scholarly journals Reaktion von Weisstannen auf ein- bis mehrmaligen Verbiss entlang von Lichtgradienten

2014 ◽  
Vol 165 (7) ◽  
pp. 198-207 ◽  
Author(s):  
Anna Camille Kolly ◽  
Andrea Doris Kupferschmid
Keyword(s):  
Light Availability ◽  
Total Mortality ◽  
Abies Alba ◽  
Tree Height ◽  
Canopy Openness ◽  
Silver Fir ◽  
Low Light ◽  
Lateral Shoot ◽  
Light Gradient ◽  
Terminal Shoot

Response of Abies alba saplings to single and repeated browsing along light gradients Browsing of silver fir (Abies alba) saplings by ungulates is one of the most important issues concerning decreasing regeneration of this tree species. In addition to genetic drivers, environmental factors such as light availability play an important role for the response of a browsed tree. Using an experimental design with fences, we investigated the influence of natural browsing on tree growth along a light gradient. The few fir saplings that responded by flagging up a lateral shoot compensated the browsing induced height difference compared to unbrowsed trees within four vegetation periods. Most firs however reacted with new shoots and remained smaller than unbrowsed ones. The more often a fir sapling was damaged on its terminal shoot, the smaller the tree remained. A positive relation between tree height and light was found only up to a canopy openness of 11%. Mortality over the whole five years was high in low light (<10%) and in forest gaps (>15%), due to desiccation, competition with other plants or browsing (50% of total mortality). We recommend regenerating firs under moderately shaded conditions.

scholarly journals The influence of stand canopy openness on the growth of common yew (Taxus baccata L.)

2015 ◽  
Vol 76 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Marzena Niemczyk ◽  
Anna Żółciak ◽  
Wrzesiński Piotr
Keyword(s):  
Light Transmission ◽  
Abies Alba ◽  
Extended Period ◽  
European Beech ◽  
Ex Situ ◽  
Canopy Openness ◽  
Silver Fir ◽  
Taxus Baccata ◽  
Height Increment ◽  
Transmission Index

Abstract The aim of this study was to evaluate the development of common yew, Taxus baccata L., with respect to canopy openness. The plants were growing in ex-situ conservation plantations (established in 2008) in the understory of different tree species. Eleven forest plantations belonging to the following five forest districts were inventoried: Rokita, Baligród, Kołaczyce, Międzylesie and Henryków. In each plantation, the height and height increment of 200 yews were measured and gap light transmission indices were determined. The canopy species affecting yew growth most significantly were oak (Quercus sp.) and Scots pine (Pinus sylvestris L.), followed by Norway spruce (Picea abies Karst.), silver fir (Abies alba L.) and European beech (Fagus sylvatica L.). The most favorable development of yew occurred at 30% canopy openness. An increasing light transmission index correlated with a decrease in the proportion of treelike yews. An insufficient amount of light resulted in a low height increment of yews growing under the canopy and an extended period of direct competition of yews with herbaceous species.

Light-dependent seedling survival and growth of four tree species in Costa Rican second-growth rain forests

2005 ◽  
Vol 21 (4) ◽  
pp. 383-395 ◽  
Author(s):  
Silvia Iriarte Vivar Balderrama ◽  
Robin L. Chazdon
Keyword(s):  
Tree Species ◽  
Seedling Survival ◽  
Light Availability ◽  
Light Transmittance ◽  
Growth Responses ◽  
Low Light ◽  
Growth Increments ◽  
Light Gradient ◽  
Second Growth ◽  
Survival And Growth

The dependence of tree seedling survival and growth on light availability was evaluated over 15 mo in three second-growth, wet forest stands (15–18 y old) in north-eastern Costa Rica. Seedlings of four canopy tree species (Dipteryx panamensis, Hyeronima alchorneoides, Virola koschnyi and Vochysia guatemalensis) were planted into four canopy treatments in three replicated stands and in a pasture site, spanning a nearly complete gradient of light availability. Survival and growth of all species increased in response to increasing light availability, but species differed in survival in shaded microsites (6–20% light transmittance) and in growth increments per light increase. Hyeronima showed the highest mortality at low light levels and the highest relative height growth increase per light increase. In contrast, Virola showed high survival at low and moderate light, but showed the lowest leaf area and above-ground biomass per light increase among all species. Dipteryx and Vochysia maintained relatively high rates of survival and growth across the entire light gradient. Hyeronima and Virola showed trade-offs between growth and survival responses to light, unlike Dipteryx and Vochysia. Differences among species in seedling survival at low light may be determined by a variety of physiological and morphological traits that may or may not be mechanistically linked to growth responses.

