scholarly journals Current Status and Recent Stand Structure Dynamics in Mixed Silver Fir—European Beech Forests in Croatian Dinarides: Are There Differences between Managed and Unmanaged Forests?

2021 ◽  
Vol 13 (16) ◽  
pp. 9179
Author(s):  
Jura Čavlović ◽  
Marijana Andabaka ◽  
Mario Božić ◽  
Krunoslav Teslak ◽  
Karlo Beljan
Keyword(s):  
Basal Area ◽  
Forest Monitoring ◽  
Current Status ◽  
Stand Dynamics ◽  
Silver Fir ◽  
Recent Past ◽  
Beech Forests ◽  
Private Forests ◽  
Large Trees ◽  
Crown Defoliation

The environmental, social and economic potential of Dinaric uneven-aged forests along with the complex stand dynamics influenced by different long-term management approaches and environmental factors require comprehensive forest monitoring. This study aimed to explore differences in the current status and recent past dynamics of stand structures between unmanaged and managed mixed fir-beech forests in the Croatian part of the Dinaric Alps using large-scale data from an established monitoring system. From the 74 permanent sample plots distributed within the forest type measured in 2008 and re-measured in 2019, we stratified four strata (types of management regimes): (1) forests out of regular management and tree harvest for at least 30 years, (2) managed state forests on carbonate bedrock, (3) managed state forests on non-carbonate bedrock and (4) managed private forests. In each sample plot, 34 structural attributes were computed to assess indicators of their current status and recent past dynamics of stands in the studied forests. An increasing Q shape diameter distribution with a high number of large and very large trees characterize unmanaged forests and managed forests on non-carbonate bedrock. In managed state forests and private forests, variable (rotated sigmoid) and constant (negative exponential) results were obtained, respectively. Principal component analysis (PCA) distinguished managed and unmanaged forests with decreasing harvest volume and recruitment, increasing basal area, number of very large trees, average diameter at breast height (DBH), crown defoliation of firs and basal area of died beech trees. The current structure, recent and expected stand dynamics in the unmanaged forests (accumulation of standing volume, increase of large diameter trees and large snags, large share of beech, large mean DBH) can be recognized as old-growth attributes. The differences between the studied forest types, potential of both unmanaged and state managed fir-beech forests and approaches to sustain multifunctional forest management in the Dinaric region were discussed.

scholarly journals Crown defoliation decreases reproduction and wood growth in a marginal European beech population

2018 ◽  
Author(s):  
Sylvie Oddou-Muratorio ◽  
Cathleen Petit-Cailleux ◽  
Valentin Journé ◽  
Matthieu Lingrand ◽  
Jean-André Magdalou ◽  
...  
Keyword(s):  
Basal Area ◽  
High Growth ◽  
European Beech ◽  
Population Level ◽  
Forest Tree ◽  
List Type ◽  
Female Fecundity ◽  
Large Trees ◽  
Crown Defoliation ◽  
The Impact

ABSTRACTAbiotic and biotic stresses related to climate change have been associated to increased crown defoliation, decreased growth and a higher risk of mortality in many forest tree species, but the impact of stresses on tree reproduction and forest regeneration remains understudied. At dry, warm margin of species distributions, flowering, pollination and seed maturation processes are expected to be affected by drought, late frost and other stresses, eventually resulting in reproduction failure. Moreover, inter-individual variations in reproductive performances versus other performances (growth, survival) could have important consequences on population’s dynamics.We investigated the relationships between individual crown defoliation, growth and reproduction in a drought-prone population of European beech, Fagus sylvatica. We used a spatially explicit mating model and marker-based parentage analyses to estimate effective female and male fecundities of 432 reproductive trees, which were also monitored for basal area increment and crown defoliation over nine years.Female and male fecundities markedly varied among individuals, more than did growth. Both female fecundity and growth decreased with increasing crown defoliation and competition and increased with size. Male fecundity only responded to competition, and decreased with increasing competition. Moreover, the negative effect of defoliation on female fecundity was size-dependent, with a slower decline in female fecundity with increasing defoliation for the large individuals. Finally, a trade-off between growth and female fecundity was observed in response to defoliation: some large trees maintained significant female fecundity at the expense of reduced growth in response to defoliation, while some other defoliated trees rather maintained high growth at the expense of reduced female fecundity.Synthesis. Our results suggest that while decreasing their growth, some large defoliated trees still contribute to reproduction through seed production and pollination. This non-coordinated decline of growth and fecundity at individual-level in response to stress may compromise the evolution of stress-resistance traits at population level, and increase forest tree vulnerability.

