scholarly journals Outer bark thickness decreases more with height on stems of fire-resistant than fire-sensitive Floridian oaks (Quercus spp.; Fagaceae)

2014 ◽  
Vol 101 (12) ◽  
pp. 2183-2188 ◽  
Author(s):  
S. J. Graves ◽  
S. W. Rifai ◽  
F. E. Putz
Keyword(s):  
Bark Thickness ◽  
Outer Bark ◽  
Quercus Spp

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 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

THE BIOLOGY AND ECOLOGY OF THE TWOLINED CHESTNUT BORER, AGRILUS BILINEATUS (COLEOPTERA: BUPRESTIDAE), ON OAKS, QUERCUS SPP., IN WISCONSIN

1982 ◽  
Vol 114 (5) ◽  
pp. 385-396 ◽  
Author(s):  
Robert A. Haack ◽  
Daniel M. Benjamin
Keyword(s):  
Starch Content ◽  
Pupal Stage ◽  
Fourth Instar ◽  
Adult Longevity ◽  
Red Oak ◽  
Initial Attack ◽  
Outer Bark ◽  
Larval Instars ◽  
Root Starch ◽  
Quercus Spp

AbstractAgrilus bilineatus (Weber) is univoltine in Wisconsin. Adults were present from early June through mid-September; however, peak flight and oviposition occurred during the second half of June. Adults consumed significantly more oak foliage than foliage of hardwoods other than oak. Stressed oaks attracted significantly more adults than did uninjured controls, as measured by density of captured adults on sticky traps. Four larval instars were determined; instar IV was the overwintering stage. Fourth instar larvae generally overwintered in pupal cells in the outer bark or in sapwood if the bark was thin. Larvae, especially third and fourth instars, damaged oaks by girdling the conducting xylem and phloem. Attacked oaks had low root starch content relative to those unattacked. Tree death normally resulted after 2 or 3 years of borer infestation, yet tree death may occur in a single season. Initial attack usually began in the live crown and proceeded downward in succeeding years with no apparent reinfestation of previously killed areas. Mean adult longevity in days for adults fed red oak foliage was 28.1 at 20°, 37.8 at 24°, and 8.3 at 30 °C. Mean duration of the pupal stage in days was 11.7 at 24 °and 8.5 at 30 °C.

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.

scholarly journals Phytophthora ramorum as the Cause of Extensive Mortality of Quercus spp. and Lithocarpus densiflorus in California

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 205-214 ◽  
Author(s):  
D. M. Rizzo ◽  
M. Garbelotto ◽  
J. M. Davidson ◽  
G. W. Slaughter ◽  
S. T. Koike
Keyword(s):  
The Netherlands ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Central Coast ◽  
Outer Bark ◽  
Canker Disease ◽  
Quercus Agrifolia ◽  
Lithocarpus Densiflorus ◽  
Quercus Spp ◽  
Diagnostic Symptoms

A new canker disease, commonly known as sudden oak death, of Lithocarpus densiflorus, Quercus agrifolia, Q. kelloggii, and Q. parvula var. shrevei in California is shown to be caused by Phytophthora ramorum. The pathogen is a recently described species that previously was known only from Germany and the Netherlands on Rhododendron spp. and a Viburnum sp. This disease has reached epidemic proportions in forests along approximately 300 km of the central coast of California. The most consistent and diagnostic symptoms on trees are cankers that develop before foliage symptoms become evident. Cankers have brown or black discolored outer bark and seep dark red sap. Cankers occur on the trunk at the root crown up to 20 m above the ground, but do not enlarge below the soil line into the roots. Individual cankers are delimited by thin black lines in the inner bark and can be over 2 m in length. In L. densiflorus saplings, P. ramorum was isolated from branches as small as 5 mm in diameter. L. densiflorus and Q. agrifolia were inoculated with P. ramorum in the field and greenhouse, and symptoms similar to those of naturally infected trees developed. The pathogen was reisolated from the inoculated plants, which confirmed pathogenicity.

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.

Biscogniauxia (Hypoxylon) Canker or Dieback in Trees

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Claudia Paez ◽  
Jason A. Smith
Keyword(s):  
Water Stress ◽  
Tree Species ◽  
Soil Compaction ◽  
Urban Areas ◽  
Root Disease ◽  
Poor Health ◽  
Green Spaces ◽  
Opportunistic Pathogens ◽  
Wide Range ◽  
Quercus Spp

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009).  Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).

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’.

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