Old Trees Wave

The New World ◽  
2021 ◽  
pp. 34-34
Keyword(s):  
Nature ◽  
2003 ◽  
Author(s):  
Helen Pearson
Keyword(s):  

2021 ◽  
Vol 22 (2) ◽  
pp. 527
Author(s):  
Małgorzata Podwyszyńska ◽  
Monika Markiewicz ◽  
Agata Broniarek-Niemiec ◽  
Bożena Matysiak ◽  
Agnieszka Marasek-Ciolakowska

Among the fungal diseases of apple trees, serious yield losses are due to an apple scab caused by Venturia inaequalis. Protection against this disease is based mainly on chemical treatments, which are currently very limited. Therefore, it is extremely important to introduce cultivars with reduced susceptibility to this pathogen. One of the important sources of variability for breeding is the process of polyploidization. Newly obtained polyploids may acquire new features, including increased resistance to diseases. In our earlier studies, numerous tetraploids have been obtained for several apple cultivars with ‘Free Redstar’ tetraploids manifesting enhanced resistance to apple scab. In the present study, tetraploids of ‘Free Redstar’ were assessed in terms of phenotype and genotype with particular emphasis on the genetic background of their increased resistance to apple scab. Compared to diploid plants, tetraploids (own-rooted plants) were characterized with poor growth, especially during first growing season. They had considerably shorter shoots, fewer branches, smaller stem diameter, and reshaped leaves. In contrast to own-rooted plants, in M9-grafted three-year old trees, no significant differences between diplo- and tetraploids were observed, either in morphological or physiological parameters, with the exceptions of the increased leaf thickness and chlorophyll content recorded in tetraploids. Significant differences between sibling tetraploid clones were recorded, particularly in leaf shape and some physiological parameters. The amplified fragment length polymorphism (AFLP) analysis confirmed genetic polymorphism of tetraploid clones. Methylation-sensitive amplification polymorphism (MSAP) analysis showed that the level of DNA methylation was twice as high in young tetraploid plants as in a diploid donor tree, which may explain the weaker vigour of neotetraploids in the early period of their growth in the juvenile phase. Molecular analysis showed that ‘Free Redstar’ cultivar and their tetraploids bear six Rvi genes (Rvi5, Rvi6, Rvi8, Rvi11, Rvi14 and Rvi17). Transcriptome analysis confirmed enhanced resistance to apple scab of ‘Free Redstar’ tetraploids since the expression levels of genes related to resistance were strongly enhanced in tetraploids compared to their diploid counterparts.


Author(s):  
Athanase R. Cyamweshi ◽  
Shem Kuyah ◽  
Athanase Mukuralinda ◽  
Catherine W. Muthuri

AbstractAlnus acuminata Kunth. (alnus) is widely used in agroforestry systems across the globe and is believed to provide multiple ecosystem services; however, evidence is lacking in agroforestry literature to support the perceived benefits, particularly in Rwanda. To understand carbon sequestration potential and other benefits of alnus, a household survey, tree inventory and destructive sampling were conducted in north-western Rwanda. Over 75% of the respondents had alnus trees in their farms. The trees provide stakes for climbing beans, firewood and timber. They also improve soil fertility and control soil erosion. Farmers had between 130 and 161 alnus trees per hectare with an average height of 7.7 ± 0.59 m and diameter at breast height of 16.3 ± 1.39 cm. The largest biomass proportion was found in stems (70.5%) while branches and leaves stock about 16.5 and 13% of the total biomass, respectively. At farm level, aboveground biomass of alnus trees was estimated to be 27.2 ± 0.7 Mg ha−1 representing 13.6 Mg of carbon (C) per hectare. Biomass carbon increased with tree size, from 7.1 ± 0.2 Mg C ha−1 in 3 years old trees to 34.4 ± 2.2 Mg C ha−1 in 10 years old trees. The converse was observed with elevation; biomass carbon decreased with increasing elevation from 21.4 ± 1.29 Mg C ha−1 at low (2011–2110 m) to 9.6 ± 0.75 Mg C ha−1 in the high elevation (> 2510 m). In conclusion, alnus agroforestry significantly contributes to carbon sequestration, although the magnitude of these benefits varies with tree age and elevation. Planting alnus trees on farms can meet local needs for stakes for climbing beans, wood and soil fertility improvement, as well as the global need for regulation of climate change.


