About

Alejandra Domic is an Assistant Research Professor in the Department of Anthropology at Penn State University. Her research focuses on understanding the impact of climate change and humans on ecosystems across time. She studies how climate and human activities have affected ecosystems over both short-term (decades) and long-term (centuries and thousands of years) scales, with an emphasis on their resiliency to disturbance. Her work provides a paleoecological outlook into ecological problems, particularly how tropical ecosystems responded to changes in climatic conditions and habitat transformation over time. This research is critical for understanding how vegetation and human societies will respond to the intensification of extreme climatic events in the modern era.

Research topics

• Biology
• Geography
• Botany
• Archaeology
• Sociology
• Horticulture
• Genetics
• Demography
• Ecology
• Agronomy
• Forestry

Selected publications

• Early evidence of avocado domestication from El Gigante Rockshelter, Honduras

  Proceedings of the National Academy of Sciences · 2025-03-03 · 3 citations

  articleOpen access

  Molecular research suggests that avocados ( Persea americana Mill.) were domesticated multiple times in the Americas. Seed exchange, hybridization, and cloning have played an essential role across their wild distribution from Mexico to South America to create the modern varieties of today. Archaeological sites with well-preserved and directly radiocarbon-dated botanical assemblages are rare, however, so we know very little about the complexities of the domestication process. Here, we define an early locus of avocado domestication using well-dated desiccated and carbonized avocado remains from El Gigante rockshelter in western Honduras spanning the last 11,000 y. Measurements of avocado seeds and rinds show evidence for long-term management resulting in selection for larger, more robust fruits through time that culminated by 2,250 to 2,080 calendar B.P. (cal. B.P.). However, human-directed selection for larger fruits with thicker rinds is evident as early as 7,565 to 7,265 cal. B.P. Seed morphology is similar to P. americana var. guatemalensis and is congruent with genetic data for the development of this variety in both the highlands of Guatemala and Honduras. Increases in seed size and rind thickness through time are consistent with genetic evidence for the enrichment of putative candidate genes for fruit development and ripening in this variety.

  PublisherDOI

• Historic manioc genomes illuminate maintenance of diversity under long-lived clonal cultivation

  Science · 2025-03-06 · 11 citations

  article

  Manioc-also called cassava and yuca-is among the world's most important crops, originating in South America in the early Holocene. Domestication for its starchy roots involved a near-total shift from sexual to clonal propagation, and almost all manioc worldwide is now grown from stem cuttings. In this work, we analyze 573 new and published genomes, focusing on traditional varieties from the Americas and wild relatives from herbaria, to reveal the effects of this shift to clonality. We observe kinship over large distances, maintenance of high genetic diversity, intergenerational heterozygosity enrichment, and genomic mosaics of identity-by-descent haploblocks that connect all manioc worldwide. Interviews with Indigenous traditional farmers in the Brazilian Cerrado illuminate how traditional management strategies for sustaining, diversifying, and sharing the gene pool have shaped manioc diversity.

  PublisherDOI

• Wetlands of Mountain Regions of Bolivia

  2025-01-17 · 1 citations

  other1st authorCorresponding

  Andean mountain wetlands are ecosystems found in the semiarid and arid Bolivian Andes between 3500 and 5000 m a.s.l. They are characterized by the presence of unique and distinctive plant communities adapted to extreme environmental conditions, including large daily temperature variations, night frosting, and exposure to high levels of UV light. Indigenous communities rely heavily on mountain wetlands, and they have developed a suite of strategies to maintain and expand peatlands over generations. Despite major efforts to document the flora and fauna associated with these ecosystems during the past decades, global warming and land-use intensification constitute major threats to the stability of these ecosystems. Conservation programs should include the active participation of local indigenous communities to develop new strategies for conservation planning in the light of climate change.

  PublisherDOI

• Archaeology, ethnography, and geosciences reveal central role of traditional lifeways in shaping Madagascar’s dry forests

  Journal of Social Archaeology · 2024-06-24 · 4 citations

  articleOpen access

  Many communities in southwestern Madagascar rely on a mix of foraging, fishing, farming, and herding, with cattle central to local cultures, rituals, and intergenerational wealth transfer. Today these livelihoods are critically threatened by the intensifying effects of climate change and biodiversity loss. Improved understanding of ancient community-environment dynamics can help identify pathways to livelihood sustainability. Multidisciplinary approaches have great potential to improve our understanding of human-environment interactions across spatio-temporal scales. We combine archaeological survey data, oral history interviews, and high-resolution multispectral PlanetScope imagery to explore 400 years of human-environment interaction in the Namonte Basin. Our analysis reveals that settlement and land-use led to significant changes in the region's ecology, both during periods of occupation and after settlement abandonment. Human activity over this period may have stabilized vegetative systems, whereby seasonal changes in vegetative health were reduced compared to surrounding locations. These ecological legacies may have buffered communities against unpredictable climate challenges.

