Seasonal changes of frost hardiness in Piceaabies and Pinussylvestris in Finland

1992 ◽  
Vol 22 (12) ◽  
pp. 1949-1957 ◽  
Author(s):  
T. Repo
Keyword(s):  
Norway Spruce ◽  
Tree Species ◽  
Seasonal Changes ◽  
Maximum Rate ◽  
Shoot Elongation ◽  
Frost Damage ◽  
Frost Hardiness ◽  
Impedance Method ◽  
Visual Scoring ◽  
The Mean

The frost hardiness of 15- to 25-year-old Scots pine (Pinussylvestris L.) and Norway spruce (Piceaabies (L.) Karst.) growing under central Finnish conditions was followed during 1985–1987. Shoots were subjected to artificial frost in the laboratory. Frost hardiness was assessed by the impedance method and by visual scoring. Frost hardiness varied during the years from −3.5 °C to lower than −40 °C. The rate of dehardening increased after about mid-April in both tree species when the daily mean temperature increased by several degrees above 0 °C. The maximum rate of dehardening varied slightly from year to year. In both species the frost hardiness of the previous year's shoot decreased during shoot elongation. This phenomenon was more prominent in pine than in spruce. Shoots were most susceptible to frost damage at the time when shoot elongation was ceasing. The onset and development of hardiness in autumn varied from year to year, especially in spruce. Some difference in hardening was found between the current and the previous year's shoots. The rate of hardening increased typically around mid-September in both species, when the mean daily temperatures decreased to within the range of 5–10 °C.

scholarly journals Morphological Variation in Absorptive Roots in Downy Birch (Betula pubescens) and Norway Spruce (Picea abies) Forests Growing on Drained Peat Soils

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 112
Author(s):  
Azadeh Rezapour ◽  
Marika Truu ◽  
Martin Maddison ◽  
Gristin Rohula-Okunev ◽  
Arvo Tullus ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Morphological Variation ◽  
Tree Species ◽  
Morphological Traits ◽  
Morphological Changes ◽  
Management Practice ◽  
Specific Response ◽  
Downy Birch ◽  
Absorptive Roots ◽  
The Mean

Peatland drainage based on ditch systems is a widely used forestry management practice in the boreal and hemiboreal forests to improve tree growth. This study investigated the morphological variation in absorptive roots (first- and second-order roots) across the distance gradient from the ditch with four sampling plots (5, 15, 40, and 80 m) in six drained peatland forests dominated by Downy birch and Norway spruce. The dominating tree species had a significant effect on the variation in absorptive root morphological traits. The absorptive roots of birch were thinner with a higher specific root area and length (SRA and SRL), higher branching intensity (BI), and lower root tissue density (RTD) than spruce. The distance from the ditch affected the absorptive root morphological traits (especially SRA and RTD), but this effect was not dependent on tree species and was directionally consistent between birch and spruce. With increased distance from the ditch (from plot 5 to plot 80), the mean SRA increased by about 10% in birch and 5% in spruce; by contrast, the mean RTD decreased by about 10% in both tree species, indicating a potential shift in nutrient foraging. However, soil physical and chemical properties were not dependent on the distance from the ditch. We found a species-specific response in absorptive root morphological traits to soil properties such as peat depth, pH, and temperature. Our results should be considered when evaluating the importance of morphological changes in absorptive roots when trees acclimate to a changing climate.

Synchrony of frond dynamics among patches of the clonal seaweed Mazzaella parksii (Rhodophyta) at local spatial scale

2004 ◽  
Vol 84 (5) ◽  
pp. 883-886 ◽  
Author(s):  
Ricardo Scrosati
Keyword(s):  
Spatial Scale ◽  
Seasonal Changes ◽  
Pacific Coast ◽  
Spatial Scales ◽  
Sampling Effort ◽  
Confidence Limits ◽  
Seasonal Trends ◽  
Intertidal Seaweed ◽  
The Mean

