Impact of mistletoe infestation on tree water status in Anatolian black pine trees in a semi-arid Mediterranean forest stand

Mehmet Said Özçelik; Şükran Oğuzoğlu

Article Details

Impact of mistletoe infestation on tree water status in Anatolian black pine trees in a semi-arid Mediterranean forest stand

Authors:

Mehmet Said Özçelik | Şükran Oğuzoğlu

Publisher:

Isparta University of Applied Sciences

Main Topics:

Orman Entomolojisi ve Orman Koruma

Journal:

Turkish Journal of Forestry Vol.26 Issue 3, pp.310-318

Document Type:

Article

Publication Date:

9/2025

Document Language:

English

Document ID (Org No.):

2001359791

pISSN:

2149-3898

Keywords:

Abstract:

 Mistletoes can adversely affect the hydraulic functioning of their host trees by continuously extracting water and nutrients. This study investigated the effects of pine mistletoe Viscum album subsp. austriacum on water status in Anatolian black pine Pinus nigra subsp. pallasiana trees in a natural forest stand in Mediterranean Region, Türkiye, where mistletoe-infected and non-infected trees coexisted. Continuous stem radius change measurements were obtained throughout the 2024 growing period using automatic band dendrometers to compare maximum daily shrinkage MDS and tree water deficit TWD between infected and non-infected trees. Simultaneously, soil water potential was measured, and meteorological variables were recorded by a nearby station. Mistletoe-infected trees exhibited 92 higher TWD and 12 higher MDS compared to non-infected trees. In both groups, TWD and MDS were closely associated with meteorological variables. TWD showed significant correlations with soil water potential, global radiation, and vapor pressure deficit, while MDS was mainly related to air temperature, solar radiation, and soil water potential. Precipitation influenced MDS in non-infected trees but had no significant effect on infected trees. Moreover, correlation coefficients with environmental factors were consistently higher in infected trees. These findings indicate that pine mistletoe is associated with a marked deterioration in host water status, suggesting increased drought sensitivity and reduced physiological resilience under Mediterranean climatic conditions. Overall, this highlights the potential ecological risk posed by mistletoe infestation in drought-prone forest ecosystems.

 Mistletoes can adversely affect the hydraulic functioning of their host trees by continuously extracting water and nutrients. This study investigated the effects of pine mistletoe Viscum album subsp. austriacum on water status in Anatolian black pine Pinus nigra subsp. pallasiana trees in a natural forest stand in Mediterranean Region, Türkiye, where mistletoe-infected and non-infected trees coexisted. Continuous stem radius change measurements were obtained throughout the 2024 growing period using automatic band dendrometers to compare maximum daily shrinkage MDS and tree water deficit TWD between infected and non-infected trees. Simultaneously, soil water potential was measured, and meteorological variables were recorded by a nearby station. Mistletoe-infected trees exhibited 92 higher TWD and 12 higher MDS compared to non-infected trees. In both groups, TWD and MDS were closely associated with meteorological variables. TWD showed significant correlations with soil water potential, global radiation, and vapor pressure deficit, while MDS was mainly related to air temperature, solar radiation, and soil water potential. Precipitation influenced MDS in non-infected trees but had no significant effect on infected trees. Moreover, correlation coefficients with environmental factors were consistently higher in infected trees. These findings indicate that pine mistletoe is associated with a marked deterioration in host water status, suggesting increased drought sensitivity and reduced physiological resilience under Mediterranean climatic conditions. Overall, this highlights the potential ecological risk posed by mistletoe infestation in drought-prone forest ecosystems.

 Mistletoes can adversely affect the hydraulic functioning of their host trees by continuously extracting water and nutrients. This study investigated the effects of pine mistletoe Viscum album subsp. austriacum on water status in Anatolian black pine Pinus nigra subsp. pallasiana trees in a natural forest stand in Mediterranean Region, Türkiye, where mistletoe-infected and non-infected trees coexisted. Continuous stem radius change measurements were obtained throughout the 2024 growing period using automatic band dendrometers to compare maximum daily shrinkage MDS and tree water deficit TWD between infected and non-infected trees. Simultaneously, soil water potential was measured, and meteorological variables were recorded by a nearby station. Mistletoe-infected trees exhibited 92 higher TWD and 12 higher MDS compared to non-infected trees. In both groups, TWD and MDS were closely associated with meteorological variables. TWD showed significant correlations with soil water potential, global radiation, and vapor pressure deficit, while MDS was mainly related to air temperature, solar radiation, and soil water potential. Precipitation influenced MDS in non-infected trees but had no significant effect on infected trees. Moreover, correlation coefficients with environmental factors were consistently higher in infected trees. These findings indicate that pine mistletoe is associated with a marked deterioration in host water status, suggesting increased drought sensitivity and reduced physiological resilience under Mediterranean climatic conditions. Overall, this highlights the potential ecological risk posed by mistletoe infestation in drought-prone forest ecosystems.