scholarly journals Vertical Variability in Bark Hydrology for Two Coniferous Tree Species

2021 ◽  
Vol 4 ◽  
Author(s):  
Anna Ilek ◽  
John T. Van Stan ◽  
Karolina Morkisz ◽  
Jarosław Kucza
Keyword(s):  
Storage Capacity ◽  
Water Storage ◽  
Abies Alba ◽  
Tree Height ◽  
Silver Fir ◽  
Atmospheric Conditions ◽  
Bark Thickness ◽  
Water Storage Capacity ◽  
Coniferous Tree Species ◽  
Canopy Water

As the outermost layer of stems and branches, bark is exposed to the influence of atmospheric conditions, i.e., to changes in the air’s relative humidity and wetting during storms. The bark is involved in water interception by tree canopies and stemflow generation, but bark–water relations are often overlooked in ecohydrological research and insufficiently understood. Relative to other canopy ecohydrological processes, little is known about vertical variation in bark properties and their effect on bark hydrology. Thus, the objective of this study was to analyze changes in physical properties (thickness, outer to total bark thickness ratio, density, and porosity) and hydrology (bark absorbability, bark water storage capacity, and hygroscopicity) vertically along stems of Norway spruce [Picea abies (L.) Karst.] and silver fir (Abies alba Mill.) trees. Our null hypotheses were that bark hydrology is constant both with tree height and across measured physical bark properties. We found that bark thickness and the ratio of outer-to-total bark thickness decreased with tree height for both species, and this was accompanied by an increase in the bark water storage capacity. In contrast, the bark’s density, porosity, and hygroscopicity remained relatively constant along stems. These results inform ecohydrological theory on water storage capacity, stemflow initiation, and the connection between the canopy water balance and organisms that colonize bark surfaces.

scholarly journals Height-Diameter Models for Mixed-Species Forests Consisting of Spruce, Fir, and Beech

2014 ◽  
Vol 56 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Rudolf Petráš ◽  
Michal Bošeľa ◽  
Julian Mecko ◽  
Julius Oszlányi ◽  
Ionel Popa
Keyword(s):  
Goodness Of Fit ◽  
Abies Alba ◽  
Tree Height ◽  
European Beech ◽  
Coefficient Of Determination ◽  
Stand Age ◽  
Silver Fir ◽  
Mathematical Form ◽  
Mixed Species ◽  
Regression Parameters

AbstractHeight-diameter models define the general relationship between the tree height and diameter at each growth stage of the forest stand. This paper presents generalized height-diameter models for mixed-species forest stands consisting of Norway spruce (Picea abies Karst.), Silver fir (Abies alba L.), and European beech (Fagus sylvatica L.) from Slovakia. The models were derived using two growth functions from the exponential family: the two-parameter Michailoff and three-parameter Korf functions. Generalized height-diameter functions must normally be constrained to pass through the mean stand diameter and height, and then the final growth model has only one or two parameters to be estimated. These “free” parameters are then expressed over the quadratic mean diameter, height and stand age and the final mathematical form of the model is obtained. The study material included 50 long-term experimental plots located in the Western Carpathians. The plots were established 40-50 years ago and have been repeatedly measured at 5 to 10-year intervals. The dataset includes 7,950 height measurements of spruce, 21,661 of fir and 5,794 of beech. As many as 9 regression models were derived for each species. Although the “goodness of fit” of all models showed that they were generally well suited for the data, the best results were obtained for silver fir. The coefficient of determination ranged from 0.946 to 0.948, RMSE (m) was in the interval 1.94-1.97 and the bias (m) was -0.031 to 0.063. Although slightly imprecise parameter estimation was established for spruce, the estimations of the regression parameters obtained for beech were quite less precise. The coefficient of determination for beech was 0.854-0.860, RMSE (m) 2.67-2.72, and the bias (m) ranged from -0.144 to -0.056. The majority of models using Korf’s formula produced slightly better estimations than Michailoff’s, and it proved immaterial which estimated parameter was fixed and which parameters were free

