Revegetation of abandoned copper mines: the role of seed banks and soil amendments
Mining is one of the main causes of environmental pollution by heavy metals and (re)vegetation of mine spoils is the most effective method of preventing wind and water erosion and the consequent spread of contaminants to surrounding areas. However, plant establishment and growth are conditioned by s...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-09-01
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| Series: | Web Ecology |
| Online Access: | http://www.web-ecol.net/13/69/2013/we-13-69-2013.pdf |
| Summary: | Mining is one of the main causes of environmental pollution by heavy metals
and (re)vegetation of mine spoils is the most effective method of preventing
wind and water erosion and the consequent spread of contaminants to
surrounding areas. However, plant establishment and growth are conditioned
by some limiting factors of mine soils, such as low pH, low fertility, high
heavy metal concentration, and a small seed bank to initiate plant
establishment. Improving soil physical and chemical properties is required
in many cases for successful (re)vegetation programs.
<br><br>
In the copper mine of Touro, Galicia, Spain there is a
large-scale project of soil amendment underway using technosols, a mixture
of several organic residuals, to improve the conditions of mine soils. We
evaluated the seed bank of several types of technosols, mine soil and soil
from a control area outside the mine by studying seedling emergence in these
soils. In a second experiment we evaluated the impact of increasing pH with
liming and the admixing of nutrient-rich soil on the growth of two grasses
(<i>Lolium perenne</i> and <i>Dactylis glomerata</i>) and two legumes
(<i>Medicago sativa</i> and <i>Trifolium subterrraneum</i>) both sown
individually and in mixtures.
<br><br>
Seedling emergence and species richness were highest in the
technosols. Soil amendments promoted plant growth, with the addition of
high-nutrient soil being the best amendment for the four plant species
tested. Plant growth was impaired in the mine soil. <i>Lolium perenne</i>
was the only plant species that germinated and grew in this soil. We found
that soil amendments, either through the addition of technosols, pH buffering
or nutrient enrichment, are essential for promoting the revegetation of mine
areas. |
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| ISSN: | 2193-3081 1399-1183 |