scholarly journals Silver Fir Decline in Pure and Mixed Stands at Western Edge of Spread in Croatian Dinarides Depends on Some Stand Structure and Climate Factors

2021 ◽  
Vol 13 (11) ◽  
pp. 6060
Author(s):  
Damir Ugarković ◽  
Anamarija Jazbec ◽  
Ivan Seletković ◽  
Ivica Tikvić ◽  
Vinko Paulić ◽  
...  
Keyword(s):  
Retention Time ◽  
Climatic Factors ◽  
Potential Evapotranspiration ◽  
Forest Monitoring ◽  
Quality Data ◽  
Silver Fir ◽  
Mixed Stands ◽  
Transition Dynamics ◽  
Crown Diameter ◽  
Crown Defoliation

Silver fir is one of the most threatened conifer species in Croatia, especially at the western edge of its spread in Croatian Dinarides, where the decline in fir trees has resulted in significant ecological and economic issues. The aim of this study was to determine, over an 18-year monitoring period, the relationships of silver fir crown defoliation with climatic factors and structural attributes. We further analyzed the tree retention time in a given defoliation class and transition dynamics between defoliation classes, as well as the survival/mortality of trees. Data on silver fir defoliation were analyzed in two different forest types: in pure silver fir and in mixed silver fir and common beech stands. The climatic factors, primarily vegetation period air temperature, potential evapotranspiration, and dry season water deficit, were correlated with crown defoliation. Regarding the structural attributes, in the mixed stand with predominantly smaller trees, crown defoliation increased with reduced diameter at breast height, crown diameter, social class, and crown illumination. In the pure fir stand, crown defoliation increased with reduced crown diameter, greater crown asymmetry, greater crown illumination, and on trees with a stork’s nest crown. The retention time in defoliation classes differed for research sites. Transition dynamics were different only for trees in the highest defoliation class (dead trees). At the end of the study period, silver fir mortality was higher in the pure fir stand. Increased silver fir defoliation and mortality can be expected in the future, particularly in overmature stands under prolonged drought stress. Permanent forest monitoring could ensure the high-quality data needed for adaptive management of fir stands that could positively influence the structure of these stands and, thus, improve their health status.

scholarly journals Population structure of Fagus grandifolia subsp. mexicana in the cloud forest of Hidalgo State, Mexico

2016 ◽  
Vol 94 (3) ◽  
pp. 483 ◽  
Author(s):  
Adriana Beatriz Ortiz-Quijano ◽  
Arturo Sánchez-González ◽  
Lauro López-Mata ◽  
José Villanueva-Díaz
Keyword(s):  
Population Structure ◽  
Community Structure ◽  
Environmental Conditions ◽  
Cloud Forest ◽  
Basal Area ◽  
Fagus Grandifolia ◽  
Species Level ◽  
Anthropogenic Activity ◽  
Recent Past ◽  
Beech Forests

