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Tending operation model for red oak stands
133-136Views:199Red oak (Quercus rubra L.) is our most important exotic oak species, that possesses growing culture with almost one hundred years in our country. Plantation character of red oak growing predominates principally by applied regeneration method (mostly artificial), regular planting space, applying defined method and planting space regulation system. Forest tending model for red oak, that considered stopgap in the native literature is intended to serving the latter. Especially important equation in the viewpoint of stand growing, that describes relationship of stem number (N, in hectare) and diameter at breast height (D1.3 in cm) is: N=e9.80220-1.12607lnD1.3.
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Studies of Cryphonectria parasitica (MURR.) BARR subpopulations on Quercus petraea in Ukraine
70-75Views:143Chryphonectria parasitica (Murr.) Barr, the casual agent of chestnut blight disease, which is one of the most important fungal pathogens of chestnut (Castanea sativa). The disease seriously affected the chestnut in Northern-America and in Europe as well. It is important to mention that the pathogen does not only infect the chestnut but oak species (Quercus spp.) also. In the Carpathian-Basin, the chestnut is endemic in the Mecsek mountains, in Zala, in Somogy counties but it also can be found in the Danube-Bend. In the Carpathian-Basin (outside Hungary) the chestnut is found in Slovakia, Ukraine, Romania. In our study bark samples infected by Cryphonectria parasitica were collected from Bobovyshche, Serednje and Rostovjatica (Ukraine). The rate of infected chestnut tree were higher than 90% around Bobovyshche and beside chestnut, the symptoms were detected on oak trees as well. We collected bark samples from chestnut and oak as well and then we isolated the pathogen Cryphonectria parasitica in the lab of University of Debrecen. Symptomatological observations, laboratory examinations on fungus morphology, as well as comparisons of ITS sequency homology were made and approved that the causal agent of new disease was Cryphonectria parasitica. Our results proved that the Cryphonectria. parasitica infects oak trees beside chestnut in the Carpathian-Basin. Further studies are needed to determine the VCG (Vegatative Compatibility Group) group of the Cryphonectria parasitica found on oak trees.
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Physiological plasticity of main tree species of lowland hornbeamoak forest as a results of forest gap regeneration
99-103Views:200Specific leaf area (SLA) of English oak (Quercus robur L.) and hornbeam (Carpinus betulus L.) as members of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the inert forest. The artificial opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important ways for plant life and plant production basically influenced by altered light condition resulted in opening process. Efficient photosynthesis is important for plant life, plant production, but species-dependent plasticity of photosynthesis makes one species more tolerant, than others. The specific leaf area is acceptable parameters for characterising plant production, dry matter content and leaf structure. The dry matter content based on known leaf area is higher in oak both sun and shade leaves, than hornbeam. The different place of leaves in the canopy of trees did not influence the values of SLA.
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Influence of mammal fossorial activity on bearing-out some chemical elements on up of soil cover
117-120Views:97Fossorial activity of mammals is conductive to trace of microelements from more deep soil horizons into zone of its active involving to biological cycle. As a result of researches have established the mostly intensive migration of micro- and macroelements that is goes at the expense of mammals fossorial activity it is typical for humid gully lime-and-ash with oak wood. A middle position in speed of entering chemical elements is belonging to artificial oak wood in the watershed and humid lime-and-ash with oak wood in floodplain. Mostly slow migration in speed of entering elements is typical for middle-dry pine wood on sandy terrace.
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Yield and crown structure characteristics in a red oak (Quercus rubra L.) stand: Case study
49-53Views:138The paper provides the results of a detailed analysis of timber volume and several important crown variables of red oak (Quercus rubra L.) based on an experimental plot in eastern Hungary. At the age 32 years the crop trees belonged to different height classes. If the volume of the mean tree from height class I was considered as 100%, the volume of the mean tree of class II was 59%, and the mean tree of class III was only 36%. It appeared that there was a significant correlation between crown indices and yield. For this reason, diameter at breast height showed a positive linear correlation with crown diameter (R2= 0.6211). Additionally, there was also positive linear relationship between crown diameter and volume (R2= 0.6908). The variation of crown indices is height even within the same stand and indicates the importance of following a selective thinning operation method.
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Seasonal changes of photosynthetical parameters as a results of forest gap model
133-136Views:174Photosynthetic parameters of English oak (Quercus robur L.) as a member of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the host forest. The artifical opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important way for plant life and plant production. In the centre of photosynthetic efficiency the quality and quantity traits of photosynthetic pigments are standing. During our work some photosynthetic parameters of plants (in the gap and in the forest as well) were measured: relative chlorophyll content as SPAD index, chlorophyll a and b content, total chlorophyll content and ratio of chlorophyll a and b. Based on our results no significant differences among our data in early spring. Although, during the summer significant differences occurred between the measured values in the gap and in the forest area. Lower total chlorophyll content was experienced in the gap, than in the forest area due to the lower chlorophyll-b content. Because of the high light intensity higher chla/chlb ratio was measured in the gap. The lower chlorophyll contents of gap habitat may have a part of the acclimatization process of photosynthetic apparatus against high light stress, which can determinate the survival chance of individual.
