Stem Height Growth Research Articles

Growth adaptation of leaves and internodes of poplar to irradiance, day length and temperature

The adaptation of absolute growth rate of leaves and internodes of Populus euramericana (Dode) Guinier cv. 'Robusta' to irradiance and day length proceeds by increases in the volume of the apex. Diameter and height of the apex increase linearly with time, resulting in linear increases in rates of leaf initiation and stem height growth that can be described by an acceleration factor. The acceleration factor is proportional to day length. The relationship between the acceleration factor and irradiance is curvilinear and saturates at irradiances above about 300 W m(-2). Absolute stem height growth rate is the product of mean relative growth rate in stem height and the length of the growing part of the stem. The temperature-dependent growth pattern of each individual leaf or internode reflects a specific relationship between its relative growth rate and organ age that is independent of irradiance and plant age; however, it is dependent on day length during the primordial phase. The constancy of the growth patterns and the correlation between leaf length and leaf initiation rate indicate that growth of primordia is predetermined in the apex, presumably by the precisely structured vascular system.

Modelling Stem Height and Diameter Growth in Plants

A model of stem height and diameter growth in plants is developed. This is formulated and implemented within the framework of an existing tree plantation growth model: the ITE Edinburgh Forest Model. It is proposed that the height:diameter growth rate ratio is a function of a within-plant allocation ratio determined by the transport-resistance model of partitioning, multiplied by a foliage turgor pressure modifier. First it is demonstrated that the method leads to a stable long-term growth trajectory. Diurnal and seasonal dynamics are also examined. Predicted time courses over 20 years of stem mass, stem height, height:diameter ratio, and height:diameter growth rate ratio are presented for six treatments: control, high nitrogen, increased atmospheric carbon dioxide concentration, increased planting density, increased temperature and decreased rainfall. High nitrogen and increased temperature give initially higher stem height:diameter ratios, whereas high CO2gives an initially lower stem height:diameter ratio. However, the responses are complex, reflecting interactions between factors which often have opposing influences on height:diameter ratios, for example: stem density, competition for light and for nitrogen; carbon dioxide and decreased water stress; rainfall, leaching and nitrogen nutrition. The approach relates stem height and diameter growth variables via internal plant variables to environmental and management variables. Potentially, a coherent view of many observations which are sometimes in apparent conflict is provided. These aspects of plant growth can be considered more mechanistically than has hitherto been the case, providing an alternative to the empirical or teleonomic methods which have usually been employed.

Recruitment of tall arborescent palms in the Yasuní National Park, Amazonian Ecuador: are large treefall gaps important?

An evaluation of whether large arborescent palms depend on large treefall gaps for recruitment to the adult stage is reported. Specifically three hypotheses were tested: (1) The light requirement of juveniles of tall arborescent palms increases as they grow in size. (2) Tall arborescent palms depend on gaps over 0.10 ha for growth and survival to maturity, due to high light requirements during the stem height growth phase. (3) Stilt-rooted palms are not dependent on gaps for juvenile height growth. The hypotheses were evaluated using data on size and crown position of individuals of tall arborescent palm species as well as data on the forest-phase in which each individual grew. The study site was a 50-ha plot in old-growth rain forest in Amazonian Ecuador. The first hypothesis was accepted for the two most common species, Iriartea deltoidea and Oenocarpus bataua, but tentatively rejected for the arborescent palm community as a whole. The second hypothesis was rejected for Iriartea and the community as a whole. Only Oenocarpus had strongly gap-dependent recruitment. The results for Iriartea and Oenocarpus were consistent with the third hypothesis.

Forest Colonization and Developmental Growth of the Invasive Shrub Lonicera maackii

Abstract The invasive shrub Lonicera maackii (Rupr.) Herder (Amur honeysuckle) dominates the understory of many deciduous forests in southwestern Ohio and other areas. Extensive sampling of an isolated population of L. maackii was used to elucidate its colonization of a forest woodlot and subsequent growth and development. The current population age structure indicated that colonization likely occurred by a series of small dispersal events. The population remained small for about ten years and then increased dramatically, presumably due to the seed reproduction of the early colonizers. Young prereproductive shrubs are characterized by rapid height growth and high stem recruitment. After shrubs become reproductive at age 5–8, height growth continues but basal stem recruitment is reduced and radial growth increases shrub basal area. Allocation of primary production apparently shifts from stem recruitment and height growth in young shrubs to a balance of height growth, radial expansion and reproduction in ol...

