Seed survival of Heracleum mantegazzianum
Heracleum mantegazzianum (Apiaceae: EPPO List of Invasive Alien Plants) is invasive in managed and unmanaged ecosystems, being a threat to biodiversity, eroding riverbanks, decreasing recreational resources, causing economic losses and posing a health risk to humans as the sap can cause skin blistering on contact. Due to the impact of the species on native biodiversity and ecosystem services, it is regulated at the EU level (EU 1143/2014) and included in the list of invasive alien species of Union concern. To evaluate seed persistence in the soil, seeds of the species were buried at depths of 5-10 cm at ten locations in different regions in the Czech Republic to cover a range of climatic, geographic and soil conditions. At each site, soil chemical properties were recorded. After 1 year of burial, some of the seeds were exhumed and tested for viability. This was repeated 2, 3, 5, and 7 years after burial. The mean percentage of viable seeds was 8.8 after year 1, 2.1 after year 2, 1.2 after year 3, 0.4 after year 5 and 0.1 after year 7. There was a significant correlation between the percentage of non-viable seeds and the content of total and organic carbon in the soil. The authors suggest that following presumed eradication of the species, the managed area should be monitored well beyond the reported period of seed bank persistence (i.e. 7 years).
Sources
Moravcová L, Pyšek P, Krinke L, Müllerová J, Perglová I, Pergl J (2018) Long-term survival in soil of seed of the invasive herbaceous plant Heracleum mantegazzianum, Preslia 90, 225-234.