Rebuilding Burned Soils: Knowing the Difference Between Bioremediation, Phytoremediation, and Phytoextraction

Arroyo Lupine seedling growing through applied compost and locally sourced wood chip mulch

Increasingly intense wildfires have left our landscapes scorched, not just above ground, but deep within the soil. The microbial communities that once thrived beneath our feet, orchestrating nutrient cycling and detoxifying contaminants, are often reduced to ash. As we turn toward nature-based solutions to restore these ecosystems, it’s critical to understand the tools at our disposal and not conflate them.

Bioremediation: Microbial Healing Through Compost

Bioremediation is the process of using living organisms—primarily microbes—to break down and neutralize contaminants in soil. When we apply biologically active compost, we’re reintroducing a diverse suite of bacteria, fungi, protozoa, and nematodes that can metabolize toxins, rebuild soil structure, and restore ecological function. This is not just “adding compost”  it’s a targeted microbial intervention.

• Key agents: soil microbes sourced from healthy compost.

• Mechanism: microbes degrade pollutants and rebuild soil health.

• Best used for: hydrocarbons, heavy metals (with chelators), and restoring microbial balance.

Phytoremediation: Plants as Detoxifiers

Phytoremediation uses plants to stabilize, extract, and/or transform contaminants. Through their roots, plants can absorb pollutants, stimulate microbial activity, and prevent erosion. But unlike compost-based bioremediation, phytoremediation is slower and often limited by plant species and seasonal growth.

• Key agents: specific plant species with known uptake or stabilization properties.

• Mechanism: plants absorb or immobilize contaminants.

• Best used for: stabilizing soils, shallow contamination, erosion control.

Phytoextraction: Mining Metals with Green Leaves

Phytoextraction is a subset of phytoremediation where plants specifically absorb heavy metals into their tissues. These plants are later harvested and disposed of safely. It’s a useful strategy for removing metals like lead, cadmium, chromium, and arsenic but it doesn’t necessarily rebuild soil biology or structure alone.

• Key agents: hyperaccumulator plants (e.g. Sunflowers, Telegraph Weed)

• Mechanism: uptake of metals into plant biomass

• Best used for: heavy metal removal, not biological restoration

Why the Distinction Matters

Too often, these terms are used interchangeably, leading to confusion in recovery efforts. Compost-based bioremediation is not the same as planting sunflowers, and just planting sunflowers won’t restore microbial diversity. Each method has its place, but only bioremediation with biologically active compost can rebuild the living soil systems that wildfires destroy.

Reintroducing Life: Microbes First

Post-fire soil is biologically barren. Before we can stabilize, extract, or revegetate, we must reintroduce the biology from local sources, including charred organic matter. This means:

• Sourcing compost and microbial inoculants locally,

• Using community green waste to build compost piles,

• Avoiding long-distance hauling of materials that already exist nearby.

This isn’t just ecological—it’s economical. Local sourcing reduces emissions, supports community resilience, and keeps green assets circulating within the watershed.

Rethinking Best Management Practices

Current emergency response protocols often prioritize erosion control and debris removal, overlooking the microbial foundation of soil health. It’s time to revisit these practices, and:

• Integrate compost-based bioremediation into early recovery,

• Support local composting infrastructure,

• Train emergency crews in soil biology and nature-based solutions.

A Community-Driven Path Forward

Nature already provides the tools we need - the microbes, plants, and organic matter. But the key is local regeneration. By recovering, processing, and redistributing green assets within the community, we create a closed-loop system of healing. One that’s less expensive, more effective, and deeply rooted in place.  Let’s stop importing solutions and start cultivating them right here, in the soil beneath our feet.