2021 ◽  
Author(s):  
Kaja Rola ◽  
Vítězslav Plášek ◽  
Katarzyna Rożek ◽  
Szymon Zubek

Abstract Aim Overstorey tree species influence both soil properties and microclimate conditions in the forest floor, which in turn can induce changes in ground bryophyte communities. The aim of the study was to investigate the effect of tree species identity and the most important habitat factors influencing understorey bryophytes. Methods We assessed the effect of 14 tree species and related habitat parameters, including soil parameters, vascular plant presence and light intensity on bryophytes in monospecific plots covered by nearly fifty-year-old trees in the Siemianice Experimental Forest (Poland). Results The canopy tree species determined bryophyte species richness and cover. The strongest differences were observed between plots with deciduous and coniferous trees. Soils with a more acidic pH and lower content of macronutrients supported larger bryophyte coverage. We also found a positive correlations between vascular plants and availability of light as well as bryophyte species richness. Conclusion Tree species identity and differences in habitat conditions in the forest floor lead to changes of ground bryophyte richness, cover and species composition. Consequently, the changes in the dominant tree species in the stand may result in significant repercussions on ground bryophyte communities. We indicated that the introduction of alien tree species, i.e. Quercus rubra, has an adverse effect on bryophyte communities and suggested that the selection of tree species that contribute to the community consistent with the potential natural vegetation is highly beneficial for maintaining ground bryophyte biodiversity.


1994 ◽  
Vol 8 (4) ◽  
pp. 840-848 ◽  
Author(s):  
Chester L. Foy ◽  
Susan B. Harrison ◽  
Harold L. Witt

Field experiments were conducted at two locations in Virginia to evaluate the following herbicides: alachlor, diphenamid, diuron, metolachlor, napropamide, norflurazon, oryzalin, oxyfluorfen, paraquat, pendimethalin, and simazine. One experiment involved newly-transplanted apple trees; the others, three in apple and one in peach trees, involved one-year-old trees. Treatments were applied in the spring (mid-April to early-May). Control of annual weed species was excellent with several treatments. A broader spectrum of weeds was controlled in several instances when the preemergence herbicides were used in combinations. Perennial species, particularly broadleaf species and johnsongrass, were released when annual species were suppressed by the herbicides. A rye cover crop in nontreated plots suppressed the growth of weeds. New shoot growth of newly-transplanted apple trees was increased with 3 of 20 herbicide treatments and scion circumference was increased with 11 of 20 herbicide treatments compared to the nontreated control. Growth of one-year-old apple trees was not affected. Scion circumference of one-year-old peach trees was increased with 25 of 33 herbicide treatments.


IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Teresa Quilhó ◽  
Helena Pereira ◽  
Hans Georg Richter

The axial variation of bark thickness and quantitative anatomical features of Eucalyptus globulus bark were analysed for one site based on individual measurements of ten 15-year-old trees at six height levels (DBH, 5%, 15%, 35%, 55% and 75% of total tree height). The parameters studied were: length, tangential diameter and percentage of sieve tubes; length, width, cell wall thickness and percentage of fibres; height and percentage of rays; percentage of sclereids in the secondary phloem. Bark thickness decreases from base to top of the tree. Fibre width and wall thickness decrease from base upwards. No distinct axial patterns of variation were observed for the other biometric variables studied. Parenchyma is the main cell type of the bark (50%) followed by fibres (27.9%), rays (12.1%), sieve tubes (2.7%), and sclereids (7.3%). The cell type proportions vary significantly within the tree, i.e., parenchyma, ray and sclereid proportions decrease, fibre and sieve tube proportions increase towards the top of the tree.


1989 ◽  
Vol 67 (4) ◽  
pp. 1066-1070 ◽  
Author(s):  
C. Féraud-Keller ◽  
H. Espagnac

The proliferation of parenchymatous foliar tissue of Quercus ilex was obtained from current year leaves taken from old trees and cultivated in vitro on modified Murashige and Skoog's medium supplemented with benzylaminopurine (4 mg ∙ L−1) and naphthyl acetic acid (0.5 mg ∙ L−1). Only the fragments cultured in October reacted. The neoformations only appeared on calluses that had not been subcultured for 7 months. Primary nodules arising on these calluses were removed and subcultured on the same medium either in the dark or in the light. In the dark only, they produced secondary nodules, which were the source of somatic embryos both in light and dark. Presently, they seem to regulate their structure in the dark but they do not develop in a way that leads to germination.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1775
Author(s):  
Savvas Iezekiel ◽  
Reuven Yosef ◽  
Constantinos Themistokleus ◽  
Dimitrios E. Bakaloudis ◽  
Christos G. Vlachos ◽  
...  

As is well-known, endemic island bird species are especially vulnerable to extinction from anthropogenic environmental change and reduced fitness compared with mainland taxa. The Cyprus Scops Owl, Otus cyprius, is a recently recognized island endemic species whose ecology and breeding biology have not been studied. It nests mainly in holes in trees and buildings, so the felling of old trees, modern architectural practices, and the renovation of old houses in villages may reduce nest site availability. Its population trend is also unknown. Therefore, to better determine its ecological requirements and habitat preferences we placed nest boxes in rural areas adjacent to the forest, in the forest, and in the ecotone between them, and used breeding success as our indicator of habitat suitability. We found that breeding parameters like laying date, clutch size, length of the incubation period, hatching day, hatching success, and number of nestlings did not differ between the three habitats. Despite the low level of nest box occupancy rate (5–11%) the endemic Cyprus Scops Owl readily breeds in artificial nests. Therefore, although we are unaware of any current threats to the Cyprus Scops Owl, we recommend that its conservation be prioritized, including studies, monitoring, habitat conservation, and the provision of nest boxes.


