NEW YORK ( TheStreet) -- There's something to be said for looking outside the box in terms of considering including asset classes in your portfolio. In the past, I've espoused the potential benefits of exposure to water, as one example.Timber, a positive in portfolio construction, has historically had low correlations with more traditional asset classes, is another outside-the-box item. As an asset class timber has outperformed the S&P 500 over a bevy of time periods, and several challenging market environments, typically with a lower level of risk than equities. In 2008, for instance, while the S&P 500 fell 38%, the value of timberland rose 9.5%. There's also plenty of evidence to suggest that timber is a good hedge against inflation, a phenomenon that I'm afraid we'll be experiencing in the near future (and already are to a certain extent as consumers), given the fact that the government has been running the printing presses at full speed. There are a few ways that investors can get exposure to timber. Exchange traded funds such as the I Shares Global Timber & Forestry Index ( WOOD) or Guggenheim Timber ETF ( CUT) offer exposure to portfolios of both U.S. and international timber related names. Or, for more direct and concentrated exposure, there are publicly traded timber REITs. Like other companies that are organized as REITs, by law these companies must pay out at least 90% of taxable income to shareholders, so the yields are typically decent. These companies also own vast amounts of land, presenting opportunities to sell off those properties that potentially have a higher and better use than for timber. Plum Creek Timber ( PCL) is the largest private landholder in the U.S., and the first ever publicly held timber REIT. The company owns 6.6 million acres in 19 states, with the largest concentrations of property in Montana, Maine, Michigan, Arkansas, Mississippi, Georgia, and Florida. For perspective, consider that 6.6 million acres is more than 10,300 square miles, or an area 101.5 miles by 101.5 miles. That's larger than the area of 8 individual states, and roughly the size of Maryland. About 900,000 acres are of "higher and better use," which the company intends to divest over the next 15 years for conservation, residential or recreational uses.