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Ecological value of wood energy plantations in the support of some animal groups
143-148Views:55Today, some environmental problems have reached such severe proportions that it is no longer enough to recognise them, but environmentally friendly solutions must be used to reduce them. The reduction in the area of natural forests of native species is causing problems in several ways.
This research aimed to highlight how environmental, conservation and economic interests can be reconciled. In addition to natural forests, wood energy plantations are becoming increasingly important. Energy import dependency is a problem for most countries, for which wood energy plantations can partly offer an alternative. Native forests can be protected, and their area increased where possible. Meanwhile, energy plantations can be established in areas with low agricultural productivity.
In this experiment, I studied a plantation of Pedunculate Oak (Quercus robur), a Black Locust (Robinia pseudoacacia) and a Paulownia (Paulownia Shan Tong). I selected burrowing birds and ground-dwelling arthropods as indicator groups. I did this by establishing a nesting colony and soil trapping. I wanted to demonstrate that, in addition to natural forests, wood energy plantations have a role not only in economic terms but also in maintaining certain animal groups. Soil trapping tests were carried out in all three tree plantations.
The obtained results showed that in the Paulownia plantation, the occupancy rate of nest boxes was almost 100%, while in the Black Locust plantation it was around 30%. Among the species that occupied the nesting sites, the Common Starling (Sturnus vulgaris) and the Eurasian Tree Sparrow (Passer montanus) were more abundant, while Great Tit (Parus major) was present in the Black Locust plantation. These are opportunistic species for which nesting opportunity is the most important factor, since their feeding area (in the case of the Common Starling and the Eurasian Tree Sparrow) is not typical of the nesting area. The soil trap investigations show that there are no significant differences in the composition of the arthropod group (beetles, spiders) in the study areas.
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Matériel et conditions de reproduction du ver à soie de chêne Antheraea pernyi Guer (Bombycidae)
58-60Views:70In this study we highlighted the conditions that need to be fulfilled in order to have successful oak silkworm reproduction.
Thus, conditions for best cocoon hibernation should be as follows: strata of 10-15 cm with optimal temperature around 0oC, relative humidity of 60-70%. The cocoons must be moved every 10 days and must also be daily aired.
Butterfly mating should take place either the night of their coming out or the second day. It takes 14-15 hours; male butterflies outnumber females by 10%.
After mating, the optimal temperature for laying eggs is 18-20oC; relative humidity is 80%; egg laying takes place in the dark. -
Correlation between cultivation methods and quality in some vegetable species
313-317Views:150Quality parameters of 5 table root varieties were tested on 3 sowing dates with different cultivation methods: open field on 15 April and 9 July 2010 and under plastic tents on 19 August. The highest red pigment content (betanin) was measured in the varieties Akela and Mona Lisa (~ 80 mg 100 g-1) of the second (July) crop. This crop is in general use in Hungary. In comparison, in the late sown varieties (August, under plastics) a further pigment increase (10–20 mg 100 g-1) was observed in the same varieties as related to the earlier sowing dates. Yellow pigments (vulgaxanthins) showed similar trends. Roots of the late sowing date (with harvest in December) contained the highest vulgaxanthin values (103.3–124.18 mg kg-1).
Varieties reacted differently to temperature changes during the production period and thus to sugar accumulation. In the second crop (July) higher water soluble solids content was measured on the average of varieties (10.12%) in comparison to the April sowing (7.76%). Beetroots of the spring sowing are recommended for fresh market while the second (July) crop with autumn harvest can satisfy industry requirements. Late sowing under unheated plastic tents supply us with fresh beetroot in late autumn and early winter and prolong the usability of plastic tents.
Six lettuce species/subspecies were tested in the open field and under plastic tents in 3 repetitions for nitrate nitrogen, vitamin-C, polyphenol (gallus acid equivalent – mg GAE 100 g-1) and mineral element (Ca, K, Mg, Na) contents. Our measurements showed lower nitrate nitrogen values under plastic than in the open field (89.10± 8.13 and 127.06±14.29 mg kg-1) on the average of genotypes. Lettuce grown in the field had higher vitamin-C content (1.4 mg%) which is nearly 50% more than in plants under plastic. The highest polyphenol content was found in samples from the field with a conspicuous value of 804.17±56.47 mg GAE 100 g-1 in Piros cikória. Samples grown under plastic were richer in mineral elements (Ca, K, Mg, Na) which can be explained by the higher nutrient content of the soil. In this environment superior Mg content was observed in Edivia (4616.33±
311.21 mg kg-1).Besides the well- known headed lettuce, Piros cikória (Red chicory),the red leaved Lollo Rossa and Tölgylevel (Oak leaf lettuce) should be
mentioned which well deserve further testing in order to supply us with nourishing, healthy food.