Interactive effects of season and light environment on growth and leaf dynamics of evergreen tree seedlings in the humid subtropics

1996 ◽  
Vol 74 (4) ◽  
pp. 589-598 ◽  
Author(s):  
J. H. C. Cornelissen
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Leaf Size ◽  
Light Environment ◽  
Interactive Effects ◽  
Tree Seedlings ◽  
Total Leaf Area ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Total Leaf

Interactive effects of season and light environment on tree seedling growth were studied in four evergreen species in the humid subtropics of China. These species were the needle-leaved pioneer Pinus massoniana and the broad-leaved shade-tolerant Castanopsis fargesii, Sloanea leptocarpa, and Elaeocarpus japonicus. The experimental outdoor light environments, which broadly simulated those in forest gaps and clearings, were 100, 55, 33, and 18% of incident light quantity. Mean relative growth rates for both total leaf area and s tem height revealed interaction of season and light environment in Pinus, Castanopsis, and Elaeocarpus. In these species, mean relative growth rates were higher in summer in more shaded environments and in autumn in more exposed environments, but this shift was not as clear in Castanopsis. Winter growth was virtually nil in all species, although Pinus still achieved some winter stem height change. The hypothesis that late-successional rather than early-successional species would demonstrate interactions of season and light environment on growth and development was not sufficiently supported by the data. Variation in mean relative growth rates for total leaf area was due to changes in whole-plant average leaf size as well as leaf numbers. In Sloanea and Elaeocarpus seedlings in high light environments, reduced leaf size and enhanced leaf abscission rates gave rise to negative mean relative growth rates for total leaf area. The more sun-tolerant Castanopsis seedlings revealed no such leaf size response and shed few, if any, leaves in any of the light environments. These results indicate that seasonal variability in the growth response of tree seedlings to the light environment is an important factor to be taken into account in studies on gap dynamics of subtropical forests. Keywords: China, leaf area, leaf turnover, leaf size, mean relative growth rate, shade, subtropical, sun.

The effect of barley yellow dwarf virus on early plant growth in ryegrass (Lolium spp.)

1989 ◽  
Vol 40 (2) ◽  
pp. 293 ◽  
Author(s):  
DR Eagling ◽  
RJ Sward ◽  
GM Halloran
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Barley Yellow Dwarf Virus ◽  
Dry Weight ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Barley Yellow Dwarf ◽  
Yellow Dwarf Virus

Measurements were made on the effect of barley yellow dwarf virus (BYDV) infection on the early growth of four commercial cultivars of ryegrass (Lolium spp.) under two different temperatures (24�C and 16�C). At 24'C, BYDV infection was associated with reduced root dry weight (30-40%) in all cultivars; the effect of infection on shoot dry weight and leaf area was variable. At 16�C, the effect of BYDV infection was variable, being associated with increases in root dry weight, shoot dry weight, and leaf area in one cultivar (Grasslands Ariki) and decreases in another (Victorian). In two other cultivars, root dry weight, shoot dry weight and leaf area were not significantly affected (P>0.05) by infection with BYDV.At 24�C, the reductions in root dry weight associated with BYDV infection were not concomitant with reductions in the root relative growth rates. Up to at least 28 days after inoculation (46-50 days after germination) reductions in root dry weight were associated with both aphid-feeding damage and virus infection. Experiments with the cultivar Victorian, showed that shoot dry weight was not significantly affected (P>0.05) by feeding with viruliferous (BYDV) or non-viruliferous aphids (Rhopalosiphum padi L.). At 16�C, changes in root and shoot dry weight were associated with changes in the root and shoot relative growth rates.

A study of growth in swards of timothy and meadow fescue. I. Uninterrupted growth

1958 ◽  
Vol 51 (3) ◽  
pp. 347-352 ◽  
Author(s):  
R. H. M. Langer
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Leaf Size ◽  
Dry Weight ◽  
Meadow Fescue ◽  
Area Index ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Number Of Leaves ◽  
Total Dry Weight

1. Swards of S. 48 timothy and S. 215 meadow fescue growing alone or together were sampled at intervals of 3 weeks throughout the season. The number and weight of leaves, stems and ears were determined, and leaf area was estimated.2. Despite high rainfall, the total number of tillers in both species declined from the beginning of the experiment until early July, but increased again from then onwards until the original complement had been approximately restored. The number of leaves failed to show a corresponding increase in the autumn because each tiller carried fewer leaves than earlier in the year.3. In the spring total dry weight increased more rapidly in meadow fescue than in timothy which in turn out-yielded meadow fescue later in the season. Both species attained their greatest dry weight soon after ear emergence, a period which was marked by considerable crop growth and relative growth rates.4. Leaf area index reached a maximum before total dry weight had increased to its highest level, but then declined in both species. Meadow fescue differed from timothy by producing a second crop of foliage after the summer with a leaf area index of about 7. This second rise appeared to be due mainly to increased leaf size in contrast to timothy whose leaves became progressively smaller towards the end of the season.5. The differences in growth between the species discussed with reference to their dates of ear emergence which in this experiment differed by about 6 weeks.

