Lunch being had we crowd into a new room to hear Stephen Peck, a biologist from Brigham Young University down the road a ways in Provo. Stephen is talking about ecological boundaries.
A group of ecologists set up seven different ecosystem groups for agroecosystem studies. They debated how to define an ecosystem, and it simply got harder. They needed a biological indicator to determine the state of the ecosystem and couldn't even get to defining the latter. Over fifteen years, he hasn't been able to figure it out.
Properties of ecosystem boundaries:
- Fuzzy
- Non-regulated -> Highly regulated
- Perspectival
- Structured by multiple processes
- Multiple scales of space and time
- Not fixed spatiotemporally
- Resistant to general definition
They have various degrees of boundary sharpness, they are regulated in different ways, they depend on the perspective of the observer, structured by a range of underlying processes, they move and shift. A list of structuring processes followed.
Why do boundaries matter? Evolution - gene flow and isolation depend on boundaries (what puts the "sym" in sympatric); ecology - it's where the competition happens.
Boundaries are perspectival - relative to what the boundary is constituted by. E.g., lake trout versus muskrat as markers of a lake boundary. One has different "edges".
Territorial boundaries structured by conspecifics as well as ecological resources. E.g., warblers and nesting sites determined by light and places to nest.
Is there a theory of boundaries? Do they have something in common? How can we recognise them?
Divide the world into patches and boundaries. Steeper gradients across boundaries, boundary function may be defined by flow of energy across them. [Cadenasso et al.]
Relevance to conservation of areas like Yellowstone.