Scrutinizing the paleoecological record of the Maya forest

Human expansion into and occupation of the New World coincided with the great transition from the Pleistocene to the Holocene epoch, yet questions remain about how we detect human presence in the paleoecological record. In the Maya area of southern Mesoamerica, archeological evidence of the human imprint is largely invisible until ∼4,000 years ago. How do environmental changes after that time correspond and relate to human impacts? Are the archeological signatures of initial settlements in the Early Preclassic detected? Later, by ∼2,000 years ago when the Maya had fully settled the landscape, how does the evidence of forest compositional changes relate to human intervention? This paper evaluates published paleoecological data in light of the rise of the Maya civilization and reflects on interpretations of how swidden agriculture and the milpa cycle impacted the environment. Evaluating the contrast between the long archeological sequence of successful Maya development and paleoecological interpretations of destructive human-induced environmental impacts requires a concordance among pollen data, archeological evidence, ethnohistoric observations, ethnological studies of traditional Maya land use, and the historical ecology of the Maya forest today.

Conservation of Biocultural Diversity in the Huasteca Potosina Region, Mexico

The Huasteca Potosina region has a relevant landscape heritage of biocultural diversity, due to high biological diversity and the presence of the Teenek (Huastec Mayan), Nahua, and Xi’iuy (Pame) ethnic groups. The object of this study is to analyze, among the different cultural groups of the region, how the performances of the relevant Socioecological Systems (SESs) influence the conservation of biocultural diversity. Quantitative approaches are used to determine the expected trends of indices (Informant Consensus Factor, ICF; Cultural Importance Index, CII; Shannon–Wiener Biodiversity Index, SWI) commonly used in the ethnobotanical field. Data of the main domestic forest species used by the groups mentioned above were collected in 2021. We analyzed the SES profile for each of the ethnic groups and a mestizo group, as well as their relationship with the biome they mainly inhabit and the domestic functions fulfilled by the ethnobotanical species. As a result, we found that the low deciduous forest and the sub-evergreen tropical forest biomes, which co-evolved mainly with the Nahua and the Teenek SESs, present higher diversity and effective use of species so that offer better chances for conserving the landscape heritage of biocultural diversity. Otherwise, the results also show the critical nature regarding the biomes inhabited by the Pame and the mestizo’s SESs.

A Tale of Maize, Palm, and Pine: Changing Socio-Ecological Interactions from Pre-Classic Maya to the Present Day in Belize

The environmental impact of the ancient Maya, and subsequent ecological recovery following the Terminal Classic decline, have been the key foci of research into socio-ecological interactions in the Yucatán peninsula. These foci, however, belie the complex pattern of resource exploitation and agriculture associated with post-Classic Maya societies and European colonisation. We present a high-resolution, 1200-year record of pollen and charcoal data from a 52-cm short core extracted from New River Lagoon, near to the European settlement of Indian Church, northern Belize. This study complements and extends a previous 3500-year reconstruction of past environmental change, located 1-km north of the new record and adjacent to the ancient Maya site of Lamanai. This current study shows a mixed crop production and palm agroforestry management strategy of the ancient Maya, which corroborates previous evidence at Lamanai. Comparison of the two records suggests that core agricultural and agroforestry activities shifted southwards, away from the centre of Lamanai, beginning at the post-Classic period. The new record also demonstrates that significant changes in land-use were not associated with drought at the Terminal Classic (ca. CE 1000) or the European Encounter (ca. CE 1500), but instead resulted from social and cultural change in the post-Classic period (CE 1200) and new economies associated with the British timber trade (CE 1680). The changes in land-use documented in two adjacent records from the New River Lagoon underline the need to reconstruct human–environment interactions using multiple, spatially, and temporally diverse records.

The pre-Columbian introduction and dispersal of Algarrobo (Prosopis, Section Algarobia) in the Atacama Desert of northern Chile

Archaeological and palaeoecological studies throughout the Americas have documented widespread landscape and environmental transformation during the pre-Columbian era. The highly dynamic Formative (or Neolithic) period in northern Chile (ca. 3700-1550 yr BP) brought about the local establishment of agriculture, introduction of new crops (maize, quinoa, manioc, beans, etc.) along with a major population increase, new emergent villages and technological innovations. Even trees such as the Algarrobos (Prosopis section Algarobia) may have been part of this transformation. Here, we provide evidence that these species were not native to the Atacama Desert of Chile (18-27°S), appearing only in the late Holocene and most likely due to human actions. We assembled a database composed of 41 taxon specific AMS radiocarbon dates from archaeobotanical and palaeoecological records (rodent middens, leaf litter deposits), as well an extensive bibliographical review comprising archaeobotanical, paleoecological, phylogenetic and taxonomic data to evaluate the chronology of introduction and dispersal of these trees. Although Algarrobos could have appeared as early as 4200 yr BP in northernmost Chile, they only became common throughout the Atacama over a thousand years later, during and after the Formative period. Cultural and natural factors likely contributed to its spread and consolidation as a major silvicultural resource.

Modern tree species composition reflects ancient Maya "forest gardens" in northwest Belize

Ecology and ethnobotany were integrated to assess the impact of ancient Maya tree-dominated home gardens (i.e., "forest gardens"), which contained a diversity of tree species used for daily household needs, on the modern tree species composition of a Mesoamerican forest. Researchers have argued that the ubiquity of these ancient gardens throughout Mesoamerica led to the dominance of species useful to Maya in the contemporary forest, but this pattern may be localized depending on ancient land use. The tested hypothesis was that species composition would be significantly different between areas of dense ancient residential structures (high density) and areas of little or no ancient settlement (low density). Sixty-three 400-m2 plots (31 high density and 32 low density) were censused around the El Pilar Archaeological Reserve in northwestern Belize. Species composition was significantly different, with higher abundances of commonly utilized "forest garden" species still persisting in high-density forest areas despite centuries of abandonment. Subsequent edaphic analyses only explained 5% of the species composition differences. This research provides data on the long-term impacts of Maya forests gardens for use in development of future conservation models. For Mesoamerican conservation programs to work, we must understand the complex ecological and social interactions within an ecosystem that developed in intimate association with humans.