scholarly journals Stem density and growth of Attalea maripa and Astrocaryum aculeatum: implication for arborescent palms distribution across Amazonian forests

2004 ◽  
Vol 4 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Rodolfo Salm
Keyword(s):  
Growth Rates ◽  
Stem Growth ◽  
Stem Density ◽  
Laboratory Measurements ◽  
Palm Trees ◽  
Astrocaryum Aculeatum ◽  
Amazonian Forests

This study examines aspects of the stem density and growth of two large arborescent palms Attalea maripa and Astrocaryum aculeatum and discusses their implication for the palm trees distribution in Amazonia. Stem density and growth were investigated through both laboratory measurements and field estimates of growth rates. The densities of stem samples collected within one individual of each studied species were very distinct. The samples of A. maripa stem were more homogeneous in density than those of A. aculeatum, both from the internal to the external, and from the lower to the upper parts of the stem. Field estimates of stem growth rates revealed that A. maripa growth is also more constant through development in height. Short A. aculeatum palms had faster growth rates than A. maripa, as they get taller, stem growth rates are reduced and approach A. maripa rates. The implications for arborescent palms distribution across Amazonian forests are discussed.

scholarly journals A model for the importance of large arborescent palms in the dynamics of seasonally-dry amazonian forests

2005 ◽  
Vol 5 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Rodolfo Salm ◽  
Euphly Jalles-Filho ◽  
Cynthia Schuck-Paim
Keyword(s):  
Forest Regeneration ◽  
Forest Canopy ◽  
Forest Succession ◽  
Secondary Forest ◽  
Forest Disturbance ◽  
Dry Forest ◽  
Forest Patch ◽  
Seasonally Dry ◽  
Palm Trees ◽  
Amazonian Forests

In this study we propose a model that represents the importance of large arborescent palms in the dynamics of seasonally-dry Amazonian forests. Specifically, the model is aimed at guiding the investigation of the role of large arborescent palms on forest regeneration and succession. Following disturbance, the high level of luminosity reaching recently formed forest gaps favors the quick proliferation of shade-intolerant lianas that, by casting shade on the crowns of mature forest trees and increasing tree-fall probability, suppress forest succession. Due to their columnar architecture palm trees are, however, not severely affected by vines. As the palms grow, the canopy at the gaps becomes gradually higher and denser, progressively obstructing the passage of light, thus hindering the growth of shade-intolerant lianas and enabling late-successional tree development and forest regeneration. Owing to the long time associated with forest regeneration, the model cannot be tested directly, but aspects of it were examined with field data collected at an Attalea maripa-rich secondary forest patch within a matrix of well-preserved seasonally-dry forest in the Southeastern Amazon. The results indicate that (1) forest disturbance is important for the recruitment of large arborescent palms species, (2) these palms can grow rapidly after an event of disturbance, restoring forest canopy height and density, and (3) secondary forest dominated by palm trees species may be floristically similar to nearby undisturbed forests, supporting the hypothesis that the former has undergone regeneration, as purported in the model.

Wind-generated gravity-capillary waves: laboratory measurements of temporal growth rates using microwave backscatter

1975 ◽  
Vol 70 (3) ◽  
pp. 417-436 ◽  
Author(s):  
T. R. Larson ◽  
J. W. Wright
Keyword(s):  
Growth Rates ◽  
Water Waves ◽  
Friction Velocity ◽  
Capillary Waves ◽  
Spectral Amplitude ◽  
Bragg Scattering ◽  
Laboratory Measurements ◽  
Wind Speeds ◽  
Tightly Coupled ◽  
Microwave Backscatter

