How is land, purchased with the intent of selling it after a period, zakat-eligible?

Land purchased with the intention of sale falls into one of two categories: If the intention behind it is to preserve wealth, then no zakat (definition) is due on it. However, if the intention is trade and profit, then zakat is obligatory on it, and its value should be assessed at its current market price upon the completion of the hawl (one lunar year). The amount of zakat is one-quarter of a tenth (2.5%). The hawl for the land is the same as the hawl for the money with which it was purchased.