Lyophilised needle homogenates, obtained from spruce trees (Picea abies L), were biochemically characterised in relation to the environmental conditions (natural stand or open-top chambers). Biochemical parameters assayed were intermediates of energy (adenine and pyridine nucleotides) and carbohydrate metabolism (carbon partitioning between starch and sucrose). Generally, there were considerable differences between developing (current year) and older needles, in that developing needles had significantly higher adenosine triphosphate (ATP)/ adenosine diphosphate (ADP) and redox ratios. Needles from declining trees showed increased levels of both ratios of ATP/ADP and reduced nicotinamide adenine dinucleotide (NADH)/ nicotinamide adenine dinucleotide (NAD), and also a higher fructose 2,6-biphosphate content.