Rozprawa naukowa nr 460

Wiele badań pokazuje możliwość zastosowania harwesterów do pozyskiwania drewna gatunków liściastych. Jednocześnie wskazuje, iż lokalne uwarunkowania kształtujące drzewa danego gatunku, wielość gatunków oraz róż­norodność głowic harwesterowych wymagają badań prowadzących do przyporząd­kowania tych ostatnich do wybranych gatunków drzew (z uwzględnieniem różnic fenotypowych). Uogólnienia te pozwoliły na podjęcie decyzji o przeprowadzeniu podobnych badań w Polsce.

Zasadność podjęcia badań przedstawionych w niniejszej pracy oparto na czterech przesłankach: 1) zmiana składu gatunkowego lasów w Polsce na korzyść gatunków liściastych, 2) zwiększanie udziału pozyskiwania drewna technologiami zmechani­zowanymi, 3) brak podobnych analiz dla drzew wyrosłych w warunkach przyrod­niczych i klimatycznych Polski oraz 4) brak w dostępnej literaturze dokładnych, opartych na wielu aspektach (oprócz wydajności i kosztów) analiz efektywności pozyskiwania drewna gatunków liściastych technologiami zmechanizowanymi.

[fragment książki]

1. WSTĘP

2. STAN BADAŃ
2.1. Maszyny wielooperacyjne w pozyskiwaniu drewna
2.2. Rozwój pozyskiwania zmechanizowanego w Polsce
2.3. Pozyskiwanie harwesterem drewna gatunków liściastych

3. CEL I ZAKRES PRACY

4. MATERIAŁ I METODY
4.1. Teren badań
4.2. Prace wstępne
4.3. Dobór harwestera, pozyskiwane sortymenty
4.4. Metody

5. WYNIKI
5.1. Wydajność
5.2. Koszty
5.3. Okrzesywanie i przerzynka
5.4. Zakres wykorzystania pnia na sortymenty
5.5. Dokładność przerzynki
5.6. Jakość okrzesywania
5.7. Uszkodzenia sortymentów

6. DYSKUSJA
6.1. Uwagi ogólne
6.2. Wydajność
6.3. Koszty
6.4. Czasochłonność okrzesywania i przerzynki
6.5. Zakres wykorzystania pnia na sortymenty
6.6. Dokładność przerzynki
6.7. Jakość okrzesywania
6.8. Uszkodzenia sortymentów
6.9. Podsumowanie

7. STWIERDZENIA I WNIOSKI

LITERATURA

SUMMARY
 

Harvester use was initially confined to accessible coniferous forests. Recent development of the machine has allowed timber harvesting in mountain areas and of broad­ leaved species, although in both cases there are still restrictions. The limitation for broadleaved species can be caused by morphological irregularity, especially in stem shape and branching. The objective of the research was to determine the potential of the use of the Sampo Rosenlew 1066 harvester (with Keto 150 LD head) for birch tim­ber harvesting in 46- and 61-year-old mixed birch-pine stands, in the North of Poland.

The effects were analysed by means of a detailed comparative study (between birch and pine) comprising seven parameters:
1) productivity,
2) costs,
3) time consumption of processing,
4) stem utilisation,
5) cross-cutting accuracy,
6) quality of delimbing
and 7) assortment damage (wounds).

The results obtained indicate that the productivity was higher but the costs and processing time were lower for the birch in comparison with the pine in the same age-class stand. The operational productivity of the birch (40.46 and 26.95 m³·h^-1 in the 4^th and 3^rd age class, respectively) was bigger than that of the pine (28.62 and 18.68 m³·h^-1 in the 4^th and 3^rd age class, respectively). Consequently, the unit cost of the birch harvesting was lower (11.77 and 17.67 PZL·m^-3) than that of  the pine (16.64 and 25.49 PZL·m^-3, in the 4^th and 3^rd age class). The processing times were longer for the birch trees  (27.20 and 15.04 s per tree) than for the pine (17.12  and 12.23 s per tree, in the 4^th and 3^rd age class, respectively)  within the same age classes.
However, the processing time calculated per 1 m³ of harvested  timber was shorter for the birch than for the pine. Moreover, the top diameters of the birch assortments were bigger compared to the pine. In the 4^th age class, the average smallest top diameter of the birch was 16.2 cm, while for the pine it was 10.6 cm. In the 3^rd age class, the process­ ing continued up to 12.3 cm for the birch and 9.4 cm for the pine. The total assortment lengths were of a lower differentiation and for the birch amounted to 11.23 and 10.00 m (the 4^th and 3^rd age class), while for the pine they were slightly bigger, amounting to 11.54 and 11.56  m (the 4^th and 3^rd age class). The cross-cutting  accuracy was the best for the butt ends  of the older  pine, where  more than 60%  of the assortments were of a length tolerance set in the harvester computer (2.53–2.55 m). The least accurately cut logs within this category were the top pine assortments obtained from the 3^rd age-class stand (ca. 45% logs within the range of 2.53–2.55 m). The biggest stubs were observed on the birch logs (the 4^th age class) with a mean height of 34 mm, while on the birch logs from the younger stand, the mean stub height was 26 mm. On the pine logs, the stubs were of the smallest height: 13 and 12 mm (the 4^th and 3^rd age class). The biggest wounds (bark and wood shavings) occured on the birch assortments, particularly on the logs processed from the older trees (the 4^th age class) (mean 0,0646 m², on the logs from the younger trees: 0.0399 m²). On the pine logs, the wounds were of a similar average size: 0,0270 and 0,0243 m² (the 4^th and 3^rd age class, respectively). The biggest number of wounds occurred on the birch assortments from the 3^rd age-class stand (1.18 of wounds per log), nearly twice as many as on the pine logs from the 4^th age-class stand (0.66 of wounds per log). It can therefore be concluded, based on the results presented, that the Sampo Rosenlew 1066 harvester with Keto 150 LD head can be recommended for birch timber harvesting of the 3^rd and 4^th age classes in the North of Poland. In addition, the potential of harvester use for bradleaved or coniferous species can be appropiately measured using comprehensive methods including the seven parameters.