This study investigated the synchrony of frond dynamics among patches of the intertidal seaweed Mazzaella parksii (=M. cornucopiae; Rhodophyta: Gigartinales) at local spatial scale. At Prasiola Point (Pacific coast of Canada), the mean synchrony of the seasonal changes in frond density among seven permanent, 100-cm2 quadrats was significant (mean Pearson's r=0·73, with 0·65–0·81 as 95% confidence limits) between 1993 and 1995. This indicates that predicting seasonal trends for non-monitored patches at local spatial scale can be done relatively well based on observations on a limited number of quadrats. The identification of the spatial scales at which seaweed populations covary synchronously will permit minimizing sampling effort while retaining the ability to make valid predictions for non-monitored sites.

scholarly journals A COMPARISON OF METABOLITES IN WOOD-FORMING TISSUES FROM EIGHT COMMERCIAL TIMBER TREE SPECIES OF HEILONGJIANG PROVINCE IN CHINA

Wood Research ◽  
2021 ◽  
Vol 66 (5) ◽  
pp. 746-761
Author(s):  
JIANGTAO SHI ◽  
JUNYI PENG ◽  
CHONGYANG XIA ◽  
JIAN LI
Keyword(s):  
Malic Acid ◽  
Tree Species ◽  
Wood Formation ◽  
Deciduous Trees ◽  
Glucose Content ◽  
Coniferous Trees ◽  
Timber Tree ◽  
Neutral Sugars ◽  
The Mean ◽  
Species Specific

Four coniferous and four deciduous commercial tree species from Northeastern ofChina were selected to investigate the differences ofmetabolites in wood-forming tissues bygas chromatography-mass spectrometry. The results showed that the identified metabolites mainly consisted of neutral sugars, lipids, and organic acids. The mean contents of both arabinofuranose and 1-cyclohexene-1-carboxylic acid were higher in coniferous trees thanin deciduous ones. Similarly, the D-fructose and D-glucose content was significantly higherin coniferous trees than deciduous trees, but the total contents of these two sugars was roughly equal among most tree species. The mean content of lactic acid, glycerol and malic acid was lowerin coniferous trees than deciduous trees. The malic acid content decreased in later-stages of wood formation than in early-stagefor all tree species. The content of L-proline and myo-inositol was greater in later-stage of wood formation than early-stage.The contentof octadecanoic acid, D-fructose and D-glucose decreased in later-stage of wood formationfor most tree species. All of thissuggested that the metabolites in wood-forming tissues showed the significance of species-specific and seasonal dynamic differences among the eight tree species.

scholarly journals Modelling Bark Thickness of Norway Spruce (Picea abies Karst)

2019 ◽  
Vol 10 (2) ◽  
pp. 125-135
Author(s):  
Jusuf Musić ◽  
Velid Halilović ◽  
Jelena Knežević ◽  
Admir Avdagić ◽  
Aida Ibrahimspahić ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Bosnia And Herzegovina ◽  
Timber Harvesting ◽  
Bark Thickness ◽  
Optimal Model ◽  
Breast Height ◽  
Starting Point ◽  
Mean Diameter ◽  
The Mean ◽  
Actual Method

