JOHNSON-GROH, CINDY, L., LAURA SCHOESSLER*, CHANDA RIEDEL, AND KRISSA SKOGEN. Department of Botany, Gustavus Adolphus College, 800 W. College Ave., St. Peter, MN 56082. - Underground distribution and abundance of Botrychium gametophytes and juvenile sporophytes.
A significant portion of the life history of Botrychium, the
gametophyte and juvenile sporophytes stages, are spent underground.
Experiments were conducted to determine the distribution and abundance
of underground structures of eight species of Botrychium. Soil
samples were collected in a 200 m2 area, sieved through a
series of soil sieves and then processed using a centrifugation
technique separating out the lighter plant material. The underground
distribution of Botrychium is clumped and not regularly
distributed. Only 30% of the samples processed contained underground
structures. The gametophytes of B. campestre are most abundant
followed by B. mormo with 2021 and 700
gametophytes/m2 respectively. B. montanum and B.
fennestratum also have relatively high abundances of 580 and 480
gametophytes/m2. B. virginianum and B.
gallicomontanum were the least abundant at 70 and 10
gametophytes/m2. B. campestre and B.
gallicomontanum both produce vegetative propagule (gemmae) but
there was no apparent correlation with this character and abundance of
gametophytes underground. The "underground structure bank"
is the source of juvenile plants that will eventually emerge and
sustain the populations. The underground bank greatly exceeds in
number the visible aboveground portion of the population. Its size
and health is critical to sustain the aboveground reproductive portion
of the population.
Key words: Botrychium, ecology, moonwort, subterranean gametophytes, underground structures