Growth and Fire Response of Selected Epacridaceae of South-Western Australia

1996 ◽  
Vol 44 (5) ◽  
pp. 509 ◽  
Author(s):  
TL Bell ◽  
JS Pate
Keyword(s):  
Growth Ring ◽  
Shoot Biomass ◽  
Ring Extension ◽  
Growth Rings ◽  
Ring Number ◽  
Root Stock ◽  
Xylem Growth ◽  
Root Starch ◽  
Shoot Removal ◽  
Bud Initiation

Recruiting populations of seeder (Astroloma xerophyllum (DC.) Sond. and Leucopogon conostephioides DC.) and resprouter (Leucopogon verticillatus R.Br. and Conostephium pendulum. Benth.) epacrids were examined over an 8 year period, using time of fire, shoot morphology and root xylem ring number to age plants. The seeders commenced flowering earlier, achieved three-fold higher shoot:root ratios but accumulated much smaller root starch reserves than the resprouters. The resprouting potential of L. verticillatus was 'bud initiation-limited', since progressive shoot removal exhausted the bud-producing potential but did not fully deplete the starch reserves of the root stock. Apparent conversion efficiency of starch to new shoot biomass was 88%. The corresponding response in C. pendulum was 'energy reserve-limited', with shoot removal eliminating root starch but leaving many unexpanded buds. Dendroecological analyses of root xylem growth rings were undertaken on 15 year-old plants of C. pendulum recruiting from seed in unburnt and adjacent periodically burnt habitats. Growth ring extension of burnt plants resumed after each fire at rates faster than their unburnt counterparts, suggesting that improved access by resprouting shoots to light, water and nutrients compensated for destruction of the previous shoot system.

Distribution of juvenile wood in two stems of Larixlaricina

1986 ◽  
Vol 16 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
K. C. Yang ◽  
C. A. Benson ◽  
J. K. Wong
Keyword(s):  
Juvenile Wood ◽  
Growth Ring ◽  
Ring Width ◽  
Tree Level ◽  
Growth Rings ◽  
Vertical Variation ◽  
Strong Negative Correlation ◽  
Ring Number ◽  
Tracheid Length ◽  
Growth Ring Width

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.

scholarly journals Number of Cells in Xylem, Phloem and Dormant Cambium in Silver Fir (Abies Alba), in Trees of Different Vitality

IAWA Journal ◽  
2009 ◽  
Vol 30 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Jožica Gričar ◽  
Luka Krže ◽  
Katarina Čufar
Keyword(s):  
Forest Management ◽  
Growth Ring ◽  
Abies Alba ◽  
Anatomical Structure ◽  
Silver Fir ◽  
Study Group ◽  
Growth Rings ◽  
Axial Parenchyma ◽  
Xylem Growth ◽  
Number Of Cells

We investigated the anatomical structure of phloem and xylem growth rings as well as the dormant cambium in relation to vitality in 81 adult silver fir trees (Abies alba Mill.). Specifically, we investigated the number of cells produced in the current phloem growth ring (PR), xylem growth ring (XR) and their ratio, the number of cells in the dormant cambium (CC), and the structure of the PR, which included characterisation of the early phloem (EP), the late phloem (LP), and the presence, absence, and continuity of tangential bands of axial parenchyma (AP). EP was relatively stable with respect to number and types of cells as PR width changed, but LP was quite variable. The CC of more vital trees produced more xylem than phloem cells. The ratio of XR to PR number decreased with decreasing vitality of trees and in the most severely affected trees (4% of the study group), more cells were formed in the PR than in the XR. The number of cells in phloem, xylem and dormant cambium is positively correlated. The use of width and structure of phloem and the ratios between PR, XR and CC can provide information on tree conditions and, consequently, can be a useful tool for forest management.

