Environmental Engineering Reference
In-Depth Information
(a)
(b)
Figure 2.2.
(a) Viola calaminaria, Festuca ovina subsp. guestphalica and Thlaspi caerulescens
at the ancient mining site of Schmalgraf, Belgium. (b) Armeria maritima s.l., Viola
calaminaria and Thlaspi caerulescens at what was one of the richest metallophyte habitats
of northwestern Europe at Rabotrath, Belgium. Most of the metallophyte communities
have disappeared in the last 4 years since the land was taken into agricultural
production. Photos: A. Van der Ent.
See colour plate section
.
1. Metallophytes
a. Obligate metallophytes
b.
Facultative metallophytes
2. Associate species
a. Metal-tolerant species
b. Non-metal-tolerant species
(1a) Obligate metallophytes: species with an exceptional tolerance to heavy
metals in soils as well as a dependence upon the occurrence of these metals in
soil. Some are also hyper-metal-accumulators ('hyperaccumulators'). They are
not found outside this narrow ecological amplitude within the same
phytogeographical area. These species are local endemics with sometimes a
large geographical distribution. Examples are: Alyssum pintodasilvae (Dudley
1986
), Viola guestphalica and V. lutea subsp. calaminaria (Hildebrandt et al.
2006
;
Bizoux & Mahy
2007
).