The highest densities and largest areas of <em>Fagus grandifolia</em> subsp. <em>mexicana</em> in Mexico grow in the cloud forest of the state of Hidalgo. Although this taxon is endangered, there is little information about its population structure. This study provides data on the structure of heights, diameters and ages of <em>Fagus</em> in three populations in Hidalgo. Additionally, information was obtained on the structure of the beech forests, whose canopy is dominated by <em>Fagus</em>. At each locality, three to five 400 m<sup>2</sup> sample plots, depending on the size of the respective forest, were randomly selected. Within each plot, density and basal area of each species of tree and shrub with diameter greater than 2.5 cm (1.30 m) were estimated. At the species level, populations are dynamic, with a high percentage of young individuals; however, at one of the localities, changes have occurred in the last decade due to anthropogenic activity, and the structure of sizes and diameters in the youngest age categories has changed. Diameter was a good indicator of the age of the trees. At the community level, the dominance of <em>Fagus</em> and other species differed between localities, which is probably related to the degree of disturbance. Population and community structure are related and could be considered as indicators of changes in environmental conditions in the recent past and today.

scholarly journals Silver Fir Defoliation Likelihood Is Related to Negative Growth Trends and High Warming Sensitivity at Their Southernmost Distribution Limit

ISRN Forestry ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Juan Carlos Linares ◽  
J. Julio Camarero
Keyword(s):  
Abies Alba ◽  
Basal Area ◽  
Basal Area Increment ◽  
Silver Fir ◽  
Climatic Data ◽  
Vegetation Shifts ◽  
Temperature And Precipitation ◽  
Crown Defoliation ◽  
Visual Assessments

Changes in radial growth have been used to estimate tree decline probability since they may indicate tree responses to long- and short-term stressors. We used visual assessments of crown defoliation, an indicator of decline, and retrospective tree-ring analyses to determine whether climate-growth sensitivity and tree growth rates may be used as predictors of tree die-off probability in Abies alba (silver fir) at the Spanish Pyrenees. We used climatic data to calculate standardized temperature and precipitation data and drought indexes. Basal area increment was measured for declining (defoliation > 50%) and nondeclining (defoliation < 50%) silver firs in stands with contrasting defoliation. Logistic regressions were applied to predict tree die-off. Since the early 1980s, a synchronised reduction in basal area increment was observed in declining trees. The basal area increment trend correctly classified 64% of declining trees and 94% of nondeclining trees. The growth sensitivity to water deficit, temperature, and a drought index also significantly predicted silver fir decline, but providing underestimated predictions. Our findings underscore the idea that long-term climatic warming seems to be a major driver of growth decline in silver fir. Ongoing growth reduction and enhanced mortality may promote vegetation shifts in declining Pyrenean A. alba forests.

scholarly journals The Fate of a Tropical Rainforest in Nigeria: Abeku Sector of Omo Forest Reserve

2013 ◽  
Vol 6 (2) ◽  
pp. 116-130 ◽  
Keyword(s):  
Basal Area ◽  
Floristic Composition ◽  
Abundant Species ◽  
Diversity Indices ◽  
Forest Monitoring ◽  
Forest Reserve ◽  
Mean Values ◽  
Permanent Sample Plots ◽  
Large Trees ◽  
Number Of Stems

