Figure 4 demonstrates the forecaste

Figure 4 demonstrates the forecasted diameters of the teak in Gunung Kidul Regency, Yogyakarta being compared with the published diameters in Costa Rica, whereas Figure 5 demonstrates the forecasted heights of teak trees in Gunung Kidul Regency, Yogyakarta being compared with the published diameters in Costa Rica and Indonesia.
Economic Valuation
Modelling
In recent years several private enterprises offering investment in teak plantation with different scenarios in term of investment value, schedule of harvesting and profit sharing. It is not the intension of this paper to discuss each of the private enterprises economic valuation; rather to focus comparing the economic benefits of having different harvesting schedules.
The harvesting schedules being compared were:
1. Model 1: Company “X” offering an early harvesting of all teak plantation at the age of five years (Soeroso and Poedjowadi, 2009).
2. Model 2: Company “Y” offering harvesting schedule at the age of seven years (50%), 10 years (25%) and 13 years (25%) (JAR, 2012).
3. Model 3: Hallet et al. (2011) suggested harvesting schedule at the age of three years (36%), six years (14%), 10 years (14%), 15 years (9%) and 23 years (27%).
4. Model 4: this model was designed to start harvesting at the age of 14 years to the amount of 10% each year and continues the harvesting of 10% each year until the last 10% of trees are at the age of 23 years. There were two main reasons of this model: firstly, for environmental purpose by ensuring 90% of the land are still covered by trees, and secondly, the last harvesting period is the same with and to be compatible with Model 3 at the age of 23 years.

In all models, except Model 1, the trees being harvested were started with the smallest diameter as part of the thinning activities in which the better quality of trees were given more chance to grow better.