A comparison of rating systems for dwarf mistletoe-induced witches' brooms in ponderosa pine

Thomas J. Parker, Robert L Mathiasen

Research output: Contribution to journalArticle

8 Scopus citations


We compared four methods of assessing dwarf mistletoe infection and estimating volume of dwarf mistletoe-induced witches' brooms in ponderosa pine (Pinus ponderosa). Witches' brooms can provide important wildlife habitat and can influence fire behavior. We used Hawksworth's dwarf mistletoe rating system (DMR), Tinnin's broom volume rating system (BVR), an estimate of the percentage of live crown occupied by witches' brooms (PCB), and a new system, total broom volume (TBV). We rated 12,536 trees for southwestern dwarf mistletoe (Arceuthobium vaginatum subsp. cryptopodum) infection and broom volume. Using Hawksworth's DMR and Tinnin's BVR systems, we were not able to distinguish trees with different witches' broom volumes at all sample sizes. At all sample sizes, TBV ratings accurately and precisely identified amount of witches' broom volume. We recommend that TBV be used to quantify witches' broom volume in ponderosa pine where wildlife habitat and fire ecology are primary concerns.

Original languageEnglish (US)
Pages (from-to)54-59
Number of pages6
JournalWestern Journal of Applied Forestry
Issue number1
StatePublished - Jan 2004



  • Arceuthobium vaginatum
  • Broom volume rating
  • Dwarf mistletoe
  • Infection rating
  • Ponderosa pine
  • Witches' broom

ASJC Scopus subject areas

  • Forestry
  • Plant Science

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