Question

In studying the agricultural history of medieval Alpine settlements, climate historians long assumed that the southward contraction of viticulture during the fourteenth century resulted directly from a sudden drop in mean annual temperatures. Recent multi-proxy analyses—combining ice-core isotope records with palynological evidence from lacustrine sediments—present a more complex picture. While ice cores do confirm a marked decline in summer temperatures beginning around 1310 CE, pollen counts reveal that high-altitude terrace cultivation of barley actually expanded during this period, even on slopes previously dedicated to cold-sensitive vines. Researchers now suggest that Alpine farmers were responding less to absolute temperature shifts than to microclimatic instability, particularly unpredictably late spring frosts and shortened growing seasons. Barley, possessing a substantially shorter vegetative cycle than grapevines, offered a reliable harvest despite intra-seasonal climate volatility. Moreover, the construction of stone retaining walls for new barley terraces increased thermal mass, absorbing solar radiation during the day and mitigating nighttime frost risk at higher elevations. Thus, rather than indicating passive agrarian retreat before environmental degradation, the restructuring of Alpine crop systems demonstrates targeted technological and agronomic adaptation designed to buffer communities against climate predictability loss.

Based on the passage, which of the following can be inferred regarding fourteenth-century Alpine agricultural practices? (Select all that apply.)