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The ancient Maya culture of Mesoamerica shaped landscapes for centuries, in an area where maize ( Zea mays ) cultivation is considered a fundamental crop in the diet of present and ancient Mesoamerican cultures. Pollen records from sites with different environmental and climatic conditions of the Yucatán Peninsula (Mexico) and Peten (Guatemala) evidence a clear relationship between increased maize pollen and periods of reduced precipitation caused by El Niño Southern Oscillation (ENSO) while moist periods are characterized by low maize pollen presence. ENSO conditions were not evenly distributed across the Yucatán Peninsula, and regional droughts vary according to regional climate and geographical conditions. Our results indicate a strong relationship of increased maize and tropical forest decrease with dry periods, while the Late Preclassic Humid Period (ca. 500–200 BCE) is characterized by the absence of maize pollen. The dry Late Preclassic (300 BCE-250 CE) was a key period for increased maize production, suggesting a new conceptualization of maize. Maize changed from a basic diet crop to a pragmatic product to face adverse environmental conditions.

Tikal has long been viewed as one of the leading polities of the ancient Maya realm, yet how the city was able to maintain its substantial population in the midst of a tropical forest environment has been a topic of unresolved debate among researchers for decades. We present ecological, paleoethnobotanical, hydraulic, remote sensing, edaphic, and isotopic evidence that reveals how the Late Classic Maya at Tikal practiced intensive forms of agriculture (including irrigation, terrace construction, arboriculture, household gardens, and short fallow swidden) coupled with carefully controlled agroforestry and a complex system of water retention and redistribution. Empirical evidence is presented to demonstrate that this assiduously managed anthropogenic ecosystem of the Classic period Maya was a landscape optimized in a way that provided sustenance to a relatively large population in a preindustrial, low-density urban community. This landscape productivity optimization, however, came with a heavy cost of reduced environmental resiliency and a complete reliance on consistent annual rainfall. Recent speleothem data collected from regional caves showed that persistent episodes of unusually low rainfall were prevalent in the mid-9th century A.D., a time period that coincides strikingly with the abandonment of Tikal and the erection of its last dated monument in A.D. 869. The intensified resource management strategy used at Tikal—already operating at the landscape’s carrying capacity—ceased to provide adequate food, fuel, and drinking water for the Late Classic populace in the face of extended periods of drought. As a result, social disorder and abandonment ensued. Significance The rise of complex societies and sustainable land use associated with urban centers has been a major focus for anthropologists, geographers, and ecologists. Here we present a quantitative assessment of the agricultural, agroforestry, and water management strategies of the inhabitants of the prominent ancient Maya city of Tikal, and how their land use practices effectively sustained a low-density urban population for many centuries. Our findings also reveal, however, that the productive landscape surrounding Tikal, managed to the brink of its carrying capacity during the Late Classic period, did not have the resilience to withstand the droughts of the 9th century. These results offer essential insights that address the question of why some cities thrive while others decline.

We evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700–1200 mm year −1 ). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.

Precipitation over the last 3800 years has been reconstructed using modern pollen calibration and precipitation data. A transfer function was then performed via the linear method of partial least squares. By calculating precipitation anomalies, it is estimated that precipitation deficits were greater than surpluses, reaching 21% and <9%, respectively. The period from 50 BC to 800 AD was the driest of the record. The drought related to the abandonment of the Maya Preclassic period featured a 21% reduction in precipitation, while the drought of the Maya collapse (800 to 860 AD) featured a reduction of 18%. The Medieval Climatic Anomaly was a period of positive phases (3.8-7.6%). The Little Ice Age was a period of climatic variability, with reductions in precipitation but without deficits.

