Few pteridophytes have proven the capacity to accumulate and remediate heavy metals from contaminated soils. Pityrogramma calomelanos, a non-seasonal fast-growing, a cosmopolitan fern, is a good in...

In vitro spore germination and phytoremediation of Hg and Pb using gametophytes of Pityrogramma calomelanos

The revegetation of steep slopes after mining and infrastructure projects is not an easy task. To enhance the effectiveness of revegetation projects, the present study aimed to review (i) specific challenges of steep slope revegetation, (ii) ecological succession patterns in similar environments, (iii) soil conditioning and revegetation strategies to enhance vegetation cover, (iv) the importance of microorganisms to enhance steep slope revegetation, and (v) the functional plant traits necessary to establish on steep slopes. In general, steep slopes are characterized by high bulk densities, potentially toxic elements, and low water and nutrient availability. Additionally, high temperature and elevated radiation constrain the soil conditioning and vegetation cover establishment. Lessons from ecological succession in natural steep slope habitats show that steep slope revegetation is a long-term process. Planting strategies, including hydroseeding and geotextiles, may enhance the implementation of vegetation cover. Different plant functional groups show adaptations necessary for establishment in steep slope environments, and mixtures of species containing different functional groups can promote diverse and resilient plant communities. Promising species may be retrieved from local rupestrian ecosystems, as these floras are adapted to shallow, oligotrophic soils. Further research on combining methods of soil conditioning with individual planting and/or seeding strategies of carefully selected species is necessary to enhance steep slope revegetation and rehabilitation, contributing to slope stability, erosion reduction, and carbon fixation in the long term.

/pdf/revegetation-on-tropical-steep-slopes-after-mining-and-198u90eb.pdf

Revegetation on Tropical Steep Slopes after Mining and Infrastructure Projects: Challenges and Solutions

Silver ferns, Pityrogramma calomelanos, were observed to be growing on soil highly polluted with copper (Cu), which indicated a possible Cu phytoremediation potential. In this study, the Cu accumulation pattern of P. calomelanos was determined by exposing the ferns to different Cu levels (0 to 2500 mg L) in the soil for about 3 weeks. The Cu content of the fronds analysed at 5-days interval showed that P. calomelanos exposed to Cu levels of up to 1000 mg L were able to maintain normal levels of Cu within their fronds throughout the experiment. At high level of 2500 mg L Cu soil content, P. calomelanos exhibited an initial toxicity phase with significantly higher Cu content in their green fronds, but recovery was observed within 10 days and Cu content recovered back to normal level. The bioconcentration factor (BCF) was in the range of 0.005–0.11, where the maximum copper concentration up to 2500 mg kg. The frond’s nitrogen content had showed no significant differences between control and treated plants at the end of the experiment. Hence, the P. calomelanos has been identified as a good Cu excluder species which can potentially be used for phytostabilisation of Cu-polluted soils.

/pdf/pityrogramma-calomelanos-l-link-silver-fern-as-a-copper-3iwn0djvbr.pdf

Chin Hao Mah

Papers

Pityrogramma calomelanos (L.) Link: Silver fern as a copper excluder plant