Cyclophytic effects on wood structure in Pinusradiata D. Don. II. Tracheid morphology

1988 ◽  
Vol 18 (4) ◽  
pp. 413-420 ◽  
Author(s):  
Richard S. Dodd
Keyword(s):  
Growth Ring ◽  
Anatomical Variation ◽  
Radiata Pine ◽  
Growth Rings ◽  
Tree Form ◽  
Ring Number ◽  
Tracheid Length ◽  
Rate Of Increase ◽  
The Difference

The effects of apical ontogeny on xylem morphology in Pinusradiata were examined in grafted trees and in clonal pairs of trees grown from cuttings from hedge- and tree-form donors (H and T). At the time of sampling the grafted rootstocks were 21 years old, and trees from H and T plants were 11 years old from the date of planting rooted cuttings. In grafted trees tracheids were longer, and the rate of increase in tracheid length was greater above the graft. Since growth rings were narrower above the graft, the difference in rate of increase in tracheid length above and below the graft was greater when plotted against distance from pith than against growth ring number. In comparisons of H and T plants, T plants (expected to be at a later stage of apical ontogeny) produced fewer but longer and wider tracheids. Cell wall volumes per tracheid were greater in T plants, but because the tracheid diameters in H plants were smaller, wall volumes per unit tracheid volumes were consistently greater in H plants. The role of apical ontogeny in explaining patterns of anatomical variation within the stem is discussed. H and T plants of radiata pine were from the three mainland populations: Año Nuevo, Monterey, and Cambria. The Año Nuevo population produced the greatest numbers and the largest tracheids. The Monterey population had the shortest tracheids amongst H plants, but their tracheid lengths were equal to those of the Año Nuevo population in T plants.

scholarly journals Growth Rings, Growth Ring Formation and Age Determination in the Mangrove Rhizophora mucronata

2004 ◽  
Vol 94 (1) ◽  
pp. 59-66 ◽  
Author(s):  
A. VERHEYDEN
Keyword(s):  
Growth Ring ◽  
Age Determination ◽  
Ring Formation ◽  
Rhizophora Mucronata ◽  
Growth Rings

scholarly journals Jahrringe als Indikatoren für extreme Standortsbedingungen im Gebirge: Schnee, Lawinen und Permafrost | Growth rings as indicators of extreme site conditions in the mountains: snow, avalanches and permafrost

2004 ◽  
Vol 155 (6) ◽  
pp. 208-212 ◽  
Author(s):  
Peter Bebi ◽  
Alejandro Casteller ◽  
Andrea Corinna Mayer ◽  
Veronika Stöckli
Keyword(s):  
Natural Hazards ◽  
Growth Ring ◽  
Management Strategies ◽  
Extreme Conditions ◽  
Site Conditions ◽  
Snow Avalanches ◽  
Growth Rings ◽  
Survival And Growth ◽  
Ring Analysis

Snow, avalanches, and permafrost are extreme site conditions for plants. Reactions and adaptations to such extreme conditions can be reconstructed with growth ring analysis and linked with corresponding climate and disturbance data. On the basis of five case studies in and around the long-term research site Stillberg, near Davos, we discuss both the potential and the limits of dendroecology to understand the effect of such extreme site conditions. Despite some uncertainties in reliably assigning plant reactions, growth ring analysis is a valuable addition to better understand the effects of extreme site conditions on the survival and growth of plants. This can lead to improved management strategies associated with natural hazards, especially in the case of avalanches.

Chaparral growth-ring analysis as an indicator of stand biomass development

2016 ◽  
Vol 25 (10) ◽  
pp. 1086 ◽  
Author(s):  
Kellie A. Uyeda ◽  
Douglas A. Stow ◽  
John F. O'Leary ◽  
Christina Tague ◽  
Philip J. Riggan
Keyword(s):  
Growth Ring ◽  
Basal Area ◽  
Biomass Accumulation ◽  
Field Measurements ◽  
Solar Irradiation ◽  
Annual Precipitation ◽  
Total Biomass ◽  
Growth Rings ◽  
Close Relationship ◽  
Long Time

