scholarly journals Estimation of Fagus sylvatica L mating system parameters in natural populations

1994 ◽  
Vol 51 (2) ◽  
pp. 163-173 ◽  
Author(s):  
D Merzeau ◽  
B Comps ◽  
B Thiébaut ◽  
J Letouzey
1996 ◽  
Vol 26 (7) ◽  
pp. 1187-1192 ◽  
Author(s):  
Patrizia Rossi ◽  
Giovanni Giuseppe Vendramin ◽  
Raffaello Giannini

Mating system parameters were estimated in two Italian natural populations of European beech (Fagussylvatica L.) using a mixed mating model and considering seven allozyme loci (Idh-A, Lap-A, Mdh-B, Pgd-A, Pgd-B, Pgd-C, Skd-A). High values of multilocus estimates of the outcrossing rate were found in both populations, ranging from 94 to 98%. Comparison of single- and multi-locus estimates of outcrossing rates seems to indicate the presence of consanguineous matings, probably because the populations are substructured. This hypothesis seems to be confirmed by the presence of a heterogeneity of the pollen allele frequencies across female parent trees and by the significant coefficient of the regression of pollen allele frequencies on ovule genotype. Variation in the fixation indices in different life-cycle phases was observed, indicating possible presence of selective processes between seed set and sexual maturity. Possible explanations of these results are presented.


1991 ◽  
Vol 21 (3) ◽  
pp. 333-339 ◽  
Author(s):  
Chang Yi Xie ◽  
Bruce P. Dancik ◽  
Francis C. Yeh

EM (expectation–maximization) algorithm procedures were used to estimate mating-system parameters in four natural populations of Thujaorientalis L. from China using seven allozyme marker loci (Fest1, Idh1, Idh2, Mr, Pgi2, Skdh1, and 6Pg2). The mean single-locus outcrossing rate was 0.70 for the species, but estimates showed that there was significant heterogeneity among loci within populations. Multilocus estimates of the outcrossing rate showed that there was significant heterogeneity among populations and among trees within populations. The mean multilocus outcrossing rate (0.75) was higher than the outcrossing rate (0.63) observed in a closely related conifer, Thujaoccidentalis L., but lower than estimates that have been reported for most other conifers. Significant heterozygote deficiencies, relative to Hardy–Weinberg and mating-system equilibria, were observed in all filial populations. In contrast, the maternal populations conformed to Hardy–Weinberg and mating-system equilibria at most loci. Self-fertilization and other forms of inbreeding (e.g., sibling mating) within the sampled populations are important contributors to the low outcrossing estimates in this conifer.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Nevenka Ćelepirović ◽  
Aikaterini Dounavi ◽  
Mladen Ivanković ◽  
Heinz Rennenberg ◽  
Anamarija Jazbec ◽  
...  

The performance of European beech ( Fagus sylvatica L.) is severely threatened by abiotic and biotic stresses, but the resilience of its provenances from distinct geographic areas has not been sufficiently studied. Therefore, the performance of European beech was investigated in an international provenance trial consisting of twenty-one natural populations originating from Central Europe and Southeast Europe located on Medvednica Mountain (Croatia). The performance of European beech was investigated by characterizing I) damage types, II) crown damage intensity, III) damage frequency, and IV) clustering of provenances based on damage types. Anthracnose, galls, chewing damages, and aphids were recorded on leaves, and canker on the trunk and branches. The crown damage intensity was minute (less than 10%) for all types of disease. Anthracnose was the most common damage, followed in descending order by galls, canker, chewing damages and aphids. When the types of damage were analysed using descriptive statistics (frequency analysis and clustering), significant differences were recorded between provenances (χ2=322.19, p<0.0001). European beech provenances were classified into four clusters. Aphids and galls caused the least and the highest damage, respectively, in each cluster, except for Cluster 4, where anthracnose caused the highest damage. The results of this study showed generally good health condition of European beech provenances originating from Central and Southeast Europe in the period of the investigation.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Tamalika Chakraborty ◽  
Albert Reif ◽  
Andreas Matzarakis ◽  
Somidh Saha

European beech (Fagus sylvatica L.) trees are becoming vulnerable to drought, with a warming climate. Existing studies disagree on how radial growth varies in European beech in response to droughts. We aimed to find the impact of multiple droughts on beech trees’ annual radial growth at their ecological drought limit created by soil water availability in the forest. Besides, we quantified the influence of competition and canopy openness on the mean basal area growth of beech trees. We carried out this study in five near-natural temperate forests in three localities of Germany and Switzerland. We quantified available soil water storage capacity (AWC) in plots laid in the transition zone from oak to beech dominated forests. The plots were classified as ‘dry’ (AWC < 60 mL) and ‘less-dry’ (AWC > 60 mL). We performed dendroecological analyses starting from 1951 in continuous and discontinuous series to study the influence of climatic drought (i.e., precipitation-potential evapotranspiration) on the radial growth of beech trees in dry and less-dry plots. We used observed values for this analysis and did not use interpolated values from interpolated historical records in this study. We selected six drought events to study the resistance, recovery, and resilience of beech trees to drought at a discontinuous level. The radial growth was significantly higher in less-dry plots than dry plots. The increase in drought had reduced tree growth. Frequent climatic drought events resulted in more significant correlations, hence, increased the dependency of tree growth on AWC. We showed that the recovery and resilience to climatic drought were higher in trees in less-dry plots than dry plots, but it was the opposite for resistance. The resistance, recovery, and resilience of the trees were heterogeneous between the events of drought. Mean growth of beech trees (basal area increment) were negatively impacted by neighborhood competition and positively influenced by canopy openness. We emphasized that beech trees growing on soil with low AWC are at higher risk of growth decline. We concluded that changes in soil water conditions even at the microsite level could influence beech trees’ growth in their drought limit under the changing climate. Along with drought, neighborhood competition and lack of light can also reduce beech trees’ growth. This study will enrich the state of knowledge about the ongoing debate on the vulnerability of beech trees to drought in Europe.


2019 ◽  
Vol 39 (5) ◽  
pp. 792-804 ◽  
Author(s):  
Pierre-Antoine Chuste ◽  
Catherine Massonnet ◽  
Dominique Gérant ◽  
Berndt Zeller ◽  
Joseph Levillain ◽  
...  

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 924
Author(s):  
Astrid Stobbe ◽  
Maren Gumnior

In the Central German Uplands, Fagus sylvatica and Picea abies have been particularly affected by climate change. With the establishment of beech forests about 3000 years ago and pure spruce stands 500 years ago, they might be regarded as ‘neophytes’ in the Hessian forests. Palaeoecological investigations at wetland sites in the low mountain ranges and intramontane basins point to an asynchronous vegetation evolution in a comparatively small but heterogenous region. On the other hand, palynological data prove that sustainably managed woodlands with high proportions of Tilia have been persisting for several millennia, before the spread of beech took place as a result of a cooler and wetter climate and changes in land management. In view of increasingly warmer and drier conditions, Tilia cordata appears especially qualified to be an important silvicultural constituent of the future, not only due to its tolerance towards drought, but also its resistance to browsing, and the ability to reproduce vegetatively. Forest managers should be encouraged to actively promote the return to more stress-tolerant lime-dominated woodlands, similar to those that existed in the Subboreal chronozone.


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