NATURAL FOREST RESTORATION IN THE PLANTS OF THE NATURE MONUMENT «NIZHNESALDINSKAYA CEDAR GROVE»

Статья содержит результаты оценки естественного лесовосстановления под пологом насаждений памятника природы областного значения «Нижнесалдинская кедровая роща». Целью исследований явилось изучение особенностей формирования подроста кедра как в естественных, так и в искусственных древостоях. В основу исследований положен метод пробных площадей. В результате исследований установлено, что кедровая роща в настоящее время испытывает серьезные рекреационные нагрузки со стороны местного населения. При этом основное воздействие приходится на подрост и живой напочвенный покров. В составе древостоев достаточно много перестойных деревьев кедра с низкой интенсивностью плодо- ношения и с наличием повреждений антропогенного и природного характера. Естественное лесовосстановление кедра под пологом древостоев наблюдается на площади 13,3 га (71,9 % общей площади покрытых лесной растительностью земель). Насаждения с отсутствием подроста кедра представлены культурами кедра в возрасте не старше 59 лет (молодняками), а также ольшаником в пойме ручья с полным отсутствием кедра в составе древостоя. Плодоношение в возрасте 45–59 лет наблюдается только у отдельных деревьев кедра. В составе подроста кедра преобладают экземпляры высотой до 0,5 м. Доля жизнеспособного подроста с увеличением высоты подроста, а соответственно, и его возраста уменьшается. Результаты исследования имеют практическое значение и могут быть использованы при планировании и проведении работ по воспроизводству лесов и организации рекреационной деятельности на территории памятника природы «Нижнесалдинская кедровая роща». The article contains the results of assessing the natural reforestation under the canopy of the natural monument of regional signifi cance «Nizhnesaldinskaya cedar grove». The aim of the research was to study the features of the formation of Siberian stone pine undergrowth both in natural and artifi cial stands. The research is based on the trial plot method. As a result of research, it was found that the cedar grove is currently experiencing serious recreational stress from the local population. In this case, the main impact falls on undergrowth and living ground cover. There are a lot of overmature cedar trees with a low fruiting intensity and with the presence of anthropogenic and natural damage in the forest stands. Natural reforestation of cedar under the canopy of forest stands is observed on an area of 13,3 hectares (71,9 % of the total area covered with forest vegetation). Plantations with no cedar undergrowth are represented by cedar cultures not older than 59 years (young stands), as well as alder in the stream fl oodplain with a complete absence of cedar in the stand. Fruiting at the age of 45–59 years is observed only in individual cedar trees.The specimens up to 0,5 m in height predominate in the composition of Siberian stone pine undergrowth.The proportion of viable undergrowth decreases with an increase in the height of the undergrowth and, accordingly, its age.The results of the study are of practical importance and can be used in planning and carrying out works on forest reproduction and organization of recreational activities on the territory of the natural monument «Nizhnesaldinskaya cedar grove».

The ancestral conservative tillage of silver fir in the ‘Tisovik’ reserve of the Białowieża Primeval Forest

The ‘Tisovik’reserve, located in the Belarusian part of the Białowieża Forest, holds an isolated relic stand of silver fir, situated 120 km to the north-east of the main forest. In order to preserve this relic fir stand, a ancestral conservative tillage consisting of the Jd 92 trial (plot I) and the Jd 94 trial (plots II and III) was established between 1992 and 1994 in the Polish part of the Białowieża Forest on the territory of the Hajnówka Forest District. The growth and development of the progeny of 20 firs were characterized by means of long-term observations made in these trials. In 2000 (at the age of 18), the firs in the Jd 92 trial (plot I) reached an average height of 394.86 cm with a mean diameter at breast height of 42.42 mm and the average rate of survival amounted to 75%. In the Jd 94 trial, the rate of fir survival on plot II was 70% (at the age of 15) with an average height of 277.08 cm and a diameter at breast height of 36.62 mm, while on plot III only 50 trees with an average height of 198.6 cm and a diameter at breast height of 24.49 mm survived. The results of this study show that the fir progeny in the ‘Tisovik’ reserve is of high breeding value. Therefore, the silver fir seed stock of the ‘Tisovik’ reserve is suitable for the establishment of new plantations in the Polish part of the Białowieża Forest and the Mazury-Podlasie Region.

A 33-year Evaluation of Resistance and Pathogenicity in the Apple Scab–crabapples Pathosystem

Crabapples (Malus spp.) are popular ornamental trees in the commercial and residential landscape. Over a 33-year period at the Secrest Arboretum, Wooster, OH, 287 accessions of ornamental crabapple were evaluated for their resistance to apple scab caused by the fungus Venturia inaequalis. Of these 287 accessions, 31 had no symptoms of scab for longer than a 10-year period and were identified as resistant to the disease. Of these 31 resistant accessions, 14 eventually displayed symptoms, presumably as a result of infection by one or more newly present races of the pathogen in the trial plot. Notable resistance breakdowns in accessions previously classified as resistant include the development of scab on M. × ‘Prairifire’, M. × ‘Bob White’, M. × ‘Red Jewel’, and M. floribunda. Corresponding to these changes of resistance is the putative development of new V. inaequalis races in North America: Race 5, possessing virulence to the Vm gene in ‘Prairifire’; Race 3 that infects M. × ‘Geneva’ but not M. baccata ‘Dolgo’; and the first identification and report of scab on a M. floribunda population that was reported as resistant even before the first 25 years of the evaluation. The detection of scab on this species suggests the presence of Race 7 in North America for the first time. Five named accessions remained free from scab for the entire 33-year trial: M. sargentii ‘Sargent’, M. baccata ‘Jackii’, M. × ‘Beverly’, M. × ‘Silver Moon’, and M. × ‘White Angel’ and may serve as sources of durable resistance in crabapple and commercial apple breeding in the Midwest.

Combination of Mating Disruption and Granulosis Virus for Control of Codling Moth in Bulgaria

Combination of Mating Disruption and Granulosis Virus for Control of Codling Moth in Bulgaria An application of mating disruption by use of Ecodian CP dispensers (ISAGRO, Italy) in combination with the granulosis virus product Carpovirusine 2000 (Arysta LifeScience, France) against Codling moth (CM), Cydia pomonella, was tested near Plovdiv, Central South Bulgaria. In 2007, the method was applied in an orchard where in the previous year fruit damage reached 18.7% and the CM population was high, as indicated by 3.83 diapausing larvae per tree. Carpovirusine was applied 11 times in the trial plot in combination with Ecodian CP dispensers installed twice during the season. Before harvest, fruit damage in the trial plot amounted to 0.9% and the overwintering population in autumn 2007 was only 0.46 larvae per tree. At the same time in the reference orchard, where 15 insecticide treatments were applied during the season, fruit damage before harvest reached 12.3% and the hibernating population was 7.97 larvae per tree. So, it has been confirmed that combination of both methods might be an effective tool for control of codling moth in the orchards with high population density and resistance to conventional insecticides. This study is being continued.