness of the evaluation data. We identified probability thresholds for which the model performed best, and the best thresholds with either ≥80% sensitivity or specificity. Of the 68 models evaluated, 43 had Area Under the Receiver Operating Characteristic Curve (AUC) values ≥0.80, indicating excellent performance, and 14 had AUCs <0.7, indicating poor performance. The R-A model often over-predicted mortality for angiosperms; 5 of 11 angiosperms had AUCs <0.7. For conifers, R-A over-predicted mortality for thin-barked species and for small diameter trees. The species-specific models had significantly higher AUCs than the R-A models for 10 of the 22 models, and five additional species-specific models had more balanced errors than R-A models, even though their AUCs were not significantly different or were significantly lower. Conclusions Approximately 75% of models tested had acceptable, excellent, or outstanding predictive ability. The models that performed poorly were primarily models predicting stem mortality of angiosperms or tree mortality of thin-barked conifers. This suggests that different approaches—such as different model forms, better estimates of bark thickness, and additional predictors—may be warranted for these taxa. Future data collection and research should target the geographical and taxonomic data gaps and poorly performing models identified in this study. Our evaluation of post-fire tree mortality models is the most comprehensive effort to date and allows users to have a clear understanding of the expected accuracy in predicting tree death from fire for 44 species.

scholarly journals Bark proportion of Scots pine industrial wood

2021 ◽  
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Supply Chain ◽  
Scots Pine ◽  
Bark Thickness ◽  
Wood Supply ◽  
Volume Proportion ◽  
Bark Damage ◽  
Mass Proportion ◽  
Mean Diameter ◽  
The Mean

AbstractBark characteristics are not only used in the forest-wood supply chain, for example to calculate standing volumes, but also to transform wood volumes and masses. In this study, bark thickness, bark volume and bark mass were analyzed on the basis of 150 Scots pine discs, with a mean diameter of 13 cm. The mean double bark thickness was 3.02 mm, the mean bark volume proportion was 5.6% and mean bark mass proportion was 3.3%. Bark proportions were significantly affected by the log-specific variables ‘diameter over bark’, ‘proportion of bark damage’ and ‘double bark thickness’.

scholarly journals Investigation on the potential of poplar bark from short-rotation coppices as bio-based fungicidal additives

2021 ◽  
Author(s):  
Martina Bremer ◽  
Javane Oktaee ◽  
Daniela Einer ◽  
Steffen Fischer ◽  
André Wagenführ
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Outer Bark ◽  
Chemical Substances ◽  
Adverse Conditions ◽  
Short Rotation ◽  
Poplar Clones ◽  
Phenolic Substances ◽  
Excellent Source

AbstractBark on trees protects the plant against environmentally adverse conditions as well as fungi and insect attacks. There are different chemical substances, mostly in the outer bark of trees, which can stop fungi from developing. Bark as a by-product of wood plantations is available in high quantity and can serve as an excellent source for the production of eco-fungicides. In the presented article, bark of various poplar clones from two short-rotation coppices (SRC) in Poland and Germany was examined to determine the chemical composition, the possible extraction of potential fungicides (terpenes, aromatic and phenolic substances), and influence of their extracts on slowing the growth of mold fungi. It was proved that the content of the fungicidal substances depends strongly on the clone type. Two methods of extraction—Soxhlet and batch—were compared to obtain fungicidal extracts. Fungicidal substances were found in extracts gained with both approaches. Triterpenes, fatty acids, aldehydes, and alcohols were primarily the active fungicides in the Soxhlet extracts, whereas phenolic substances act as fungicides in the batch extracts.

scholarly journals Bark Characteristics of Scots Pine Logs

2020 ◽  
Vol 3 (1) ◽  
pp. 66
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Scots Pine ◽  
Tree Species ◽  
Waste Product ◽  
Mean Value ◽  
Bark Thickness ◽  
Water Displacement ◽  
Federal States ◽  
Bark Damage ◽  
Great Relevance ◽  
High Degree

The wood of Scots pine (Pinus sylvestris L.) shows good properties as building and construction timber but also as furniture or pulp and paper, and thus, is one of the most commercially important European tree species. Scots pine are mostly harvested and processed with a high degree of mechanization. In Northeast Germany (federal states of Brandenburg and Berlin), 36% of harvested Scots pine have a diameter at breast height (DBH) between 7 and 19.9 cm. As a typical industrial wood assortment, a large proportion of the resulting small-sized logs are used in the wood industry to produce boards. Although bark is considered a by-product or waste product of the industry, no actual study has quantified the bark thickness, bark volume, bark mass and bark damage of such Scots pine logs. Therefore, the bark characteristics from 50 logs from 10 different piles were analyzed. Bark volume was quantified using the water displacement method, bark mass by weighing, bark thickness with a precision caliper and bark damage by tape measurements. The diameters of the analyzed 150 log discs were normally distributed and the mean value was 12.9 cm. The results showed average bark damages from 12.0%, which were mostly caused during the felling and processing of logs with the harvester. No significant correlation was found between double bark thickness (mean: 3.0 mm) and the diameter; whereas fresh bark volume (mean: 5.6%) and dry bark mass (mean: 3.3%) were significantly affected by the diameter. As shown for spruce by other authors, bark characteristics may change over time and therefore, should be measured regularly. Moreover, it was shown that bark parameters are site dependent. Thus, quantifying bark characteristics for economically important tree species at both the local and national scale is of great relevance. More detailed analyzes are described by Berendt et al. (2021) [1].

Resin ducts and bark thickness influence pine resistance to bark beetles after prescribed fire

2021 ◽  
Vol 494 ◽  
pp. 119322
Author(s):  
Teresa Valor ◽  
Sharon M. Hood ◽  
Míriam Piqué ◽  
Asier Larrañaga ◽  
Pere Casals
Keyword(s):  
Prescribed Fire ◽  
Bark Beetles ◽  
Bark Thickness ◽  
Resin Ducts

FACTORS INFLUENCING THE MORTALITY OF SCOLYTUS MULTISTRIATUS (COLEOPTERA: SCOLYTIDAE) IN ELM BRANCHES IN CALIFORNIA

1985 ◽  
Vol 117 (7) ◽  
pp. 819-828 ◽  
Author(s):  
Ann E. Hajek ◽  
Donald L. Dahlsten
Keyword(s):  
Small Diameter ◽  
Sampling Period ◽  
Scolytus Multistriatus ◽  
Bark Thickness ◽  
Branch Diameter ◽  
Factors Influencing ◽  
Strong Positive Relationship ◽  
Egg Density ◽  
Ulmus Procera ◽  
Highly Correlated

AbstractPopulations of Scolytus multistriatus (Marsham) from two areas of California were sampled in 1979 to investigate various factors influencing mortality. English-elm bolts (Ulmus procera Salisb.) ranging between 2.0 and 12.9 cm in diameter yielded mean mortalities from 49.1 to 86.0%. Mortality was highly correlated with egg density for branch samples from 7.0 to 12.9 cm in diameter. The minimum acceptable elm-branch diameter (2.8 cm) was attacked only during the first sampling period (mid-May to mid-June). Branch diameter, and therefore bark thickness, demonstrated a strong positive relationship with the density of S. multistriatus eggs, attacks, gallery lengths, and emerged adults. Gallery length density was positively correlated with attack density. At low attack densities in small-diameter branches, mean gallery lengths were shorter.

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