Quantitative genetics of growth and development in Populus. III. Phenotypic plasticity of crown structure and function

The whole-tree leaf area of a poplar derives from three different shoot types, current terminal, sylleptics and proleptics. The response of these architectural components to two sharply contrasting environments was examined in two replicated plantations containing a cloned interspecific hybrid pedigree of Populus trichocarpa and P. deltoides that included the original parents, two F1 parents, and 375 F2 genotypes. In the warmer, sunnier, and better-watered environment of interior Boardman, Oregon, 2-year-old trees produced more, larger, and wider leaves, as well as more and longer branches, than in the cooler and more cloudy coastal conditions of Clatskanie, Oregon. Sylleptic branches were phenotypically more plastic than the other elements of the crown. Most trees produced significantly more and longer sylleptics in the near-optimal growth environment in Boardman than in the suboptimal environment of Clatskanie. In both environments, all crown traits displayed significant genotype effects in the F2 family, but for most traits, broad-sense heritabilities were statistically larger in Clatskanie (0.44–0.78) than Boardman (0.28–0.70). For all traits except for the number of sylleptics, the values of across-environment genetic correlations were significantly larger than zero but less than one, indicating that nonparallel responses of genotypes to environment had led to significant genotype×environment interactions, although some genetic basis was shared between the two environments. A nonsignificant genetic correlation of sylleptic number expressed in the two different environments suggests that the phenotypic plasticity of this trait is under strong genetic control. All architectural traits, except for branch and canopy traits of sylleptics, were correlated with growth more strongly in Clatskanie than Boardman. In both environments, contrary to observations in an earlier study, proleptic traits were better predictors of stem height and basal area growth than sylleptic traits.

Growth and photosynthetic responses of four Virginia Piedmont tree species to shade.

To determine the effects of shade on biomass, carbon allocation patterns and photosynthetic response, seedlings of loblolly pine (Pinus taeda L.), white pine (Pinus strobus L.), red maple (Acer rubrum L.), and yellow-poplar (Liriodendron tulipifera L.) were grown without shade or in shade treatments providing a 79 or 89% reduction of full sunlight for two growing seasons. The shade treatments resulted in less total biomass for all species, with loblolly pine showing the greatest shade-induced growth reduction. Yellow-poplar was the only species to show increased stem height growth in the 89% shade treatment. The shade treatments increased specific leaf area of all species. Quantum efficiency, dark respiration and light compensation point were generally not affected by the shade treatments. Quantum efficiency, dark respiration, maximum photosynthesis and light compensation point did not change consistently between the first and second growing seasons. We conclude that differences in shade tolerance among these species are not the result of changes in the photosynthetic mechanism in response to shade.

Effects of bending stress on taper and growth of stems of youngEucalyptus regnans trees

A glasshouse experiment investigated the effect of bending stress on stem radial and height growth and stem taper ofEucalyptus regnans seedlings. Eighteen-week-old, potted seedlings were bent continuously for 8 weeks with a static bending stress. The bending treatment was then removed and the seedlings grown for another 12 weeks. Other seedlings were stayed vertically throughout the experiment whilst control seedlings were neither bent nor stayed. Seedlings were rotated every 2 days to prevent reaction wood developing asymmetrically in the stems of bent trees. Bent trees had higher radial growth rates, developed more tapered stems and had higher safety factors (the ratio of stem radius to the minimum radius required to prevent the tree toppling over) than unbent seedlings. They produced a band of tension wood in their stems and ceased height growth whilst bent. When bending ceased, they resumed normal radial and height growth. Unbent trees developed more cylindrical stems. There were no differences in growth behaviour between stayed and control trees. Bent and unbent trees all developed a butt swell, the taper of which was not affected by treatment. It was concluded that bending stress has substantial effects on both the size and taper of tree stems. However, the development of butt swell is independent of the bending stress applied. The results were considered in relation to biomechanical theories of tree stem development.

Effects of saline nutrient solutions on the growth and accumulation of mineral elements in some tomato cultivars

Abstract Tomato cultivars were grown in a saline nutrient culture system to investigate growth and fruiting responses in relation to the application of 3 mM potassium (K), 1.5 mM phosphorus (P), and 10 mM calcium (Ca). The deleterious effects of salinity on tomato stem growth and fruit yield were ameliorated following the addition of K, P, and Ca to the nutrient solution. Potassium levels in tomato leaves were increased 4‐fold compared to control plants in the presence of applied K. The use of K resulted in an increase in Na content, however, a comparatively low level of sodium (Na) was obtained in treatments receiving K, Ca, and P. Calcium content was greater than sufficiency levels in all treatments, whereas magnesium (Mg) declined with the increase in salinity. The amount of P in tomato leaves was increased 4–5 fold when the nutrient solution was supplemented with 1.5 mM P. Correlation of vegetative parameters, such as stem height and leaf growth to salinity, revealed no significant responses, however ...

