Wetland Fields in the Maya Lowlands:
Archaeobotanical Evidence from Birds of Paradise, Belize
A thesis submitted to the
Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of
MASTER OF ARTS in the Department of Anthropology of the College of Arts and Sciences
2019 by
Martha M. Wendel
B.A., University of Cincinnati, 2015
Committee: Susan E. Allen, Ph.D., Chair
Sarah E. Jackson, Ph.D. David L. Lentz, Ph.D.
Abstract
Discoveries of rectangular canal patterns in the margins of wetlands in the ancient Maya lowlands of Guatemala, Belize, and Mexico shed light on a previously unknown agricultural practice: raised wetland fields. One example of wetland fields is found at the site Birds of Paradise (BOP) in the Rio Bravo region of northwestern Belize. For my research project, I have analyzed macrobotanical remains from BOP to: 1) identify the plants that were growing in the canals, 2) identify the plants that were growing in the features identified as raised fields, 3) assess their ecological preferences, 4) assess changing frequencies of different types of plants over time, and 5) provide some insight on how the canals and fields were used. Because this is the first time any systematic macrobotanical analysis has been done at BOP, it makes an important contribution to understanding how the Maya were interacting with their landscape with the use of these features. Additionally, innovative recovery methods such as use of a sonicator and sorting through all geological sieve fractions allowed for more robust quantitative analysis of data. These methods have wide application for use at other sites conducting archaeobotanical research.
Acknowledgments
There are so many people whom I have to thank for loving me and encouraging me during this incredibly stressful time and have given me so much support to continue in the field of archaeology. First, I would like to thank Dr. Susan Allen, who has given me so many opportunities to explore the field of archaeobotany and whose interest and enthusiasm for what she does continue to inspire me every day. I would be lost without your guidance!
Second, I would like to thank Dr. David Lentz who has taught me a lot about Maya paleoethnobotany and provided me with many opportunities for this research project. Third, I would like to thank Dr. Timothy Beach and Dr. Sheryl Luzzadder-Beach for providing me funding and for providing the opportunity to conduct research at Birds of Paradise. I would also like to thank Dr. Sarah Jackson for being on my committee and for teaching most of what I know about the ancient Maya. Thanks to Dr. Alan Sullivan for giving me great advice about life and archaeology and for providing me with the opportunity to explore the Southwest.
Additionally, I would like to thank Venicia Slotten for all of her help with collecting flotation samples, assistance with identification, and just listening to me when I needed to vent. Your friendship means so much to me. Thanks to Mariana Vazquez for help with identification of the plants collected from the survey. I would also like to thank the graduate students within my cohort at the University of Cincinnati, especially Emily Phillips and Ashley-Devon Williamston. Thanks to my parents for their support and for trying to understand what I do. Lastly, I would like to thank my partner, Rob Stambaugh, whose love and support gave me the strength I needed to complete one of the largest challenges in my life. Thank you for reading over chapters, listening to my ideas, and supporting my decisions.
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Table of Contents
Acknowledgments ...........................................................................................................................i
Table of Contents ...........................................................................................................................ii List of Figures ................................................................................................................................iii List of Tables .................................................................................................................................vi Chapter 1: Introduction ..................................................................................................................1 Chapter 2: Methodology ...............................................................................................................14 Chapter 3: Results and Discussion of Collected Taxa ..................................................................25 Chapter 4: Interpretations and Conclusions ..................................................................................61 References Cited ...........................................................................................................................70 Appendix 1....................................................................................................................................78
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List of Figures
Figure 1.1 Map of BOP Wetlands in relation to other Maya sites. Photo from Beach et al. 2009..................................................................................................................................................2
Figure 1.2 SubOp A, Lots 1, 2, and 3 in progress.........................................................................10 Figure 1.3 Northwest baulk of SubOp B Lot 1, Closing...............................................................11 Figure 1.4 Southeast baulk of SubOp B Lot 3, Closing................................................................12 Figure 1.5 SubOp A profile sketch showing stratigraphic layers and location of seeds from AMS dating. Image provided by Samantha Krause................................................................................13