This study presents limnological and morphological characteristics, physical and chemical properties of waters, and geochemistry of surface sediments for 63 aquatic ecosystems located on the karst Yucatán Peninsula and surrounding areas of Belize and the Guatemalan highlands and eastern lowlands. Our principal goal was to classify the aquatic systems based on their water variables. A principal component analysis (PCA) of the surface water chemistry data showed that a large fraction of the variance (29%) in water chemistry is explained by conductivity and major ion concentrations. The broad conductivity range, from 168 to 55,300 μS cm⁻¹ reflects saline water intrusion affecting coastal aquatic environments, and the steep NW-S precipitation gradient, from ~450 to >3,200 mm year⁻¹. Coastal waterbodies Celestún and Laguna Rosada displayed the highest conductivities. Minimum surface water temperatures of 21.6°C were measured in highland lakes, and warmest temperatures, up to 31.7°C, were recorded in the lowland waterbodies. Most lakes showed thermal stratification during the sampling period, with the exception of some shallow (<10 m) systems. Lakes Chichancanab, Milagros, and Bacalar displayed sulfate-rich waters. Waters of sinkholes had relatively high conductivities (<3,670 μS cm⁻¹) and a broad range of δ¹⁸O values (−4.1 to +3.8‰). Ca, HCO₃, and SO₄ dominated the waters of the lowland lakes, whereas Na was the dominant cation in highland lakes. Coastal aquatic ecosystems were dominated by Na and Cl. Cluster analysis based on surface water variables classified aquatic environments of the lowlands and highlands into three groups: (1) lowland lakes, ponds, wetlands, and coastal waterbodies (2) highland lakes, and (3) sinkholes and rivers. A broad trophic state gradient was recorded, ranging from the eutrophic Lake Amatitlán and the Timul sinkhole to oligotrophic Laguna Ayarza, with the highest water transparency (11.4 m). We used major and trace elements in surface sediments to assess pollution of waterbodies. Lakes Amatitlán, Atescatempa, El Rosario, Cayucón, Chacan-Lara, La Misteriosa, rivers Subín and Río Dulce, the wetland Jamolún, and the sinkhole Petén de Monos showed evidence of pollution and urban development. Their surface sediments displayed high concentrations of As, Cu, Fe, Ni, Pb, Se, Zn, and Zr, which suggest moderate to strong pollution.

Climate change is expected to cause major impacts on the spatial distribution of insects, yet limited analyses are available for assessing the impact of climate change on the distribution of rare Neotropical insects. Oxeoschistus hilara, O. tauropolis, and Viloriodes napaea are narrowly-distributed satyrine butterflies associated to mountain cloud forests in the Mesoamerican biodiversity hotspot. We investigate the habitat condition and occupancy of the study butterflies at local breeding sites in southern Mexico. We used distribution data to build potential spatial distribution models for the butterflies and host plants (Chusquea spp.), and to examine the potential favorable areas for both the butterfly species and Chusquea hostplants under current and future climate scenarios (RCP 2.6 and RCP 4.5). Habitat surveys indicated that the distribution of Chusquea longifolia was a good predictor of the satyrine distributions at the local scale. Climate projections indicated that both temperature and precipitation have a significant impact on the potential distribution areas for the butterflies and their Chusquea spp. hostplants. In both climate change scenarios, we estimated a significant contraction (between 30 and 56% for RCP 2.6, and between 46 and 82% for the RCP 4.5) in suitable climatic area for the study butterfly species. Projected joint distributions of butterfly species and Chusquea hostplants suggested an increasing overlap in potential climatic distributions of 15% for Chusquea spp. and O. tauropolis and of 4% for Chusquea spp. and O. hilara, and a decreasing concordance of 2% for Chusquea spp. and V. napaea, compared to current joint distributions.Implications for conservationConsidering significant reductions of suitable climatic area for the three butterfly species and their hostplants, we suggest that conservation efforts should be implemented in and around the high-suitability climatic areas to reduce population extinction risks. We also suggest reinforcing population-monitoring protocols at key butterfly locations to assess long-term variations.

Seasonally dry tropical forests (SDTFs) are shaped by strong climatic and edaphic constraints, including pronounced rainfall seasonality, extended dry periods, and shallow karst soils with limited water retention. Understanding how tree species respond to these pressures is crucial for predicting ecosystem resilience under climate change. In the Yucatán Peninsula, we characterized sixteen tree species along a spatial and seasonal precipitation gradient, quantifying wood density, predawn and midday water potential, saturated and relative water content, and specific leaf area. Across sites, diameter classes, and seasons, we measured ≈4 individuals per species (n = 319), ensuring replication despite natural heterogeneity. Using a principal component analysis (PCA) based on individual-level data collected during the dry season, we identified five functional groups spanning a continuum from conservative hard-wood species, with high hydraulic safety and access to deep water sources, to acquisitive light-wood species that rely on stem water storage and drought avoidance. Intermediate-density species diverged into subgroups that employed contrasting strategies such as anisohydric tolerance, high leaf area efficiency, or strict stomatal regulation to maintain performance during the dry season. Functional traits were strongly associated with precipitation regimes, with wood density emerging as a key predictor of water storage capacity and specific leaf area responding plastically to spatial and seasonal variability. These findings refine functional group classifications in heterogeneous karst landscapes and highlight the value of trait-based approaches for predicting drought resilience and informing restoration strategies under climate change.