Growth, mortality, and morphological response of European beech and downy oak along a light gradient in sub-Mediterranean forest

2005 ◽  
Vol 35 (7) ◽  
pp. 1657-1668 ◽  
Author(s):  
Georges Kunstler ◽  
Thomas Curt ◽  
Monique Bouchaud ◽  
Jacques Lepart
Keyword(s):  
Growth Models ◽  
Niche Partitioning ◽  
Light Availability ◽  
European Beech ◽  
Mediterranean Area ◽  
Low Light ◽  
Morphological Response ◽  
Growth And Survival ◽  
Probability Of Survival ◽  
Light Gradient

We examined light as a niche partitioning factor between the late-successional European beech (Fagus sylvatica L.) and the mid-successional downy oak (Quercus pubescens Willd.), two dominant species in the sub-Mediterranean area of southern France. For these species we estimated sapling growth models (in radius and in height) as a function of light availability. Beech had a higher growth in low light and a higher asymptotic growth rate than oak. We estimated species-specific growth–mortality functions. Beech showed a higher tolerance to slow growth than oak. By linking light–growth functions and growth–mortality functions, we found that beech had a lower mortality at low light than oak. Beech saplings had a higher probability of survival than oak at low and at high light levels. Beech exhibited the highest plasticity of morphological traits (i.e., biomass allocation, leaf morphology, and architectural traits) as a function of light. Since beech has higher growth and survival than oak at variable light regimes, we conclude that niche partitioning for light cannot explain the coexistence of these two species. We propose that disturbance and water stress should be explicitly taken into account to understand niche partitioning and succession in the sub-Mediterranean area.

Variation in shoot growth components among western larch families

1993 ◽  
Vol 23 (8) ◽  
pp. 1520-1527 ◽  
Author(s):  
Jian-Wei Zhang ◽  
Lauren Fins
Keyword(s):  
Shoot Growth ◽  
Unit Length ◽  
Tree Height ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Western Larch ◽  
Growing Seasons ◽  
Free Growth ◽  
Terminal Shoot ◽  
Highly Correlated

Shoot growth components, including predetermined growth, free growth, number of stem units, and mean stem unit length, were evaluated over two growing seasons (8th and 9th) for their contribution to variation in lateral shoot length of 14 families of western larch (Larixoccidentalis Nutt.). All families produced some free growth stem units in both years, averaging 21 and 20% of the total number of stem units in years 8 and 9, respectively. Significant variation was detected among families in total number of stem units and predetermined growth stem units in both years, in mean stem unit length and terminal shoot length at age 8, and in lateral shoot length and tree height at age 9. Lateral shoot length and terminal shoot length were highly correlated with each other, as well as with the total number of stem units and predetermined growth stem units in the lateral shoot. Free growth stem units in the lateral shoot at ages 8 and 9 were not significantly correlated with 8- and 9-year terminal shoot growth or height at age 9. However, the total number of stem units in lateral shoots was well correlated with 8- and 9-year terminal shoot length and with 9-year height. The implications of these results for early selection for increased height growth are discussed.

scholarly journals Evaluation of several measures of canopy openness as predictors of photosynthetic photon flux density in deeply shaded conifer-dominated forest understory

1999 ◽  
Vol 29 (9) ◽  
pp. 1438-1444 ◽  
Author(s):  
José-Luis Machado ◽  
Peter B Reich
Keyword(s):  
Flux Density ◽  
Photosynthetic Photon Flux Density ◽  
Forest Understory ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Canopy Openness ◽  
Photosynthetic Photon Flux ◽  
Low Light ◽  
Light Gradient ◽  
Hemispherical Photograph

The ability to accurately estimate light levels in shaded environments is important for understanding plant adaptations to shade. This study evaluates the effectiveness of three rapid methods of estimating the long-term integrated percentage of above-canopy photosynthetic photon flux density (PPFD) in a deeply shaded conifer-dominated forest understory. These methods included (i) hemispherical canopy photography, (ii) hemispherical sensors (LAI-2000), and (iii) instantaneous %PPFD. Transmitted PPFD was continuously measured starting in June and ending in November using photodiodes at 60 measurement points ranging from 1 to 50% PPFD. Measurements from all methods were positively and linearly related to the mean daily %PPFD measured for two different periods of the year (foliage on and foliage off). However, the strength of the relationship and closeness to a 1:1 fit was weaker for the hemispherical photograph technique. During the foliage-on period, the hemispherical sensor (LAI-2000) explained 90% of the variation in mean daily %PPFD, while the instantaneous %PPFD and hemispherical photography explained 88 and 67%, respectively. Moreover, when examining low-light conditions only (<6 %PPFD), hemispherical photographs failed to detect differences in %PPFD, while the other two techniques were nearly as effective in low light as across the entire light gradient.

