Seasonal Changes in Biomass of Wild Populations of Horsetail, Poster Board #080

Horsetail (Equisetum arvense L.) is a perennial herb with segmented stem. The plant produces spring and summer stems. Summer stalks are 0.10 to 0.40 m high, green, ribbed, branched and barren. The plant is collected for production of dried medicinal known as a Herba equiseti or for production of commercially available capsules with powdered herb. Each plant species has its specific areas of distribution or habitats. Monitoring of selected species and populations was conducted during the period of 2009–11 on three different natural locations (L1, L2, L3) in Laborecká vrchovina in Eastern Slovakia. The highest quantity of biomass was collected in 2009 and the lowest in 2011. The largest amount of the total biomass (131 ± 25 g·m^-2) was obtained from the third collection from a total of six collections for the locality L2 in 2009. The lowest amount of biomass (33 ± 1 g·m^-2) was obtained in the same locality in 2011. In 2009, the largest amount of collected biomass was obtained from the first three harvests. However, in 2010 and 2011 the largest amount of harvested biomass was obtained from the fifth and sixth collections. The locality L3 has the lowest amount of biomass, which ranged from 5 ± 1 g·m^-2 to 42 ± 5 g·m^-2 during the three experimental years. The main factors for statistical variability in the underground and aboveground biomass of horsetail (Equisetum arvense L.) were locality, year and collection. Location had the highest impact on underground and aboveground biomass.