scholarly journals On the Consequences of Using Moving Window Segmentation to Analyze the Structural Stand Heterogeneity and Debatable Patchiness of Old-Growth Temperate Forests

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 96 ◽  
Author(s):  
Jarosław Paluch
Keyword(s):  
Abies Alba ◽  
Structural Heterogeneity ◽  
Moving Window ◽  
Natural Forests ◽  
Old Growth ◽  
Fagus Sylvatica L ◽  
The Mean ◽  
Random Patterns ◽  
Smoothing Procedure ◽  
Tree Distributions

(1) Background: Early research in natural forests on decennia implanted conviction concerning the patchy patterns of their structural heterogeneity. Due to the variety of methodological approaches applied, verification of this fundamental assumption remains open. The aim of this study was to discuss the methodological limitations associated with the use of moving windows with overlap for the delineation of homogeneous patch mosaics in forest ecosystems. (2) Methods: The “patchiness” hypothesis was tested in six old-growth forests formed by Abies alba Mill., Fagus sylvatica L., and Picea abies (L.) H. Karst. localized in Bosnia and Herzegovina and southern Poland. In each stand, the tree diameter at breast height (dbh) was recorded on circular sample plots of 154 m2 regularly distributed in a 20 × 20 m lattice over an area of 10 ha. (3) Results: Computer simulations showed that patch classification based on overlapping windows results in apparent patchiness, even for completely randomized tree distributions. Analyses carried out on the empirical data indicated prevalent random patterns of structural heterogeneity. (4) Conclusions: Patchiness is not a universal feature of the investigated forest communities. The size of the moving window and the noise-smoothing procedure exert strong effects on the biasedness of patch classification, the frequency of structural types, and the mean patch size.

Gap disturbance regime in an old-growth Fagus–Abies forest in the Dinaric Mountains, Bosnia-Herzegovina

2008 ◽  
Vol 38 (11) ◽  
pp. 2728-2737 ◽  
Author(s):  
Thomas A. Nagel ◽  
Miroslav Svoboda
Keyword(s):  
Abies Alba ◽  
Quantitative Information ◽  
Silver Fir ◽  
Disturbance Regime ◽  
Natural Forests ◽  
Gap Formation ◽  
Old Growth ◽  
Old Growth Forest ◽  
Dinaric Mountains ◽  
Gap Disturbance

Due to the scarcity of old-growth forests in much of Europe, there is little quantitative information on disturbance processes that influence forest dynamics. However, this information is crucial for forest management that tries to emulate patterns and processes in natural forests. We quantified the gap disturbance regime in an old-growth forest dominated by European beech ( Fagus sylvatica L.) and silver fir ( Abies alba Miller) in the Dinaric Mountains of Bosnia and Herzegovina. We sampled 87 gaps in four stands using line-intercept sampling. The percentages of forest area in canopy gaps and expanded gaps ranged from 12% to 17.2% and 35.5% to 39.7%, respectively. Although many of the gaps were small (<100 m2) and formed from a single gapmaker, large canopy openings >1000 m2 with numerous gapmakers made up a disproportionate amount of the total gap area. More than half the gaps had more than one gapmaker and were often in separate decay classes, indicating gaps had expanded over time during separate disturbance events. Furthermore, 51% of all gapmakers were uprooted or wind-snapped, whereas only 22% died standing. These results suggest that wind disturbance plays an important role in creating intermediate to large canopy openings through both gap formation and gap expansion processes.

Intermediate wind disturbance in an old-growth beech-fir forest in southeastern Slovenia

2006 ◽  
Vol 36 (3) ◽  
pp. 629-638 ◽  
Author(s):  
Thomas A Nagel ◽  
Jurij Diaci
Keyword(s):  
Abies Alba ◽  
Basal Area ◽  
Wind Disturbance ◽  
Storm Events ◽  
Time Intervals ◽  
Old Growth ◽  
Background Mortality ◽  
Baseline Mortality ◽  
Fagus Sylvatica L ◽  
Damage Type

