Photosynthesis and respiration in black spruce (Picea mariana) parasitized by eastern dwarf mistletoe (Arceuthobium pusillum)

Under controlled laboratory conditions, it was found that during summer black spruce branches parasitized by a dwarf mistletoe have a higher rate of apparent photosynthesis and dark respiration than unparasitized branches. In winter, parasitized branches have a lower rate of apparent photosynthesis and generally a higher rate of dark respiration than non-infected branches.