Origins and expansion of Mediterranean agriculture in the context of global change Juan Pedro Ferrio ARAID – Forest Resources Unit, CITA
22-23 November 2018, University of Barcelona, Spain Structure of the talk
1) Climate Change and the Origins of Agriculture
2) Human-environment interactions in ancient agriculture Climate Change and the Origins of Agriculture
Wood charcoal from Tossal de les Tenalles, NE Spain (ca. 200 BCE; J.P. Ferrio) The Holocene: a climatic oasis
Hol. Optim. Glacial / Interglacial episodes YD
Holocene: the most stable warm period in 400,000 years NOAA climate database / Petit et al. 1999; Young & Stefen 2009 / Rockstrom et al. 2009 Origins of Agriculture
Agriculture originated in different centers of origin during the Holocene Origins of Agriculture
Neolithic revolution: 1 (Childe 1952)
10,000 years ago in the Fertile Crescent Origins of Agriculture
HOLOCENE AGRICULTURE OPTIMUM
WARM WET
COLD DRY YOUNGER GATHERING DRYAS
Willcox et al. 2009, Ferrio et al. 2011 Sustainability in ancient agriculture A multi-proxy approach
Barley grains from Vilot de Montagut, NE Spain (ca. 700 BCE; N. Alonso) Agriculture and landscape
Origin and spread of Agriculture: first example of reciprocal human-environment interaction
Jules Janick, Purdue University, USA http://www.hort.purdue.edu/newcrop/origin-of-fruit_files/frame.htm Chrispeels MJ & DE Sadava. Plants, Genes and Agriculture, Jones and Bartlett Publ. Sustainability in ancient agriculture
1 Regional and local trends in the Near East Assessing the past: pollen records
http://www.museum.state.il.us/muslink/behind/htmls/cr_bot_pal3.html The COMET Program, UCAR / Allen M. Solomon, US EPA https://scied.ucar.edu/activity/paleoclimates-and-pollen Deforestation in the Ghab Valley
HOL. OPTIMUM
YOUNG DRYAS
Agriculture Expansion
Yasuda et al. 2000, Ferrio et al. 2011 Assessing the past: archaeobotany
Charcoal within the sediment Tell Halula (J.L. Araus)
Crop & weed abundance (land use changes)
Grain size Carbon isotopes (water status & yield)
Nitrogen isotopes Fossil barley grains (soil & nutrients) Ciutat de Lleida (N. Alonso) Long-term changes in crop conditions Long-term changes in crop conditions
Carbon isotopes revealed climatic fluctuations ROMAN OPTIMUM (minima in Bronze Age and BRONZE AGE Younger Dryas)
wetter than present HOLOCENE OPTIMUM
YOUNGER DRYAS Long-term changes in crop conditions
Large expansion of agriculture after Holocene Optimum (number of sites)
HOLOCENE OPTIMUM
Agriculture Expansion Long-term changes in crop conditions
Grain size increased over time (genetic improvement) Long-term changes in crop conditions
Progressive decrease Decreasing 15N in soil fertility (lower 15N)
Expansion of agriculture = Increase land pressure
Agriculture Expansion Long-term changes in crop conditions
Regional / long-term Decreasing 15N ≈ decline soil quality
short-term / local scale?
Agriculture Expansion Land use changes & crop productivity Tell Halula, Neolithic site, Mid Euphrates (10th-8th millennia BP)
Halula, present village (Aleppo region, NW Syria)
Tell Halula, Neolithic site Land use changes & crop productivity
Tell Halula (Neolithic) Halula (present) 1300 ) -1 1200 Decrease in 1100 Grain yield 1000 (wheat) 900 Wheat 800 Barley Emmer 700
Estimated GY (Kg ha (Kg GY Estimated 600 M-PPNB L-PPNB PN Present Land use changes & crop productivity
Tell Halula (Neolithic) Halula (present) 1300 ) -1 1200 Decrease in 1100 Grain yield 1000 (wheat) 900 Wheat 800 Barley Emmer 700
Estimated GY (Kg ha (Kg GY Estimated 600 M-PPNB L-PPNB PN Present
1000 Decrease in 900 Settlement size 800 700 Abandonment 600
Estimated population 500 M-PPNB L-PPNB E-PN L-PN 1994 2004 Land use changes & crop productivity
Tell Halula (Neolithic) Halula (present) 100 Decrease in 80 legume remains
60 present cereals (barley monoculture) 40 legumes cereal weeds 20 % within crop remains crop % within Increase in % of weeds in total% of weeds remains 0 M-PPNB L-PPNB E-PN L-PN PRESENT cereal weeds Yield (Kg ha-1) Time period Land use changes & crop productivity
Tell Halula (Neolithic) Halula (present) 100 Decrease in 80 legume remains
60 present cereals (barley monoculture) 40 legumes cereal weeds 20 % within crop remains crop % within Increase in % of weeds in total% of weeds remains 0 M-PPNB L-PPNB E-PN L-PN PRESENT cereal weeds Yield (Kg ha-1) Time period 30 3.5 1.0 S H ) Decrease in ) H' (H S 25 3.0 ) diversity of H'
0.9 weed flora
20 2.5 Evenness ( Species richness ( richness Species Shannon's diversity
15 2.0 0.8 M-PPNB L-PPNB E-PN L-PN TAKE-HOME IDEAS
Climate Change and the Origins of Agriculture Agriculture originated around the world during the Holocene “Climatic Oasis”
But... causal link is still controversial
Was early agriculture sustainable? In the long term / regional level genetic improvement, but increasing land pressure (deforestation, lower soil quality)
In the short term / local level monoculture, lower yields and loss of diversity