PICEA PHYSOKERMES SCHRNK. DAMAGE IMPACT TO PICEA ABIES (L.) H. KARST DIAMETER INCREMENT IN MYRTILLOSA MEL.

ABSTRACT

According to State Forest service data in 2018 Norway spruce occupies 19% (0.533 milj. ha) from total forest area in Latvia. Disease and pest intense spread and damage in different forest ecosystems is result of climate change creating a risk to forest management. Spruce bus scale (Physokermes picea Shrnk.) in Baltics including in Latvia up to 2009 were detected only in parks growing trees but after 2009 also in different age P. abies stands especially on drained soils including Myrtillosa mel. Research aim is to analyse stand dendrometric indicators and Ph. picea damage influence on Norway spruce diameter increment in Myrtillosa mel. In 2017 were two sample plots (each 0.25 ha) established in stands damaged by Ph. picea massive proliferation in 2010. In forest, stand measurements for dendrometric indicators calculation and 122 increment bore cores made to estimate spruce bud scale impact on diameter increment. In 42 years old Norway spruce research stand with site index I average tree height is 16.4 m but DBH 16.1 cm. In average 1514 trees ha-1, growing stock 275 m3 ha-1, standing dead wood stock 79.3 m3 ha-1 and downed tree pieces 101.9 m3 ha-1 (α=0.05). Annual tree diameter increment two years after spruce bud scale proliferation was decreasing but after year 2013, diameter increment increased.

Keywords: drained mineral soils1, pest proliferation2, dendrometric indicators3