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    The distribution of pine mistletoe (Viscum album ssp. austriacum) in Scots pine (Pinus sylvestris) forests: from stand to tree level
    (Taylor & Francis As, 2020) Bilgili, Ertugrul; Coskuner, Kadir Alperen; Baysal, Ismail; Ozturk, Murat; Usta, Yetkin; Eroglu, Mahmut; Norton, David
    This paper reports and discusses the distribution of pine mistletoe in scots pine forests at stand and tree level in relation to some site, stand, and tree characteristics. Population characteristics (age, number and biomass) and distribution of pine mistletoe in the canopy of scots pine trees were also evaluated. A total of 1408 trees were measured in 114 representative sample plots in the Eastern Black Sea Region of Turkey. Of the measured trees, 648 (46%) were mistletoe infected and 760 (54%) were uninfected. The 6-class dwarf mistletoe rating system (DMRS) was used for infection severity rating. Correlation analysis results indicated significant relationships between mistletoe infection severity and stand and tree characteristics. The t-test results showed that there was a significant difference between mean stand and tree characteristics in mistletoe infected and uninfected stands. The results of the binary logistic regression analysis indicated that altitude and stand volume were the most significant predictor of the distribution of pine mistletoe at stand level. As for the population characteristics of pine mistletoe, the results indicated that the life span of pine mistletoe was about 24 years and that biomass distribution gradually increased from lower to upper part of the crowns.
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    Quantifying the effect of pine mistletoe on the growth of Scots pine
    (Wiley, 2018) Bilgili, Ertuğrul; Öztürk, Murat; Coşkuner, Kadir Alperen; Baysal, İsmail; Serdar, Bedri; Yavuz, Hakkı; Usta, Yetkin
    Mistletoe infection results in substantial growth losses in mistletoe-infected forests. This study reports and evaluates the results of retrospective analyses of radial growth of Scots pine (Pinus sylvestris) in relation to the level of infection of pine mistletoe (Viscum album ssp. austriacum). A total of 43 Scots pine trees were destructively sampled from different sites. Of these trees, 14 were uninfected and 29 were infected. Infection classes were determined using six-class dwarf mistletoe rating system (DMRS). All needle and mistletoe biomass were removed completely and weighed for each sampled tree. Subsamples from needles and all mistletoe biomass were taken to the laboratory for oven-dried weight determinations. Five-cm-thick wood discs were cut from the stem at the breast height (1.3m) to determine annual basal area increment for the last 25years. In addition to DMRS, new infection classes were created using mistletoe-to-needle biomass (MB/NB) ratio. The results showed that the radial growth losses could be as much as 41% to 64% at different infection levels. The rate of growth loss in relation to DMRS and MB/NB ratio was similar, but with a larger variability in DMRS values. The results showed that both DMRS rating and MB/NB ratio seem to be important for quantifying growth loss on Scots pine trees infected with mistletoe. The results of this study can also be invaluable in modelling the effects of mistletoe on the growth of Scots pine trees.