The growth rates of wind-induced water waves at fixed fetch were measured in a laboratory wave tank using microwave backscatter. The technique strongly filters out all wavenumber component pairs except for a narrow window at the resonant Bragg scattering conditions. For these waves the spectral amplitude was measured as a function of the time after a fixed wind was abruptly started. The radars were aligned to respond to waves travelling in the downwind direction at wavelengths of 0·7-7 cm. Wind speeds ranged from 0·5 to 15 m/s. Fetches of 1·0, 3·0 and 8·4 m were used. In every case, the spectral amplitude initially grew at a single exponential rate β over several orders of magnitude, and then abruptly ceased growing. No dependence of the growth rate on fetch was observed. For all wavelengths and wind speeds the data can be fitted by \[ \beta (k,u_{*},{\rm fetch})=f(k)\,u^n_{*}, \] with n = 1·484 ± 0·027. Here u* is the friction velocity obtained from vertical profiles of mean horizontal velocity. For each wind speed, f(k) had a relative maximum near k = kn ≃ 3·6 cm−1. Rough estimates of β/2ω, where ω is the water wave frequency, and of the wind stress supported by short waves indicate that the observed growth rates are qualitatively very large. These waves are tightly coupled to the wind, and play a significant role in the transfer of momentum from wind to water.

scholarly journals Application of brassinosteroid to Tabebuia alba (Bignoniaceae) plants

2000 ◽  
Vol 12 (3) ◽  
pp. 187-194 ◽  
Author(s):  
ELIZABETH ORIKA ONO ◽  
TERUKO NAKAMURA ◽  
SÍLVIA RODRIGUES MACHADO ◽  
JOÃO DOMINGOS RODRIGUES
Keyword(s):  
Growth Rates ◽  
Indoleacetic Acid ◽  
Anatomical Study ◽  
Stem Growth ◽  
Spongy Parenchyma ◽  
Petiole Length ◽  
Water Control ◽  
Plastic Bags ◽  
Fertilized Soil ◽  
Palisade And Spongy Parenchyma

The objective of this study was to observe the effects of brassinosteroid, gibberelin, and auxin application on the development and foliar anatomy of Tabebuia alba (Cham.) Sandw. seedlings. T. alba seedlings were grown in plastic bags with fertilized soil and treated with the following: 1- water (control); 2- brassinolide (BR1) 0.104 mM; 3- BR1 0.208 mM; 4- 3-indoleacetic acid (IAA) 0.2854 mM; 5- IAA 0.5708 mM; 6- GA3 (gibberellin A3) 0.1443 mM; 7- GA3 0.2887 mM; 8- GA3 0.072 mM + IAA 0.1427 mM; 9- GA3 0.1443 mM + IAA 0.2854 mM; 10- GA3 0.072 mM + BR1 0.052 mM; and 11- GA3 0.1443 mM + BR1 0.104 mM. Plant height and petiole length were measured before the treatments and 21 days after application of the growth regulators. These data allowed the calculation of stem and petiole growth rates. The results showed that GA3 + brassinolide produced the highest stem and petiole growth rates and brassinolide application stimulated petiole growth but not stem growth. The anatomical study of leaves showed alterations in blade and petiole thickness, palisade and spongy parenchyma height, and epidermis cells.

scholarly journals Detecting the fingerprint of drought across Europe’s forests: do carbon isotope ratios and stem growth rates tell similar stories?

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Tommaso Jucker ◽  
Charlotte Grossiord ◽  
Damien Bonal ◽  
Olivier Bouriaud ◽  
Arthur Gessler ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Growth Rates ◽  
Isotope Ratios ◽  
Stem Growth ◽  
Carbon Isotope Ratios

scholarly journals Drought responses and their effects on radial stem growth of two co-occurring conifer species in the Mediterranean mountain range

2020 ◽  
Vol 77 (4) ◽  
Author(s):  
Aylin Güney ◽  
Roman Zweifel ◽  
Semra Türkan ◽  
Reiner Zimmermann ◽  
Magnus Wachendorf ◽  
...  
Keyword(s):  
Water Deficit ◽  
Growth Rates ◽  
Water Shortage ◽  
Stem Growth ◽  
Growth Strategy ◽  
Mountain Range ◽  
Summer Drought ◽  
Cedrus Libani ◽  
Juniperus Excelsa ◽  
Species Specific

