Date of Award
2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Plant and Soil Science
First Advisor
Yolanda H. Chen
Second Advisor
Alison K. Brody
Abstract
Agriculture, or the cultivation of domesticated crops, has had great effects on arthropod biodiversity and plant-arthropod interactions. Agriculture emerged from two major human-driven processes: the artificial selection of plants to meet human necessities (or crop domestication) and the management of the environment to support crop growth (or cultivation). Interestingly, only a few studies have explored the ecological and evolutionary consequences of cultivating domesticated crops. For example, previous research has shown that novel crop traits (known as domestication syndromes) have increased the susceptibility of plants to insect herbivores due to reductions in defenses and disruptions in plant-herbivore-parasitoid interactions. Similarly, different cultivation techniques (such as intercropping, the use of mineral fertilizers, and the addition of chemical pesticides) can enhance the selective pressures experienced by both beneficial and harmful arthropods. As a consequence, it is widely believed that agriculture may have facilitated the emergence of pests. Meanwhile, crop wild relatives (and crop wild ancestors) are known for interacting differently with the arthropod communities they sustain. However, even though the emergence of agriculture could have destabilized historical plant-arthropod interactions, few studies have systematically explored the direct and interactive effects of crop domestication and cultivation. Moreover, and to our knowledge, only a handful of studies have been conducted within centers of origin.
When examining the consequences of agriculture, it is important to account for the historical phylogenetic relationships between plants and arthropods. To achieve this, more field studies are needed in centers of origin. In such geographic areas, crop wild relatives (and crop wild ancestors) have interacted with native arthropod species since prior to the emergence of agriculture. Therefore, centers of origin are also important for biodiversity conservation, as these areas are the source of major pests and beneficial interactions. However, most agricultural studies ignore the co-evolutionary history of arthropods, as they have typically been conducted outside centers of origin. Hence, more data is still needed to properly understand the ecological and evolutionary impacts of crop domestication and cultivation. To shed light on how the emergence of agriculture has molded arthropod agrobiodiversity and ecosystem services, we studied its effects in Mexico, the center of origin for many agriculturally important species (such as maize, beans, squash, and husk tomatoes).
Overall, we explored the effects of agriculture on plant traits, trophic interactions, and arthropod biodiversity in Mexico, while using a multispecies approach. By comparing multiple domestication events, we aimed to identify trends and/or dissimilarities in the impacts of agriculture. For example, we found that agriculture significantly altered leaf traits related to herbivory (such as leaf area, specific leaf area, relative chlorophyll content, and trichome density). Later, we observed how these changes may have influenced crop susceptibility to herbivores (such as insect-related leaf damage). Finally, by using metabarcoding tools, we found that crops within agroecosystems exhibit differences in arthropod diversity (such as α-diversity and β-diversity) and community composition when compared to wild relatives growing in natural habitats. Notably, the effects of agriculture on plant morphology, herbivory levels, and arthropod communities varied not only with the observed domestication event but also by the leaf traits, types of herbivory, and arthropod orders under study. Therefore, this dissertation provides valuable insights into how generalizable the effects of agriculture are, as well as the broader implications of cultivating domesticated crops for agrobiodiversity and ecosystem services.
Language
en
Number of Pages
199 p.
Recommended Citation
Ruiz-Arocho, Jorge Alfonso, "Crop Domestication And Cultivation: Major Forces Shaping Arthropod Biodiversity And Plant-Arthropod Interactions In Mexico" (2025). Graduate College Dissertations and Theses. 2076.
https://scholarworks.uvm.edu/graddis/2076
