Microclimate diversity drives grape quality difference at high-altitude: Observation using PCA analysis and...

Area of Science:

• Viticulture and Enology
• Climate Science
• Agricultural Science

Background:

• Global warming drives interest in high-altitude viticulture for cool-climate wine grapes.
• Understanding environmental influences on grape quality is crucial for optimizing cultivation.

Purpose of the Study:

• To evaluate wine grape (Cabernet Sauvignon) quality across six high-altitude regions.
• To identify key environmental factors influencing grape quality using statistical modeling.

Main Methods:

• Principal Component Analysis (PCA) for quality assessment across altitudes (1987-2540m).
• Structural Equation Modeling (SEM) to determine environmental contributions to grape quality.
• Analysis of physical attributes, chemical compositions, and phenolic compounds.

Main Results:

• PCA models effectively grouped grapes by altitude, with distinct quality scores.
• Significant variations in malic acid, tannins, phenols, acidity, anthocyanins, and skin thickness observed.
• SEM revealed temperature (soil, day-night, day air) as a major driver of grape quality, exceeding light's effect.

Conclusions:

• High-altitude grape quality exhibits spatial variation influenced by microclimatic factors.
• Temperature-related factors are more critical than light for grape quality in these regions.
• SEM is a valuable tool for analyzing climate-grape quality relationships in viticulture.