Cryptantha affinis physiology appears to be influenced by nutrients of Deer excretions. Increased
photosynthesis and higher plant nitrogen levels have been observed in habitats frequented by
mule deer,
antelope, and
Eelk. Higher nutrients appear to increase growth and reproduction in wet years. In dry years survival is increased by the shading of
Cryptantha by the presence of large shrubs. Although shading increases survival in dry years, in wet years growth and reproduction seem to be reduced even when nutrient levels in the soil are high.
Cryptantha species are dominant annuals in a wide range of habitats. In habitats where
Cryptantha is a dominant species, fire intensity reduces its density. ==References==