Are you familar with David Swensen, he runs Yale's endowment fund which over the past 10 years has had annualized gains of 17%. I have been structing my portfolio to take advantage of proper allocations without focusing as much on specific investments. Timber as part of the "real asset" percentage in my opinion just rounds my commodity exposure. I believe there is a lot to be said for portfolio allocation. There are varing returns due to the structure of different indexes as well as returns of actually owning timberland which in my case is not feasible yet. I personally prefer the S&P Global Timber index over this one but I will take what I can get for now. There are plenty of articles to read about historical returns for timber but make sure you are comparing apples to apples.