Design Innovations and Plant Selection in Tangofa Village, Central Sulawesi
In the heart of Sulawesi Island, Tangofa Village holds sweet memories of green vegetation and fertile soil. However, the dynamics of the nickel mining industry have changed the face of some of its areas. What remains now is impacted land, with reddish soil, high heavy metal content, and minimal vegetation cover.
Restoration of post-mining land is not just about planting trees; it is a multidisciplinary effort that combines soil science, ecology, and forestry to recreate a self-sufficient and productive ecosystem 2 .
Nickel mining activities leave behind critical land that is barren and polluted with heavy metals, disrupting local ecosystems and communities.
Ecosystem restoration through innovative landscape design and proper plant selection, focusing on phytoremediation technologies.
The recovery of post-mining land is a gradual process based on solid scientific principles. The Green Mining Concept emphasizes that mining operations should prioritize sustainable principles, minimize negative impacts, and carry out reclamation and reforestation efforts 1 .
The first step is to level the surface, fill holes, and create stable topography to prevent erosion and landslides 2 .
This is the core of the process, namely revegetation—replanting various types of plants to restore ecosystem functions, prevent erosion, and start a new nutrient cycle 2 .
Plant selection is key to successful revegetation. Plants must have high tolerance to stress conditions such as heavy metals, heat, and low soil fertility.
Some plant species are hyperaccumulators, which actively absorb and accumulate heavy metals in their tissues 3 .
Chrysopogon zizanioides
Excellent for erosion control and heavy metal absorption.
Various species
Nitrogen-fixing plants that improve soil fertility.
An innovative study conducted in Southeast Sulawesi (with geological conditions similar to Tangofa Village) tested the ability of Sengon trees to recover land contaminated with nickel 3 .
Researchers used a Completely Randomized Design with various planting media treatments. Post-mining nickel soil was placed in 25x25 cm polybags. Four-month-old Sengon seeds were then planted. To support growth, plants were given fertilizer and humic substances, and watered daily. Nickel levels in the soil were measured using Atomic Absorption Spectrophotometry (AAS), a tool that can detect metal concentrations with high precision 3 .
| Tool/Material | Function and Description |
|---|---|
| Atomic Absorption Spectrophotometry (AAS) | Analytical tool for accurately measuring nickel metal concentration in soil samples 3 . |
| Humic Substances | Organic compounds derived from decomposition of plant material, function to improve soil fertility and nutrient availability for plants 3 . |
| NPK Fertilizer | Provides essential macro nutrients (Nitrogen, Phosphorus, Potassium) to support plant growth in nutrient-poor soil 3 . |
| Polybags | Temporary containers for planting Sengon and the soil media being studied, facilitating observation and sampling 3 . |
| Sengon Plants | Test plants that have high efficiency in absorbing and tolerating nickel metal from the soil 3 . |
The research results showed very promising outcomes. In the treatment with 100% post-mining soil media (H0P0), Sengon plants successfully reduced nickel levels in the soil by 72.5% within a certain period 3 .
| Planting Media Treatment | Nickel Reduction Efficiency |
|---|---|
| 100% Post-Mining Soil (H0P0) | 72.5% |
This finding has significant scientific significance. Sengon proved not only to grow, but actively cleans the soil through phytoremediation mechanisms. Its ability as a phytostabilizer (stabilizing metals in the root zone) or phytoextraction (absorbing and moving metals to the above-ground parts) makes it a prime candidate for revegetation programs in Tangofa Village 3 .
Other research also confirms that soil amendments such as humic substances and compost significantly improve the quality of former nickel mining soil. These organic materials help neutralize metal toxins, increase water holding capacity, and provide nutrients, which ultimately supports the growth of revegetation plants like Sengon 3 .
| Growth Parameter | Without Organic Matter | With Humic Substances & Compost |
|---|---|---|
| Plant Height | Low | Significantly Increased |
| Stem Diameter | Thin | Larger and Stronger |
| Canopy Density | Sparse | Denser and Greener |
Sengon trees demonstrated a 72.5% reduction in soil nickel content in post-mining land, proving their effectiveness in phytoremediation.
Based on these scientific findings, the following is a proposal for an integrated revegetation design that can be adopted for land conditions in Tangofa Village.
Years 1-2
Apply hydroseeding technique—spraying a mixture of fast-growing grass seeds (such as vetiver grass which is also known to hold erosion and absorb metals), nitrogen-fixing legume seeds, fertilizer, and mulch—to immediately cover the soil and prevent further erosion .
Years 2-5
After soil stabilization, introduce proven tree species such as Sengon (Paraserianthes falcataria) on a large scale. Also interplant with native Sulawesi tree species that are tolerant of heavy metals to increase biodiversity.
Years 5+
In areas that have recovered, agroforestry plots can be developed with plants that have economic value and are tolerant of residual conditions, such as candlenut, jackfruit, or certain food crops. This ensures restoration brings ecological and economic benefits to the Tangofa Village community 2 .
Function & Benefits: Quick soil cover, erosion prevention, nitrogen fixation.
Function & Benefits: Phytoremediation, soil structure improvement, litter formation.
Function & Benefits: Increasing biodiversity, providing economic yields (agroforestry).
Restoration of post-nickel mining land in Tangofa Village is not an impossible dream. With the right scientific approach, starting from a deep understanding of soil conditions, followed by the selection of effective plant species such as Sengon which has been proven to reduce nickel pollution, and supported by a mature phased revegetation design, the wounded lands can be healed.
Ultimately, this recovery effort is a moral responsibility and commitment to restoring nature 2 . The result is not just a patch of green land, but a valuable legacy in the form of a sustainable environment for future generations in Tangofa Village, where economy and ecology can go hand in hand.
Restored biodiversity, improved soil quality, and renewed ecosystem services.
Economic opportunities through agroforestry and improved environmental quality.
Long-term environmental health and resilience against climate change impacts.