Identifying ancient land use through the functional ecology of crop weeds
Specific objectives of this project:
- To provide a method, with a database of the functional ecology of crop weeds, for the identification of ancient agricultural practices;
- To apply these methods to archaeobotanical weed assemblages in order to identify ancient crop husbandry practices.
Methodology and Approach
This project has generated a functional ecological database for archaeobotanical application, which can be used to identify past crop husbandry practices on the basis of the weed seeds found with archaeological crop remains. The database includes over 500 archaeologically attested crop weed species from Europe and Western Asia, with measurements of 15 functional attributes. The method employes utilises easy-to-measure functional attributes that are direct or indirect measures of ecological characteristics of plants validated against experimental or distributional data (Grime et al., 1997; Hodgson et al., 1999).
This method fulfils the two prerequisites for successful archaeobotanical application of modern weed ecology to identify ancient husbandry practice:
- a. it allows 'translation' from weed species characterising present-day husbandry regimes into functional attributes applicable to archaeologically attested weeds;
- b. understanding the ecological significance of each attribute enables us to identify which aspect of husbandry is indicated by the archaeological weed assemblages.
Husbandry practices – contrasting regimes in present-day studies
The weed functional attributes measured have proved useful in distinguishing the present-day weed floras of contrasting agricultural regimes:
- Irrigation: Irrigated and dry-farmed fields in Jordan and Spain could be distinguished on the basis of specific leaf area (leaf are/leaf weight), canopy size, size and number of stomata, epidermal cell size, rooting depth;
- Manuring, weeding etc: Intensively manured and weeded plots in Greece were distinguished on the basis of leaf size, canopy size, length of flowering period and type of root system;
- Crop rotation: Different rotation regimes in Jordan could be distinguished by leaf dry matter content (fesh leaf weight/dry leaf weight), canopy size and leaf thickness;
- Sowing time: Spring and winter sowing in central Europe were distinguished by germination time, date of flowering onset and duration of flowering.
Husbandry practices – archaeological application
This method has successfully been applied to archaeobotanical assemblages to identify irrigation at Khirbet Faris, Jordan, and intensive cultivation of autumn-sown crops in Central Europe.