Growth and Fertilization Responses of Hawaiian Tree Ferns

Responses of a tree fern (Cibotium glaucum) to nutrient additions were examined in two rain forest sites in Hawaii Volcanoes National Park, Hawaii. In the younger forest (ca 200 yr old), separate additions of nitrogen and of phosphorus (but not additions of all other macro- and micronutrients) increased fern stem height growth. Nitrogen but not phosphorus increased leaf production, but fertilization had no effect on maximum leaf longevity (39 mo). In the older forest (> 1000 yr old), nitrogen additions did not alter fern growth parameters; fern stem height growth and leaf production were greater in unfertilized plots of the > 1000 yr old forest than in unfertilized plots in the younger forest; and leaf longevity (maximum of 34 mo) was shorter. Leaf production (February-April) and leaf mortality (August-November) were highly seasonal, with mortality occurring several months after expansion of new leaves. The asynchronous leaf recruitment and mortality resulted in cyclic monthly variability in leaves per fern. Our data support other studies suggesting that more rapid leaf turnover occurs in nutrient-rich sites, and that nitrogen appears to be the nutrient most limiting to growth in the early stages of primary succession.

Photosynthetic and Growth Responses of Two Broad‐Leaf Tree Species to Irrigation with Municipal Landfill Leachate

AbstractA study was undertaken to investigate leaf photosynthesis and stem growth responses of saplings of two broad‐leaf tree species to irrigation with municipal solid waste (MSW) leachate in a northern temperate climate at Ontario, Canada. The objective was to quantify plant stresses or changes in plant productivity that could be attributed to this low technology option for the treatment and disposal of groundwater contaminated by municipal refuse. Red maple (Acer rubrum L.) and hybrid poplar [Populus spp. nigra × maximowiczii (NM6)] were subjected to two consecutive seasons of leachate irrigation in a three factor, RCBD split‐plot field experiment. The three factors were irrigant type (MSW leachate, water), mode of application (spray, surface trickle, subsurface irrigation), and rate of application (3.5, 7.0, and 14.0 mm d−1). The main treatment plots in each of three blocks were split into subplots planted to different tree species. In the second irrigation season, the mean seasonal photosynthesis rates increased for irrigated saplings of both species relative to rain‐fed control saplings, irrespective of irrigant type. Mean seasonal photosynthesis rates for red maple increased with irrigant application rate, but were unaffected by irrigant type. Incremental stem diameter and height growth for this species were largely unaffected by the experimental treatments. Mean seasonal photosynthesis rates for hybrid poplar were unaffected by either irrigant type or application rate, but stem growth did increase significantly with leachate irrigation. The mode of irrigant application was not a significant factor in explaining plant response for either species. Direct exposure of leaves to potentially phytotoxic compounds in MSW leachate (volatile organics, and inorganics including metals) by spraying did not induce phytotoxic symptoms in the saplings. Irrigation of a MSW leachate of relatively high ionic strength can be carried out successfully on clay soils under Ontario climatic conditions without causing significant adverse effects on saplings of these tree species. Treatment and disposal of MSW leachates in tree plantations may offer a low technology, low cost option to municipalities.

Effects of sulfur dioxide on growth, photosynthesis and enzyme activities of Chinese Guger-Tree seedlings

The Chinese Guger-Tree ( Schima superba Gard et Champ var. superba) is an important harwood species in Taiwan where the ambient SO 2 concentration in some areas is high. Seedlings were raised in field chambers with and without SO 2 to determine whether this species is affected by this pollutant. After 4 weeks of exposure to 325 ppb of SO 2, the photosynthetic rate of seedlings decreased immediately. During the fumigation period, stem height growth was not inhibited, however, the stem diameter growth was reduced significantly. The dry weight of leaves was unchanged, while stem, root and total seedling weight were lower than those of control plants. Sulfhydryl groups in leaves increased by 75%, whereas they did not change in roots following SO 2 uptake. Superoxide dismutase in leaves did not change, however, peroxidase activity increased significantly. Results suggest that ambient SO 2 in some areas in Taiwan may affect the physiology and growth of the Chinese Guger-Tree.

