The edaphic quantitative protargol stain: a sampling protocol for assessing soil ciliate abundance and diversity

Area of Science:

• Soil ecology
• Microbial ecology
• Protistology

Background:

• Species loss in low-diversity microbial groups near the base of food webs can impact terrestrial ecosystems.
• Soil ciliates, part of the microbial loop, are poorly understood due to a lack of standardized enumeration methods.
• Limited knowledge exists on ciliate diversity and their ecological interactions in soil.

Purpose of the Study:

• To introduce and validate the Edaphic Quantitative Protargol Staining (EQPS) method for soil ciliates.
• To enable simultaneous quantitative and qualitative assessment of ciliate species richness and abundance.
• To improve understanding of active and potential ciliate diversity in soil ecosystems.

Main Methods:

• Development of the Edaphic Quantitative Protargol Staining (EQPS) method.
• Integration of the Non-flooded Petri Dish (NFPD) and Quantitative Protargol Stain (QPS) techniques.
• Refinement through experiments on spatial distribution, sampling intensity, storage effects, and preparation types.

Main Results:

• The EQPS method provides a direct, rapid, and simultaneous assessment of soil ciliate diversity.
• It allows for both a "snapshot" of active diversity and a robust estimate of potential diversity.
• The method addresses limitations in previous approaches to ciliate enumeration.

Conclusions:

• The EQPS method is a valuable tool for ecological studies of soil microbial communities.
• It enhances the ability to quantify and qualify ciliate diversity and abundance.
• This method facilitates a better understanding of ciliate roles in terrestrial ecosystem functioning.