Round Top Butte A Proposed National Natural Landmark from Southwestern Oregon

Round Top Butte is located near Medford, in Jackson County

Round Top Butte is located in the National Natural Landmark’s North Pacific Border Bio-physiographic Region Also located in part of an original “North Pacific Interior Valleys Physiographic Province”

Round Top Butte is an example of the “Upland, Un-Glaciated Grasslands Subtheme” Grasslands and oak savannas dominated the valleys and foothills south of the Puget Sound in this region. As you can see here, they have mostly been replaced by agriculture, cities, towns and forests, the latter especially on the valley margins.

Round Top Butte – Ownership and Management The proposed NNL is 747 acres. It includes a 140 acre Preserve owned by The Nature Conservancy, and a 607 acre Research Natural Area managed by the Bureau of Land Management

Round Top Butte is a mix of grasslands, oak and pine savanna, chaparral and woodlands

The Round Top Butte, shown here, is located at the north end of the site, on the Nature Conservancy Preserve The south side of the butte supports a dry grassland dominated by bluebunch wheatgrass ( Pseudoroegneria spicata ) and Lemmon’s needlegrass ( Achnatherum lemmonii )

A mosaic of chaparral, grasslands and Ponderosa pine woodlands is found at the south end of the proposed NNL

Native grasslands dominated by California oatgrass (Danthonia californica) characterize the grasslands and savannas at Round Top Butte. The white flowered forb is an endemic horkelia (Horkelia daucifolia).

The largest grasslands are a mix of native perennial and introduced annual grasses. Introduced grasses have replaced natives throughout the upland, unglaciated grasslands in this region, primarily as a result of inappropriate livestock grazing. Round Top Butte has the largest concentrations of native grasslands in the region.

With fire suppression, woodlands become forests; savannas become woodlands; and grasslands vanish Round Top Butte is unusual in that fire can still be used to maintain the natural diversity of the habitats.