Comparison of modern Pacific production systems

In document Agriculture in Tongan Prehistory: An Archaeobotanical Perspective (Page 178-200)

Comparative ethnographic examples from the Western Pacific region were analysed to establish the range of plant species exploited through production or collection techniques. Nutritional, labour, and productivity data were collated from published examples, to assess and compare the nature of decision-making in a variety of production systems. These variables will be compared and contrasted to discuss decision-making and crop selection. Five systems from the Western Pacific were chosen due to the nature of comparable data available from modern ethnographic studies. These included the Gadio Enga of the New Guinea Highlands (Dornstreich 1977),

161 Tongatapu (Ministry of Agriculture and Forestry 2001), Bellona Island (Christiansen 1975), Ontong Java (Bayliss-Smith 1973, 1977, 1986) and Anuta (Yen 1973b) in the Solomon Island Outliers. These systems were chosen based on the quality and consistency (in terms of time frame for data collection) of data available within each ethnographic study, and to represent a variety of environmental contexts (atoll, high island, raised limestone islands). Several systems also involved some use of cash-cropping (Bellona, Ontong Java and Tongatapu), but it will be argued here that these cannot be easily separated from subsistence production as these contribute to total efficiency (total de-facto output divided by primary and secondary inputs) (Bayliss-Smith 1977) within these systems.

Data was collated on the range of plant species cultivated within each system, and the labour inputs and yields for each of these. Units of labour inputs were recorded as hours invested in agricultural production and collection of gathered species, specifically those invested in garden preparation, maintenance and harvesting of crops. These were compared to outputs in terms of yield in kilos and nutritional benefits over the same time frame. These figures were used to calculate basic efficiency or rate of return ratios for each of these species in terms of nutritional and yield outputs to labour investment inputs. Understanding the basic energetic inputs to output ratios of these systems, without consideration of variables such as social values, acreage planted or harvested, seasonal variation and single or multi-cropping techniques is an important first step towards detailing the nutritional costs and benefits each system within an Human Ecological framework. While it is important to acknowledge the role that other variables play in decision-making, it is not possible to create a model that incorporates all of them. These variables cannot be determined archaeologically, and so providing basic quantifiable nutritional, labour and productivity data may at least allow interpretation of the past through modelling hypothetical and testable production systems.

Nutrition

The exploited plant species listed within each of the ethnographic examples, many of which feature in the archaeobotanical record from of Talasiu (TO-Mu-2), Leka (J17) and Heketa (TO- Nt-2), were assessed for their calorific, protein, fat and carbohydrate values for 100g of edible plant material. Some spices and ceremonial or medicinal plants such as kava (Piper methysticum) and betel nut (Areca catechu) were also included in this analysis, primarily because these were cultivated and could have contributed to dietary needs, even if that was not their primary purpose. Nutritional data was collected and collated for these species, allowing comparisons to be made across each system. A total nutritional figure per 100g for each species was created that added all of the values together. These species were considered separately, and then as groups described by their authors as horticultural, semi-cultivated, or gathered (or close synonyms of these such as gardening). These nutritional values are heavily relied upon in the literature on Evolutionary Ecology and Human Ecology to predict subsistence choices, and

162 provide interesting comparison with ethnographically recorded cases of labour and energy investment.

Gadio Enga, New Guinea

Of the modern systems analysed, the largest range of utilised plant species was present within the Gadio Enga system observed by Dornstreich (1973, 1977) in Highland New Guinea. A total of 35 species was recorded over an entire subsistence season (one year). Animal foods were included in this dataset and contributed to 25% of dietary protein and 75% of fats, but were not included in this modelling exercise which targets the role of plants within diet. A range of nutritional data was collated for species, and the mean of these ranges was used as a final figure for comparison. The species were broken down into groups including horticulture, gathered,

sago and silviculture—which involves controlling the establishment, growth, composition,

health and quality of forests to meet cultural needs. Interestingly, those species with the highest calorific value for 100g of edible plant were many of the arboreal species that were either managed through silviculture or gathered (see Table 8.21). These included semi-cultivated

Pandanus spp., and gathered Canarium spp., Macaranga spp., and Elaeocarpus sp. Root crops grown through horticulture such as Colocasia esculenta, Dioscorea spp.and Ipomoea batatas

were ranked 11th, 12th and 15th according to calorific value within this system, where highest

calorific value ranked 1 and lowest value ranked 35. In terms of protein value within the same quantity of edible plant, a similar pattern within the Gadio Enga system is evident, although the top ranked species for protein is the introduced Abelmoschus manihot, a horticulturally produced plant. Aside from this cultigen and Phaseolus vulgaris, the horticultural species generally rank very low compared to the silvicultural and gathered arboreal species.