Interactive Role of Elevated CO2, Nutrient Limitations, and Water Stress in the Growth Responses of Red Spruce Seedlings

Abstract Red spruce (Picea rubens Sarg.) seedlings were grown from seed for 5 mo in ambient (362 ppm) or elevated (711 ppm) CO2 to determine the potential effect of an increase in global CO2 concentration on seedling growth and establishment. CO2 exposure treatments were crossed with two levels of soil fertility and water stress treatments to determine if seedling dry weight, size, and fixed growth responses to elevated CO2 depended on nutrient and water supply. Seedling dry weight and size responses to elevated CO2 at 5 mo did not depend on nutrient and water supply. Seedlings grown in both soil fertility treatments and water stress treatments responded similarly to CO2 treatment. Water stress and CO2 treatments did have an interactive influence on the fixed growth potential of the terminal leader. Leaf weight, leaf area, and height of the terminal leader of water-stressed seedlings were greater in seedlings exposed to elevated CO2 during budset than seedlings exposed to ambient CO2. Total new fixed growth (lateral plus terminal) and total terminal fixed growth (leaf plus stem) were greater in seedlings that formed shoot primordia in elevated CO2 than in ambient CO2. Red spruce seedlings grown in elevated CO2 for 5 mo had greater stem diameter, height, branching density, leaf weight, root weight, stem weight, total weight, and mean relative growth rate (RGR) from 3 to 5 mo than seedlings grown in ambient CO2. Red spruce seedling responses to elevated CO2 suggest that seedling establishment in natural environments may be enhanced when ambient CO2 concentrations rise even if water and nutrient availabilities are limited. FOR. SCI. 39(2):348-358.

Succession and dynamics of gorse (Ulex europaeusL.) communities in the dunedin ecological district South Island, New Zealand

Abstract Successional patterns in gorse (Ulex europaeus) communities were determined from an analysis of 125 plots in the Dunedin Ecological District. Stem diameter and height growth of gorse averaged 5 mm yr-1 and 200 mm yr-1 respectively. Plants attained a maximum age of 29 years, a maximum height of 7.0 m, and a maximum diameter of 217 mm at 100 mm above the ground. Gorse matured at about 15 years after establishment with a mean stem density of 60 000 ha-1, mean basal area value of 51 m2 ha-1, and a mean litter depth of 55 mm. Other naturalised woody species, particularly broom (Cytisus scoparius), declined in importance in older gorse stands. The establishment of native woody species was favoured by lower density, taller gorse, where litter depth was shallow, and areas of bryophyte or bare soil were available. In these stands native species reached numerical and basal area equivalence with gorse after 10–15 years on the site. However, at 60% of the sites younger than 25 years, native woody species wer...

Goldenrod Ball Gall Effects on Solidago altissima: 14C Translocation and Growth

The purpose of this investigation was to determine whether the effects of the goldenrod ball gall on carbon translocation and growth in ramets of Solidago altissima can account for changes in biomass allocation and total biomass observed in galled ramets. To do this, individual leaves of S. altissima were labeled with carbon—14 introduced as CO2. The 14C was introduced into ramets that had ball galls caused by the fly Eurosta solidaginis and into ungalled control ramets; gall size (large vs. small) and point of introduction of the label (above vs. below the gall) were experimental factors. After 5 d the ramets were harvested and their component organs were assayed for 14C using liquid scintillation. In addition, a field cohort of 359 galled and ungalled was followed during the period of gall growth to determine the effect of the gal on stem height growth. Gall size and labeling position had no effect on the percent of 14C translocated out of the labeled leaf but did affect the distribution of translocated 14C. Translocation to underground organs was reduced when the label was introduced above the gall, the reduction being related to gall size. Large galls reduced translocation to the apical bud when the label was introduced below the gall, but small galls did not. Translocation to underground organs was not affected by the gall when the label was introduced below the gall and translocation to the apical bud was not affected by the gall when the label was introduced above the gall; these results indicate that the goldenrod ball gall is a nonmobilizing gall. The presence of a gall did not significantly affect final stem height but did slow the growth of ramets during the period of most rapid gall growth. The observed effects of the gall probably explain changes in resource allocation shown by other studies but do not account for the overall decrease in biomass of galled ramets.

Nitrogen supply, apical dominance and branch growth inPinus radiata

Branch development inP. radiata seedlings and young trees is affected by the level of nitrogen supply. A marginal nitrogen deficiency reduces branch and stem diameter growth much more than it does stem height growth. On soils of low N content mature trees have better than normal form. Fertilizing young trees may have undesirable side effects such as promoting branch growth and reducing leader dominance.