Uneven aged management Flashcards
What are the traditional systems used to promote uneven aged stand structure?
Single tree
Group tree
Coppice with standards
Are uneven aged stands necessarily “old”?
No, many uneven aged stands have remnants of intolerant or early serial species
What are some characteristics of all uneven aged stands?
- composed of tolerant species
- Tend to have greater biodiversity and offer greater site protection
- regenerate in clumps which produces uneven age patterns
- high sph in low dbh classes and progressively lower spy as dbh increases in size.
What are some requirements that would make uneven aged management a good approach?
- Site protection
- specific and unique habitat types
- minimal visual disturbance
- Generating regular revenue from the forest estate
What requirements make uneven aged management an unacceptable method?
- high yield intolerant species production
- establishing alternate spa.
- forest health issues (budworm, mistletoe etc)
- Difficult to administer and control (accurate inventory is very important and choosing leave trees time consuming)
- more costly than even aged management
- steep terrain harvesting without damaging leave trees.
What 3 tasks are required to maintain an uneven aged distribution?
- perform an inventory of stand
- produce natural inverse J (diminutive quotient between 1 and 2)
- establish target maximum stem diameter and an appropriate # of SPH.
How to get Q?
- must know SPH for each dbh class
- calculate Q for each drop in SPH as DBH increases
- Average Q’s for stand Q.
What is a general characteristic of managed vs unmanaged stands?
Managed put on more volume and better quality.
What is a standard rule with Q?
The larger the Q value, the steeper the inverse j curve.
If Q = 1, what type of stand do you have ?
even aged
What factors influence Q and stand structure?
- Site productivity
- seed periodicity
- species tolerance
- species growth capacity
- Mortality
Why is Q important?
So a forester can know the optimum SPH to manage for the desired DBH class in an uneven aged system.
Is competition present in uneven age?
yes, between trees in the same dbh range.
How do you find out how long it will take a tree to grow 10 cm?
core the tree, (take an avg cm distance over 10 years for best accuracy and remember to account for radial growth). Multiply by 10.
What is clearcut equivalency?
Depending on the layer of residual trees, they can equate to a higher number of SPH than if site were CC. ex. Layer 1: 600 trees = 1200sph Layer 2: 800 = 1200 Layer 3: 1000 = 1200
