Terroir leaves its influence on the flavor build-up in grape berries by triggering biochemical reactions that ultimately shape the typicality of the produced wines. However, the complex relationship between terroir, carbon stable isotopic composition, and the biochemical composition of grapes remains poorly understood. To fill these gaps, grape berries were harvested at maturity from two grape cultivars, Cabernet Sauvignon and Merlot (Vitis vinifera L.), across 32 sites within the Eastern Foothills of the Helan Mountains region over two vintages. The climate and soil data for these sites were collected, and cultivation practices were surveyed. In parallel, the grape quality indicators were measured at maturity to explore their variations among sub-regions and the correlations between terroir factors and grape quality. Moreover, the carbon stable isotopes (δ¹³C) were measured to evaluate the water status of vines at different sites. Results indicated that organic acids and anthocyanins exhibited a strong vintage effect, with the cooler vintage exhibiting higher levels of these compounds relative to the warmer vintage. Specifically, the Hongsipu sub-region, with a cooler climate, consistently demonstrated higher anthocyanin concentrations than other sub-regions in both vintages of the study. Further analysis revealed that the cultivar Cabernet Sauvignon displayed a higher ratio of di-hydroxylated to tri-hydroxylated anthocyanins in the cooler year, whereas Merlot exhibited the opposite trend. The Mantel test identified several critical factors influencing anthocyanin concentration, including total soil phosphorus (Tp), total soil potassium (Tk), soil thickness (Thickness), precipitation (April-September precipitation, Pre4–9), April-September average temperature (4–9 Tave), April-September active accumulated temperature (4–9 Aa), April-June active accumulated temperature (4–6 Aa), July-September active accumulated temperature (7–9 Aa), temperature diurnal range (May, July, August, September, DR-5 and DR 7–9), trellis system, vine density, and δ13C. Finally, structural equation modeling (SEM) was used to analyze and summarize the relationships between terroir factors, anthocyanin concentration, and δ¹³C. The results indicated that June and September precipitation had a positive impact on anthocyanin concentrations, while soil total potassium content had a negative impact. On the other hand, the July to September temperature diurnal range, trellis system, vine perimeter, and canopy height were the main drivers of δ¹³C, which further influenced grape anthocyanin concentrations. This research contributes to a scientific foundation for grape cultivation in the Eastern Foothills of the Helan Mountains and provides valuable insights for practices in other regions.

中文翻译：

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气候、土壤和葡萄栽培因素对葡萄浆果生化成分的次区域变化产生不同的影响


风土通过触发生化反应，最终塑造所生产葡萄酒的典型性，从而对葡萄浆果的风味积累产生影响。然而，风土、碳稳定同位素组成和葡萄的生化成分之间的复杂关系仍然知之甚少。为了填补这些空白，在两个年份中，我们从赤霞珠和梅洛 （Vitis vinifera L.） 这两个葡萄品种中收获了葡萄果实，分布在贺兰山脉地区东麓的 32 个地点。收集了这些地点的气候和土壤数据，并调查了种植实践。同时，在成熟期测量葡萄质量指标，以探索它们在子区域之间的差异以及风土因素与葡萄质量之间的相关性。此外，还测量了碳稳定同位素 （δ¹³C） 以评估不同地点葡萄藤的水分状况。结果表明，有机酸和花青素表现出强烈的年份效应，相对于较暖的年份，较冷的年份表现出更高水平的这些化合物。具体来说，气候凉爽的 Hongsipu 子产区在研究的两个年份中始终表现出比其他子产区更高的花青素浓度。进一步分析表明，在凉爽的年份，赤霞珠的二羟基化花青素与三羟基化花青素的比例较高，而梅洛则表现出相反的趋势。 Mantel 测试确定了影响花青素浓度的几个关键因素，包括土壤总磷 （Tp）、土壤总钾 （Tk）、土壤厚度（厚度）、降水（4 月至 9 月降水，Pre4-9）、4 月至 9 月平均气温（4-9 塔夫）、4-9 月活动积温（4-9 Aa）、4-6 月活动积温（4-6 Aa）、7-9 月活动积温（7-9 Aa）、温度昼夜范围（5 月、 7 月、8 月、9 月、DR-5 和 DR 7-9）、棚架系统、葡萄藤密度和 δ13C。最后，采用结构方程模型 （SEM） 分析和总结风土因子、花青素浓度和 δ¹³C 之间的关系。结果表明：6 月和 9 月降水对花青素浓度有正向影响，而土壤全钾含量具有负向影响;另一方面，7 月至 9 月的昼夜温差、棚架系统、葡萄藤周长和树冠高度是 δ¹³C 的主要驱动因素，这进一步影响了葡萄花青素浓度。这项研究为贺兰山脉东麓葡萄种植奠定了科学基础，并为其他地区的实践提供了宝贵的见解。