Conserving biodiversity in nickel mining areas of Phl: An ecologically based restoration approach

Approximately five percent of the land surface of the Philippines has outcrops of ultramafic rock, which are igneous or metamorphic rocks that comprise less than 45 percent silica and have high concentrations of minerals containing magnesium, iron, chromium, cobalt and nickel. It has been well documented that most of ultramafic clays support only stunted vegetation and are poor agricultural soils. Their infertility seems to be due to locally variable combinations of imbalances in the cationic nutrients with low calcium compared to magnesium, heavy metal toxicities, and phosphorus fixation, droughtiness, compounded by the vegetation’s susceptibility to fire. Moreover, the soil chemistry changes with depth, which would further limit plant growth and hence they may be very difficult to manage if their surface layers are eroded.

To date the vegetation of the ultramafic rocks of the Philippines, Malaysia and Indonesia, with the exceptions of Sabah, and in the Philippines have been very poorly described. Only two detailed studies were undertaken 30 years ago in small areas of Sibuyan Island and in Palawan.  This lack of understanding of these unique ultramafic ecosystems has made it difficult to formulate conservation plans and priorities even to possibly many threatened species. Just the very fact that the vegetation grows on such hostile soil conditions suggests that they have highly adaptive growth and reproductive strategies.

The Society for Ecological Restoration defines “ecological restoration” as an “intentional activity that initiates or accelerates the recovery of an ecosystem with respect to its health, integrity and sustainability.”

As early as 1986, important scientists had already pointed out the need to conserve vegetation over ultramafic rocks since it is a potential source of important chemicals for medicinal and other uses.

The increased vegetation clearing due to mining and other land use conversion has severely impacted on ultramafic ecosystems.  Because of the growing awareness to conserve our ever-diminishing ecosystems, there have been recent initiatives to address these knowledge gaps.

I just recently came back to participate in the UP Visiting Professor’s program in which I was hosted by the research group of Professor Edwino Fernando and Dr. Marilyn Quimado from the Department of Forest Biological Sciences at the College of Forestry and Natural Resources, UP Los Baños. They are undertaking a major study on the biodiversity and the conservation of the ecosystems of our ultramafic regions. We have discovered new plant communities that are highly tolerant of the unique soil chemistry in the nickel rich soils. Moreover, propagation methods are being developed and trials have been initiated to reintroduce these species into the spent mining areas. The preliminary findings of this study have been presented to date in two international conferences and several scientific publications will be coming out in the following months. Practical outcomes of this concerted research will allow us to emulate the use of the endemic species in revegetation programs on severely damaged areas of nickel mining in tropical areas like New Caledonia. They had initiated their restoration research programs 25 years and have been implemented into large-scale ecosystem reconstruction programs.

Professor Edward O. Wilson from Harvard University, who coined the word biodiversity, stated that “ecological restoration is the keystone strategy for conserving biodiversity. Here is the means to end the great extinction spasm. The next century will, I believe, be the era of restoration in ecology.” We are constantly reminded that the Philippines is rapidly losing its rich biodiversity due to many unsustainable land use practices such as unregulated logging, burning of vegetation through overuse of slash and burn farming and the different types of mining.

Research in restoration ecology provides us with a unique opportunity to perform large-scale field experiments in order to test hypotheses on how ecosystems actually function by observing the ecological responses of different assemblages in relation to the different reconstructed landforms. The multi- and trans-disciplinary nature of such studies also creates another ecosystem: the intellectual ecosystem, which evolves through the sharing and testing of ideas through experimental methods. The scientific discipline of restoration ecology has just celebrated its 25th year but we already have made several inroads in various parts of the world in repairing large-scale damage to once healthy and well functioning ecosystems.

On a personal note it is a highly gratifying experience to visit field sites which one has been part of in an ecological restoration program. Over a continuum of time it is a privilege to actually observe in real time the complexity of a biotic community, taking shape in a relatively rapid time frame of decades to achieve the goal of a self-sustaining ecosystem. On our field trip to a mountainous mine site you could see the stark impact of the removal of the forest cover in order to get at the nickel rich minerals. We were on the quest to find new species of unique plants, which are highly adapted to grow on those soils. I was very encouraged to see the first set of field trials of indigenous species growing on different mined landforms with different surface amendments as well as the enthusiasm displayed not only by my fellow researchers but also the interest of the local personnel in the whole experimental process. I wish that I will be able to see in my lifetime that ultramafic mined-out area set to the path of a functioning self-sustaining ecosystem similar to the surrounding ecosystem. As E.O. Wilson emphatically stated recently, “Restoration offers new hope to life on Earth.”

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Augustine Doronila, Ph.D., was recently at the University of the Philippines, Los Baños as a visiting professor with the Department of Forest Biological Sciences, College of Forestry and Natural Resources. He is a research fellow at the School of Chemistry of University of Melbourne, Australia. His expertise is phytoremediation, restoration ecology, post-mining reclamation and biogeochemistry. You can learn more about his work through a webcast: http://upclose.unimelb.edu.au/episode/216-tailings-tidy-up-how-bioremediation-can-repair-damage-done-mining. 

His e-mail address is adoro@unimelb.edu.au.