  PublisherOA PDFDOI

• Geophysics elucidate long-term socio-ecological dynamics of foraging, pastoralism, and mixed subsistence strategies on SW Madagascar

  Journal of Anthropological Archaeology · 2024-07-14 · 3 citations

  articleOpen access

  The environmental impacts of human societies are generally assumed to correlate with factors such as population size, whether they are industrialized, and the intensity of their landscape modifications (e.g., agriculture, urban development). As a result, small-scale communities with subsistence economies are often not the focus of long-term studies of environmental impact. However, comparing human-environment dynamics and their lasting ecological legacies across societies of different scales and forms of organization and production is important for understanding landscape change at regional to global scales. On Madagascar, ecological and cultural diversity, coupled with climatic variability, provide an important case study to examine the role of smaller-scale socioeconomic practices (e.g., fishing, foraging, and herding) on long-term ecological stability. Here, we use multispectral satellite imagery to compare long-term ecological impacts of different human livelihood strategies in SW Madagascar. Our results indicate that the nature of human-environmental dynamics between different socioeconomic communities are similar. Although some activities leave more subtle traces than others, geophysics highlight similar signatures across a landscape inhabited by communities practicing a range of subsistence strategies. Our results further demonstrate how Indigenous land stewardship is integrated into the very fabric of ecological systems in SW Madagascar with implications for conservation and sustainability.

  PublisherDOI

• Carbon dynamics in high‐<scp>A</scp>ndean tropical cushion peatlands: A review of geographic patterns and potential drivers

  Ecological Monographs · 2024-07-22 · 12 citations

  reviewOpen access

  Abstract Peatlands store large amounts of carbon (C), a function potentially threatened by climate change. Peatlands composed of vascular cushion plants are widespread in the northern and central high Andes (páramo, wet and dry puna), but their C dynamics are hardly known. To understand the interplay of the main drivers of peatland C dynamics and to infer geographic patterns across the Andean regions, we addressed the following question: How do topography, hydrology, temperature, past climate variability, and vegetation influence the C dynamics of these peatlands? We summarize the available information on observed spatial and inferred temporal patterns of cushion peatland development in the tropical and subtropical Andes. Based on this, we recognize the following emerging patterns, which all need testing in further studies addressing spatial and temporal patterns of C accumulation: (1) Peatlands in dry climates and those in larger catchments receive higher sediment inputs than peatlands from wet puna and páramo and in small catchments. This results in peat stratigraphies intercalated with mineral layers and affects C accumulation by triggering vegetation changes. (2) High and constant water tables favor C accumulation. Seasonal water level fluctuations are higher in wet and dry puna, in comparison with páramo, leading to more frequent episodes of C loss in puna. (3) Higher temperatures favor C gain under high and constant water availability but also increase C loss under low and fluctuating water levels. (4) C accumulation has been variable through the Holocene, but several peatlands show a recent increase in C accumulation rates. (5) Vegetation affects C dynamics through species‐specific differences in productivity and decomposition rate. Because of predicted regional differences in global climate change manifestations (seasonality, permafrost behavior, temperature, precipitation regimes), cushion peatlands from the páramo are expected to mostly continue as C sinks for now, whereas those of the dry puna are more likely to turn to C sources as a consequence of increasing aridification.

  PublisherOA PDFDOI

• Archaeobotanical evidence supports indigenous cucurbit long-term use in the Mesoamerican Neotropics

  Scientific Reports · 2024-05-13 · 2 citations

  articleOpen access1st authorCorresponding

  The squash family (Cucurbitaceae) contains some of the most important crops cultivated worldwide and has played an important ecological, economic, and cultural role for millennia. In the American tropics, squashes were among the first cultivated crop species, but little is known about how their domestication unfolded. Here, we employ direct radiocarbon dating and morphological analyses of desiccated cucurbit seeds, rinds, and stems from El Gigante Rockshelter in Honduras to reconstruct human practices of selection and cultivation of Lagenaria siceraria, Cucurbita pepo, and Cucurbita moschata. Direct radiocarbon dating indicates that humans started using Lagenaria and wild Cucurbita starting ~ 10,950 calendar years before present (cal B.P.), primarily as watertight vessels and possibly as cooking and drinking containers. A rind directly dated to 11,150-10,765 cal B.P. represents the oldest known bottle gourd in the Americas. Domesticated C. moschata subsequently appeared ~ 4035 cal B.P., followed by domesticated C. pepo ~ 2190 cal B.P. associated with increasing evidence for their use as food crops. Multivariate statistical analysis of seed size and shape show that the archaeological C. pepo assemblage exhibits significant variability, representing at least three varieties: one similar to present-day zucchini, another like present-day vegetable marrow, and a native cultivar without modern analogs. Our archaeobotanical data supports the hypothesis that Indigenous cucurbit use started in the Early Holocene, and that agricultural complexity during the Late Holocene involved selective breeding that encouraged crop diversification.

