You can explore the interplay of pests and water use in the adaptive self-organization of Balinese rice terraces via either – or both! – of the following apps.
Lansing JS, Thurner S, Chung NN, Coudurier-Curveur A, Karakaş Ç, Fesenmyeri KA, Chew LY. 2017. Adaptive self-organization of Bali’s ancient rice terraces. Proceedings of the National Academy of Sciences USA 114:6504-9.
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In the following app*, pest loss (ρ) and water stress (δ) can be varied by moving the sliders. Click 'Run/Pause' to start the app and pause it.
ρ |
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δ |
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Explore for yourself how different levels of pest stress and water stress lead to different distributions of harvesting schedules.
In the app below, use the 'play' button to step through each harvest year-by-year, or use the 'fast forward' button to skip over 50 harvests at a time. The 'rewind' button resets the simulation to the initial state, so you can run the simulation again and explore which patterns are repeatable and which are not.
Questions:
In the app below, use the 'play' button to step through each harvest year-by-year, or use the 'fast forward' button to skip over 50 harvests at a time. The 'rewind' button resets the simulation to the initial state, so you can run the simulation again and explore which patterns are repeatable and which are not.
Questions:
- What happens when pest stress is high, but water stress is low? Or when pest stress is low, but water stress is high? Or when pest and water stresses are more evenly balanced?
- What effects does noise (i.e., poor decision making) have on the simulations?
A key point to note is that the sizes of these patches follow a power law distribution over many orders of magnitude. (A power law is indicated when the dots fall on – or nearly on – the straight line in the graph).
This power law distribution of patch sizes mimics the spatial distribution of cropping patterns observed in real subaks. This simple model thus suggests that well-documented interactions between the local and global constraints of pests and water stress are sufficient to generate surprisingly complex real-world dynamics.
This power law distribution of patch sizes mimics the spatial distribution of cropping patterns observed in real subaks. This simple model thus suggests that well-documented interactions between the local and global constraints of pests and water stress are sufficient to generate surprisingly complex real-world dynamics.
* This app was written by Andy Schauf, National University of Singapore.