Arboreal species also rank very highly in fat content, comprising the top eight-ranked species within the system. The highest ranked horticultural species is P. vulgaris which was ranked 9th, followed by A. manihot at 10th. The primary root crops are scattered throughout the

rankings below these, with Colocasia esculenta ranked 16th, Dioscorea spp. ranked 26th and

Ipomoea batatas ranked 28th. Patterning within the ranking of species for carbohydrate value

differs from those seen within the other nutritional values. Metroxylon spp. (sago) pith has the highest amount of carbohydrates per 100g within the Gadio Enga system. Several arboreal fruits rank just below this crop, but root crops such as C. esculenta (ranked 4th)rank higher than that

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Table 8.21 Nutritional figures and rankings for species within the Gadio Enga system according to calories, protein, fats, carbohydrates and total nutrition figures (data from Dornstreich 1974, 1978)

Species Mean kcal Rank kcal Protein mean Rank protein Fat mean Rank Fat Carbohydrates mean Rank carbohydrates Total figures Overall rank nutrition

Abelmoschus manihot 369.6 5 21.1 1 2.8 10 15.002 14 408.5 5

Areca catechu 249.0 8 5.0 10 4.0 7 47 2 305.0 8

Artocarpus altilis flesh 82.5 16 2.6 16 0.9 11 19.0 12 105.0 17

Artocarpus altilis seeds 150.0 9 6.0 9 0.5 14 30.0 5 186.5 10

Canarium spp. 644.0 2 14.2 5 68.5 1 5.5 27 732.2 2 Carica papaya 43.0 22 0.5 32 0.3 18 11.0 18 54.8 23 Colocasia esculenta 132.5 11 1.7 21 0.4 16 31.6 4 166.2 11 Cucumis sativa 16.0 29 0.6 30 0.1 28 3.6 29 20.3 33 Curcubita moschata 45.0 20 1.0 26 0.1 28 11.7 17 57.8 22 Cympobogon citratus 25.0 27 2.5 17 0.1 28 0.0 33 27.6 31 Dioscorea spp 128.0 12 1.8 20 0.1 26 26.9 7 156.7 13 Diplazium sp. 341.0 6 14.3 4 0.1 26 8.3 21 363.7 7 Edible ferns 50.0 18 0.3 34 3.2 8 6.0 24 59.5 21 Elaeocarpus sp. 375.0 4 15.0 3 30.0 4 16.0 13 436.0 4 Ficus sp. 13.0 32 7.6 8 9.0 5 5.3 28 34.9 28 Gnetum gnemon 28.0 26 5.0 10 0.2 24 11.0 18 44.2 27 Inocarpus fagifer 240.0 9 4.5 12 4.5 6 40.0 3 289.0 9 Ipomoea batatas 95.0 15 1.6 22 0.1 28 20.1 10 116.8 15 Lagenaria siceraria 14.0 30 0.6 30 0.0 33 3.4 30 18.0 34 Luffa sp. 13.0 32 0.7 29 0.3 17 14.34 15 28.3 30 Macaranga spp. 601.0 3 18.9 2 60.4 3 7.4 22 687.7 3 Manihot esculenta 135.0 10 0.9 28 0.0 33 24.0 8 159.9 12 Metroxylon spp. 323.5 7 0.3 34 0.3 18 79.0 1 403.1 6 Musa spp. 113.5 13 1.2 25 0.3 18 27.3 6 142.3 14 Oenanthe javanica 40.0 23 3.6 15 0.3 18 6.0 24 49.9 25 Pandanus spp. 683.0 1 11.9 6 66.0 2 22.0 9 782.9 1 Pangium edule 40.0 23 1.0 26 0.1 28 20.0 11 61.1 19 Phaseolus vulgaris 97.0 14 8.1 7 3.0 9 0.0 33 108.1 16 Piper betel 44.0 21 4.0 14 0.4 15 6.0 24 54.4 24 Rorippa sp. 17.0 28 2.0 19 0.3 23 3.0 31 22.3 32 Rungia sp. 14.0 30 2.4 18 0.3 18 0.1 32 16.8 35 Saccharum edule 38.0 25 4.1 13 0.2 24 5.5 27 47.8 26 Saccharum officinarum 58.0 17 0.5 32 0.0 33 14.0 16 72.5 18 Setaria palmifolia 22.0 27 1.4 24 0.6 13 6.5 23 30.5 29 Zingiber zerumbet 48.0 19 1.5 23 0.9 11 9.5 20 59.9 20

