9. Intensity of seeding and quality of Scots pine seeds on the second-level POPs -

Andrzej Załęski

The research results on seeding and quality of Scots pine seeds are used both in biological monitoring and current economic activity of the State Forests.

In 2003, the variability coefficients of indicators of seeding, which every year are found to be higher than the spatial variability coefficients of seed quality, were considerably higher than the average for the observation period 1996-2003 (Table 17).

The variability coefficients for those characteristics were: the mean mass of one cone - 23%, weighed output of seeds from cones - 37% and the mean number of viable (full) seeds per cone - 44%. The variability of: the mass of 1000 seeds, germination capacity and germinative energy, length and width of embryo and length and width of endosperm (coefficient values 14, 5 and 8, 6 and 9, 6 and 7%, respectively) was markedly low and approached the level of the long-term mean.

On the other hand, the resistance of seeds to the accelerated aging test showed the highest variability (coefficient of variability 529%). This was probably due to the fact that at the low value of the mean difference in germination, the stress conditions of the accelerated aging test stimulated germination of pine seeds from 2003 (negative values of the difference are shown in Table 17) in some regions of the country while in other it did not.

The pine seeds from five natural-forest regions showed the lower number of seeds per cone and lower weighed output of seeds in cones. The exception was the Mazury-Podlasie natural-forest region, where output of seeds was distinctly higher than in the previous years and the Carpathian natural-forest region, where the output of seeds was similar to the mean for the period 1996-2003. However, the statistical analysis confirmed significant differences in the mean number of seeds per cone and the weighed output of seeds in cones between the natural-forest regions. It was only proved that the mean mass of one cone from the Wielkopolska-Pomarenia natural-forest region was significantly lower than from the Baltic and Carpathian natural-forest regions.

In 2003, the pine seeds collected from the majority of the natural-forest regions were shapely. The mean mass of 1000 seeds approximated 6.6 g, i.e. the value of the country mean (c. 6.5 g) and it exceeded 6.1 g, i.e. the mass considered average in forest management [11]. The mass of seeds collected from the Wielkopolska-Pomarenia natural-forest region was distinctly lower than the long-term mean, while in the Carpathian natural-forest region it was higher by c. 0.9 g. ANOVA and Tukey`s test did not confirm statistical significance of differences in the mass of seeds between natural-forest regions. The dimensions of an embryo (Fig. 10) approximated to the long-term means, and the dimensions of an endosperm were also greater. The mean length and width of embryo were within the standard ranges and approximated the lower limit for seeds of I quality class [23]. A single exception were seeds collected from the Wielkopolska-Pomarenia natural-forest region, where the dimensions of embryo approached the level of the average for 1996-2003. Statistical analyses, however, did not prove the significance of differences in the length and width of embryo and the width of endosperm in seeds between the natural-forest regions.

The mean germination capacity and germinative energy, were generally lower than the mean for the country. This was attributable first of all to the Carpathian natural-forest region. However, the decrease in germination capacity and germinative energy in this region was affected by a very poor quality of seeds (below class III) collected from one monitored POP located in the Bircza Forest District. On all other POPs, the seeds with germinating capacity and germinative energy represented quality class I and exceptionally class II. ANOVA and Tukey's test confirmed that the viability of seeds collected from the Carpathian natural-forest region was lower than in other natural-forest regions. On the other hand, the resistance of seeds to the accelerated aging test was high. The average difference in germinating capacity between aged and unaged seeds was five times lower than the long-term mean. The phenomenon of the resistance of seeds to the accelerated aging test occurred in all natural-forest regions. The resistance of seeds to the stress conditions of the accelerated aging test stimulated germination of seeds from the Baltic and Carpathian natural-forest region (they germinated better).