scholarly journals Adaptation Capacity of Norway Spruce Provenances in Western Latvia

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 840 ◽  
Author(s):  
Zeltiņš ◽  
Katrevičs ◽  
Gailis ◽  
Maaten ◽  
Desaine ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Norway Spruce ◽  
Minimum Temperature ◽  
Transfer Functions ◽  
Rotation Period ◽  
Stem Volume ◽  
Mean Annual Temperature ◽  
Moisture Index ◽  
Adaptation Capacity

In Europe, numerous Norway spruce (Picea abies L. Karst.) provenance trials have been established and evaluated at a juvenile age. Still, information about the adaptation potential and long-term fitness of transferred seedlots in the Baltic Sea region is lacking. The aim of the study was to evaluate the adaptation capacity of provenances and assess the patterns of their long-term reaction to environmental transfer. We examined a 32-year-old provenance trial in the mild Baltic Sea coastal climate of Western Latvia. Significant differences in height and stem volume were observed among provenances. Growth superiority for certain local and Carpathian provenances was maintained over more than one-third of the rotation period. The best predictor of climate transfer functions was minimum temperature of the coldest month at the place of origin, explaining 28% variation in tree height. Populations from sites with more frost days and a colder mean annual temperature, minimum temperature, and lower annual heat-moisture index than the planting site were generally taller.

scholarly journals Imitated Whole Tree Harvesting Show Negligible Effect on Economic Value of Spruce Stands

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 841
Author(s):  
Iveta Desaine ◽  
Annija Kārkliņa ◽  
Roberts Matisons ◽  
Anna Pastare ◽  
Andis Adamovičs ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Economic Value ◽  
Forest Types ◽  
Spruce Stands ◽  
The Difference ◽  
Growing Conditions ◽  
Whole Tree Harvesting ◽  
Whole Tree ◽  
Tree Harvesting

The increased removal of forest-derived biomass with whole-tree harvesting (WTH) has raised concerns about the long-term productivity and sustainability of forest ecosystems. If true, this effect needs to be factored in the assessment of long-term feasibility to implement such a drastic forest management measure. Therefore, the economic performance of five experimental plantations in three different forest types, where in 1971 simulated WTH event occurred, was compared with pure, planted and conventionally managed (CH) Norway spruce stands of similar age and growing conditions. Potential incomes of CH and WTH stands were based on timber prices for period 2014–2020. However, regarding the economics of root and stump biomass utilization, they were not included in the estimates. In any given price level, the difference of internal rate of return between the forest types and selected managements were from 2.5% to 6.2%. Therefore, Norway spruce stands demonstrate good potential of independence regardless of stump removal at the previous rotation.

scholarly journals Learning about Stellar Dynamos from Long–term Photometry of Starspots

1991 ◽  
Vol 130 ◽  
pp. 353-369 ◽  
Author(s):  
Douglas S. Hall
Keyword(s):  
Differential Rotation ◽  
Rotation Period ◽  
Turnover Time ◽  
Rotating Stars ◽  
Photometric Variability ◽  
Solar Type ◽  
Magnetic Cycles ◽  
The Many ◽  
Rapidly Rotating Stars

AbstractSpottedness, as evidenced by photometric variability in 277 late-type binary and single stars, is found to occur when the Rossby number is less than about 2/3. This holds true when the convective turnover time versus B–V relation of Gilliland is used for dwarfs and also for subgiants and giants if their turnover times are twice and four times longer, respectively, than for dwarfs. Differential rotation is found correlated with rotation period (rapidly rotating stars approaching solid-body rotation) and also with lobe-filling factor (the differential rotation coefficient k is 2.5 times larger for F = 0 than F = 1). Also reviewed are latitude extent of spottedness, latitude drift during a solar-type cycle, sector structure and preferential longitudes, starspot lifetimes, and the many observational manifestations of magnetic cycles.

scholarly journals Assessment of Stem Volume on Plots Using Terrestrial Laser Scanner: A Precision Forestry Application

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 301
Author(s):  
Dimitrios Panagiotidis ◽  
Azadeh Abdollahnejad ◽  
Martin Slavík
Keyword(s):  
Norway Spruce ◽  
Laser Scanner ◽  
Estimation Methods ◽  
Coefficient Of Determination ◽  
Stem Volume ◽  
Small Scale ◽  
Terrestrial Laser Scanner ◽  
Precision Forestry ◽  
Total Tree ◽  
European Oak

Timber volume is an important asset, not only as an ecological component, but also as a key source of present and future revenues, which requires precise estimates. We used the Trimble TX8 survey-grade terrestrial laser scanner (TLS) to create a detailed 3D point cloud for extracting total tree height and diameter at breast height (1.3 m; DBH). We compared two different methods to accurately estimate total tree heights: the first method was based on a modified version of the local maxima algorithm for treetop detection, “HTTD”, and for the second method we used the centers of stem cross-sections at stump height (30 cm), “HTSP”. DBH was estimated by a computationally robust algebraic circle-fitting algorithm through hierarchical cluster analysis (HCA). This study aimed to assess the accuracy of these descriptors for evaluating total stem volume by comparing the results with the reference tree measurements. The difference between the estimated total stem volume from HTTD and measured stems was 2.732 m3 for European oak and 2.971 m3 for Norway spruce; differences between the estimated volume from HTSP and measured stems was 1.228 m3 and 2.006 m3 for European oak and Norway spruce, respectively. The coefficient of determination indicated a strong relationship between the measured and estimated total stem volumes from both height estimation methods with an R2 = 0.89 for HTTD and R2 = 0.87 for HTSP for European oak, and R2 = 0.98 for both HTTD and HTSP for Norway spruce. Our study has demonstrated the feasibility of finer-resolution remote sensing data for semi-automatic stem volumetric modeling of small-scale studies with high accuracy as a potential advancement in precision forestry.

Organohalogens of Natural and Industrial Origin in Large Recipients of Bleach-Plant Effluents

1991 ◽  
Vol 24 (3-4) ◽  
pp. 373-383 ◽  
Author(s):  
A. Grimvall ◽  
H. Borén ◽  
S. Jonsson ◽  
S. Karlsson ◽  
R. Sävenhed
Keyword(s):  
Baltic Sea ◽  
Point Sources ◽  
The Baltic Sea ◽  
Long Distance ◽  
Long Distance Transport ◽  
Open Sea ◽  
Receiving Waters ◽  
The Baltic ◽  
Organic Halogens

The long-term fate of chlorophenols and adsorbable organic halogens (AOX) was studied in two large recipients of bleach-plant effluents: Lake Vättern in Sweden and the Baltic Sea. The study showed that there is a long-distance transport (>100 km) of chloroguaiacols from bleach-plants to remote parts of receiving waters. However, there was no evidence of several-year-long accumulation of chloro-organics in the water-phase. A simple water-exchange model for Lake Vättern showed that the cumulated bleach-plant discharges from the past 35 years would have increased the AOX concentration in the lake by more than 100 µg Cl/l, if no AOX had been removed from the water by evaporation, sedimentation or degradation. However, the observed AOX concentration in Lake Vättern averaged only about 15 µg Cl/l, which was less than the average AOX concentration (32 µg Cl/l) in the “unpolluted” tributaries of the lake. Similar investigations in the Baltic Sea showed that non-point sources, including natural halogenation processes, accounted for a substantial fraction of the AOX in the open sea. The presence of 2,4,6-trichlorophenol in precipitation and “unpolluted” surface waters showed that non-point sources may also make a considerable contribution to the background levels of compounds normally regarded as indicators of bleach-plant effluents.

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