Sixteen permanent sample plots of one hectare each, established in 1985 at Abeku sector of Omo Forest Reserve, South west Nigeria by the European Economic Community/ Nigeria Federal Government (High Forest Monitoring Plots Project) (EEC/HFMPP) were used for this study. The plots were re-enumerated in 1987. Further assessment took place in 1997 and 2000 respectively for the purpose of assessing the floristic characteristics of the plots. The present study aims at assessing the floristic composition during the sampling years. Out of the original 16 plots only eleven and nine plots were available for assessment in 1997 and 2000 respectively. The remaining plots had been converted to plantations of arable and cash crops. The numbers of tree species encountered were 98, 109, 95 and 71 for 1985, 1987, 1997 and 2000 enumerations respectively. Also 28,31, 29 and 23 families were encountered in 1985, 1987, 1997 and 2000 respectively. In terms of density, basal area and spread, the ten most abundant species are Diospyros iturensis (Plant nomenclature follows Hutchinson and Dalziel (1954-72); Keay (1989) and Lowe and Soladoye (1990)), (DIAL),Tabernaemontana pachysiphon (TAPA), Octolobus angustatus (OLAN), Strombosia pustulata (SBPU), Diospyros dendo (DIDE), Diospyros suaveolens (DISU), Drypetes gossweileri (DRGO), Rothmania hispida (ROHI), Hunteria unbellata (HUUM) and Anthonotha aubryanum (ASAU) and the six most prominent families are Ebenaceae, Apocynaceae, Euphorbiaceae, Sterculiaceae, Olacaceae and Rubiaceae .Mean number of stems per hectare ranges from 400.44 to 1134.0 for the small trees (5-20cm dbh); 89.78 to 174.25 for the medium trees (20-40cm dbh) and 8.33 to 17.06 for the large trees (> 40cm dbh) Mean basal area per hectare ranges from 4.94m2 to 8.81m2 for the small trees, 5.4m2 to 9.63m2 for the medium trees and 4.64m2 to 9.04m2 for the large trees. Inverse of Simpson diversity indices range between 15.1 to 16.27 for the small tree, 13.43 to 16.37 for the medium trees and 23.44 to 26.34 for the large trees. The highest mean values per hectare of these parameters were found in 1987 enumeration, while the least values were found in the year 2000 enumeration. This variability may not be due only to the number of plots available for enumeration alone, but also as a result of poaching in the remaining plots before the 2000 enumeration. The study recommends that conscious efforts should be made to protect and maintained the permanent sample plots not only to reduce the possibility of encroachment but also to achieve the objective for which they were established which was to elucidate the dynamics and growth pattern of the natural rainforest. There is also a need for international assistance to achieve this.

scholarly journals Crown defoliation decreases reproduction and wood growth in a marginal European beech population

2021 ◽  
Author(s):  
Sylvie Oddou-Muratorio ◽  
Cathleen Petit-Cailleux ◽  
Valentin Journé ◽  
Matthieu Lingrand ◽  
Jean-André Magdalou ◽  
...  
Keyword(s):  
Basal Area ◽  
High Growth ◽  
European Beech ◽  
Population Level ◽  
Forest Tree ◽  
Female Fecundity ◽  
Individual Level ◽  
Large Trees ◽  
Crown Defoliation ◽  
The Impact

Abstract Background and Aims Abiotic and biotic stresses related to climate change have been associated with increased crown defoliation, decreased growth and a higher risk of mortality in many forest tree species, but the impact of stresses on tree reproduction and forest regeneration remains understudied. At dry warm margin of species distributions, flowering, pollination and seed maturation are expected to be affected by drought, late frost and other stresses, eventually resulting in reproduction failure. Moreover, inter-individual variation in reproductive performance versus other performance (growth, survival) could have important consequences for population dynamics. This study investigated the relationships among individual crown defoliation, growth and reproduction in a drought-prone population of European beech, Fagus sylvatica Methods We used a spatially explicit mating model and marker-based parentage analyses to estimate effective female and male fecundities of 432 reproductive trees, which were also monitored for basal area increment and crown defoliation over nine years. Key Results Female and male fecundities markedly varied between individuals, more than did growth. Both female fecundity and growth decreased with increasing crown defoliation and competition, and increased with size. Moreover, the negative effect of defoliation on female fecundity was size-dependent, with a slower decline in female fecundity with increasing defoliation for the large individuals. Finally, a trade-off between growth and female fecundity was observed in response to defoliation: some large trees maintained significant female fecundity at the expense of reduced growth in response to defoliation, while some other defoliated trees maintained high growth at the expense of reduced female fecundity. Conclusions Our results suggest that while decreasing their growth, some large defoliated trees still contribute to reproduction through seed production and pollination. This non-coordinated decline of growth and fecundity at individual-level in response to stress may compromise the evolution of stress-resistance traits at population level, and increase forest tree vulnerability.