Chaparral wildfires typically create even-aged stands of vegetation that grow quickly in the first 2 decades following a fire. Patterns of this growth are important for understanding ecosystem productivity and re-establishment success, but are logistically challenging to measure over long time periods. We tested the utility of a novel method of using shrub growth rings to estimate stand-level biomass accumulation at an annual time scale in southern California chaparral. We examined how temporal variation in precipitation and spatial variation in solar irradiation influence that accumulation. Using field measurements and a relationship between stem basal area and aboveground biomass, we estimated current biomass levels in an 11-year-old chaparral stand, and used growth-ring diameters to estimate growth in each year from age 4 to 11 years. We found that annual growth as measured by shrub growth rings tracked closely with patterns of annual precipitation, but not with time since fire. Solar irradiation was not found to be a significant covariate with total biomass by plot, possibly due to sampling area limitations. The close relationship of annual biomass accumulation with annual precipitation indicates that shrub growth-ring measurements can provide a useful metric of stand-level recovery.

Hydraulic Conductivity in Trunk Xylem of Elm, Ulmus Americana

IAWA Journal ◽  
1985 ◽  
Vol 6 (4) ◽  
pp. 303-307 ◽  
Author(s):  
George S. Ellmore ◽  
Frank W. Ewers
Keyword(s):  
Fluid Flow ◽  
Hydraulic Conductivity ◽  
Fluid Transport ◽  
Growth Ring ◽  
Theoretical Calculations ◽  
Transport Pathway ◽  
Growth Rings ◽  
Ulmus Americana ◽  
Xylem Transport ◽  
Flow Through

The notion that most xylem transport in stems of ring-porous trees occurs in the outermost growth ring requires experimental support. Significance of this ring is challenged by workers who find tracer dyes appearing in 4 to 8 growth rings rather than in only the outermost increment. We test the hypothesis that the outermost growth ring is of overriding significance in fluid transport through stems of Ulmus, a ring-porous tree. Fluid flow through the outermost ring was quantified by removing that ring, calculating gravity flow rates (hydraulic conductivity at 10.13 kPa m-1 ), and by tracing the transport pathway through control and experimental stem segments. From measurements corroborating theoretical calculations based on Poiseuille's law, over 90% of fluid flow through the stem occurs through the outermost ring. Remaining rings combine to account for less than 10% of xylem transport. As a result of dependence upon transport in the most superficial xylem, ring-porous trees such as elm, oak, ash, and chestnut are particularly susceptible to xylem pathogens entering from the bark.

An assessment of the relationship between tree-ring counts and basal girth of high-altitude populations of Eucalyptus pauciflora (Myrtaceae)

2009 ◽  
Vol 57 (7) ◽  
pp. 583 ◽  
Author(s):  
Libby Rumpff ◽  
Seraphina C. Cutler ◽  
Ian Thomas ◽  
John W. Morgan
Keyword(s):  
High Altitude ◽  
National Park ◽  
Linear Growth ◽  
Growth Ring ◽  
Tree Line ◽  
Growth Rings ◽  
Regression Methods ◽  
Ski Resorts ◽  
Non Linear ◽  
The Relationship

We investigated the relationship between the number of growth rings (a surrogate for approximate age of stems) and basal girth for Eucalyptus pauciflora (Maiden & Blakely) L.A.S.Johnson & Blaxell. Using basal-girth measurements and growth-ring counts obtained from trees felled on ski slopes at three Victorian alpine ski resorts, as well as seedlings destructively sampled from near the tree line on four summits, we modelled the relationship between growth rings and basal girth by using simple linear and non-linear regression methods. We compared our data to growth-ring–basal-girth data collected from low- and high-altitude E. pauciflora woodland stands in Kosciuszko National Park. The relationship between the number of tree rings and basal girth at Victorian sites was non-linear (growth rings = 3.62 × girth0.63, R2 = 0.96). In general, the Victorian and Kosciuszko datasets were in broad agreement, although caution is required when attempting to estimate the age of trees with >115-cm girth. We suggest that the model we have developed can be combined with dendrological techniques to estimate the age of older trees accurately.

scholarly journals Growth-Ring Analysis of Diploknema butyracea Is a Potential Tool for Revealing Indigenous Land Use History in the Lower Himalayan Foothills of Nepal