scholarly journals `Ben Lear' and `Stevens' Cranberry Root and Shoot Growth Response to Soil Water Potential

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 795-798 ◽  
Author(s):  
Dana L. Baumann ◽  
Beth Ann Workmaster ◽  
Kevin R. Kosola
Keyword(s):  
Root Growth ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Area ◽  
Growth Rates ◽  
Soil Water Potential ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Water Potentials ◽  
Whole Plant

Wisconsin cranberry growers report that fruit production by the cranberry cultivar `Ben Lear' (Vaccinium macrocarpon Ait.) is low in beds with poor drainage, while the cultivar `Stevens' is less sensitive to these conditions. We hypothesized that `Ben Lear' and `Stevens' would differ in their root growth and mortality response to variation in soil water potential. Rooted cuttings of each cultivar were grown in a green-house in sand-filled pots with three different soil water potentials which were regulated by a hanging water column below a fritted ceramic plate. A minirhizotron camera was used to record root growth and mortality weekly for five weeks. Root mortality was negligible (2% to 6%). Whole plant relative growth rates were greatest for both cultivars under the wettest conditions. Rooting depth was shallowest under the wettest conditions. Whole-plant relative growth rates of `Ben Lear' were higher than `Stevens' at all soil water potentials. `Stevens' plants had significantly higher root to shoot ratios and lower leaf area ratios than `Ben Lear' plants, and produced more total root length than `Ben Lear' at all soil water potentials. Shallow rooting, high leaf area ratio, and low allocation to root production by `Ben Lear' plants may lead to greater susceptibility to drought stress than `Stevens' plants in poorly drained cranberry beds.

Coping with herbivory at the juvenile stage: responses to defoliation and stem browsing in the African savanna tree Colophospermum mopane

2012 ◽  
Vol 28 (2) ◽  
pp. 161-169 ◽  
Author(s):  
David C. Hartnett ◽  
Jacqueline P. Ott ◽  
Kathryn Sebes ◽  
Marks K. Ditlhogo
Keyword(s):  
Leaf Area ◽  
Plant Biomass ◽  
Leaf Size ◽  
Lateral Branch ◽  
Negative Effects ◽  
Total Leaf Area ◽  
Branch Number ◽  
Colophospermum Mopane ◽  
Total Leaf ◽  
Imbrasia Belina

Abstract:Responses of plants to herbivory are dependent on the type of damage and the ontogenetic stage of the plant. We compared the effects of stem pruning and defoliation on seedlings of Colophospermum mopane, an ecologically important tree species widely distributed in southern Africa. The growth of 160 greenhouse-grown juveniles were measured for 6-mo after germination and then 6-mo after treatments including 50% defoliation, 100% defoliation, 50% stem pruning and controls. Pruning resulted in 30% reductions in total leaf area, height and biomass. Partial defoliation resulted in 30% reductions in total leaf area and plant biomass. However, complete defoliation resulted in a 30% increase in biomass production, a doubling in leaf and lateral branch number, a 45% reduction in leaf size, and no change in total leaf area. Thus, completely defoliated seedlings showed greater performance than those that were only partially defoliated, indicating that C. mopane has become adapted to the chronic and severe defoliation inflicted by Imbrasia belina caterpillars. Comparison of our results with other studies indicates that C. mopane seedlings are less herbivory-tolerant than adults and that pruning has more negative effects than defoliation. Thus, seedling browsers may constrain recruitment in C. mopane, influencing its population dynamics and abundance.

scholarly journals Effects of Fertilizers, Salinity, and Medium on Growth of Phalaenopsis Orchid

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 764C-764
Author(s):  
Yin-Tung Wang
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Water Salinity ◽  
Fresh Weight ◽  
Total Leaf Area ◽  
Total Leaf ◽  
O 10 ◽  
Receiving Water