Figure 2.1 View of south baulk of SubOp A canal after column sampling..................................15
Figure 2.2 BOP Field Season 2016 Images: a) Flote-Tech Model A flotation machine at Programme for Belize, b) agitating the heavy fraction soil during the flotation process, c) heavy and light fractions drying after flotation, d) sorting the heavy fraction at Maya Research Program..........................................................................................................................................17
Figure 2.3 VWR Ultrasonic Bath Model 75T ..............................................................................20 Figure 2.4 BOP 10025 sieve fractions after ultrasonic bath.........................................................20 Figure 2.5 Archaeobotanical remains recovered from sorting after ultrasonic bath.....................21
Figure 3.1 Absolute counts of Eleocharis sp., Cladium jamaicense, and Spilanthes cf. acmella
and all other identified non-wood seeds in SubOp A Canal and Field..........................................28
Figure 3.2 Absolute counts of Eleocharis sp., Cladium jamaicense, and Spilanthes cf. acmella
and all other identified non-wood seeds in SubOp B Canal and Field..........................................29 iii
Figure 3.3 Example of an E. prostrata achene found in only two flotation samples...........................................................................................................................................32
Figure 3.4 Example of a Spilanthes cf. acmella achene from BOP..............................................33 Figure 3.5 Example of a Celtis sp. fruit from BOP.......................................................................34 Figure 3.6 Example of a Chenopodium ambrosioides seed from the canal of BOP.....................35 Figure 3.7 Example of a Cayaponia sp. seed from SubOp B.......................................................36 Figure 3.8 Example of a Carex polystachya seed from BOP.......................................................37 Figure 3.9 Example of a Cladium jamaicense seed from BOP....................................................38 Figure 3.10 Example of a Cyperus sp. seed from BOP................................................................39 Figure 3.11 Example of an Eleocharis sp. seed from BOP..........................................................40 Figure 3.12 Example of a Fimbristylis cf. dichotoma achene from BOP Canal...........................41 Figure 3.13 Example of a Scirpus sp. seed from BOP..................................................................42 Figure 3.14 Example of a Physalis sp. seed found in only one sample (BOP 10004) from SubOp B.....................................................................................................................................................43
Figure 3.15 Example of a Solanum sp. seed recovered from BOP...............................................44 Figure 3.16 Example of a Najas guadalupensis seed recovered from BOP.................................45 Figure 3.17 Example of a Juncus sp. seed found in two samples (BOP 10026 and BOP 10027) from SubOp A Canal.....................................................................................................................46
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Figure 3.18 Example of an Andropogon sp. seed found in only one sample (BOP 10004) from SubOp B Canal..............................................................................................................................47
Figure 3.19 Example of a Panicum sp. seed found in two samples (BOP 10015 and BOP 10017) from SubOp A Field.......................................................................................................................48
Figure 3.20 Example of a Paspalum sp. seed found in only one sample (BOP 10004) of SubOp B ....................................................................................................................................................49
Figure 3.21 Example of a Polygonum sp. seed recovered from BOP...........................................50 Figure 3.22 Example of a Portulaca sp. seed recovered from BOP.............................................51 Figure 3.23 Wood density from SubOp A flotation sample depths..............................................53 Figure 3.24 Wood density from SubOp B flotation sample depths..............................................53 Figure 3.25 Transverse (100x) and tangential (200x) section of Bucida buceras........................55 Figure 3.26 Transverse (100x) and tangential (120x) sections of H. campechianum..................56 Figure 3.27 Transverse (50x) section of Mimosa sp.....................................................................58 Figure 3.28 Transverse (100x) and tangential (100x) sections of Licaria sp...............................59 Figure 3.29 Transverse section of Ficus sp. at 100x magnification.............................................60 Figure 4.1 SubOp A: Relative frequency of seeds associated with wet, wet/dry, and dry ecological conditions.....................................................................................................................62
Figure 4.2 SubOp B: Relative frequency of seeds associated with wet, wet/dry, and dry ecological conditions.....................................................................................................................63
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List of Tables
Table 1.1 List of 40 out of 44 identified herbarium specimens collected in 2016 qualitative field survey...............................................................................................................................................7
