Host physiological condition regulates parasitic plant performance: Arceuthobium vaginatum subsp. cryptopodum on Pinus ponderosa

Christopher P. Bickford, Thomas E Kolb, Brian W. Geils

Research output: Contribution to journalArticle

44 Scopus citations


Much research has focused on effects of plant parasites on host-plant physiology and growth, but little is known about effects of host physiological condition on parasite growth. Using the parasitic dwarf mistletoe Arceuthobium vaginatum subsp. cryptopodum (Viscaceae) and its host Pinus ponderosa, we investigated whether changes in host physiological condition influenced mistletoe shoot development in northern Arizona forests. We conducted two studies in two consecutive years and used forest thinning (i.e., competitive release) to manipulate host physiological condition. We removed dwarf mistletoe shoots in April, before the onset of the growing season, and measured the amount of regrowth in the first season after forest thinning (Study I: n=38 trees; Study II: n=35 trees). Thinning increased tree uptake of water and carbon in both studies, but had no effect on leaf N concentration or δ 13C. Mistletoe shoot growth was greater on trees with high uptake of water and carbon in thinned stands than trees with low uptake in unthinned stands. These findings show that increased resource uptake by host trees increases resources to these heterotrophic dwarf mistletoes, and links mistletoe performance to changes in host physiological condition.

Original languageEnglish (US)
Pages (from-to)179-189
Number of pages11
Issue number2
StatePublished - Dec 2005



  • Arizona
  • Dwarf mistletoe
  • Forest management
  • Host-parasite physiology
  • Photosynthesis
  • Water relations

ASJC Scopus subject areas

  • Ecology

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