 Ökse otları, konukçu ağaçtan sürekli su ve mineral madde alarak konukçu ağacın hidrolik işlevini olumsuz etkileyebilmektedir. Bu çalışma, çam ökse otunun Viscum album subsp. austriacum karaçam Pinus nigra subsp. pallasiana ağaçlarının su durumu üzerindeki etkilerini araştırmayı amaçlamaktadır. Araştırma, Türkiyenin Akdeniz Bölgesinde, hem ökse otu ile enfekte olmuş hem de sağlıklı karaçam bireylerinin bir arada bulunduğu doğal bir meşcerede yürütülmüştür. 2024 yılı büyüme dönemi boyunca, enfekte ve sağlıklı ağaçlara kurulan otomatik şerit dendrometreler ile gövde yarıçapı değişiklikleri sürekli olarak kaydedilmiş; bu veriler kullanılarak maksimum günlük daralma MGD ve ağaç su açığı ASA parametreleri hesaplanmıştır. Eşzamanlı olarak toprak su potansiyeli ölçülmüş ve sahaya kurulan meteoroloji istasyonu aracılığıyla meteorolojik değişkenler izlenmiştir. Sonuçlar, enfekte ağaçların sağlıklı ağaçlara kıyasla 92 daha yüksek ASA ve 12 daha yüksek MGD değerlerine sahip olduğunu göstermiştir. Hem enfekte hem de sağlıklı ağaçlardaki ASA ve MGD değerlerinin meteorolojik değişkenlerle yakından ilişkili olduğu belirlenmiştir. ASA, toprak su potansiyeli, küresel radyasyon ve buhar basıncı açığı ile güçlü korelasyon gösterirken, MGD hava sıcaklığı, güneş radyasyonu ve toprak su potansiyeli ile ilişkili bulunmuştur. Yağış, sağlıklı ağaçların MGDsi üzerinde etkili olurken, enfekte ağaçlar üzerinde anlamlı bir etkisi gözlenmemiştir. Ayrıca, ağaç su durumu parametreleri ile çevresel faktörler arasındaki korelasyon katsayılarının enfekte ağaçlarda daha yüksek olduğu tespit edilmiştir. Bulgular, ökse otunun karaçam ağaçlarında su durumunu olumsuz etkilediğini, bu durumun Akdeniz iklim koşullarında enfekte ağaçların kuraklığa duyarlılığını artırabileceğini ve fizyolojik dayanıklılığını azaltabileceğini ortaya koymaktadır.

Article Details

Impact of mistletoe infestation on tree water status in Anatolian black pine trees in a semi-arid Mediterranean forest stand

Authors:

Mehmet Said Özçelik | Şükran Oğuzoğlu

Publisher:

Isparta University of Applied Sciences

Main Topics:

Orman Entomolojisi ve Orman Koruma

Journal:

Turkish Journal of Forestry Vol.26 Issue 3, pp.310-318

Document Type:

Article

Publication Date:

9/2025

Document Language:

English

Document ID (Org No.):

2001359791

pISSN:

2149-3898

Drought stress

Maximum daily shrinkage

Pinus nigra

Tree water deficit

Viscum album parasitismKuraklık stresi

Maksimum günlük daralma

Pinus nigra

Ağaç su açığı

Viscum album parazitizmi

Issues

Article Details

Authors: Mehmet Said Özçelik | Şükran Oğuzoğlu

Publisher: Isparta University of Applied Sciences

Main Topics: Orman Entomolojisi ve Orman Koruma

Journal: Turkish Journal of Forestry Vol.26 Issue 3, pp.310-318

Document Type: Article

Publication Date: 9/2025

Document Language: English

Document ID (Org No.): 2001359791

pISSN: 2149-3898

Issues

Authors:

Mehmet Said Özçelik | Şükran Oğuzoğlu

Publisher:

Isparta University of Applied Sciences

Main Topics:

Orman Entomolojisi ve Orman Koruma

Journal:

Turkish Journal of Forestry Vol.26 Issue 3, pp.310-318

Document Type:

Article

Publication Date:

9/2025

Document Language:

English

Document ID (Org No.):

2001359791

pISSN:

2149-3898