As 3.4 the question correctly states, none of the existing prescriptions can sustain high quality squirrel habitat in the 8-10 rating group. This animal appears to want open, medium density stands with 20 inch to large sized trees for nesting. Two different prescriptions might meet this need. a). Even-aged prescription 4 (Rx4) for accelerated tree growth to both open the stand and to encourage the quick development of large diameter size 6 (24 inch DBH trees). Under prescription 1 the plantation strategy creates a size 4 tree in five years which is very marginal for the squirrel. If different genetic stock was used for planting, site improvement like drainage, fertilizer was used, and planting and thinning to lower stand density could create a size 5 tree by five years, then this prescription might work. the rotation will have to remain at 5 years so that at least one acre will be in the oldest size class each year. This will sustain the required one acre of high quality squirrel habitat every year by year 5. b). Uneven-aged prescription 5 (Rx5) with low residual growing stock and large diameter crop trees. This can be created with a series of entries into either stand 1 or stand 2. In the case of stand 1 it's a matter of reducing density with some early heavy cuts and then maintaining an open stand with infrequent entries cutting through the size classes. We estimate that the resulting residual stand will vary between vegetation types M6M and M5M, both of which are good habitat. For stand 1 we start with an all aged stand currently of size M4M. Here we will take light initial entries and encourage the larger trees to grow as fast as possible. Eventually this stand will achieve the same target structure as Stand 1. And 2 acres of high quality squirrel habitat can be sustained. Prescription 5 is used to illustrate the answer to question 3.4. The two yield tables for these prescriptions are shown below. PHIt, WHRt, and SNHt conditions are at the start of the year, after growth and before harvest. Years of Growth from Current time
___________ 0 1 2 3 4 5 6 7 8 9 10
Stand 1, Rx5 PHIt
____ 15 11 12 8 10 6 8 5 6 4 6
Stand 2 Rx5 WHRt
_____ M6D M6M M6D M6M M6M M5M M6M M5M M6M M5M M6M
HIt
____ 5 0 5 0 5 0 4 0 3 0 3
SNHt
______ 8 9 8 10 10 8 10 8 10 8 10
PHIt
_____ 8 10 11 10 9 10 6 8 5 6 4
HIt
____ 0 0 3 2 0 5 0 4 0 3 0
WHRt
_____ M4D M4M M5M M5M M5M M6M M6M M6M M5M M6M M5M
SNHt
______ 6 6 8 7 8 10 10 10 8 10 8
One possible answer to question 3.4 using new uneven-aged prescription RX5.
Year Rx: year
1 2 3 4 5 6 7 8 9 10
Stand 1
Rx 5
Stand 2 Rx5
M4M/8/1 6 M4D/10/1 6 M5M/11/ 1 8 * M5M/10/ 1 7 * M5M/9/1 8 M6M/10/ 1 10 * M6M/6/1 10 M6M/8/1 10 * M5M/5/1 8 M6M/6/1 10 *
Stand 3
Rx1/6
Stand 4
Rx1/6
Stand 5
Rx1/6
Activities and outcomes Stand Harv cut/acres Per cut acre
1/1 3/1 1/1, 2/1 2/1, 4/1 1/1 2/1, 5/1 1/1 2/1, 3/1 1/1 2/1, 4/1 5 3 5, 3 2, 6 5 5, 12 4 4, 12 3 3, 12
Harv. Vol.
5 3 8 8 5 17 4 16 3 15
PHI
Acres Good SNH
1 1 2 1 2 2 2 2 2 2
M6D/15/1 8 * M6M/11/ 1 9 M6D/12/1 8 * M6M/8/1 10 M6M/10/ 1 10 * M5M/6/1 8 M6M/8/1 10 * M5M/5/1 8 M6M/6/1 10 M5M/4/1 8
P2M/1/1 0 P3D/3/1 0 * P1P/0/1 0 P2M/1/1 0 P3D/3/1 0 P4D/6/1 0 P4D/10/1 0 P4D/12/1 2 * P1P/0/1 0 P2M/1/1 0
P1P/0/1 0 P2M/1/1 0 P3D/3/1 0 P4D/6/1 0 * P1P/0/1 0 P2M/1/1 0 P3D/3/1 0 P4D/6/1 0 P4D/10/1 2 P4D/12/1 0 *
P1P/0/1 0 P2M/1/1 0 P3D/3/1 0 P4D/6/1 0 P4D/10/1 0 P4D/12/1 2 * P1P/0/1 0 P2M/1/1 0 P3D/3/1 0 P4D/6/1
24 26 29 31 32 35 27 32 24 29
This solution shows a variable year to year harvest that averages about 9 units per year and 2 acres of sustainable squirrel nesting habitat. This is more than the average harvest of 6 units under policy 2. Given up was two acres of habit that developed only under the processes of nature. The option of only assigning stand 1 to prescription 5 would sustain one acre of squirrel habitat and increase the harvest about another 1 unit per year You can and should look at the yield tables for RX5 and debate whether they make silvicultural and biological sense. Since this is an imaginary forest we can't do an empirical check. You could also consider the even-age prescription RX4 to solve the problem of sustaining at least 1 acre of squirrel habitat. To do this you would need to make up some yield tables similar to those above and work through your solution. To further hone your thinking , try explaining how this problem might apply to the forests in your local area and for some real animal whose habitat is considered threatened. Essentially this will require you to use vegetation/habitat types in your area and develop some plausible yield tables to illustrate how some different policies and prescriptions will affect the long term outcomes of the forest.