Seedling Phalaenopsis (P. Taisuco Eagle × P. Taisuco Rose) plants with an 8- to 10-cm leaf span were grown in 10-cm pots filled with a medium consisting of 70% fine fir bark and 30% peatmoss (by volume). Plants were given (in N–P2O5–K2O) 10–30–20, 15–10–30, 15–20–25, 20–5–19, 20–10–20, or 20–20–20 fertilizers at the 100 or 200 mg N/liter rate. Pots were leached with water following every two fertigations. After 7 months, leaf span, leaf size, total leaf area, and fresh weight were not affected by fertilizer type. The differences in leaf numbers were small. The higher rate of fertilizer resulted in plants with wider leaf span (32.8 vs. 28.5 cm), more (5.5 vs. 4.8), larger (103 vs. 89 cm2) leaves, and greater total leaf area (355 vs. 275 cm2) than did the lower rate. In another experiment, similar plants with a leaf span of 15 to 18 cm were grown in 10-cm pots with 100% fine fir bark or a mixture of 80% fine fir bark and 20% peatmoss. They were fertigated with water having an EC - 0.05, 0.40, 0.75, 1.10, or 1.40 dS·m–1 containing 1 g·liter–1 20–20–20 fertilizer three times and then drenched with their respective water containing 0.6 g·liter–1 Ca NO3)2·4H2O. After 11 months, water salinity did not affect the date of spiking. Plants receiving water with EC = 1.10 dS·m–1 had more leaves and spikes than other treatments. Plants in the bark/peatmoss mix began spiking earlier, had more leaves (6.7 vs. 5.7), and more inflorescences (1.9 vs. 1.5) than those in 100% bark. There was no salinity x medium interaction in all the parameters recorded.

scholarly journals Differential growth responses in seedlings of ten species of Dipterocarpaceae to experimental shading and defoliation

2012 ◽  
Vol 28 (4) ◽  
pp. 377-384 ◽  
Author(s):  
C. E. Timothy Paine ◽  
Martin Stenflo ◽  
Christopher D. Philipson ◽  
Philippe Saner ◽  
Robert Bagchi ◽  
...  
Keyword(s):  
Growth Rates ◽  
Community Assembly ◽  
Light Availability ◽  
Tree Seedlings ◽  
Growth Responses ◽  
Differential Growth ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Trade Offs ◽  
Tropical Tree Seedlings

Abstract:The responses of plants to shade and foliar herbivory jointly affect growth rates and community assembly. We grew 600 seedlings of ten species of the economically important Dipterocarpaceae in experimental gradients of shading (0.3–47.0% of full sunlight) and defoliation (0, 25%, 50% or 75% of leaf area removed). We assessed stem diameters initially, after 2 and 4 mo, and calculated relative growth rates (RGR) with a linear model. Shading interacted with defoliation, reducing RGR by 21.6% in shaded conditions and 8.9% in well-lit conditions. We tested three hypotheses for interspecific trade-offs in growth responses to shading and defoliation. They could be positively related, because both reduce a plant's access to carbon, or inversely related because of trade-offs between herbivore resistance and tolerance. We observed, however, that species varied in their response to shading, but not defoliation, precluding an interspecific trade-off and suggesting that plants tolerate shade and herbivory with differing strategies. Shading most strongly reduced the growth of species with less-dense wood and larger seeds. The strong and variable growth responses to shade, contrasted with the weak and uniform responses to defoliation, suggest that variation in light availability more strongly affects the growth of tropical tree seedlings, and thus community assembly, than does variation in herbivory.

Effects of Seed Size on Growth and Yield of Maize in the Kenya Highlands

1979 ◽  
Vol 15 (1) ◽  
pp. 73-79 ◽  
Author(s):  
R. C. Hawkins ◽  
P. J. M. Cooper
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
Leaf Size ◽  
Plant Size ◽  
Growth And Yield ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Matter Production ◽  
Significant Yield ◽  
Relative Differences

SUMMARYMaize was grown from three batches of seed, with mean 1000-grain weights of 225, 432 and 649 g. Initial plant size was larger when grown from large seed, but development rates were similar for all three sizes and relative growth rates were similar during the early stages. Relative differences in plant size became smaller as the crop matured. Crop growth rates during the linear phase of dry matter production were the same, and there were no significant yield differences. Comparisons of leaf and spikelet initiation, and individual leaf size are also reported.

