Clonal expansion in the deciduous understory shrub, devil's club (Oplopanax horridus; Araliaceae)

2002 ◽  
Vol 80 (10) ◽  
pp. 1052-1062 ◽  
Author(s):  
Trevor C Lantz ◽  
Joseph A Antos

To examine clonal growth and the ability of devil's club (Oplopanax horridus (Sm.) Torr. & A. Gray ex Miq.) to persist throughout stages of forest succession, we sampled populations in three classes of stand development: clearcuts (1–10 years old), young stands (11–50 years old), and maturing stands (51–200+ years old). We completely excavated and mapped all clonal fragments (systems of ramets connected by decumbent stems) in a plot at each site and determined ramet and clonal fragment age using annual growth rings on stem cross sections. Clonal fragment density and size, ramet density and age, decumbent stem length, annual stem elongation, annual ramet recruitment, lateral meristem formation, and the number of persistent dead ramets were significantly (P < 0.05) related to stand development class. Clonal fragments in clearcut stands were large, predating the year of stand establishment, with many dead, old ramets, but many young stems. Ramet recruitment and lateral meristem formation were highest in clearcut stands, which contributed to replacement of older ramets lost to the disturbance. Clonal fragments in young stands were few and small, consisting of a few ramets and short decumbent stems. In maturing stands, clonal fragments were numerous but consisted of few ramets with extensive decumbent stem connections. No devil's club seedlings were observed in any of the stands sampled. Devil's club populations are maintained by prolific basal stem sprouting following disturbance and continual layering and clonal fragmentation throughout stand development.Key words: age structure, clonal architecture, clonal shrubs, demography, layering, population dynamics.

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 523-524 ◽  
Author(s):  
Marvin Stokes ◽  
Tom Harlan ◽  
Marvin Harris ◽  
J. Benton Storey

Analyses of stem cross sections of 97 pecan [Carya illinoinensis (Wangenh.) K. Koch] and 22 post oak (Quercus stellata Wangenh.) trees from seven sites showed tree rings were sensitive to the environment and were datable by tree, among trees within a site, among sites, and between species. Pecan had well-defined annual growth rings averaging from 1.25 to 3.36 mm in width and that varied synchronously among trees. Pecan had a mean sensitivity of about 0.3 compared to 0.4 for post oak, indicating a smaller but adequate response of pecan to reflect climatic variations and to use pecan tree rings in other dendrological studies.


IAWA Journal ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 359-379 ◽  
Author(s):  
Fritz Hans Schweingruber

Cross sections of 760 trunks of approximately 670 species from 47 families of shrubs, dwarf shrubs, and trees were examined to study the incidence and appearance of different categories of growth zones. In montane/alpine sites with relatively cool winter temperatures all the woody plants form distinct growth rings similar to those seen in boreal and temperate regions throughout the world, and thus these rings are considered to represent annual rings. Most species from this phytogeographical zone are useful for crossdating. In the savannahs, the jarrah and karri woodlands of the southwest and the subtropical rain forests of the southeast identifiable growth zones are formed in most species. The approximate age of the woods can be determined, but crossdating is difficult or impossible. In the desert areas woody plants form irregular growth zones, the number of which may correspond to the incidence of rainfall, and age determination and crossdating is mostly impossible. Members of the well-studied families Cupressaceae, Epacridaceae and Myrtaceae form growth zones that are more distinct than the Mimosaceae and Proteaceae. Included phloem is present in all Chenopodiaceae, one Loranthaceae and two species of Verbenaceae.


2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>


1967 ◽  
Vol 45 (9) ◽  
pp. 1643-1651 ◽  
Author(s):  
J. Johanna Clausen ◽  
T. T. Kozlowski

Tamarack (Larix laricina (DuRoi) K. Koch) produces long shoots which bear two kinds of needles. Early needles are present in the bud and elongate rapidly after budbreak. Late needles, few of which are present in the bud, elongate later than early needles. Short shoots bear early needles only, and stem length seldom exceeds 1 mm. Seasonal changes in length and weight of needles and stems of both shoot types were measured. In long shoots, 75% of stem elongation, more than 70% of stem weight increment, and 65–70% of late needle elongation occurred after early needles were full-sized. Stem and late needle elongation ceased simultaneously, after which time needle weight decreased and stem weight increased. Early needles probably drew on food reserves while developing, and then themselves contributed to stem and late needle elongation. Final stem weight increase probably used photosynthate from both late and early needles of the current year.Shading of current and last year's needles showed that shoots in which photosynthesis was interrupted in this way produced shorter, lighter-weight stems than did control shoots.


