DLSU-DOST Bioindicator Poster Research Congress
METAL BIOINDICATOR PLANT SPECIES OF THE PHILIPPINES
PCIEERD-DOST and DLSU Project under the Program:
“Rehabilitation and Restoration of
Mining Areas through Phytotechnologies”
with Ateneo de Manila University
and University of the Philippines, Los Banos
Priority Areas/STAND Classification: High Impact Technology Solutions (HITS) Program Conducted in study sites in: 1) Kalinga; 2) Marinduque; 3) Rapu-Rapu Island, Albay; 4) Cebu; 5) Negros; and 6) Compostela Valley
Project Leader: George Banez
Proponents: Esperanza Maribel Agoo, Marissa Noel, Gil Nonato Santos
Heavy metal contamination of soils resulting from human activities, like mining, continues to be a major environmental concern throughout the world. In order to mitigate the harmful effects of heavy metal contamination of soils early detection and rapid assessment of the extent of contamination is crucial. Likewise, it is important that the technology to detect contamination be cheap, easy to understand or accessible to environmental managers and to ordinary citizens alike.
· The presence in mine tailings or in abandoned mines of metallophyte plant species or those known to naturally occur only in soils of high metal content like ultramafic soils can be used as a bio-indicator of heavy metal contamination.
· Moreover, the presence of metallophyte plant species that are metal hyperaccumulators (or those species that have the ability to scavenge and store metals in their tissue at concentrations many thousand-folds than non-metallophytes) can help confirm the presence of high concentrations of metals contaminating the soil.
· Plant species that normally thrive in non-metalliferous soil conditions but “tolerate” or survive in soils with high metal concentrations through morphological adaptations that are easy to detect can also indicate contamination. Changes in the gross morphology, morphometric characteristics and the physiology of these species as they adapt to high concentrations of heavy metals in their growing environment under controlled conditions in a pot experiment will provide easy-to-recognize indication of heavy metal contamination.
· The same bio-indicator plant species may also be used as potential phytostabilization agents, phytoremediators, even candidates for phytomining in the recovery of metals taken up in the biomass. Thus, the technology to propagate these species is important to the rehabilitation and restoration of mining areas.
Given the importance of reducing the impact of anthropogenic heavy metal soil contamination, the potential use of plant species naturally occurring in metal-rich soils as bioindicators and phytoremediation agents, this project aims to:
1.1 Create check list published in an online database (accessible to stakeholders) of metallophyte hyperaccumulator plant species naturally occurring in Metal-rich (or ultramafic soils).
1.2 Create a checklist of obligate and facultative metallophyte species that naturally occur in metal-rich and adjacent non metal-rich soils in the six study sites.
1.3 Determine the plasticity in the morphological and physiological responses and adaptations of selected facultative species exposed to varying concentrations of heavy metals through a pot experiment.
1.4. Establish a protocol and a training kit to build the capacity of environmental managers and stakeholders to detect heavy metal contamination in soils using bioindicator species. Also establish a network of DOST partner institutions, State Universities and Colleges (SUCs) and La Salle Philippines affiliated schools; also, provide training to network members in the identification, monitoring, propagation and conservation of hyperaccumulator species in the six sites.
1.5. Recommend a set of cultural management practices for the propagation of selected hyperaccumulator species identified as potential bio-indicator species and potential phytoremediation agents from each of the six sites in order to promote the use of in restoration.
The six study sites natiowide, Kalinga, Rapu-Rapu, Marinduque, Cebu, Negros, and Compostela Valley represent phytogeographic regions in the Philippines.
Table showing six study and sampling sites:
Component 1. Conducting a taxonomic survey of plants in the six study sites, through quadrat and transect methods covering different vegetation types within the natural metal-rich and non metal-rich sites;
· Performing Atomic Absorption Spectroscopy (AAS) analysis of the metal concentration in the above and below ground biomass of field collected plants from metal-rich and non metal-rich sampling sites using and comparing those with the metal concentrations in the soil in order to characterize plants’ ability to exclude, extract or hyperaccumulate metals.
· Characterizing the ultrastructural metal composition of the plants collected from metal rich and non metal-rich sampling sites using SEM-EDX
Table showing metal concentration of shoots and roots (in ppm) of plants collected from Cebu with (highlighted) species determined to have concentrations beyond threshold levels considered to be hyperaccumulators (threshold levels written under each metal).
Component 2. Describing morphometric or morphological adaptations of facultative plants (or plants that can grow in metal rich and non-metal rich soils) in order characterize bioindicator species.
Component 3. Determining tolerance or response of facultative candidate bioindicator plant species to different concentrations of heavy metals using a pot experiment (growing selected plants under growth chamber and nursery conditions)
Component 4. Establishing a protocol and developing training materials for environmental managers to recognize bioindicator plant species; Networking with DOST partner institutions and La Salle Philippines affiliated schools within the vicinity of the study sites.
Component 5. Determining the cultural requirements for the propagation of selected species that are potential biondicator species or phytoremediation agents.