scholarly journals Biomass Allocation into Woody Parts and Foliage in Young Common Aspen (Populus tremula L.)—Trees and a Stand-Level Study in the Western Carpathians

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 464 ◽  
Author(s):  
Bohdan Konôpka ◽  
Jozef Pajtík ◽  
Vladimír Šebeň ◽  
Peter Surový ◽  
Katarína Merganičová
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Biomass Allocation ◽  
Tree Size ◽  
Populus Tremula ◽  
Tree Biomass ◽  
Area Index ◽  
Biomass Models ◽  
Maximum Value ◽  
Independent Variable

Our research of common aspen (Populus tremula L.) focused on the forested mountainous area in central Slovakia. Forest stands (specifically 27 plots from 9 sites) with ages between 2 and 15 years were included in measurements and sampling. Whole tree biomass of aspen individuals was destructively sampled, separated into tree components (leaves, branches, stem, and roots), and then dried and weighed. Subsamples of fresh leaves from three crown parts (upper, middle, and lower) were scanned, dried, and weighed. Allometric biomass models with stem base diameter as an independent variable were derived for individual tree components. Basic foliage traits, i.e., leaf mass, leaf area, and specific leaf area, were modelled with regard to tree size and leaf position within the crown. Moreover, biomass stock of the woody parts and foliage as well as the leaf area index were modelled using mean stand diameter as an independent variable. Foliage traits changed with both tree size and crown part. Biomass models showed that foliage contribution to total tree biomass decreased with tree size. The total foliage area of a tree increased with tree size, reaching its maximum value of about 12 m2 for a tree with a diameter of 120 mm. Leaf area index increased with mean stand diameter, reaching a maximum value of 13.5 m2 m−2. Since no data for biomass allocation for common aspen had been available at either the tree or stand levels, our findings might serve for both theoretical (e.g., modelling of growth processes) and practical (forestry and agro-forestry stakeholders) purposes.

Growth of spring barley under drought: crop development, photosynthesis, dry-matter accumulation and nutrient content

1981 ◽  
Vol 96 (1) ◽  
pp. 167-186 ◽  
Author(s):  
D. W. Lawlor ◽  
W. Day ◽  
A. E. Johnston ◽  
B. J. Legg ◽  
K. J. Parkinson
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Spring Barley ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Water Deficits ◽  
Maximum Value ◽  
Grain Filling Period

SUMMARYThe effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.

Foliage and canopy characteristics in relation to aboveground dry matter increment of seven jack pine provenances

1986 ◽  
Vol 16 (3) ◽  
pp. 464-470 ◽  
Author(s):  
S. Magnussen ◽  
V. G. Smith ◽  
C. W. Yeatman
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Basal Area ◽  
Jack Pine ◽  
Tree Size ◽  
Stem Volume ◽  
Dry Matter Content ◽  
Cross Sectional ◽  
Area Index

This paper reports on foliage and tree size data collected in 1984 in an Ontario Pinusbanksiana Lamb, (jack pine) provenance trial established in 1954 at the Petawawa National Forestry Institute, Chalk River, Ont. The ratio of total needle area to needle dry weight of seven provenances showed a substantial within-tree, between-tree, and between-provenance variation that was associated with position within the tree and the average provenance tree size. Provenance mean values ranged from 11.7 to 14.3 m2/kg. The highest values were found in the tallest trees. Tree size and dry matter content varied significantly among provenances, but the relative growth rates of stem volume and aboveground biomass between the ages of 29 and 34 years averaged 5.7 and 4.9% per year in all provenances respectively. Aboveground dry matter production per hectare per year increased linearly with increasing projected leaf area index. The average increase was 1.9 t dry matter per l m2 increase in the leaf area index. Projected leaf area indices for optimally stocked stands averaged 5.0 m2/m2. The results indicated an almost constant net assimilation rate of 1.9 g aboveground dry matter per square decimetre of projected foliage per year in all provenances. Canopy foliage area was strongly correlated with basal area at 1.3 m and stem cross-sectional area at the base of the live crown. Total foliage area per unit basal area averaged 0.31 m2/cm2 at breast height and 0.70 m2/cm2 in the live crown. No significant differences were found between provenances.

The growth and development of Corchorus olitorius (L.) grown alone and intercropped with tomato (Lycopersicon esculentum (Mill.))

1987 ◽  
Vol 109 (1) ◽  
pp. 39-45 ◽  
Author(s):  
I. M. Ojeifo ◽  
E. O. Lucas
Keyword(s):  
Lycopersicon Esculentum ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Growth And Development ◽  
Morphological Characters ◽  
Corchorus Olitorius ◽  
Economic Returns ◽  
Area Index ◽  
Maximum Value ◽  
Significant Difference

SummaryTwo experiments were conducted on two varieties of Corchorus olitorius(‘NHCo 6’ and ‘NHCo 7’). The first one was on the effect of density of planting on their growth and development whilst the second was on the best planting ratio for Corchorus-tomato intercropping.There was no significant difference in morphological characters of the two varieties. The maximum value of leaf area index for the two varieties was around 3. Maximum marketable and edible yields were obtained for the two varieties at 30 × 5 cm (666600 plants/ha) and the best time for harvesting was 44 days after sowing.The best planting ratio for Corchorus-tomato intercrop was 2 rows of Corchorus and 1 row of tomato for maximum edible yield of Corchorus but for maximum economic returns, the best ratio was 1 row of Corchorus to 2 rows of tomato.

Carbon stock trends along forested peatland margins in central Saskatchewan

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 321-333 ◽  
Author(s):  
J. S. Bhatti ◽  
R. C. Errington ◽  
I. E. Bauer ◽  
P. A. Hurdle
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Carbon Stocks ◽  
Tree Biomass ◽  
Negative Power ◽  
Area Index ◽  
Soil C ◽  
C Stocks ◽  
Water Tables

Forested peatlands store significant amounts of soil carbon (C) compared with upland forests and are strongly influenced by climatic parameters. Carbon stocks at peatland margins, although likely to be most sensitive to changes in climate, have not been well quantified, making it difficult to predict their response to climate change. The purpose of this study was to characterize the physical environment and associated changes in C stocks across the forested margins of two boreal fens. Peat depth increased and water table depth decreased toward the peatland centre, and these parameters acted as the controlling environmental variables. Above-ground biomass C was primarily derived from tree biomass and decreased from upland to peatland, despite an opposite trend in understorey (herbaceous and shrubby) biomass stocks. Leaf area index was related to peat depth through a negative power function and increased linearly with above-ground tree biomass. Total ecosystem C increased from upland to peatland, with minimum and maximum values of 270 and 2100 Mg C ha-1, respectively, and was largely dominated by soil C stocks, even at the upland end of the gradient. Although numerous small trees toward the peatland interior might allow a rapid increase in tree biomass C with lowering water tables, it seems likely that this would be a limited response, overshadowed in the long term by declines in the more substantial soil C stocks. Key words: Peatlands, carbon stocks, biomass, soil, leaf area index, peat depth

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