Computational Ecology, Macrosystems, and Emergent Patterns

How does a forest assemble itself? Why do human civilizations consistently bump against the same resource limits? Can we predict which communities will thrive under climate change?

Professor Hammond and his graduate students tackle these questions by applying the same analytical lens to both ecosystems and human societies. Their work examines how simple physical principles and biological interactions create the complex patterns we observe across scales; from individual plants competing for sunlight to global patterns in biodiversity and human settlement.

Hammond's research interests rest on three key concepts: 1) Emergent complexity arises from simple rules, 2) Scaling relationships serve as universal constraints, and 3) Simulations (physical and computational) can reveal invisible mechanisms and relationships. Building off these three core components, much of Hammond's work centers on computational models that serve as "existence proofs" - demonstrating which mechanisms are actually necessary to generate observed patterns versus which are merely sufficient.

UND Faculty Researchers: Sean T. Hammond

Allometric Theory and Biomechanical Constraints

Using individual-based computational models, Hammond simulates forest growth from first principles: allometry, biomechanics, and competition for light and space. If you build a virtual tree that must support itself against gravity and harvest light efficiently, do you automatically get the quarter-power scaling laws?^[0.75] The answer appears to be yes: physics creates corridors of existence within which evolution must operate. These models successfully predict phenomena they weren't programmed to produce, rom realistic species diversity patterns to the emergence of plant size-density relationships. This approach allows experimental manipulations impossible in real forests: what happens if we eliminate distance-dependent mortality? How do forests reassemble after dam removal? Can urban greenspaces serve as migration corridors under rapid climate change?

Human Macroecology: Applying Ecological Principles to Civilization

Humans are organisms bounded by the same physical laws as any other species. Hammond's work in human macroecology examines how food spoilage rates, transportation technologies, and energy constraints have shaped, and continue to shape, human settlement patterns, empire sizes, and civilization trajectories.

By analyzing pre-industrial shipping distances, terrestrial empire sizes, and technological innovation, Hammond examines how physical constraints create recurring patterns in human history. This quantitative approach to historical dynamics shows that many "unique" historical developments actually represent predictable outcomes of underlying physical and biological principles that have applications in modeling human settlement patterns along ancient coastlines, predicting climate refugia as wet-bulb temperatures approach human tolerance limits, and understanding how the physics of food systems must shape any sustainable future.

The Bigger Picture

Whether modeling forests, studying food transport networks, or analyzing ancient empires, Hammond's work reveals a consistent pattern: complex systems self-organize from simple rules operating within physical constraints. Understanding these emergent properties requires bridging scales, from individual organisms to global patterns, and crossing traditional disciplinary boundaries between biology, physics, history, and sustainability science.

As humanity faces unprecedented challenges (climate change, resource limitations, biodiversity loss) it needs predictive frameworks grounded in fundamental principles, not just curve-fitting to past data. Hammond's work attempts to provide exactly that: computational laboratories where one can test interventions, explore counterfactuals, and develop strategies for systems too complex or too slow to experiment with directly.

Research Group

• Allison Hinton: "Remote sensing and spatial analysis of oak refugia and migration corridors: modeling climate resilience, evaluating conservation ROI and policy adoption in the Chicago Metropolitan Area"
• Kim Berthet: "Advancing Aeromicrobiology: Investigating the Stratospheric Microbiome and Climate Impact Through the Innovation of a STEM-Focused Bioaerosol Sampling Kit"
• Tori McIntosh: "Rain Harvesting & Garden Potential: Promoting Self-Sufficiency Across North Dakota"
• Morticia Moonchilde
• Derek Grimm
• Isaac Chenoweth