164 A total nutritional figure was created by combining the values for calories, protein, fat and carbohydrates for each species from 100g of edible material (see Figure 8.7). This enabled an overall comparison of all species within the system. According to this value, Pandanus spp. had the highest nutritional value with a total figure of 782.9/100g, followed by a number of gathered arboreal species. The highest ranked horticulturally produced crop is again A. manihot, with a figure of 408.5/100g, while root crops such as C. esculenta rank 11th with a figure of

166.2/100g, and Dioscorea spp. rank 13th with a figure of 156.7/100g. When the averages of

each of the production groups are compared, sago production ranks the highest; however, this is biased by this group containing only this single species. When the remaining groups are compared, those species grown using silviculture appear to have the highest total nutrition figures with an average of 246.4/100g, followed closely by gathered species which have an average of 225.9/100g. Surprisingly, horticulturally produced species have the lowest average— 99.4/100g within the Gadio Enga system.

Figure 8.7 Nutritional comparison of species within the Gadio Enga plant production system (data from Dornstreich 1974, 1978)

Bellona, Solomon Islands

The plant production system on Bellona was recorded by Christiansen (1975) between the years 1965-66, describing a total of 29 plant species utilised within this system. Species within this system were categorised by the author into two groups: horticulture and semi-cultivated. The latter group includes plants which require some anthropogenic manipulation for initial growth but are mostly untended after this time apart from harvesting on a regular basis or opportunistically. This semi-cultivated category includes many arboreal species from which fruits are harvested and mostly eaten raw, or through some processing to remove toxins

165 (Christiansen 1975:36-7). Gathering or hunting of plant, animals and fish is described by Christiansen as a means of filling the temporal gap in food supplies during different seasons, during which the bulk of available foods are sourced from outside horticultural practices for at least a month or more.

Firstly, in terms of calories, the highest ranked species are again the arboreal semi- cultivated species such as Pandanus spp. and Canarium spp., which is similar to the rankings seen in the Gadio Enga system (see Table 8.22). Here though, the highest ranked horticultural species is Cocos nucifera (coconut), ranked 3rd with a calorific value of 425.5/100g for the

mature meat of the fruit. This is followed by the horticulturally produced root crop Pueraria lobate (kudzu vine), the rhizome of which has a calorific value of 382/100g. Kudzu is not often cultivated today, but instead is naturalised on many Pacific Islands. The common root crops such as Colocasia esculenta (12th) and Dioscorea spp.(14-15th, 17-18th, 23rd)appear within the

middle of the spread of calorific rankings along with Musa spp. (16th). Many of the arboreal

species of which fruits are eaten raw, such as Spondias dulcis and Syzygium spp., rank the lowest of all the utilised species.

Comparison of protein values reveals a similar pattern to calories. Semi-cultivated arboreal species dominate the highest rankings based on protein content, with the highest ranking horticultural species, Artocarpus altilis (seeds) being ranked 6th. Root crops generally

rank very low (>15th), apart from Tacca leontopetaloides (Polynesian arrowroot), which ranks

7th with a protein value of 5.1/100g. The fat content of these species again follows a similar

pattern to calories and protein, with C. nucifera ranking the highest of the horticultural species with 34-43/100g (ranked 3-4th), followed by T. leontopetaloides ranked at 8th with 2.6/100g. The

remaining root crops all have less than 0.4/100g and rank lower than 15th. Similar to the

patterning observed within the Gadio Enga system, the carbohydrate values of these species provides a different distribution of rankings compared to the other nutritional figures.