  PublisherOA PDFDOI

• Carbon dynamics of high-elevation tropical cushion peatlands in the Andes

  2024-03-11 · 1 citations

  preprintOpen access

  High-Andean tropical peatlands occur up to 5000 m a.s.l., where conditions vary from cool to freezing cold on a daily basis. In the tropical and subtropical Andes, these high-elevation peatlands are mainly composed of vascular cushion plants and occur in topographically wet locations in climates ranging from very humid paramos in the north to arid puna in the south. Like other peatlands, Andean cushion peatlands store large amounts of carbon, but with high amount of sediments and higher recent carbon accumulation rates. Often, these amounts have not been quantified, nor are the controls on carbon gains and losses sufficiently known to predict changes in carbon storage due to land-use and climate change. We reviewed the literature on carbon stocks and dynamics in (sub-)tropical Andean cushion peatlands, aiming to understand the topographic, hydrologic, climatic and biotic drivers and geographic patterns. We identified important roles for catchment size and sediment inputs, temperature in combination with water availability, and vegetation, but none of these roles can be quantified yet based on currently available data. However, it is clear that predicted regional differences in climatic changes (seasonality, permafrost behavior, temperature, precipitation regimes) imply that carbon-balance trends of cushion peatlands will differ regionally, with those in paramo most likely to continue as C sinks, while those in dry puna are more likely turning to C sources under increasing aridification.

  PublisherDOI

• Trans–Holocene Bayesian chronology for tree and field crop use from El Gigante rockshelter, Honduras

  PLoS ONE · 2023 · 7 citations

  • Archaeology
  • Geography
  • Biology

  El Gigante rockshelter in western Honduras provides a deeply stratified archaeological record of human-environment interaction spanning the entirety of the Holocene. Botanical materials are remarkably well preserved and include important tree (e.g., ciruela (Spondias), avocado (Persea americana)) and field (maize (Zea mays), beans (Phaseolus), and squash (Cucurbita)) crops. Here we provide a major update to the chronology of tree and field crop use evident in the sequence. We report 375 radiocarbon dates, a majority of which are for short-lived botanical macrofossils (e.g., maize cobs, avocado seeds, or rinds). Radiocarbon dates were used in combination with stratigraphic details to establish a Bayesian chronology for ~9,800 identified botanical samples spanning the last 11,000 years. We estimate that at least 16 discrete intervals of use occurred during this time, separated by gaps of ~100-2,000 years. The longest hiatus in rockshelter occupation was between ~6,400 and 4,400 years ago and the deposition of botanical remains peaked at ~2,000 calendar years before present (cal BP). Tree fruits and squash appeared early in the occupational sequence (~11,000 cal BP) with most other field crops appearing later in time (e.g., maize at ~4,400 cal BP; beans at ~2,200 cal BP). The early focus on tree fruits and squash is consistent with early coevolutionary partnering with humans as seed dispersers in the wake of megafaunal extinction in Mesoamerica. Tree crops predominated through much of the Holocene, and there was an overall shift to field crops after 4,000 cal BP that was largely driven by increased reliance on maize farming.

  PublisherOA PDFDOI

• DYNAMICS OF ABRUPT CHANGE IN TROPICAL AFRICAN FORESTS

  Abstracts with programs - Geological Society of America · 2023-01-01

  article
  PublisherDOI

Frequent coauthors

• José M. Capriles

  25 shared

• Julien Emile‐Geay

  University of Southern California

  8 shared

• Kristina Douglass

  Lamont-Doherty Earth Observatory

  7 shared

• Gerardo R. Camilo

  Saint Louis University

  7 shared

• Antonio Maldonado

  7 shared

• Silvia C. Gallegos

  Martin Luther University Halle-Wittenberg

  7 shared

• Logan Kistler

  National Museum of Natural History

  6 shared

• Douglas J. Kennett

  6 shared

Education

• Ph.D., Biology

  Saint Louis University

• Licenciatura, Biology

  Universidad Mayor de San Andres

  2003