We studied the immediate effects of two successive storms in 1983 and 2004 in an old-growth Fagus sylvatica L. – Abies alba Mill. forest in the Dinaric Alps, southeastern Slovenia. In the 1983 and 2004 storms the density and basal area of wind-killed trees were 27.4·ha–1 and 5.98 m2·ha–1 and 11.2·ha–1and 4.02 m2·ha–1, respectively. In both storm events, mid-sized to large stems were more prone to wind mortality than small stems, and A. alba was more susceptible than F. sylvatica. In the 2004 storm, 70% of wind-killed trees were uprooted and 30% were snapped. Tree size (diameter at breast height) was more important than species in determining damage type, smaller stems being more prone to uprooting and larger stems to snapping. The combined mortality due to the two storms was similar to a decade of baseline mortality, and wind-killed trees were larger than trees that died from background mortality processes. In both storms, wind-killed trees had a clumped spatial distribution, which resulted in the formation of many multiple-tree-fall gaps up to 1500 m2 in size. We suggest that intermediate wind disturbance occurs at time intervals similar to or less than the life expectancy of most canopy tree species in central Europe, and may play a more important role in forest dynamics than previously thought.

scholarly journals Adult Feeding Preference and Fecundity in the Large Pine Weevil, Hylobius abietis (Coleoptera: Curculionidae)

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 473
Author(s):  
Petr Doležal ◽  
Lenka Kleinová ◽  
Markéta Davídková
Keyword(s):  
Betula Pendula ◽  
Food Source ◽  
Abies Alba ◽  
Feeding Preference ◽  
Hylobius Abietis ◽  
Feeding Preferences ◽  
Single Female ◽  
Coniferous Species ◽  
Adult Feeding ◽  
The Mean

Adult feeding preferences of Hylobius abietis on Picea abies, Larix decidua, Pinus sylvestris, Pseudotsuga menziesii, Abies alba and Betula pendula were tested in outdoor conditions. The preferred food source was P. menziesii, and the mean bark area consumed per seedling was 440.8 ± 147.9 mm2. The second most preferred host was P. abies. The coniferous species that suffered the least damage was A. alba (76.8 ± 62.56 mm2 per seedling). B. pendula was the least preferred source of food, and it caused mortality of 60% of weevils that fed on it. Weevils exhibited large differences in fecundity when fed with different tree species in a laboratory experiment. The largest number of eggs was laid by females fed with P. abies. Mean egg numbers reached 26.4 ± 24.89 eggs per experiment for P. abies. Similar fecundity was observed in weevils fed with twigs of P. sylvestris. Oviposition was approximately six times lower in females fed with L. decidua and P. menziesii. The maximum number of eggs laid by a single female during a one-month experiment was 90. The results are discussed in relation to management of H. abietis.

Differential climate–growth relationships in Abies alba Mill. and Fagus sylvatica L. in Mediterranean mountain forests

2014 ◽  
Vol 32 (3) ◽  
pp. 220-229 ◽  
Author(s):  
Angelo Rita ◽  
Tiziana Gentilesca ◽  
Francesco Ripullone ◽  
Luigi Todaro ◽  
Marco Borghetti
Keyword(s):  
Fagus Sylvatica ◽  
Abies Alba ◽  
Mountain Forests ◽  
Fagus Sylvatica L

scholarly journals The Dinaric Mountains versus the Western Carpathians: Is structural heterogeneity similar in close-to-primeval Abies–Picea–Fagus forests?

2020 ◽  
Author(s):  
J. Paluch ◽  
S. Keren ◽  
Z. Govedar
Keyword(s):  
Spatial Scale ◽  
Structural Complexity ◽  
Abies Alba ◽  
Basal Area ◽  
Biomass Accumulation ◽  
European Beech ◽  
Structural Heterogeneity ◽  
Western Carpathians ◽  
Silver Fir ◽  
Canopy Trees

Abstract In this study, we analysed patterns of spatial variation in the basal area of live and dead trees and structural complexity in close-to-primeval forests in the Dinaric Mts. The results were compared with an analogous study conducted in the Western Carpathians. The research was carried out in the Janj, Lom and Perucića forest reserves (Bosnia and Herzegovina) in mixed-species stands of silver fir Abies alba Mill., European beech Fagus sylvatica L. and Norway spruce Picea abies (L.) H. Karst. In the core zones of the reserves, concentric sample plots (154 and 708 m2) were set in a regular 20 × 20 m grid covering approximately 10 ha. The analyses revealed varying distribution patterns of live canopy trees, suggesting that these characteristics may fluctuate to some extent at the regional level. At the spatial scale of 708 m2, attractive associations between dead canopy trees were found, but this tendency disappeared with increasing area. Although stands in the Dinaric Mts. are characterized by an almost twofold greater biomass accumulation compared to those from the Western Carpathians, the study revealed analogous bell-shaped distributions of stand basal areas of live trees and a very similar trend of decreasing variation in stand basal area and structural heterogeneity with increasing spatial scale. Nonetheless, the higher growing stocks, lower ratios of dead to live tree basal area and lower proportion of homogeneous structure types found in the Dinaric Mts. may suggest a less severe disturbance history over recent decades in this region compared to the Western Carpathians.