Table 3.1 Radiocarbon dates from BOP SubOp A canal and field...............................................26 Table 3.2 Summary of identified plant remains recovered from flotation samples during the 2016 field season at BOP, organized alphabetically by scientific name. C/F denote the context of recovery as Canal (C) or Field (F).................................................................................................27
Table 3.3 Analyzed hand-collected wood specimens with species, depth, SubOp, and context............................................................................................................................................54
Table 4.1 SubOp A species classified by ecological preferences: wet, wet/dry, or dry...............61 Table 4.2 SubOp B species classified by ecological preferences: wet, wet/dry, or dry................63
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Chapter 1: Introduction
The ancient Maya civilization spanned most of Mexico, Guatemala, Honduras, Belize, and El Salvador from 1800 BCE – 1530 CE (Coe and Houston 2015). The complex political and cultural organization of the Maya relied on a strong agriculturally based society adapted to a wide range of ecological and topographical settings. While their management was by no means uniform, they were able to adapt agricultural methods based on soil type, size of the land, location, etc. In order to sustain their growing population in the Late Classic Period (250 – 800 CE), the Maya used a variety of agricultural methods such as terracing, milpas, slash and burn, and small household garden plots (Lentz 1991; Beach and Dunning 1995). However, these forms of cultivation could not be used in all of the diverse environmental settings occupied by the ancient Maya, especially the swampy lowlands. Discoveries of rectangular canal patterns in wetland margins in the Maya lowlands of Guatemala, Belize, and Mexico shed light on a previously unknown agricultural practice: raised wetland fields (Turner and Harrison 1983; Jacob 1995; Fedick 1996; Pohl et. al 1996; Beach et al. 2009). These narrow, rectangular plots, elevated above the low-lying, seasonally inundated land bordering rivers or bajos, enabled the Maya to grow crops in these otherwise uncultivable areas (Coe and Houston 2015:20). The use of these wetlands allowed for the Maya to be resilient during droughts and other hardships and allowed for independence of smaller communities (Beach et al. 2009).
Throughout the Maya Lowlands, wetland agricultural use shows intensification contemporary with population increase of the ancient Maya, especially during the Classic period (Beach et al. 2009). There are three types of wetland fields: raised, drained, and recessional (Beach et al. 2009:1715). At Birds of Paradise (BOP) (Figure 1.1), features interpreted as raised fields and canals have been detected (Beach et al. 2009). Macrobotanical evidence provides one
1avenue for testing the hypothesis that these features at BOP were used as raised agricultural fields. Whereas past research has focused on pollen and stable carbon isotope evidence to understand these features, this thesis aims to use macrobotanical analysis to address questions that have long been asked about BOP. Prior to this study, only a limited preliminary macrobotanical study had been undertaken at BOP (Goldstein 2007). Macrobotanical analysis, in contrast to pollen analysis, provides a more local index of vegetation changes which can help to support or refute the hypothesis that these features were managed fields.
Figure 1.1 Map of BOP Wetlands in relation to other Maya sites. Photo from Beach et al. 2009:1711.
The goals of this research are to: 1) identify the plants that were growing in the canals, 2) identify the plants that were growing in the features identified as raised fields, 3) assess their ecological preferences, 4) assess changing frequencies of different types of plants over time, and
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5) provide some insight into how the canals and fields were used. The reported findings are based on 28 flotation samples and 14 hand-collected charcoal specimens. This research is significant because it marks the first time any standardized macrobotanical analysis has been done at BOP, and therefore makes an important contribution to understanding Maya interaction with the fields and canals and changes in land use over time. Moreover, the lab protocols adopted here provide a model for future studies where small seeds dominate the assemblage.
Thesis Organization
The first chapter will give an overview of the site Birds of Paradise, provide background information on the environmental settings at BOP and discuss past excavations conducted at BOP. Additionally, it also includes information on archaeobotanical analysis in Mesoamerica and discusses the BOP 2016 excavation. The following chapter, Chapter 2, outlines the research methodologies that were used in the recovery, identification, and quantification of archaeobotanical remains from BOP. Chapter 3 presents the macrobotanical results and findings. Chapter 4 discusses the implications of this research for BOP in particular and the outcomes of methodological practices implemented in this thesis and potential avenues for further research. Appendix 1 includes a complete inventory of the plant remains.
Birds of Paradise Overview
BOP is a wetland field site located between three to five km of the large Maya center at
Blue Creek and Gran Cacao in northwest Belize. It occupies at least 1km2 of the savanna floodplain and more in the surrounding forest (Beach et al. 2015b:1622). The features identified as Maya wetland fields at this site are rectilinear areas with one to two m wide canals running east to west and north to south at interval of approximately ten m (Beach et al. 2015b:1622).
