Timing Matters: Viticultural Land Use Determines Responses in Structure and Function of Fungal Stream Communities...

Area of Science:

• Aquatic Ecology
• Mycology
• Environmental Science

Background:

• Fungal communities drive leaf decomposition in streams, a vital ecosystem process.
• Anthropogenic stressors and natural seasonal cycles can disrupt fungal communities and decomposition rates.
• The interplay between seasonal variation and stressor exposure on fungal-driven decomposition remains understudied.

Purpose of the Study:

• To investigate how fungal community composition and leaf decomposition vary seasonally under different land use conditions (forest vs. viticulture).
• To assess the impact of altered stressor exposure on fungal communities and decomposition by transplanting leaves between sites.
• To determine the combined effects of seasonality and land use on stream ecosystem function.

Main Methods:

• Leaf bags were deployed and transplanted across forest and viticultural stream sites over an agricultural growing season.
• Fungal community composition was analyzed using molecular techniques.
• Leaf decomposition rates were quantified by measuring mass loss over time.

Main Results:

• Leaf decomposition was consistently lower in viticultural sites compared to forest sites.
• Transplanted leaves showed decomposition patterns more similar to their original forest colonization site.
• Fungal communities diverged between treatments later in the season, coinciding with fungicide application in viticultural areas.

Conclusions:

• Both fungal community structure and leaf decomposition function exhibit significant seasonal and stressor-dependent variability.
• Land use impacts on fungal communities and decomposition are influenced by seasonal timing and specific stressor regimes.
• Future research on land use effects must integrate seasonal dynamics and actual stressor exposure for accurate assessment.