Bioindicators of enhanced nitrogen deposition

Area of Science:

• Ecology
• Environmental Science
• Plant Biology

Background:

• Atmospheric nitrogen (N) deposition from agriculture impacts European vegetation biodiversity.
• Intensive farming practices contribute significantly to N pollution.
• Vegetation composition is altered by increased N levels.

Purpose of the Study:

• To assess the effectiveness of bioindicators in monitoring nitrogen (N) deposition.
• To investigate vegetation changes in response to ammonia (NH3) gradients.
• To establish relationships between N deposition and plant tissue N and amino acid concentrations.

Main Methods:

• Utilized species-based bioindicators like the Ellenberg N index.
• Measured total tissue N and free amino acids in key plant species.
• Analyzed data from a mixed woodland with a known ammonia concentration gradient.

Main Results:

• All examined bioindicators correlated with N deposition, indicating vegetation changes.
• Total tissue N showed a strong link (r(2) > 0.97) with ammonia concentrations.
• Arginine concentrations were also closely related (r(2) > 0.78) to ammonia levels and N deposition.

Conclusions:

• Bioindicators effectively signal vegetation responses to N deposition.
• Plant tissue N and arginine are sensitive indicators of ammonia pollution.
• Monitoring these indicators can help manage agricultural N impacts on ecosystems.