Abstract Key message Patterns of stem radial variations showed thatCedrus libaniA. Rich. was less limited by summer drought than co-occurringJuniperus excelsaM. Bieb.Cedrus libanirecovered faster from tree water deficit and showed significantly higher radial growth rates and annual stem increments thanJ. excelsa. However, the ability ofJ. excelsato grow more hours per year may indicate a potential benefit in more extreme conditions. Context Knowledge about species-specific drought responses is needed to manage productive forests in drought prone areas. Under water shortage, trees commonly show stem shrinkage, which is assumed to inhibit growth. Aims We investigated whether the two co-existing conifers Juniperus excelsa M. Bieb. and Cedrus libani A. Rich. (growing at the Taurus Mountains, SW-Turkey) show differences in water relations and stem growth in order to evaluate their respective drought tolerance. Methods Stem radius changes were hourly monitored over 2 years using high-resolution point dendrometers. Radial stem growth, tree water deficit-induced stem shrinkage, and maximum daily shrinkage were extracted from stem radius change measurements, investigated for their patterns, and related to environmental conditions. Results Cedrus libani recovered from tree water deficit under higher temperature and vapor pressure deficit than J. excelsa. The number of hours during which stem growth occurred was higher for J. excelsa; however, growth rates and annual increments were significantly lower than in C. libani. Both species showed highest maximum daily shrinkage during the driest months indicating the ability to maintain gas exchange all year round. Conclusion Juniperus excelsa showed a more conservative growth strategy while C. libani was less limited by summer drought and showed more annual stem increment under the conditions investigated.

scholarly journals Resistance of a lowland rain forest to increasing drought intensity in Sabah, Borneo

2004 ◽  
Vol 20 (6) ◽  
pp. 613-624 ◽  
Author(s):  
D. M. Newbery ◽  
M. Lingenfelder
Keyword(s):  
Growth Rates ◽  
Rain Forest ◽  
Tree Mortality ◽  
Mortality Rates ◽  
Stem Growth ◽  
Lowland Rain Forest ◽  
Drought Intensity ◽  
Tree Survival ◽  
Climatic Environment ◽  
Absolute Growth

Occasional strong droughts are an important feature of the climatic environment of tropical rain forest in much of Borneo. This paper compares the response of a lowland dipterocarp forest at Danum, Sabah, in a period of low (LDI) and a period of high (HDI) drought intensity (1986–96, 9.98 y; 1996–99, 2.62 y). Mean annual drought intensity was two-fold higher in the HDI than LDI period (1997 v. 976 mm), and each period had one moderately strong main drought (viz. 1992, 1998). Mortality of ‘all’ trees ≥10 cm gbh (girth at breast height) and stem growth rates of ‘small’ trees 10–<50 cm gbh were measured in sixteen 0.16-ha subplots (half on ridge, half on lower slope sites) within two 4-ha plots. These 10–50-cm trees were composed largely of true understorey species. A new procedure was developed to correct for the effect of differences in length of census interval when comparing tree mortality rates. Mortality rates of small trees declined slightly but not significantly between the LDI and HDI periods (1.53 to 1.48% y−1): mortality of all trees showed a similar pattern. Relative growth rates declined significantly by 23% from LDI to HDI periods (11.1 to 8.6 mm m−1 y−1): for absolute growth rates the decrease was 28% (2.45 to 1.77 mm y−1). Neither mortality nor growth rates were significantly influenced by topography. For small trees, across subplots, absolute growth rate was positively correlated in the LDI period, but negatively correlated in the HDI period, with mortality rate. There was no consistent pattern in the responses among the 19 most abundant species (n≥50 trees) which included a proposed drought-tolerant guild. In terms of tree survival, the forest at Danum was resistant to increasing drought intensity, but showed decreased stem growth attributable to increasing water stress.

scholarly journals Correction to: Comparative transcriptome analyses define genes and gene modules differing between two Populus genotypes with contrasting stem growth rates

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiao Han ◽  
Yi An ◽  
Yangyan Zhou ◽  
Chao Liu ◽  
Weilun Yin ◽  
...  
Keyword(s):  
Growth Rates ◽  
Stem Growth ◽  
Comparative Transcriptome ◽  
Gene Modules ◽  
Transcriptome Analyses

