ДИНАМІКА СТАНУ ПРИМІСЬКОЇ ДІБРОВИ УРОЧИЩА «ГОЛЕНДЕРНЯ» В ЗВ’ЯЗКУ З ОРГАНІЗАЦІЄЮ ОХОРОННОГО РЕЖИМУ ЇЇ ТЕРИТОРІЇ

Анотація

THE DYNAMICS OF THE STATE OF THE SUBURBAN OAK GROVE OF THE UROCHISHCHE HOLENDERNYA LANDMARK (LANDSCAPE UNIT) IN A CONNECTION WITH ORGANIZATION OF THE TERRITORY PROTECT REGIME

S. Galkin, N. Dragan, N. Doyko

In the conditions of climate instability, of an anthropogenic pressure, the forest phytocenoses are under stressful growth conditions and it requires of active urgent measures for rehabilitation.

The Urochishche Holendernya is a suburban forest planting, which, in 2008, was attached to the Alexandria arboretum. The Urochishche was left without care and also had a hard recreational load. In order to organize the monitoring of a state of the century-old oak grove, in 2010, the researches of conditions of oak growth, a botanical inventory, a phytosanitary survey of oaks was carried out. In 2017, the second forest-pathological survey of oak grove was conducted to define the current state of the oak grove and the dynamics of its state in the conditions of the protect regime of this territory.

The vital state of plants was determined on the scale of the categories of states, which were accepted in the forest pathology ("The Sanitary rules in forests of the Ukraine", 1995). The estimation of the state of individual plantings was given through the index of the state of plantings, which was calculated as the average-weighted value according to the data of a state estimation of individual trees from the grove ("The Forests Monitoring...", 1990). The trees diseases damages were determined visually by the presence of fruit bodies, cancer wounds, hollows, etc. (V.N. Stark, 1932).

The area of the oak grove remained at the same level - 35.35 hectares.  The territory of the oak grove still remains a sharply differentiated in the structure of the plantings, the degree of degradation and the forest-pathological condition. According to the level of degradation of the trees and the grass cover, on the territory of the oak grove there are three parts types: 1) with saved forest structure for a total area of 15.8 hectares (44.7%), where 983 oaks (56.5%)are growing; 2) with the falling out of one or another tier or tent from the structure of plantings for a total area of 9.5 hectares (25.6%), where 685 oak (39.4%) are growing; 3) are represented only by oak trees and grass cover area of 6.35 hectares (18.0%) with 72 oaks (4.1%). Another 15 hectares (11.7%) in the oak grove area was trampled or burnt down to the mineral part and deprived of tree vegetation in 2010.

During the monitoring period, the number of oaks decreased from 1787 to 1740 exemplars, (considering the trees, which belonged to the V-VI categories of vital states during the preliminary survey). In the main, these oaks grew at the degraded areas and at the areas with a simplified phytocoenic structure.

Since the previous survey, the phyto-sanitary condition of the oak grove has considerably improved . On the one hand, by the reason of conducted phytosanitary measures of dead wood removing, on the other, by introducing a protective regime and the restrictions visitors.

Any of active processes of oak drying does not occur at the Urochishche Holendernya. From the 46 oak trees of the IV-th vital state category (in 2010), only 12 exemplars went to the V-th category (in 2017), from the III -d to the IV-th – 6 exemplars. The number of healthy trees (the I-st category) in the oak grove is 430 exemplars (24, 7%); they are mainly concentrated at the areas with saved forest structure.

The pathology of the butt zone was detected in 237 trees (13.6% of the total number), of the trunks - 417 (24%), of the top of trees - 316 (18.2%). Simultaneous damage of several tree zones has 279 trees (16%) and there are 42 oak trees (2.4%) which have damages of entire tree.

In all trunk zones, the number of pathologies is the smallest in the oak grove with the saved forest structure, the largest is in degraded areas and areas with a simplified structure.

From the time of the previous survey no major changes of the state of the old oak grove occurred. In some areas the number of trees with pathologies has slightly increased or decreased. A significant increase in all of the trees areas with some improvement in the condition of the top tree zone is noted both in the oak groves of the "Holendernya" and of the "Alexandria" and, obviously, is not related to the restriction of the recreational load.

The absence of acute negative changes, also a small amount of new deadwood - 12 exemplars, the non-transition of trees majority from the IV-th category into the V-th category is an essential reaction of the oak grove to the introduced protection regime.

The most significant changes have occurred with the state of the grass cover.

About 3 hectares (of 15 hectares)of the territory, which were trampled down to the mineral part, became growing with herbaceous vegetation now, the wheel tracks are "disappearing", also overgrown are the places of picnics, and in some places we can observe the hardwood self-seeding. It is obvious that such changes in the future will have a positive effect to the condition of woody vegetation.

With the simplification of the structure and growth of degradation processes in the areas, the density of oak growth decreases, while increases the number of trees, which are affected by diseases, with thin out of tops and dry-topped, with the hollows, increases the number of the trees falling out. Moreover, the degradation processes in the researched area are local in its nature; they are clearly expressed in places of permanent picnics, while in a few dozen meters, where there are no marks of visitors' rest, the state of the oak trees is quite satisfactory.

Accordingly,  the oak grove of the Urochishche Holendernya is a textbook example of the negative impact of a human on forest cenozes.

At the present time, the main tasks are to normalize strictly the recreational load on the old oak grove of the Urochishche Holendernya and to develop a system of the oak grove areas recovering, which were anthropogenically degraded.