Olives were first cultivated 7’000 years ago

Since the olive does not grow naturally in the Jordan Valley, the inhabitants must have deliberately planted the trees around 7,000 years ago, according to the researchers.

Analysis of a collection of charred wood from an archaeological site at Tel Tsaf in Israel's Jordan Valley revealed the presence of burnt wood from 16 different tree species, including olive trees (Olea europea) and fig trees (Ficus carica). The researchers believe that the olive trees did not grow naturally in the Jordan Valley, but must have been deliberately planted by the inhabitants around 7,000 years ago. This would be the earliest known example of olive tree domestication in the Mediterranean region and worldwide.

The groundbreaking study was led by Dr. Dafna Langgut of the Jacob M. Alkow Department of Archaeology & Ancient Near Eastern Cultures and the Steinhardt Museum of Natural History at Tel Aviv University. The charcoal remains were found during the archaeological excavation led by Prof. Yosef Garfinkel of the Institute of Archaeology at the Hebrew University. The findings were published in the journal Scientific Reports.

Tel Tsaf is located in the central Jordan Valley, 32.5 km south of the Sea of Galilee, on the western bank of the Jordan River. The chronology shows that the settlement began in the last quarter of the 8th millennium BC and ended in the first quarter of the 7th millennium BC. The remains of the stone settlements include courtyards, residential buildings, and large silos capable of storing 20–30 tonnes of grain. The large capacity of these silos would have exceeded the needs of the inhabitants, pointing to successful agriculture and a complex economic system of surplus accumulation and wealth.

Among the seeds found at the site were those of crops such as barley, wheat, lentils, and peas. Of particular interest to the researchers, however, was the presence of charred wood fragments found at various locations across the site. A total of 662 charred wood samples were analyzed, and it was determined that most came from Quercus ithaburensis (Mt. Tabor oak, 39.8 percent) and Tamarix spp. (22.3 percent). The researchers identified the species through microscopic examination of the anatomical characteristics of the wood (e.g., vessels and their arrangement, size and arrangement of rays, and the patterns of parenchyma and fibers).

Wood from olive trees (6.4%) and fig trees (6.5%) was also present in the assemblages. «Based on archaeobotanical research, it is generally accepted that the presence of wood and/or charcoal remains from fruit trees at a site indicates their cultivation in the surrounding area«, according to the study's authors.

A number of olive pits were also collected at Tel Tsaf, suggesting that olive groves existed in the vicinity of the site. Interestingly, the central Jordan Valley lies outside the natural range of wild olives, and this appears to have been the case in the 7th millennium BCE as well. The olives must therefore have been planted there by the local inhabitants.

Trees, even when burned to charcoal, can be identified by their anatomical structure. Wood was the “plastic” of the ancient world. It was used for construction, for making tools and furniture, and as an energy source. Identifying tree remains found at archaeological sites — such as charcoal from hearths — is therefore key to understanding which species of trees grew in the natural environment at the time, and when people began to cultivate fruit trees.

Dr. Dafna Langgut

The samples from the charred fig tree consisted primarily of young branches, a part that is not normally used as building or fuel material. The branches were dated to between 6,960 and 6,860 years before our era. The researchers believe that the presence of these young branches is attributable to their having been cut from larger trees to encourage fruit production. This would also serve as evidence of horticultural practices associated with fig orchards. Both figs and olives can be preserved and transported, and would therefore have been useful trade commodities.

According to Dr. Langgut, olive trees grow in the wild in the land of Israel, but not in the Jordan Valley. «This means that someone intentionally brought them there — the knowledge and the plant itself were brought to a location outside their natural habitat. In archaeobotany, this is considered irrefutable evidence of domestication, which means that we have here the earliest evidence of olive tree domestication in the entire world.«

«I also found many remains of young fig branches. While the fig tree grew naturally in the Jordan Valley, its branches were of no value as firewood or as raw material for tools or furniture, so people had no reason to collect large quantities and bring them to the village. These fig branches apparently come from pruning, a method still used today to increase the yield of fruit trees..»

The evidence for the cultivation of fruit trees, along with the large silos and dwellings at Tel Tsaf, suggests that the inhabitants were prosperous and possessed considerable material resources. The presence of other exotic items such as obsidian, beads made from rare minerals, complex pottery, and a copper awl supports the interpretation that the society was wealthy and likely engaged in trade.

«The storage capacities [at Tel Tsaf] were up to 20 times greater than the caloric consumption of a single family, so these were clearly storage facilities for great wealth.«, said Professor Yosef Garfinkel, who led the archaeological excavation. «The wealth of the village was evident in the production of elaborate pottery, painted with remarkable skill. We also found objects brought from far away: Ubaid culture ceramics from Mesopotamia, obsidian from Anatolia, a copper awl from the Caucasus, and much more.«

Dr. Langgut and Professor Garfinkel were not surprised to discover that the inhabitants of Tel Tsaf were the first in the world to deliberately cultivate olive and fig groves, as the cultivation of fruit trees is a sign of luxury, and this site was known to be exceptionally prosperous.

«The domestication of fruit trees is a process that takes many years and therefore suits a society of abundance rather than one struggling to survive«, said Dr. Langgut. «The trees do not bear fruit until 3–4 years after planting. Since fruit tree groves require a considerable initial investment and then continue to thrive for a long time, they carry great economic and social significance with regard to land ownership and its inheritance by future generations — practices that point to the beginnings of a complex society.«

Furthermore, it is quite possible that the inhabitants of Tel Tsaf traded in the products of the fruit trees, such as olives, olive oil, and dried figs, which have a long shelf life. Such products could have enabled long-distance trade, leading to the accumulation of material wealth and possibly even taxation — first steps toward a society with a socioeconomic hierarchy supported by an administrative system.

The olive tree arrived in Italy around 3’400 years ago, and on the Iberian Peninsula around 2’500 years ago.