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Timothy Beach and colleagues have been excavating at BOP since 2005 trying to understand the significance of these anthropogenic fields. On the basis of radiocarbon dates from the BOP
wetland fields and canals, the site’s occupation is dated from the Classic (250 – 900 CE) to
Postclassic (900 -1200 CE) periods (Beach et al. 2009; Luzzadder-Beach et al. 2012). Dr. Beach and Dr. Sheryl Luzzadder-Beach propose that the use of raised fields was one way that people adapted to environmental change, specifically as a response to rising sea level and the attendant higher water table and lower water quality (Beach et al. 2009; Luzzadder-Beach et al. 2012; Beach et al. 2015; Coe and Houston 2015). Understanding the archaeology behind wetland fields will add key insights to interpreting how humans have had to adapt to changing environments throughout time (Beach et al. 2009).
Environmental Setting of BOP
Geography
BOP is situated in northwestern Belize in an active floodplain near the confluence of
three rivers (Rio Azul, Rio Bravo, and Booth’s River) within the Rio Bravo Conservation and
Management Area in Northwestern Belize (Beach et al. 2009). Near the borders with Mexico and Guatemala, all three of these countries include well-drained upland karst ridge, bajos, river valleys, and the coastal plain (Beach et al. 2013). Topography in the Rio Bravo includes level and gently rolling areas, hills, and escarpments with deep ravines (Brokaw and Mallory 1993).
The local bedrock of this region is mostly limestone marl and clay, the surface of which is deeply weathered into a calcareous material known locally as sascab (Darch 1981). The floodplain and depressions are filled with Quaternary calcareous clays, marls, and peats, the upper portions of which contain abundant secondary carbonate and especially gypsum (Pohl et
4al. 1990). In the canals and fields at BOP, the soil is composed of clay and moderate quantities of gypsum, carbonate, and organic matter (Beach et al. 2009). Gypsum in the soil is derived from a geological unit that the groundwater encountered in the Rio Bravo fault zone as it rose to this elevation (Luzzadder-Beach et al. 2012:3649).
Climate
BOP has a tropical wet and dry climate with an average annual temperature is 26.4°C
(79.52°F) and receives about 1500 mm (60 in) of precipitation annually, mostly during the rainy season between June and December (Beach et al. 2009; Beach et al. 2015b:1613). The highest rainfall occurs in June and September (Beach et al. 2009). Rio Bravo lies between 17° and 18° N latitude, in the outer- or sub-tropics. There is minor seasonal variation in temperature and strong seasonality of precipitation, which puts Rio Bravo in the subtropical moist life zone of the Holdridge Life Zone System (Holdridge and Poveda 1975; Brokaw and Mallory 1993:5). Belize experiences a lot of humidity, due in part to the influence of the trade winds that collect moisture over the Caribbean Sea (Bridgewater 2012). The fluctuations in rain and temperature encourage the growth of vegetation in the general category of subtropical moist forests, with broadleaf, semi-deciduous forests (Brokaw and Mallory 1993). Because climate has not changed significantly for the past 3,000 years within Mesoamerica, modern conditions reflect a climate that is similar, with some fluctuations, to that during the occupation of the ancient Maya (Markgraf 1989).
Vegetation
During the 2016 field season, Lentz, Wendel, and Slotten conducted a qualitative field survey of several habitats surrounding the BOP excavations, both to better understand the local
5vegetation and to collect comparative materials for use in identifying materials recovered from flotation samples (Wendel et al. 2017). Two specimens of each plant were collected, with one given to the Belize herbarium in Belmopan and the other exported to the University of Cincinnati. Plants were collected from the following zones: savanna, scrub forest or floodplain forest, riparian forest, and the wetland vegetations adjacent to Cacao Creek. When a plant was in flower or had fruits it was collected, identified, dried, and then pressed for mounting on herbarium sheets. Although collection took place during the dry season, few plants were in flower at the time. During survey, we recorded the coordinates, frequency, and a list of features (habitat, flower color, bark texture, etc.) for each specimen collected. A total of 44 specimens were collected in the field and 40 were identified in the lab (Table 1.1). Five species (Bucida
buceras, Cyperus sp., Ficus sp., Panicum sp., Solanum sp.) collected during our field survey
were also found in the flotation samples at BOP.
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Table 1.1 List of 40 out 44 identified herbarium specimens collected in 2016 qualitative field survey.
Collection number