Background and Purpose: Bark thickness and its share in the volume of roundwood are the most important characteristics of the bark, particularly in the process of timber harvesting, and during scaling of processed logs. Therefore it is very important to have at disposal relatively accurate data regarding these characteristics of bark for particular tree species. The main goal of this paper is to investigate the thickness of the bark and its share in the volume of roundwood of Norway spruce. Materials and Methods: The research was carried out in the area of the Canton 10 of the Federation of Bosnia and Herzegovina and it encompassed 393 trees of Norway spruce from 10 cm to 115 cm of thickness at breast height. Measuring of the mean diameter and double thickness of bark was conducted by section method. In total, 4,647 diameters and bark thicknesses were measured in different relative lengths of stems or in average 10.6 measurements per one stem. Results: As an optimal model for the evaluation of double thickness of the bark of Norway spruce depending on mean diameter of roundwood the function with designated determination coefficient of 0.7142 was selected. The obtained results have confirmed the previously defined relations of investigate characteristics, which are as following: a) with the increase of mean diameter of roundwood (section) double bark thickness is increased from 9.26 mm (thickness class 12.5 cm) to 31.65 mm (thickness class 92.5 cm); b) with the increase of mean diameter of roundwood the share of bark in its volume decreased from 14.26% (thickness class 12.5 cm) to 6.73% (thickness class 92.5 cm). Conclusions: By the actual method of estimating bark thickness or the share of bark in the volume of roundwood of Norway spruce in the forestry of the Federation of Bosnia and Herzegovina a significant error was created which increases with the increase of mean diameter. The obtained results point to the necessity of investigation of these bark characteristics in Bosnia and Herzegovina and represent an inevitable starting point for making adequate tables of bark thickness and its percentage share in the volume of roundwood of Norway spruce.

scholarly journals The effect of spring frosts on the nectar production and the bee visitation of fruit trees

2000 ◽  
Vol 6 (1) ◽  
Author(s):  
P. Benedek ◽  
J. Nyéki ◽  
I. Amtmann ◽  
F. Bakcsa ◽  
J. Iváncsics ◽  
...  
Keyword(s):  
Tree Species ◽  
Fruit Trees ◽  
Frost Damage ◽  
Fruit Tree ◽  
Wild Plants ◽  
Cold Weather ◽  
Nectar Production ◽  
Spring Frost ◽  
Fruit Orchards ◽  
Spring Frosts

Fruit tree species suffered very strong spring frosts in 1997 in Hungary. This caused partial or total damages at buds and flowers depending on site and time of blooming. It was demonstrated at a number of experiments that frost and cold weather also strongly affected the nectar production of surviving flowers. No or very little amount of nectar was measured in flowers first of all of early blooming fruit tree species (apricot) but also of pear and apple in some places. In spite of this fact intensive honeybee visitation was detected in the flowers of fruit trees that suffered partial frost damage only at those sites where honeybee colonies were placed in or at the experimental plantations and the lack of sufficient amount of nectar did not affected bee behaviour seriously on fruit flowers. This means that bad nectar production failed to affect bee visitation of fruit trees definitely. The reason for this was the fact that not only fruit trees but another early bee plants (wild plants, too) suffered frost damage. Accordingly, in lack of forage bees intensively searched for food at blooming fruit trees with some living flowers. Consequently, there was an acceptable yield at those plantations where bud and flower damage was not complete. Accordingly, intensive bee visitation (that is moving additional bee colonies to overpopulate fruit orchards with honeybees) can be an effective tool to decrease or eliminate the detrimental effect of spring frost on the yield of fruit trees where bud or fruit damage is not too high.  

Shelter selection by a small mammal community in the wet-dry tropics of Australia.

1989 ◽  
Vol 12 (2) ◽  
pp. 55
Author(s):  
R.W. Braithwaite
Keyword(s):  
Habitat Selection ◽  
Small Mammal ◽  
Tree Species ◽  
Average Distance ◽  
Small Species ◽  
Dry Tropics ◽  
Open Forest ◽  
Shelter Selection ◽  
Small Mammal Community ◽  
The Mean

The location of shelter used by nine species of small mammals released after capture during a mark-recapture study in tropical woodland and open forest was recorded whenever possible. A quantitative profile of such post-release behaviour by different species permits its incorporation into analyses of habitat selection. Characteristics of post-release behaviour also provide clues about the nature of predation pressure on various species. Arboreal species tended to select tree species with boles having camouflage potential. Small species used small holes. Scansorial species used the greatest range of sheltering sites. Average distance moved to shelter was inversely related to the mean density of a species.