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 242
Author(s):  
Md. Qumruzzaman Chowdhury ◽  
Teeka Ram Bhattarai ◽  
Maaike De Ridder ◽  
Hans Beeckman
Keyword(s):  
Land Use ◽  
Oral Tradition ◽  
Growth Ring ◽  
Indigenous Communities ◽  
Land Use History ◽  
Growth Rings ◽  
Slash And Burn ◽  
Himalayan Foothills ◽  
Ring Analysis ◽  
Indigenous Land

Slash-and-burn is a farming practice of the indigenous communities in the Himalayan foothills of Nepal. The traditional land-tenure system is based on a customary oral tradition. However, the government’s persistent denial of land rights has fueled the indigenous conflicts in the last few decades. Deliverance of scientific evidence-based arguments may underpin the ongoing conflict-resolution dialogues between the authorities and the indigenous communities. Dating growth rings of trees in a slash-and-burn system might help the indigenous people to find evidence of their historic land uses in the mountainous landscape. In this pilot study, we examined the potential of Diploknema butyracea (Roxb.) H. J. Lam growth rings for documenting land use history of Nepalese indigenous farming practices, as this species is being preserved during the slash-and-burn practices. The species is an economically important and ecologically interesting (as it flushes leaves when everything is dry, and sheds leaves while everything is green) deciduous tree species belonging to Sapotaceae family and widely distributed in Sub-Himalayan tracts. Five stem discs were studied which were originated from the Kandrang valley of the Chitwan district, Nepal. For the first time, we revealed distinct growth rings in this species which are marked by fibers with thicker cell walls. Growth-ring anomalies, i.e., wedging and partially missing rings, were also found. Four out of five samples could be crossdated at a marginal level (GLK ≥ 60 and t ≥ 2.0) which is a confirmation of the annual nature of growth rings. One of the samples showed black spots of oxidized wood which are traces of fire, suggesting evidence of slash-and-burn practices in the study area since 1933. This study suggests a strong potential of D. butyracea for growth-ring analysis to reconstruct indigenous land use history in Nepal.

scholarly journals Overexpression of GSK3-like Kinase 5 (OsGSK5) in rice (Oryza sativa) enhances salinity tolerance in part via preferential carbon allocation to root starch

2017 ◽  
Vol 44 (7) ◽  
pp. 705 ◽  
Author(s):  
Maysaya Thitisaksakul ◽  
Maria C. Arias ◽  
Shaoyun Dong ◽  
Diane M. Beckles
Keyword(s):  
Oryza Sativa ◽  
Salt Stress ◽  
Salinity Tolerance ◽  
Carbon Allocation ◽  
Oryza Sativa L ◽  
Rice Seedling ◽  
Shoot Biomass ◽  
Salt Shock ◽  
Seedling Roots ◽  
Root Starch

Rice (Oryza sativa L.) is very sensitive to soil salinity. To identify endogenous mechanisms that may help rice to better survive salt stress, we studied a rice GSK3-like isoform (OsGSK5), an orthologue of a Medicago GSK3 previously shown to enhance salinity tolerance in Arabidopsis by altering carbohydrate metabolism. We wanted to determine whether OsGSK5 functions similarly in rice. OsGSK5 was cloned and sequence, expression, evolutionary and functional analyses were conducted. OsGSK5 was expressed highest in rice seedling roots and was both salt and sugar starvation inducible in this tissue. A short-term salt-shock (150 mM) activated OsGSK5, whereas moderate (50 mM) salinity over the same period repressed the transcript. OsGSK5 response to salinity was due to an ionic effect since it was unaffected by polyethylene glycol. We engineered a rice line with 3.5-fold higher OsGSK5 transcript, which better tolerated cultivation on saline soils (EC = 8 and 10 dS m–2). This line produced more panicles and leaves, and a higher shoot biomass under high salt stress than the control genotypes. Whole-plant 14C-tracing and correlative analysis of OsGSK5 transcript with eco-physiological assessments pointed to the accelerated allocation of carbon to the root and its deposition as starch, as part of the tolerance mechanism.

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