INSTYTUT DENDROLOGII

European yew (Taxus baccata L.) in Bardzkie Mountains - status and trends of population growth

In the Bardzkie Mountains are relatively numerous and very valuable yew populations. Although in the years 1958 and 1959 established two nature reserves "Cisowa Góra" and "Cisy", however, single individuals are often found outside the reserves. As with many other yew populations in Poland, also in the Mountains Bardzkie species does not regenerate.
The aim of this study was:
- finding of all adult yew trees, their measurement, determine the location, conditions of occurrence and health status;
- identify conditions favored persistence, often age-yew in Bardzkie Mountains, as the basis for further protection;
- identify methods for protecting yew seedlings and bring about such status, which secure the subsistence of the population of T. baccata in the Bardzkie Mountains.
Determination of the number of individuals consisted on finding of all adults specimens of yew trees in the Bardzkie Mountains. Each tree was measured and permanently labeled. This has provided information on the number of individuals, their morphology and spatial structure in the whole area of the Bardzkie Mountains.
In order to examine the determinants of natural regeneration of T. baccata was established experience in the reserve Cisowa Góra. It was assigned four variants of protection: 1) using of individual shields on single seedlings; 2) fencing the forest area with adult trees and seedlings; 3) observation of selected seedlings without protection, 4) replanting of seedlings from the reserve to the fenced area and with weed control. Each of six years, at the end of each growing season, field observations and results were documented.
As a result of the measurements it was found that the number of all adult yew trees in the Bardzkie Mountains was 3648, in the nature reserve "Cisowa Góra" 865, in the nature reserve "Cisy" - 1425 and outside the reserves - 1358.
The highest percentage of seedling survival found in the plot protected by individual shields, these seedlings were also the best state of health. On the control plot, without protection, it was found that the seedlings before they die, do not pass through the stage of weakness and withering, but simply disappear. The most probable cause is browsing or taking out by deer. The highest average height reached seedlings in areas with the greatest access of light in the case of all plots.
As a result of research formulated the following conclusions:
1. Yew populations in the Mountains Bardzkie are one of the largest in Poland, but they health condition, and first of all the lack of juvenile stages is disturbing. It can be improved by periodic thinning of canopy trees, with intensity adapted to local conditions.
2. The correct sex ratio (nearly 1:1) and distribution of yew trees on relatively large area determine good conditions for the emergence of regeneration, while maintaining the principles of correct and active conservation.3. There is a big chance for natural regeneration of yew promising hope for the future. In the case of interruption, populations will be destroyed rapidly, primarily by deer browsing.as in fully-developed leaves, typical of the given species.