Saccharum officinarum (sugarcane) ranks the highest, with a total value of 100/100g— meaning that this species is entirely composed of carbohydrates. Root crops such as Alocasia macrorrhiza, Colocasia esculenta, Tacca leontopetaloides, Ipomoea batatas and Dioscorea spp. also rank very highly according to carbohydrate value, along with some semi-cultivated arboreal species. These figures are not all that surprising, considering that the carbohydrate value of these species is generally argued to be the reason that they were initially domesticated.

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Table 8.22 Nutritional figures and rankings for species within Bellona Island system according to calories, protein, fats, carbohydrates and total nutrition figures (data from Christiansen 1975)

Species Mean kcal Rank kcal Protein mean Rank protein Fat mean Rank Fat Carbohydrates mean Rank carbohydrates Total figures Overall rank nutrition

Alocasia macrorrhiza 106.0 18 2.0 17 0.2 22 22 10 130.1 18

Amorphophallus paeoniifolius 135.0 10 2.2 14 0.1 27 18.19 18 155.5 13

Artocarpus altilis flesh 82.5 22 2.6 12 0.9 12 19.0 17 105.0 22

Artocarpus altilis seeds 150.0 9 6.0 6 0.5 13 30.0 5 186.5 10

Burckella sp. 56.0 25 1.1 25 1.3 11 20.1 12 78.5 24

Canarium spp. 644.0 2 14.2 2 68.5 1 5.5 27 732.2 2

Canavalia sp. 372.0 6 34.8 1 1.5 10 51.7 3 460.0 5

Cocos nucifera immature meat 105.0 20 2.4 13 8.0 7 7.0 26 122.4 19

Cocos nucifera mature meat 425.5 3 4.4 9 43.2 3 10.5 23 483.6 3

Cocos nucifera mature milk 328.5 7 3.4 10 34.5 4 5.5 27 371.9 7

Colocasia esculenta 132.5 12 1.7 21 0.4 15 31.6 4 166.2 11 Cucumis melo 34.0 28 0.8 27 0.2 18 8.0 25 43.0 29 Dioscorea alata 119.7 15 2.1 16 0.1 25 19.6 16 141.5 16 Dioscorea bulbifera 106.0 18 1.9 18 0.1 27 25.3 8 133.3 17 Dioscorea esculenta 120.3 14 1.8 19 0.2 21 20.05 14 142.3 14 Dioscorea nummularia 106.7 17 1.7 22 0.1 29 13.3 20 121.7 20 Dioscorea pentaphylla 82.0 23 1.7 20 0.1 25 20.0 15 103.8 23 Ficus sp. 13.0 31 7.6 5 9.0 6 5.3 29 34.9 30 Gnetum sp. 28.0 29 5.0 8 0.2 18 11.0 22 44.2 28 Ipomoea batatas 95.0 21 1.6 23 0.1 23 20.1 12 116.8 21 Mangifera sp. 60.0 24 0.8 27 0.4 14 15.0 19 76.2 25 Manihot esculenta 135.0 10 0.9 26 0.0 30 24.0 9 159.9 12 Morinda citrifolia 38.0 27 2.7 11 1.8 9 12.0 21 54.5 26 Musa spp. 113.5 16 1.2 24 0.3 16 27.3 6 142.3 15 Pandanus spp. 683.0 1 11.9 3 66.0 2 22.0 10 782.9 1 Pueraria lobata 382.0 4 2.1 15 0.1 23 27.1 7 411.3 6 Saccharum officinarium 375.0 5 0.0 31 0.0 30 100.0 1 475.0 4 Spondias dulcis 43.7 26 0.8 27 0.3 16 3.65 31 48.5 27 Syzygium spp. 21.0 30 0.7 30 0.2 18 5.3 29 27.2 31 Tacca leontopetaloides 122.0 13 5.1 7 2.6 8 89.4 2 219.1 9 Terminalia sp. 258.0 8 9.6 4 24.0 5 8.3 24 299.9 8

167 Finally, the total nutritional figures for all 29 plant species within the Bellona Island system were compared (see Figure 8.8). From these, Pandanus spp. again ranks the highest, followed by Canarium spp., another group of semi-cultivated arboreal species. The highest value of the horticulturally produced species was recorded in C. nucifera mature meat with a total nutritional figure of 483.5/100g. A mixture of cultivated grasses (sugarcane), fruits (Canavalia spp. and C. nucifera mature milk), and root crops (Pueraria lobata) all had total figures greater than 300/100g, and thus were ranked higher than the next highest ranked semi- cultivated species— Terminalia spp.When the two groups are compared, the averages of each are essentially very similar. Horticulturally produced species have an average total nutritional figure of 215.8/100g, while semi-cultivated species have an average of 205.9/100g.

