Mature forest seed banks of three habitat types in central Idaho

Soils were sampled in two 5-cm layers under mature forests in Pseudotsuga menziesii/Physocarpus malvaceus, Abies grandis/Acer glabrum, and Abies grandis/Vaccinium globulare habitat types in central Idaho. Seed content of sampled soils was determined using a wet sieve seed extraction process followed by greenhouse germination tests. Viable seeds representing more than 80 different species were recorded, with viable seed densities averaging 1065 ± 727/m2 and ranging as high as 4116/m2. Most viable seeds (67%) were found in the top 0- to 5-cm soil layer. Ceanothus velutinus, Physocarpus malvaceus, and Carex spp. accounted for nearly 50% of all viable seeds encountered. Buried seed constancies are presented to compare buried seed occurrence by habitat type.