Although natural regeneration is often an efficient process for recovering degraded areas, the emergence of invasive species can complicate this process and lead the ecosystem to an alternative stable state (ASS) that disrupts ecosystem functioning. Identifying this condition is a key step in the design of restoration strategies. In this sense, we used a spatially explicit approach using the landscape metric area and the analysis of land-use and land-cover change to identify the dynamics of areas dominated by P. aquilinum, an invasive species well known for producing ASS. In our study site, a Mexican semi-evergreen tropical forest and seasonal lowland flooded forest, P. aquilinum has been in ASS for decades. We analyzed P. aquilinum dynamics in a period of 28 years (1989–2017) using a supervised classification of Landsat imagery. We found that, at the landscape scale, agriculture and livestock increased 224%, while semi-evergreen tropical forest and P. aquilinum cover showed losses of 13% and 72%, respectively. At the patch scale, we also found a statistically significant decrease in P. aquilinum patch area between 1989 and 1997 and 2017, but not between 1997 and 2017. Our results show that the areas dominated by P. aquilinum only change in time mainly through management toward productive activities, while patches not managed retain their area. Our study highlights the importance of spatial scale analysis for the understanding of landscape ecosystem dynamics for guiding decision-making and further research.

The role of invasive species in ecosystem functioning represents one of the main challenges in ecology. Pteridium aquilinum is a successful cosmopolitan invasive species with negative effects on the ecological mechanisms that allow secondary succession. In this study, we evaluated the influence of P. aquilinum on secondary succession under different disturbances in a seasonal dry forest of the Yucatán Peninsula. We determined species richness, composition and the relative importance value in four sampling units. Fabaceae followed by Asteraceae, Meliaceae, Rubiaceae, Sapindaceae and Verbenaceae were the most species rich families. A dissimilarity analysis determined significant differences in beta diversity between sampling units. With a generalized linear model we found that species richness was best explained by site conditions, followed by calcium and soil organic matter. Also, the generalized linear model showed that abundance resulted in a strong correlation with site conditions and soil characteristics. Specific soil conditions related to phosphoro and calcium were also detected as beneficiary to the successional processes. Our results suggest that applying fire restriction and periodic cutting of the bracken fern, this can increase a higher diversity of species.

Open-pit mining is a common activity in the Yucatan Peninsula for the extraction of limestone. These areas are characterized by the total removal of the natural vegetation cover and soil in order to access calcareous material. The present study shows the composition and structure of the vegetation in five quarries after approximately ten years of abandonment, and the target vegetation near to the quarries in southeastern Mexico. A linear mixed model showed that P availability is one of the limiting factors for species establishment in the quarries. Using a canonical correspondence analysis (CCA), the distribution of the species was determined in relation to the edaphic variables: soil depth, the percentage of organic matter (OM), cationic exchange capacity (CEC), pH and texture. Twenty-six families, 46 genera and 50 species were recorded in the quarries, and 25 families, 45 genera and 47 species were recorded in the conserved areas. The dominant species in the quarries belong to the families Poaceae, Fabaceae, Rubiaceae and Anacardiaceae. The quarries with higher values of OM (2%), CEC (24 Cmol/kg), depth (11 cm) and sand percentage (31%) include the following species Lysiloma latisiliquum (L.) Benth., Metopium brownei (Jacq.) Urb. and Bursera simaruba (L.) Sarg., which are common in secondary forests. Quarries with lower values of OM (0.4%), CEC (17 Cmol/kg) and depth (5.02), and with a higher percentage of silt (42%) were dominated by herbs belonging to Poaceae and by Borreria verticillate (L.) G. Mey., which are typical in disturbed areas of southeastern Mexico. In all cases, the pH was slightly alkaline due to the content of calcium carbonate (CaCO3), characteristic of the soils of the region.