COMMISSION DECISION of 13 December 2006 on a Community financial contribution for 2006 and 2007 to cover expenditure incurred by Portugal for the purpose of combating Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle et al. (pinewood nematode) (notified under document number C(2006) 6433) (Only the Portuguese text is authentic) (2006/923/EC)