Soil nitrogen recovery and seasonal changes of xylem sap amino acids of Amazonian tree species following pasture abandonment

Plant Ecology ◽  
2019 ◽  
Vol 220 (6) ◽  
pp. 633-648 ◽  
Author(s):  
Vanderlei Borboni Ferreira de Araújo ◽  
Gilberto Costa Justino ◽  
Carlos Eduardo Moura da Silva ◽  
Saul Alfredo Antezzana Vera ◽  
Lays Lins ◽  
...  
Keyword(s):  
Amino Acids ◽  
Soil Nitrogen ◽  
Tree Species ◽  
Seasonal Changes ◽  
Xylem Sap ◽  
Nitrogen Recovery

Site Index Curves for Norway Spruce in Southern Ontario1

1989 ◽  
Vol 6 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Andrew M. Gordon ◽  
Peter A. Williams ◽  
Edward P. Taylor
Keyword(s):  
Norway Spruce ◽  
Soil Texture ◽  
Sandy Soils ◽  
Site Index ◽  
Height Growth ◽  
Stem Analysis ◽  
Mean Values ◽  
Breast Height ◽  
Drainage Class ◽  
The Mean

Abstract Four dominant or codominant Norway spruce trees from each of 55 sites were destructively sampled and the annual height growth determined by stem analysis. The sampled sites were stratified by soil textural class (coarse, medium, and fine) and depth to distinct mottling (0-16, 16-40, and 40 in.). Two sets of an-amorphic site index curves were constructed using a total age of 30 years (SI30), and breast height age of 25 years (SIBH25) as base ages. The mean SI30 from Ontario (53 ft) was found to be 17.8% higher than the mean values published from Vermont (45 ft) and currently used in Ontario. SIBH25 values had a range of 34.6 to 74.8 ft with a mean of 55.3 ft. Analysis of variance showed significant differences in SIBH25 due to soil texture and drainage class, and in years to breast height (BH) due to drainage class. SIBH25 was highest on sites with loamy soils and distinct mottling at 16-40 in. It took an average of 6.5 years for seedlings to reach BH with a range of 3 to 12 years. Years to BH was lowest on sites with sandy soils and those with distinct mottling below 40 in. North. J. Appl. For. 6(1):23-26, March 1989.

Glucose absorption by isolated perfused rat proximal straight tubules

1990 ◽  
Vol 259 (4) ◽  
pp. F580-F586 ◽  
Author(s):  
J. L. Garvin
Keyword(s):  
Glucose Concentration ◽  
Maximum Rate ◽  
Glucose Absorption ◽  
Fluid Absorption ◽  
Flow Rates ◽  
Straight Tubules ◽  
Proximal Straight Tubule ◽  
Rate Of Absorption ◽  
The Mean ◽  
Limiting Value

Glucose absorption was investigated in isolated perfused proximal straight tubules from rats by use of a newly developed ultramicrofluorometric assay. This assay takes advantage of the increase in fluorescence associated with the reduction of NAD to NADH while glucose is degraded to 6-phosphogluconate. When tubules were perfused at 6.70 +/- 0.42 nl.mm-1.min-1, the mean rate of glucose absorption was 11.0 +/- 1.0 pmol.mm-1.min-1, and the mean rate of fluid absorption was 0.61 +/- 0.06 nl.mm-1.min-1. Glucose transport is generally due to Na-glucose cotransport in the proximal nephron. In the rat proximal straight tubule, glucose absorption also appeared to be primarily due to Na-glucose cotransport, since 10(-4) M phlorizin inhibited absorption by 100%, as did inhibition of Na(+)-K(+)-ATPase by K removal. To determine the maximum rate of transport, tubules were perfused at rates greater than 20 nl.mm-1.min-1 with a solution containing 5.5 mM glucose. The maximum rate of glucose absorption was approximately 20 pmol.mm-1.min-1 under these conditions. The concentration of glucose that supports 50% of the maximum rate of absorption, Km, was 0.6 mM. When tubules were perfused at flow rates of less than or equal to 2 nl.mm-1.min-1, the luminal glucose concentration reached a limiting value of 0.47 mM with 5.5 mM glucose in the bath. The glucose permeability was 3.1 X 10(-6) cm/s.

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