Northern softwood species impart superior stiffness compared to southern softwoods. Softwoods are not necessarily softer than hardwoods. Hardwoods are typically much more durable than softwoods. Conversely, some softwoods (e.g. yew) are harder than many hardwoods. Powderpost beetles feed on deciduous trees, including certain hardwoods or softwoods depending on the species. The majority of Australia's trees are hardwoods, typically eucalypts, rather than softwoods like pine. Wood is separated into two categories, hardwoods and softwoods. Turners of hardwoods and ivory select different tools than those used for cutting softwoods. However, because hardwoods are more closely grained, they are typically harder to work than softwoods. Typically the slope is 1&colon;6 for softwoods, and a shallower 1&colon;8 slope for hardwoods. Roughly half the county remains forested with both softwoods and hardwoods. Many softwoods will season (dry) much more quickly than many hardwoods. The density of softwoods ranges from to , while hardwoods are to . Hardwood such as jarrah and karri were better than softwoods such as fir. Not all hardwoods have a higher potential energy content than all softwoods.