Figure 8.8 Nutritional comparison of species within the Bellona Island plant production system, showing exponential trend lines for horticultural and semi-cultivated taxa (data from Christiansen 1975)

Anuta, Solomon Islands

An ethnographic, ecological and archaeological survey of Anuta was carried out by Yen and others (1973b) over several field seasons in 1970-71. Details of Anutan subsistence were recorded over a period of 37 days, with the aim of investigating the reputed intensity of agricultural practice on the island (Yen and Gordon 1973). The use of 19 plant species was recorded within this survey. When the nutritional values of these species are compared, some very different patterning can be observed from both the Gadio Enga and Bellona Island systems, primarily due to the reduced number of exploited arboreal species (see Table 8.23). Unlike the other modern systems, the Anutan plant species were not divided by the authors into any groups. However, since labour and productivity data were recorded for only a few of these, this was taken to indicate that these were primary crops, while all others were most likely

168

supplementary species. This assumption may not be correct, and so the interpretation of these categories within the nutritional figures will not carry the same weight as those used in the other systems.

The archaeology and ecology of Anuta and nearby Tikopia have been compared by researchers in the past (Firth 1939; Kirch 1995; Kirch and Yen 1982). Agricultural production on Tikopia was similar to Anuta in a number of ways including major crop dominance, the use of some tree species as well as root crops, and the mulching of taro and manioc with coconut fronds (Yen and Gordon 1973). Some important differences also existed in the past between these two locations. Sweet potato is significantly more important in Tikopia than Anuta, but is produced alongside other root crops using less intensive agricultural techniques within the mountainous areas where dryland terracing is absent (Firth 1939; Yen and Gordon 1973). Tikopian agriculture was instead more intensive in flat corraline areas where rotational practices with crop successions of taro, manioc or sweet potato predominate. These factors were taken into consideration alongside the availability of labour and yield data when deciding to use data from Anuta, rather than Tikopia. It was decided that, as described by Yen (1973), Anuta represented a highly intensive agricultural system, possibly the most intensive within the Pacific and presented a unique case study for this modelling exercise.

Calorific comparison indicates that the highest ranked species are the few arboreal species within this system, including Canarium spp. with a value of 644/100g, followed by mature meat of Cocos nucifera with a value of 425.5/100g. Those species with little other data recorded, being supplementary species such as Curcuma longa (turmeric), Metroxylon salomonense (sago), and Inocarpus fagifer, are often ranked higher than ‘primary crops’ such as

Colocasia esculenta, Manihot esculenta (cassava), and Cyrtosperma merkusii (giant swamp taro). A slightly different range of supplementary crops dominate the highest rankings according to protein content. Canarium spp. again takes out the top rank with a value of 14.2/100g, followed by another fruit tree, Barringtonia procera, with a value of 9.7/100g. These arboreal species are then followed in ranking by a number of root crops (Curcuma longa and Tacca leontopetaloides). The highest ranked ‘primary crop’ is Cocos nucifera with a protein value of 4.35/100g within mature meat. All primary root crops have a protein value of less than 2/100g.

Comparison of the fat content of these plant species indicates that both primary and supplementary arboreal species generally have higher values than root crops. Those that differ from this trend include C. longa with a ranking of 3rd, and T. leontopetaloides with a ranking of

9th out of the 21 total species. Carbohydrate values provide a different trend, but both of these

root crops again rank very highly. In fact, T. leontopetaloides has the highest carbohydrate content with a value of 89.4/100g. Primary root crops such as Colocasia esculenta, Dioscorea

169 spp.and Manihot esculenta all range from 20-30/100g and rank in the top ten of the 19 species. Again, this trend was expected.