2012 ◽  
Vol 40 (1) ◽  
pp. 243 ◽  
Author(s):  
S. Filiz GUCLU ◽  
Fatma KOYUNCU

This study was carried out on 1-year old trees of ‘0900 Ziraat’ variety grafted onto ‘Kuş kirazi’, ‘Kara idris’, ‘Sari idris’, ‘MaxMa 14’, ‘MaxMa 60’ and ‘Gisela 5’ in order to determine their compatibility. For this purpose, total peroxidase activity was determined by spectrophotomery assay. Taking ground tissue samples were planned three times as before the grafting (beginning), and then 8 and 12 months after grafting. Total peroxidase activities of rootstocks before grafting varied between 10.80 ΔAg.min. (‘Kuş kirazi’) and 7.83 ΔAg.min. (‘Kara idris’) and were found to be statistically important. The peroxidase activity of ‘0900 Ziraat’ was 11.07ΔAg.min. and the closest value occurred in Prunus avium rootstock. The most different values occurred in rootstocks of ‘Kara idris’ and ‘Gisela 5’. The results showed that peroxidase activity increased in rootstock and graft scion. This increase had higher values in heterogenetic combinations especially in ‘0900 Ziraat’/‘Gisela 5’ and ‘0900 Ziraat’/‘Kara idris’ grafts. Peroxidase activity was decreased at the 12th month for all combinations. The highest value was obtained from ‘0900 Ziraat’/‘MaxMa 14’ combinaion with 29.17 ΔAg.min. while lowest one was ‘0900 Ziraat’/‘Kuş kirazi’ with 17.39. The findings showed that peroxidase activity could be used as a parameter in early determination of graft incompatibility.


FLORESTA ◽  
2013 ◽  
Vol 43 (3) ◽  
pp. 439 ◽  
Author(s):  
Saulo Jorge Téo ◽  
Alan Marcon ◽  
Tiago Ehlers ◽  
Júlio César Bianchi ◽  
Adriano Peloso ◽  
...  

Os objetivos deste trabalho foram ajustar e selecionar modelos de afilamento para estimar diâmetros a várias alturas e volume total, com e sem casca, de árvores de Pinus elliottii Engelm., na região de Caçador, SC, para estudar a forma dos fustes das árvores de diferentes idades. Ao todo, 78 árvores, com idades de 10, 18 e 27 anos, foram abatidas, cubadas rigorosamente e tiveram os seus volumes obtidos por meio do método de Smalian. Os modelos de afilamento testados foram os Polinômios de 2º e de 5º Graus e o Polinômio de Potências Fracionárias de Hradetzky. A função de afilamento que apresentou melhor desempenho para estimar o diâmetro com e sem casca ao longo do fuste das árvores foram baseadas no Polinômio de Potências Fracionárias de Hradetzky, para as idades de 10, 18 e 27 anos. O Polinômio de 2º Grau propiciou as melhores estimativas de volume total com casca para as idades de 10 e 27 anos e de volume total sem casca para as idades de 18 e 27 anos. Já o Polinômio de Potências Fracionárias apresentou melhores estimativas de volume com casca para 18 anos e de volume sem casca para árvores de 10 anos. Os fustes das árvores de Pinus elliottii apresentam melhor forma nas idades mais avançadas. AbstractTaper models for Pinus elliottii, at different ages, in the region of Caçador - SC. The research aims to fit and select taper models in order to estimate diameters at different heights and total volumes, inside and outside bark, of Pinus elliottii Engelm. trees, in the region of Caçador - SC, Brazil, as well as to analyze  behavior of stem form for trees at different ages. Altogether, 78 trees at 10, 18 and 27 years of age, had been cut and their volumes obtained by Smalian method. The taper models tested were the 2nd and 5th Degree Polynomial and the Hradetzky Polynomial of Fractioned Potencies. The best performance taper function for estimate diameters inside and outside bark throughout the stem were based on the Hradetzky Polynomial of Fractioned Potencies, for 10, 18 and 27 years of age. The 2nd Degree Polynomial provided the best estimates of outside bark volume for 10 and 27 years of age, and of inside bark volume for 18 and 27 years of age, although the Hradetzky Polynomial presented the best estimates of outside bark volume for 18 years of age and of inside bark volume for 10 years old trees. The stems of the Pinus elliottii trees present better form for the oldest tress.Keywords: Polynomial models; profile models; stem form.


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