Heli Maaria Huhtamaa

Reconstructing crop yield variability in Finland: Long-term perspective of the cultivation history on the agricultural periphery since ad 760

Lack of documentation on past harvest fluctuations limits the exploration of long-term trends in crop production and agricultural adaptation strategies. A long-term perspective is needed, however, to understand the wide spectrum of potential human responses to environment and climate change. Therefore, we used tree-ring density series as proxy data to reconstruct climate-mediated yield ratio (harvested grain in relation to sown) in central and northern Finland over the period ad 760–2000. The reconstruction explains 50% of the variance in recorded yield ratio variability over the calibration period (ad 1866–1921). The reconstruction illustrated several intervals of increased and reduced yield ratio over the past 13 centuries. The long-term development of the agricultural prerequisites is characterized by distinct intervals defined statistically as ad 760–1106 (highest yield ratios), 1107–1451, 1452–1694, 1695–1911 (lowest yield ratios) and 1912 onwards. The results provide insight into the establishment and development of crop cultivation in the agricultural margin. The reconstruction suggests that continuous crop cultivation was established in the study region during a favourable period of climatic conditions supporting high yields. Thereafter, the climate-mediated yield ratio declined in the long run until the turn of the 20th century. Periods of agricultural transformations, those previously demonstrated in pollen data and historical documents, followed the onsets of the low yield ratio phases indicated by our reconstruction. Thus, we suggest that ever since the establishment of crop cultivation, climate can be considered as an important factor contributing to the development of the agricultural history in the north.

Climatic anomalies, food systems, and subsistence crises in medieval Novgorod and Ladoga

Climatic factors have affected subsistence strategies throughout human history. In northern Europe and Russia, short-term climatic anomalies and weather extremes are commonly thought to underlie famines in the Middle Ages. However, medieval subsistence crises were not just natural disasters and medieval people were not passive victims of climatic anomalies. In addition, the capacity to cope with climatic anomalies has varied temporally and spatially throughout the Middle Ages. Yet only a few studies have explored the climatic impact on regional medieval food systems comprehensively. This article examines the significance of climate variability on subsistence crises in medieval Novgorod and Ladoga (Russia), focusing on the relationship between short-term climate anomalies and crop cultivation. In addition, this paper evaluates the impact of crop failures, frosts, and other weather phenomena on the food system. The materials are drawn from medieval sources, paleoclimatological reconstructions, and archaeological evidence. The results show that short-term climatic anomalies alone rarely lead to severe subsistence crises, and during every famine period there is evidence of other contributing factors, such as unfavourable weather phenomena, disease, or social unrest. The variety of cultivated crops and agricultural techniques is shown to increase the region’s resilience to climatic anomalies and to crop failures.

Combining Written and Tree-Ring Evidence to Trace Past Food Crises: A Case Study from Finland

The lack of written source material on population and food availability has hindered studies on medieval and early modern food crises in many parts of the world. Examining the case of sixteenth and seventeenth century Finland, this article explores how indirect evidence—so called proxy data—could be used to identify past food crises. The proxies of past climate, grain harvest, storage capacity and population variability were derived from tree-ring studies and early administrative accounts. Evidence from “natural” and written archives supplemented each other. The applicability and limitations of using proxy data to trace past food crises is further discussed by comparing the examples of the sixteenth and seventeenth century to the better documented famine period of the 1860s. It was found that tree-ring data and early administrative accounts provides valuable material to identify past food crises.