ISO 23611-5:2011

Overview

ISO 23611-5:2011 - Soil quality - Sampling of soil invertebrates - Part 5: Sampling and extraction of soil macro-invertebrates - specifies a standardized, rapid-assessment method for collecting, extracting and preserving soil macro-invertebrates (organisms >10 mm) from both the litter zone and soil. The protocol is based on the Tropical Soil Biology and Fertility (TSBF) method with adaptations for temperate regions and is intended to support the use of macro-invertebrates as bio-indicators in soil quality assessment, monitoring and ecological research.

Key topics and technical requirements

• Scope and applicability: Applicable to most soil types except extreme conditions (hard, frozen or flooded soils) and non-soil matrices (trees, lichens). Sampling design is covered in ISO 23611-6.
• Rapid field assessment: Designed to complete sampling of a plot in one or two days using basic equipment and a small team.
• Field procedures:
  • Litter sampling using a metallic frame (preferably 250 mm × 250 mm); litter collected and hand-sorted in trays.
  • Temperate regions: two-step procedure - formalin extraction (0.2% formalin applied, two applications of ~1.5 L at ~10 min interval) followed by hand-sorting of the upper 150 mm of soil.
  • Tropical regions: monolith sampling (250 × 250 × 300 mm), hand-sorted by 100 mm layers; no formalin application, sometimes increased depth for endogenic earthworms.
• Reagents and preservation:
  • 70% ethanol for most specimens; 4% formalin (fixation and preservation for soft-bodied taxa; transfer to ethanol after ~4 days possible).
  • 0.2% formalin for in-field extraction in temperate climates.
• Laboratory processing:
  • Cleaning, transfer to labeled vials, identification under a stereo-microscope (ideally to species; genus or morphospecies acceptable).
  • Biomass determination using preserved specimens (surface-dry with filter paper; precision balance to 0.001 g). Note: preservation reduces mass (approx. 15–40% loss).
• Labeling and storage: Mandatory label fields (country, region, locality, collector, date); monitor preservative levels and change solutions periodically.

Applications and users

• Practical uses:
  • Soil quality assessment and biological classification
  • Long-term biomonitoring and impact assessment (pollution, land-use change, forest and crop management)
  • Biodiversity inventories and functional ecology studies of soil fauna
• Typical users:
  • Soil scientists, ecologists and taxonomists
  • Environmental monitoring agencies and consultants
  • Agricultural and forestry researchers, land managers and conservationists

Related standards

• ISO 23611 series (sampling of soil invertebrates): Parts 1–6 (see ISO 23611-1 for earthworms; ISO 23611-6 for sampling design)
• Complementary physico-chemical soil standards cited for site characterization: ISO 10390, ISO 10694, ISO 11274, ISO 11277, ISO 11461, ISO 11465

Keywords: ISO 23611-5, soil quality, sampling of soil macro-invertebrates, TSBF method, soil monitoring, bio-indicators, extraction, preservation, soil biodiversity.