In the United States, protected lands are diverse and varied in size, ownership, designation and management. To better understand the contributions of various land protection mechanisms to protecting natural vegetation types, we assessed the contribution of fee-simple lands and easements across the conterminous United States, emphasizing the contribution of conservation easements to the overall protection of habitat within the protected lands network. The most recent version of Existing Vegetation Type (EVT 210) released by LANDFIRE, the Protected Areas Database (PAD-US (CBI Edition) Version 2), and the National Conservation Easement Database (NCED) were used to characterize the current state of natural vegetation in the protected lands network. Protected lands are often narrowly defined as lands with permanent protection that are managed to maintain a natural or nearly natural state. For this spatial analysis, however, we evaluated these lands as one of three protected land categories, along with land that is permanently protected and allows multiple uses including some extractive uses (second category) and conservation easements (third category). The additional categories were included to more completely describe the protection status of natural vegetation in the United States.
The data indicate that protection levels vary widely and are specific to the context of the region of the country as well as the spatial extent of the vegetation type. We identify and examine the spatial extend of the top ten most protected natural vegetation types, including Subalpine Woodland and Parkland, Loblolly Pine Forest and Woodland, Mountain Hemlock Forest and Woodland, Loblolly Pine-Slash Pine Forest and Woodland, Dry Tundra, Mangrove, Spruce-Fir Forest and Woodland, Red Fir Forest and Woodland, Lodgepole Pine, Forest and Woodland, and Western Hemlock-Silver Fir Forest. Grasslands are an under-protected natural vegetation type by all three land protection mechanisms. Future research on highly vulnerable vegetation types, like grasslands, can build from this analysis to evaluate potential climate impacts to inform management and acquisition strategies in the protected areas network. Future analysis will use climate scenario models to identify additional vegetation types under the greatest threat. We will examine how these shifts in vegetation may change the character of the protected lands network to inform acquisition strategies and future management of existing or newly acquired protected lands and waters.