1990 ◽  
Vol 115 (6) ◽  
pp. 910-914 ◽  
Author(s):  
A.M. Armitage ◽  
N.G. Seager ◽  
I.J. Warrington ◽  
D.H. Greer ◽  
J. Reyngoud

Incremental increases in temperature from 14 to 22 to 30C resulted in linear increases in stem length and node number and decreases in stem diameter and stem strength of Oxypetalum caeruleum (D. Don.) Decne. Higher temperatures also resulted in additional flower abortion, reduced time to flowering, and fewer flowering stems per inflorescence. Reduction in the photosynthetic photon flux (PPF) from 695 to 315 μmol·s-1·m-2 had similar effects as increasing the temperature on vegetative characteristics, but had little effect on reproductive ones. The rate of stem elongation was greatest at low PPF for all temperatures and at high temperature for all PPF treatments. Net photosynthesis rose between 14 and 22C and declined at 30C for all PPF treatments. Long photoperiods (12 or 14 hours) resulted in longer internodes, longer stems, and more flowers per cyme than short photoperiods (8 or 10 hours), but photoperiod had little effect on flowering time. Treatments to reduce latex coagulant and silver thiosulfate treatments had no significant effect on vase life.


IAWA Journal ◽  
1988 ◽  
Vol 9 (3) ◽  
pp. 269-274 ◽  
Author(s):  
Frank W. Telewski

The majority of detailed studies on circumnutational growth movements have focused on herbaceous plants or on the primary growth of woody plant seedlings, ignoring completely secondary growth in woody plants. The relatively rapid movement in herbaceous tissues consists of two components: an autonomous growth rhythm and a gravitropic response. Since there is a gravitropic component to circumnutational movement and a gravitropic stimulus can induce compression wood formation, the formation of a compression wood spiral may be expected if there is a circumnutational movement of a woody stern. It is suggested here, that observed spirals of compression wood within annual growth rings in Pinus taeda L. and Abies concolor (Gord. ' Glend.) Lindl. ex Hildebr. represents an annual record of a slower circumnutational growth movement. Data derived from observations of greenhouse- grown 3-year-old Pinus taeda seedlings indicate that there are two distinct circumnutational patterns of different rotation al frequency present in woody plants associated with primary and secondary tissues.


Author(s):  
Joanna D. Haigh ◽  
Peter Cargill

This chapter looks at how the Sun varies in terms of its emissions of radiation and particles and how these changes might be associated with variations in weather and climate on Earth. Investigations of climate variability and climate change depend crucially on the existence, length, and quality of meteorological records. Ideally, records would consist of long time series of measurements made by well-calibrated instruments densely situated across the globe. For longer periods, and in remote regions, records have to be reconstructed from indirect indicators of climate known as proxy data. The chapter introduces one well-established technique for providing proxy climate data: dendrochronology, or the study of the successive annual growth rings of trees.


2019 ◽  
Vol 284 ◽  
pp. 07006 ◽  
Author(s):  
Wojciech Skowroński ◽  
Bohdan Stawiski

For many years work has been performed to obtain sufficiently accurate correlation between the results of ultrasonic tests and the results of strength tests for evaluation of the strength parameters of wood in a structure. It is also important to ensure the development of methods which will facilitate the work of construction mycologists; that is, non-invasive methods of determining the volume of missing materials caused by biological corrosion. The study presents the idea of the objective examination of the thickness of a corroded layer by measuring the velocity of ultrasonic pulse along the fibre length using for this spot heads with thin waveguides. Another testing method presented in the study is controlling the velocity of ultrasonic wave in the direction tangential to annual growth rings by conducting tests on the corner of the corroded beam.


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