Leaf area dynamics in Liquidambar styraciflua saplings: responses to nitrogen fertilization

1998 ◽  
Vol 28 (11) ◽  
pp. 1660-1670 ◽  
Author(s):  
Karen Kuers ◽  
Klaus Steinbeck
Keyword(s):  
Leaf Area ◽  
Temporal Distribution ◽  
Leaf Size ◽  
N Fertilization ◽  
Liquidambar Styraciflua ◽  
Total Leaf Area ◽  
Leaf Production ◽  
N Supply ◽  
Total Leaf ◽  
Autumn Leaf

Total leaf production, vertical foliage profiles, and the timing of leaf production and loss were compared in fertilized and unfertilized 3-year-old sweetgum (Liquidambar styraciflua L.) saplings. Nitrogen (N) fertilization increased total leaf area and mass through increased leaf size rather than changes in leaf number or specific leaf mass. Both the vertical and temporal distribution of foliage shifted in response to N. Fertilization increased leaf area primarily in the mid- to upper crown. The midheight of the tree crowns shifted upward throughout the season as leaf abscission occurred from the base to the top of the tree and acropetally along the branches. Peak leaf display occurred in July regardless of N supply. However, fertilized trees had twice the leaf area of the unfertilized trees by early autumn. Leaf area production and loss were modeled separately as a function of fertilization and crown height and the equations combined to model temporal changes in leaf area display.

scholarly journals Developmental genetics of leaf formation in Lolium 3. Inheritance of a developmental complex

1970 ◽  
Vol 16 (1) ◽  
pp. 17-28 ◽  
Author(s):  
K. J. R. Edwards
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Leaf Length ◽  
Developmental Genetics ◽  
Time Interval ◽  
Total Leaf Area ◽  
Total Leaf ◽  
Leaf Formation ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

SUMMARYUsing four lines derived from a single base population of Lolium perenne by selection for large leaf size (LL), small leaf size (SL), fast rate of leaf appearance (FR), and slow rate of leaf appearance (SR), the inheritance of a number of related characters specifying various aspects of leaf development was studied. F1 and F2 generations were produced for all possible crosses between these four lines.The genetic differences between the selection lines were largely additive for all characters studied and entirely so for rate of leaf appearance, duration of elongation of a single leaf and for the time interval between the maturation of leaf 3 and the unfolding of the next youngest leaf on the same side of the apex, leaf 5. The non-additive variances noted in rate of total leaf area formation, individual leaf size and its components length and width, and in the rate of leaf elongation, were associated with a tendency towards heterosis in these characters. This was quite marked in some crosses and tended to be larger for the more complex characters, rate of total leaf area formation and leaf size, suggesting that the heterosis was, to a considerable extent, due to interactions between genes controlling component characters.The data confirmed the earlier finding that the negative correlated selection response between leaf size and rate of leaf appearance was due to a basic association between the maturation of a leaf and the unfolding (onset of rapid elongation) of the next youngest leaf on the same side of the apex. Thus an increase in rate of leaf appearance reduces the duration of elongation of a leaf and this in turn will reduce leaf length. However, the basic association, which seems to be controlled by vascular development of the young leaf, is not entirely invariate.

Ecological Differentiation Between Species of Scribbly Gums [Eucalyptus Informal Subseries Haemastominae (MATK) Prior & Johnson] and Angophora in Seedling Responsiveness to Mineral Nutrients

1983 ◽  
Vol 31 (6) ◽  
pp. 645 ◽  
Author(s):  
J Mowatt ◽  
PJ Myerscough
Keyword(s):  
Leaf Area ◽  
Nutrient Availability ◽  
Growth Rates ◽  
Nutrient Supply ◽  
Natural Soils ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Nutrient Levels ◽  
Mean Relative Growth Rate ◽  
Infertile Soils

When four species of scribbly gums (Eucalyptus subseries Haemastominae) and four species of Angophora, together with Eucalyptus pilularis, were grown in a range of nutrient levels from distilled water to full Hoagland's nutrient solution, the two groups reacted differently, reflecting their contrasting distributions in relation to soil fertility. Their mean relative growth rates were similar, but the magnitude of the response to increasing nutrient availability varied among the angophoras although it was very similar for all the scribblies. The degree of response of the angophoras was correlated with the fertility of their natural soils: A. floribunda, coming from the most fertile soils, showed the greatest response in mean relative growth rate to increasing nutrient supply. Specific leaf areas did not vary among nutrient levels but, as with mean relative growth rates, the angophoras showed a correlation between the fertility of their natural soils and the specific leaf area: A. hispida, from the least fertile soils, developed the thickest leaves. The angophoras differed from each other in leaf area ratio whereas the scribblies did not. This characteristic was influenced by nutrient availability: the angophoras growing at the higher levels of nutrient supply developed greater leaf areas ratios. There was little difference among the four scribbly gum species in their response to nutrients. They all occur on infertile soils and showed little response to increased nutrient supply.

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