The overall nutrition figures suggest that in general, those species grouped here as supplementary have higher nutritional value than those grouped as primary crops (Figure 8.9), as expected if production costs are lower for certain crops with low-to-medium nutritional value. The averages of these groups confirm this trend, where supplementary species have an average of 310.5/100g, while primary species only have an average of 190.3/100g. Within this pattern it was also observed that arboreal species tend to have higher values than root crops. The highest overall ranked species was Canarium spp. with a value of 732.2/100g, followed by C. nucifera mature meat with 483.5/100g. The highest ranked root crop was C.longa with a value of 437/100g, and the next was T. leontopetaloides with 219.1/100g. The highest ranked primary root crop was C. esculenta, followed closely by M. esculenta.

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Table 8.23 Nutritional figures and rankings for species within Anutan system according to calories, protein, fats, carbohydrates and total nutrition figures (data from Yen 1973b)

Species Mean kcal Rank kcal Protein mean Rank protein Fat mean Rank Fat Carbohydrates mean Rank carbohydrates Total figures Overall rank nutrition

Alocasia macrorrhiza 106.0 16 2.0 12 0.2 17 22 11 130.1 16 Areca catechu 249.0 7 5.0 5 4.0 8 47 4 305.0 7 Artocarpus altilis 82.5 19 2.6 10 0.9 11 19.0 15 105.0 19 Barringtonia procera 243.0 8 9.7 2 11.8 4 35.3 6 299.8 8 Burckella obovata 56.0 20 1.1 17 1.3 10 20.1 12 78.5 20 Canarium sp. 644.0 1 14.2 1 68.5 1 5.5 20 732.2 1

Cocos nucifera immature meat 105.0 17 2.4 11 8.0 6 7.0 18 122.4 17

Cocos nucifera mature meat 425.5 2 4.4 7 43.2 2 10.5 17 483.6 2

Cocos nucifera mature milk 328.5 5 3.4 9 34.5 3 5.5 20 371.9 6

Colocasia esculenta 132.5 11 1.7 14 0.4 13 31.6 7 166.2 11 Curcuma longa 354.0 4 8.0 3 10.0 5 65.0 3 437.0 3 Cyrtosperma merkusii 122.0 13 0.5 19 0.2 16 19.91 14 142.6 14 Dioscorea spp. 128.0 12 1.8 13 0.1 18 26.9 9 156.7 13 Inocarpus fagifer 240.0 9 4.5 6 4.5 7 40.0 5 289.0 9 Ipomoea batatas 95.0 18 1.6 15 0.1 19 20.1 12 116.8 18 Manihot esculenta 135.0 10 0.9 18 0.0 20 24.0 10 159.9 12 Metroxylon salomonense 323.5 6 0.3 21 0.3 14 79.0 2 403.1 4 Musa spp. 113.5 15 1.2 16 0.3 14 27.3 8 142.3 15 Piper betel 44.0 21 4.0 8 0.4 12 6.0 19 54.4 21 Saccharum officinarum 375.0 3 0.5 20 0.0 20 14.0 16 389.5 5 Tacca leontopetaloides 122.0 13 5.1 4 2.6 9 89.4 1 219.1 10

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Figure 8.9 Nutritional comparison of species within the Anutan plant production system, showing exponential trend lines for primary and supplementary taxa (data from Yen 1973b)

Tongatapu, Tonga Archipelago

In 2001, an agricultural census was conducted by the Tongan Ministry of Agriculture and Forestry. This included a survey of agricultural holdings, productivity and labour investment, from which a list was provided of all plant species utilised on Tongatapu. This list contains 22 plant species, and was again broken down for comparative purposes into two groups,

horticultural and semi-cultivated based on ethnographic data from European Contact-era recordings of subsistence strategies (Beaglehole and Beaglehole 1941; Cook in Beaglehole 1969; Cook 1875; Gifford 1929; La Perouse 1799; La Billardiere 1800; Mariner in Martin 1991; Maude 1965; Wilson 1799; Waldegrave 1873). This census was chosen over Maude’s (1965) research based on the geographic scope (all of Tongatapu) and consistency of labour investment with yield data in terms of the time period of data collection (one year).

The distribution of calorific values of these crops follows a similar trend to most of the

In document Agriculture in Tongan Prehistory: An Archaeobotanical Perspective (Page 178-200)