A story of inappropriate technology: in the 1970s it was decided to modernize the rice farming of Sri Lanka, whose system that had not changed much for 3000 years. The goal was to replace the water buffalo with the modern tractor, but the attempt had disastrous consequences...

Buffalos create "wallows", pools of muddy water without which they cannot control their temperatures. Always filled with water, these wallows create many eco-services: in the dry season the become a haven for fish that then migrate back to the paddies when these fill with water.

The fish is a valuable source of proteins for landless laborers and greatly help control the population of malaria causing mosquitoes who breed in the rice paddies. The vegetation around the wallows are breeding and hunting grounds for snakes and water monitor lizards who prey...

...on rats that eat the rice and the crabs that burrow into the sides of the rice paddies eventually causing them to lose integrity, leading to collapses of entire paddy systems.

Without the water buffalo wallows, villagers no longer had a place to soak the palm fronds they needed to thatch their roofs, leading them to rely on locally made clay roof tiles, which caused massive deforestation as trees were cut down to fuel the tile kilns.