Blowouts in the Nebraska Sandhills: The Habitat of Penstemon haydenii

摘要: The Nebraska Sandhills is the largest area of sand dunes in Western Hemisphere, occupying over 5 million ha northcentral Ne­ braska. rolling to steep range height from a few meters 60 m. Soils are poorly developed wind deposited sand. con­ tinental climate characterized by 425 625 mm annual precipitation, an average temperature 10 C, and frost-free period 130-155 days. Upland vegetation primarily tall grasses midgrasses such as bluestem (Andropogon gerardii var. paucipilus (Nash) Fern.), prairie sandreed (CaLamovilfa LongifoLia (Hook.) Scribn.), little (Schi­ zachyrium scoparium (Michx.) Nash), switchgrass (Panicum virgatum L.). Forbs common. Wind erosion occurs when protective cover destroyed. Blowouts active sites erosion. irregular or conical craters formed deep, loose sands removed swirling action ofthe prevailing northwesterly winds. Blowout penstemon (Penstemon haydenii S. Wats.) only found on these early successional species. Important asso­ ciated species blowouts include blowoutgrass (RedfieLdiaflexuosa (Thurb.) Vasey) lemon scurfpea (Psora Lea LanceoLata Pursh). number has decreased with control fire improved man­ agement techniques. Loss suitable habitat one reasons for decline blowout penstemon. At same time, there many that seem offer where not found.