Ornamental Phytoremediation in Cities: Context-Dependent Roles in Managing Potentially Toxic Elements

Area of Science:

• Environmental Science
• Ecology
• Urban Planning

Background:

• Potentially toxic element (PTE) contamination in urban soils presents ecological and public health risks.
• Ornamental vegetation is a key component of green infrastructure for risk management.

Purpose of the Study:

• To synthesize evidence on phytoremediation using ornamental plants.
• To characterize the scope, reporting structure, and design of existing studies.
• To map the evidence base for context-aware interpretation and future standardization.

Main Methods:

• A systematic review and synthesis of 167 field studies (>120 plant species).
• Analysis of element investigation patterns (e.g., Pb, Cd, Zn) and reporting breadth.
• Principal component analysis to identify co-reporting profiles of elements.
• Regression analysis to explore associations between environmental type and element richness.

Main Results:

• Lead, cadmium, and zinc were the most frequently investigated PTEs (67%).
• Element richness varied by site type (e.g., wastewater-affected vs. urban parks).
• Accumulation was the most reported outcome (56.8%), followed by translocation (25.3%) and stabilization (17.9%).
• Aboveground tissue sampling predominated over root sampling.
• Study findings reflect context-dependent reporting rather than harmonized remediation outcomes.

Conclusions:

• Phytoremediation research using ornamental plants is diverse but lacks standardized reporting.
• Accumulation-focused strategies require defined maintenance to prevent PTE recirculation.
• An evidence map is provided to guide interpretation and promote future study standardization.