An amendment to this paper has been published and can be accessed via the original article.

scholarly journals Stem growth of woody species at the Nkuhlu exclosures, Kruger National Park: 2006–2010

Koedoe ◽  
2011 ◽  
Vol 53 (1) ◽  
Author(s):  
Peter F. Scogings
Keyword(s):  
Ecosystem Management ◽  
Growth Rates ◽  
Woody Species ◽  
Dry Season ◽  
Stem Growth ◽  
Wet Season ◽  
Conservation Areas ◽  
Large Herbivores ◽  
Chemical Defences ◽  
Conservation Implications

An important aspect of managing African conservation areas involves understanding how large herbivores affect woody plant growth. Yet, data on growth rates of woody species in savannas are scarce, despite its critical importance for developing models to guide ecosystem management. What effect do browsing and season have on woody stem growth? Assuming no growth happens in the dry season, browsing should reduce stem growth in the wet season only. Secondly, do functional species groups differ in stem growth? For example, assuming fine-leaved, spiny species’ growth is not compromised by carbon-based chemical defences, they should grow faster than broad-leaved, chemically defended species. Dendrometers were fixed at 20 cm in height on the main stems of 244 random plants of six woody species in three plots (all large herbivores excluded, partial exclusion, and control) and observed from late 2006 to early 2010. Average monthly increment (AMI) per dendrometer and season (dry, wet) was calculated and the interaction between plot and season tested per species, controlling for initial stem girth. AMIs of Combretum apiculatum, Dichrostachys cinerea and Grewia flavescens were zero in the dry season, whilst those of Acacia exuvialis, Acacia grandicornuta and Euclea divinorum were either positive or negative in the dry season. Wet-season AMI of D. cinerea and dry-season AMI of G. flavescens tended to be reduced by browser exclusion. Net AMI (sum of the seasonal AMIs) was tested per species, but results suggested that only D. cinerea tended to be affected by browser exclusion. The results also suggested that stem radial growth of some fast-growing species is more prone to reduction by browser exclusion than the growth of other species, potentially reducing their competitiveness and increasing their risk of extirpation. Finally, the usefulness of grouping woody species into simple functional groups (e.g. fine-leaved vs. broad-leaved) for ecosystem management purposes in savannas requires further consideration. Conservation implications: Growth rates of woody plants are important parameters in savanna models, but data are scarce. Monitoring dendrometers in manipulative situations over several years can help fill that gap. Results of such studies can be used to identify species prone to high risk of extirpation.

Growth and net assimilation rates in thinned and unthinned stands of balsam fir

1988 ◽  
Vol 18 (9) ◽  
pp. 1205-1210 ◽  
Author(s):  
M. B. Lavigne
Keyword(s):  
Growth Rates ◽  
Stem Growth ◽  
Balsam Fir ◽  
Competitive Position ◽  
Stem Respiration ◽  
Photosynthetic Rates ◽  
Respiration Rates ◽  
Net Assimilation ◽  
Lower Ratio

Current annual stem growth rates per hectare of unthinned young stands of balsam fir (Abiesbalsamea (L.) Mill.) were 2–3 times greater than in adjacent stands thinned 4–6 years earlier, largely because unthinned stands contained 2.5–4.0 times more foliar weight per hectare. Stem growth rates per tree in thinned stands were 3–8 times greater than those in unthinned stands because of the reduced competition and the lower ratio of heterotrophic to autotrophic tissues (S/F). However, the foliar efficiencies, as measured by annual stem growth per unit of foliar weight (E), of thinned plots were not significantly greater than those of unthinned plots, in spite of the reduced competition and lower S/F ratio. The lack of response of foliar efficiency to thinning is discussed in relation to published information about photosynthetic rates and stem respiration rates. In all stands, the E values of dominant trees were equal to, or less than, those of subordinate trees, in spite of their superior competitive position and lower S/F ratio. The lack of correlation between competitive position and foliar efficiency is also discussed.

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