Meet the winners of nature’s very own metal-heavy survival show in the forests

Mother Nature has its own way of running the business. 

From the process of photosynthesis where plants sustain themselves through turning light into energy to the symbiotic relationships between plants and animals, earth’s flora are seen to exhibit an extraordinary ability of survival and adaptation.

One of these processes include carbon sequestration—the process of capturing and keeping carbon dioxide (CO2) found in the atmosphere. 

Often called carbon capture and storage (CCS), this natural process within plants is seen to be an effective way as to how nature reduces the risk of climate change and global warming making them carbon sinks or natural absorbents of CO2.

In a recent study by researchers from the University of the Philippines Los Baños (UP), the ecological importance of CCS and plants thriving in metal-heavy conditions to climate change mitigation and biodiversity preservation.

Metal-rich Forests

Metallophytes—plants that have evolved to adapt and thrive in environments with high contents of heavy metals such as chromium, cobalt, manganese, and silver, are seen to thrive in ultramafic forests.

These forests are unique due to their ecosystems which grow on ultramafic or serpentine rocks or soils rich in heavy metals such as copper and nickel but are poor on basic nutrients commonly needed by plants to live.

In the Philippines, the study has mentioned that ultramafic soil makes up five percent of the country’s total land area.

Spanning across Luzon, Visayas, and Mindanao, these rich carbon sinks are particularly found in areas such as Zambales, Camarines Norte, Samar, Surigao, and Palawan.

Evolution and Adaptation

Under the harsh conditions of ultramafic soils such as their low soil water availability, scarce macronutrient content, high silica content, and abundant supply of siderophilic metals such as nickel, common vegetation are seen to rarely prosper in these areas which result in low economic value.

However, the study underscores the importance of special plants which adapt to these harsh conditions. 

The researchers note that these plants have a potential in environmental clean-up as well as phytoremediation technologies.

These processes use a plant’s natural microbes to clean and store toxic metals originally found in the soil. This makes it an important, sustainable way to maintain soil richness, promoting the biodiversity in the area. 

Nature’s Detoxifiers

Assessing the floristic diversity of 12 ultramafic forests in Palawan used for various purposes most especially mining, the UP study found that these forests are directly significant with the presence of unique plant species.

Among these are hyperaccumulator plants, a specific type of metallophyte. Known as “metal-eating” plants, they are seen to play big roles in phytoremediation through absorbing and detoxifying unwanted metals from the soil. 

These plants are seen to be helpful in soils near mining sites which usually contain high amounts of metals. Acting as nurse species, these plants “eat” the metal contents of the soil and store them in their stems and leaves to purify the soil.

Like a sponge, the absorbed metals do not harm the plant as these plants use special proteins to safely store the metals. This becomes a sustainable and cost-effective way to make areas safe for normal vegetation to thrive in.

Significant Roles to Nature

The researchers were said to study an active mining site as well as a former chromite mine site that is undergoing natural succession—a process of change within an ecosystem’s composition.

Within these sites the researchers have observed and identified significant species based on their density and frequency within the area. Through the numbers, they have found that ultramafic forests usually house plants with low stature—showing trees only standing well over 20 meters, as well as low diversity with only a limited number of species in the area.

They note that these observations are concerning given the big role these plants play in the CCS process of these forests as carbon sinks.

Although the study mentions that characteristics of these ultramafic forests still vary upon previous activities done in the land, the need for conservation of the ecosystems that work double-time in these soils must still be prioritized.

The contribution of the unique plants and life that thrive on soils not-suitable for life to bloom in climate mitigation shows the peculiar beauty of nature and life and how simple survival and growth become symbols of strength and hope.