Selaginella densa reflectance: relevance to rangeland remote sensing.

Abstract

Selaginella densa Ryd. is a shallow-rooted spikemoss that grows on sparsely vegetated short and mid-grass prairie. It covers a proportion of bare soil which may rival that covered by grasses. Not a forage plant, it is treated in agronomic research as background to the edible plants. Even when it appears to the eye as dry and without active chlorophyll, its spectral reflectance resembles more closely that of forage plants than that of soil background. It is distinguishable from dense stands of chlorophyll-rich fortes and grasses using the normalized differential vegetation index, but S. densa in all cases resembles sparse grasses. Its presence must be considered when estimating range condition using remote sensing techniques.