VARDAMAN VIRTUAL FORESTRY COMPANY

The Most Direct Link to Knowledge Workers in the Southeast Forest Economy

THE LATEST TECHNOLOGY OF GROWING TREES AND THE VARDAMAN 1993 HYPOTHESIS

We have millions of loblolly-pine forests in our computer, all managed to earn desired financial returns by utilizing selected combinations of the most modern techniques. Making all this possible is PTAEDA2V+ECONV, our unique growth-and-yield model and financial-analysis program. With it we can simulate any desired forest-management plan and test it for possible flaws before installing it at great expense on the ground. Keeping PTAEDA2V+ECONV abreast of the large amount of research in progress is essential, and here is a description of how we do so.

Only July 15 and 16, 26 JMV&CO five-star clients, 21 JMV&CO managers, and nine distinguished forest scientists met in Atlanta in an unusual seminar to learn the latest developments in the technology of growing trees and to consider how they work together. Presentations by the scientists were outstanding; discussion by all parties was thorough and frank. We have never before participated in such an intensive learning session.

Finale of the seminar was a panel discussion to determine how to use all the new knowledge to predict future yields with PTAEDA2V. Each scientist brought to bear his specialized knowledge on the effect of each technique. Then Jim Vardaman chose a specific input that seemed to represent the consensus, and these selections formed in Vardaman 1993 Hypothesis.

We hypothesize the following:

1. Use of broadcast herbicides in site preparation to control herbaceous vegetation will create an Establishment Quality Boost (EQB) of two years. (An EQB of two years means that we can grow a stand in eight years that normally requires ten years to produce.) If no herbicide is used in this manner, seedling mortality in year one will average as least 10% more than normal.

2. Use of broadcast herbicides in site preparation to control woody vegetation will reduce hardwood competition in the canopy to 2.4%. If no herbicide is used in this manner, the input for hardwood competition must be determined by measuring a sample of conditions on each tract, such competition commonly runs 15% to 30%.

3. Use of first-generation, genetically-improved seedlings will increase site index by 8%; second-generation seedlings will increase it by 11%. Although certain families probably will do better than others on certain sites, we cannot quantify the effect until we see more data.

4. Use of genetically-improved seedlings will reduce pulpwood-quality trees to 16% of the total.

5. Use of seedlings grown at 15 per square foot in the nursery bed to minimum groundline diameters of 5mm will create an EQB of one year.

6. If tests reveal that the site is deficient in phosphorus, the property amount to be added and the expected increase in site index from it shall be determined from the chart presented by Dr. H. Lee Allen. No Other fertilization is needed in site preparation.

7. Cultivation is not needed on the majority of sites. On very wet sites, however, bedding is essential and will create one or two years of EQB, depending upon the degree of wetness. On very dry sites, ripping will create one year of EQB, a 2% increase in site index, and a 10% increase in initial survival. On sites with a plowpan, ripping will produce an EQB of one year, probably an increase of one foot in site index, but no increase in survival. Prescriptions and therefore inputs for such special situations will depend upon the individual site.

As we said earlier, Jim Vardaman selected these inputs. If they prove to be correct, the scientists get the credit; if they prove to be incorrect, JMV&CO alone gets the blame. If you want to compare them to those of the 1990 Hypothesis, please refer to our Green Sheet of 15 October 1991.

Comparison of Results with 1990 Hypothesis

In this presentation, Vardaman analyzed a hypothetical plantation utilizing the old technology common to plantations in the original data base and calculated Bare Land Value(BLV) to be $36.38. He analyzed another hypothetical plantation on the same tract utilizing the technology covered in the Vardaman 1990 Hypothesis and calculated BLV to be $311.19. An analysis of a hypothetical plantation on the same tract using the latest technology covered in the Vardaman 1993 Hypothesis gives a BLV of $283.12 for first-generation seedlings and $304.23 for second-generation seedlings.

Surprised? Does this mean that science is going backward, that nothing new has been learned, that we wasted the effort of conducting the seminar? Not at all. The big minus is recognition that site preparation with herbicides might reduce hardwood competition in the canopy only to 2.4% instead of to 0%. If we had used 0% hardwood instead of 2.4%, the 1993 BLVs would have been $308.96 and $332.45. (Incidentally, this calculation demonstrates how PTAEDA2V+ECONV is used. By quantifying the economic impact of allowing a small amount of hardwood competition in the main canopy, it enables the manager to decide what to do about this hardwood. If site preparation can be changed to remove the hardwood for a cost of, say, $10.00, he should change it; if on the other hand the cost is $50.00, he should accept the hardwood.) Even with the slight reduction from the 1990 figures, values created by employing new technology far surpass those created by old technology.

The absence of significant change is also due to the fact that the tract is average. If there had been anything wrong with it, for example, if it had been very wet, very dry, or deficient in phosphorus and therefore of very low productivity, we could have employed the new techniques of fertilization or cultivation to improve its yield dramatically.

But whether the 1993 figures are higher or lower doesn't matter to us. We aren't trying to create a trend that shows steady improvement year after year. Our sole desire is to assure that PTAEDA2V can simulate the effects of the latest developments and also makes accurate predictions. We maintain close and constant contact with these scientists and will change the hypothesis whenever we receive data that warrant doing so.