Simulating atmospheric drought: Silica gel packets dehumidify mesocosm microclimates.

Area of Science:

• Ecology
• Environmental Science

Background:

• Global temperature rise increases drought frequency and severity.
• Traditional drought experiments often focus solely on soil moisture, neglecting atmospheric conditions.

Approach:

• Silica gel packets were used to create atmospheric drought in outdoor mesocosms.
• Relative humidity (RH), temperature, and vapor pressure deficit (VPD) were monitored over five months.
• Treatments included soil drought (reduced watering) and/or atmospheric drought (silica packets).

Key Points:

• Silica packets reduced microclimate RH by -5% most effectively when combined with reduced soil water.
• Microclimate VPD increased by +0.4 kPa most effectively with reduced soil water and temperatures above 20°C.
• Consistent atmospheric drought simulation required silica packet replacement every three days.

Conclusions:

• Silica gel packets are effective agents for inducing atmospheric drought in experimental settings.
• Integrating atmospheric drought simulation into ecological experiments improves understanding of drought's ecological impacts.