Botanic gardens in the age of climate change - PlantNetwork

Theme 3 Session 2: From seed to thriving plant
SOIL SAMPLES AS “CONTAINERS” FOR EX SITU SEED
CONSERVATION
Bernhardt Karl-Georg, Wernisch M. & Kropf M.
karl-georg.bernhardt@boku.ac.at, Department of Integrative Biology and Biodiversity Research,
Institut of Botany, Austria
Different methods have been used for collecting and handling soil samples, assessing soil seed
banks, and for subsequent ex situ seed storage. However, given basic problems in finding adult
plants for the collection of mature seeds, collection of very small seeds, and the amount of effort
involved, we tested the use of soil cores as “seed samples” for ex situ conservation storage. We
investigated rare and endangered species of the phytosociological class Isoeto-Nanojuncetea,
which are restricted to temporary pools and other ephemeral wetlands.
We generated two types of soil samples for ex situ conservation storage:
1. Original soil samples directly taken in the field
2. Collections of individual plants, which were transferred into wet sand to allow fruiting
Soil samples were air dried, and for those collected in the wet sand, further dried for two
weeks in an exsiccator. Subsequently, both types of soil samples were stored by -20 °C for five
months. Later they were spread out and seedling emergence monitored.
Storing of original soil cores raised problems with clay soils prohibiting germination.
However, for Limosella aquatica, the second method was very promising, as two primary plants
gave rise to more than 120 individuals. Therefore, this strategy might allow taking only a few
plants and finally obtaining a lot of viable seeds for ex situ storage. Given difficulties with the
first method, when natural soil is not a sandy substrate, we will continue testing a mixture of the
original soil samples and sand to avoid clumping of soil particles.
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