Mistletoe Lecture Flashcards
DMT is an obligate parasite. describe what this means.
It requires living tissue to survive. Gets all nutrition and water from Host.
What is an added threat to trees infected with DMT
The entry points of the DMT holdfasts allows for Decay Fungus Cankers to bypass tree defenses and utilize the nutrient rich wood.
If a tree has DMT on it and you are cruising, what would that imply.
Implies that the tree is suspect decay
Does a the presence of “brooms” assure the presence of DMT?
No, other pathogens can result in brooming as well.
Which host species exhibit localized brooming/swelling ?
Hw and Lw
Which host species exhibit systemic brooming?
Pl, Fd
How long do aerial shoots survive and what typically can destroy them?
3 - 5 years and are destroyed more often in areas that are subject to snow and ice. (Higher elevations, Northern latitudes)
What is the average horizontal rate of spread of DMT in an even aged stand?
0.5m - 1.0m/year
What is the avg. vertical rate of spread?
0.4m/year
Would mistletoe spread faster in a dense stand like Hw or a less dense stand like Pl?
Less density = Further seed travel, so the less dense stand has a faster rate of spread.
what does LAI stand for?
Leaf area index = density of foliage
In which part of the lifecycle of a stand is DMT spread the fastest?
Juvenile stands have a higher rate of spread due to decreased density.
What slows the rate of spread as trees mature?
- Crown closure due to
- Targets growing and getting closer as well as increasing in density.
- Shade decreases production
Obligate parasites do better on higher branches. Why?
Obligate parasites do better on highly productive branches that recieve more light.
What silvicultural technique could increase the spread of DMT?
Juvenile spacing can deliver light to infected branches that are lower in the canopy, giving the DMT a higher chance of reproducing and spreading.
Why are brooms only evident in older host specimens?
Self pruning of branches during growth eliminates branches before brooming can occur.
What things does the development of DMT depend on?
- Continuous presence of host
- Species composition
- Fires (intense fires reset stands and eliminate DMT)
What percentages of volume could you expect to be lost in Hw or Pl stands?
what about Fd and Lw stands.
Slower growing species like Hw and Pl can expect to see 20-40% loss at harvest
Faster growing stands like Fd and Lw can expect to see 30-60% loss at harvest
How does DMT effect quality of lumber?
- Larger Knots
- Deformed Bole
- Reaction wood (weak crappy wood)
What does “predisposition” refer to?
Refers to the reaction of a tree to stress. Stress pre-disposes a tree to additional infection.
What aspects of DMT work to our advantage?
- Long life cycle
- Slow spreading
- Host specific
