Serpentinite and heavy-mineral soils

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MikeHardman

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Serpentinite and heavy-mineral soils
« on: December 31, 2011, 02:30:59 PM »
Serpentinite is a rock type, and may contain various minerals, including serpentine. The word 'serpentine' is often used in a broad sense to mean or include serpentinite.

Soils developed from- or overlaying serpentinite can make life difficult for many plants.

Soils with significant amounts of heavy metals (eg. chromium, mercury, cadmium, arsenic, thallium, lead) can also be challenging. In low concentrations, some of these metals are important for plant growth (eg. copper, selenium, zinc). The problem arises with high concentrations, partly because the metals can bioaccumulate. Heavy metal soils can arise by industrial contamination or through natural processes.

Such problem soils occur here and there worldwide, including areas with a mediterranean climate. Well known serpentinous areas exist in California and Cyprus. I know of heavy-metal soils in Belgium-Netherlands-western Germany because yellow zinc violet (Viola calaminaria) and blue zinc violet (Viola guestphalica) grow there (they are metallophytes).

If you have serpentinous or heavy metal soils in your garden, there are two main options:
1. hard landscaping only
2. grow tolerant plants
Other options are:
3. remediation (difficult)
4. replacement (expensive and not necessariyl successful)
5. neglect

To concentrate on (2)...

The MGS web site has a very useful list of serpentine tolerant plants -
http://gimcw.org/plants/cult_serpentine.cfm.
Note that the list is California-biassed (I was very pleased to see Salvia sonomensis included).
There is a bibliography at the end of that page, but there are many more books and papers on the subject.

These soils provide a blessing in disguise. Because so many plants have trouble growing on them, the remainder may do better through reduced competition.

That's just to introduce this topic...
« Last Edit: December 31, 2011, 02:37:56 PM by MikeHardman »
Mike
Geologist by Uni training, IT consultant, Referee for Viola for Botanical Society of the British Isles, commissioned author and photographer on Viola for RHS (Enc. of Perennials, The Garden, The Plantsman).
I garden near Polis, Cyprus, 100m alt., on marl, but have gardened mainly in S.England