scholarly journals Effect of earthworms on mycorrhization, root morphology and biomass of silver fir seedlings inoculated with black summer truffle (Tuber aestivum Vittad.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tina Unuk Nahberger ◽  
Gian Maria Niccolò Benucci ◽  
Hojka Kraigher ◽  
Tine Grebenc
Keyword(s):  
Root System ◽  
Root Biomass ◽  
Fine Root ◽  
Abies Alba ◽  
Fine Root Biomass ◽  
Root Tip ◽  
Silver Fir ◽  
Tuber Aestivum ◽  
Root Tips ◽  
Root Parameters

AbstractSpecies of the genus Tuber have gained a lot of attention in recent decades due to their aromatic hypogenous fruitbodies, which can bring high prices on the market. The tendency in truffle production is to infect oak, hazel, beech, etc. in greenhouse conditions. We aimed to show whether silver fir (Abies alba Mill.) can be an appropriate host partner for commercial mycorrhization with truffles, and how earthworms in the inoculation substrate would affect the mycorrhization dynamics. Silver fir seedlings inoculated with Tuber. aestivum were analyzed for root system parameters and mycorrhization, how earthworms affect the bare root system, and if mycorrhization parameters change when earthworms are added to the inoculation substrate. Seedlings were analyzed 6 and 12 months after spore inoculation. Mycorrhization with or without earthworms revealed contrasting effects on fine root biomass and morphology of silver fir seedlings. Only a few of the assessed fine root parameters showed statistically significant response, namely higher fine root biomass and fine root tip density in inoculated seedlings without earthworms 6 months after inoculation, lower fine root tip density when earthworms were added, the specific root tip density increased in inoculated seedlings without earthworms 12 months after inoculation, and general negative effect of earthworm on branching density. Silver fir was confirmed as a suitable host partner for commercial mycorrhization with truffles, with 6% and 35% mycorrhization 6 months after inoculation and between 36% and 55% mycorrhization 12 months after inoculation. The effect of earthworms on mycorrhization of silver fir with Tuber aestivum was positive only after 6 months of mycorrhization, while this effect disappeared and turned insignificantly negative after 12 months due to the secondary effect of grazing on ectomycorrhizal root tips.

scholarly journals Impact of Industrial Pollution on Radial Growth of Conifers in a Former Mining Area in the Eastern Carpathians (Northern Romania)

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 640
Author(s):  
Cristian Gheorghe Sidor ◽  
Radu Vlad ◽  
Ionel Popa ◽  
Anca Semeniuc ◽  
Ecaterina Apostol ◽  
...  
Keyword(s):  
Air Pollution ◽  
Industrial Pollution ◽  
Radial Growth ◽  
Abies Alba ◽  
Mining Operation ◽  
Mining Area ◽  
Silver Fir ◽  
Local Pollution ◽  
Eastern Carpathians ◽  
The Impact

The research aims to evaluate the impact of local industrial pollution on radial growth in affected Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.) stands in the Tarnița study area in Suceava. For northeastern Romania, the Tarnița mining operation constituted a hotspot of industrial pollution. The primary processing of non-ferrous ores containing heavy metals in the form of complex sulfides was the main cause of pollution in the Tarnița region from 1968 to 1990. Air pollution of Tarnița induced substantial tree growth reduction from 1978 to 1990, causing a decline in tree health and vitality. Growth decline in stands located over 6 km from the pollution source was weaker or absent. Spruce trees were much less affected by the phenomenon of local pollution than fir trees. We analyzed the dynamics of resilience indices and average radial growth indices and found that the period in which the trees suffered the most from local pollution was between 1978 and 1984. Growth recovery of the intensively polluted stand was observed after the 1990s when the environmental condition improved because of a significant reduction in air pollution.

Sign in / Sign up

Export Citation Format

Share Document