Beech sapling architecture following small and medium gap disturbances in silver fir-beech old-growth forests in Slovenia

2005 ◽  
Vol 156 (12) ◽  
pp. 481-486 ◽  
Author(s):  
Jurij Diaci ◽  
Lahorka Kozjek
Keyword(s):  
Light Intensity ◽  
Quality Characteristics ◽  
Stem Length ◽  
Silver Fir ◽  
Beech Forests ◽  
Vertical Growth ◽  
Relative Light Intensity ◽  
Stem Bending ◽  
Negative Effect

The objective of our research was to examine the effect of canopy shading on beech sapling architecture in the oldgrowth silver fir-beech forests of Pecka and Rajhenavski Rog. In August 2003 we sampled one plot (352 m2) in a large gap in Pecka, which was a result of a strong windstorm in 1983, and eight small gaps (26–78 m2) with similar sapling heights (3.8–8 m). A ground view of each gap was drawn including the characteristics of gap border trees and the density of separate sapling layers was recorded. The height and diameter were measured for each sapling, as well as the following quality characteristics on selected dominant saplings: width of the crown,number of larger branches and knots (&gt;1/3 DBH), intensity of stem bending, deviation from vertical growth, number of terminal shoots, and the type of damage. The results show a negative effect of high canopy shading (estimated relative light intensity was below 5%) on the architectural quality of saplings. A lower overall density of saplings, greater intensity of bending and deviation from vertical growth, a shorter stem length without branches, a larger number of saplings with two terminal shoots, and a larger number of damaged saplings were observed in small gaps.

scholarly journals Big trees drive forest structure patterns across a lowland Amazon regrowth gradient

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tassiana Maylla Fontoura Caron ◽  
Victor Juan Ulises Rodriguez Chuma ◽  
Alexander Arévalo Sandi ◽  
Darren Norris
Keyword(s):  
Forest Structure ◽  
Natural Regeneration ◽  
Basal Area ◽  
Significant Decline ◽  
Forest Regrowth ◽  
Large Trees ◽  
Amazonian Forests ◽  
Mammal Diversity ◽  
Structure Patterns ◽  
Plot Type

AbstractDegraded Amazonian forests can take decades to recover and the ecological results of natural regeneration are still uncertain. Here we use field data collected across 15 lowland Amazon smallholder properties to examine the relationships between forest structure, mammal diversity, regrowth type, regrowth age, topography and hydrology. Forest structure was quantified together with mammal diversity in 30 paired regrowth-control plots. Forest regrowth stage was classified into three groups: late second-regrowth, early second-regrowth and abandoned pasture. Basal area in regrowth plots remained less than half that recorded in control plots even after 20–25 years. Although basal area did increase in sequence from pasture, early to late-regrowth plots, there was a significant decline in basal area of late-regrowth control plots associated with a decline in the proportion of large trees. Variation in different forest structure responses was explained by contrasting variables, with the proportion of small trees (DBH < 20 cm) most strongly explained by topography (altitude and slope) whereas the proportion of large trees (DBH > 60 cm) was explained by plot type (control vs. regrowth) and regrowth class. These findings support calls for increased efforts to actively conserve large trees to avoid retrogressive succession around edges of degraded Amazon forests.

scholarly journals Biotic and Abiotic Determinants of Soil Organic Matter Stock and Fine Root Biomass in Mountain Area Temperate Forests—Examples from Cambisols under European Beech, Norway Spruce and Silver Fir (Carpathians, Central Europe)

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 823
Author(s):  
Anna Zielonka ◽  
Marek Drewnik ◽  
Łukasz Musielok ◽  
Marcin K. Dyderski ◽  
Dariusz Struzik ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Norway Spruce ◽  
Root Biomass ◽  
Fine Root ◽  
Stand Density ◽  
European Beech ◽  
Fine Root Biomass ◽  
Silver Fir ◽  
Beech Forests

Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.

scholarly journals Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

2021 ◽  
Vol 13 (12) ◽  
pp. 2297
Author(s):  
Jonathon J. Donager ◽  
Andrew J. Sánchez Meador ◽  
Ryan C. Blackburn
Keyword(s):  
Ponderosa Pine ◽  
Laser Scanning ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Absolute Error ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Structural Configurations ◽  
Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

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