scholarly journals Evidence of elevation-specific growth changes of spruce, fir, and beech in European mixed mountain forests during the last three centuries

2020 ◽  
Vol 50 (7) ◽  
pp. 689-703 ◽  
Author(s):  
Hans Pretzsch ◽  
Torben Hilmers ◽  
Peter Biber ◽  
Admir Avdagić ◽  
Franz Binder ◽  
...  
Keyword(s):  
Abies Alba ◽  
European Beech ◽  
Spatiotemporal Pattern ◽  
Silver Fir ◽  
Mountain Forests ◽  
Growth Trend ◽  
Dependent Change ◽  
Fagus Sylvatica L ◽  
Growth Changes

In Europe, mixed mountain forests, primarily comprised of Norway spruce (Picea abies (L.) Karst.), silver fir (Abies alba Mill.), and European beech (Fagus sylvatica L.), cover about 10 × 106 ha at elevations between ∼600 and 1600 m a.s.l. These forests provide invaluable ecosystem services. However, the growth of these forests and the competition among their main species are expected to be strongly affected by climate warming. In this study, we analyzed the growth development of spruce, fir, and beech in moist mixed mountain forests in Europe over the last 300 years. Based on tree-ring analyses on long-term observational plots, we found for all three species (i) a nondecelerating, linear diameter growth trend spanning more than 300 years; (ii) increased growth levels and trends, the latter being particularly pronounced for fir and beech; and (iii) an elevation-dependent change of fir and beech growth. Whereas in the past, the growth was highest at lower elevations, today’s growth is superior at higher elevations. This spatiotemporal pattern indicates significant changes in the growth and interspecific competition at the expense of spruce in mixed mountain forests. We discuss possible causes, consequences, and silvicultural implications of these distinct growth changes in mixed mountain forests.

scholarly journals Relationships between Structural Indices and Conventional Stand Attributes in an Old-Growth Forest in Southeast Europe

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 4 ◽  
Author(s):  
Srđan Keren ◽  
Miroslav Svoboda ◽  
Pavel Janda ◽  
Thomas A. Nagel
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Structural Heterogeneity ◽  
Tree Species Diversity ◽  
Southeast Europe ◽  
Old Growth ◽  
Old Growth Forest ◽  
Plot Area ◽  
Stand Attributes ◽  
Structural Indices

Structural indices are often proposed as guiding measures for increasing structural heterogeneity. However, few studies have examined the association between such indices and conventional stand attributes. The primary objectives of this study were to evaluate changes in structural heterogeneity and tree species diversity at different plot sizes and to quantify the relationships between conventional stand attributes (mean tree diameter, absolute tree density, basal area, species proportion) and structural indices in a mixed old-growth forest in Southeast Europe. Paired tests were used to identify significant changes in structural heterogeneity with increased plot area, while the relationships between stand attributes and analyzed indices (Gini, diameter differentiation, species mingling, and Shannon’s index) were evaluated with Pearson’s correlations. The index values of Gini, diameter differentiation, and tree species mingling were rather stable with the increase of plot size, whereas tree species diversity increased significantly with the increase of plot area from 200 m2 to 1500 m2. The measures of tree species mingling and tree species diversity were strongly associated with each other, while their association with diameter variability was weak to moderately strong. Tree species mingling index was strongly associated with the changes in tree species proportions. However, conventional stand attributes were generally not strongly correlated with the examined indices. For restoring and maintaining old-growth characteristics, forest managers may use structural indices to increase small-scale structural heterogeneity, tree species mingling, and diversity, but only as an additional set of measures, not as surrogates for conventional stand attributes.

Sign in / Sign up

Export Citation Format

Share Document