As we have limited online access to the book Questioning Collapse: Human Resilience, Ecological Vulnerability, and the Aftermath of Empire, below are a few ideas to help get you started. You certainly have many societies discussed in the book to choose from, as shown in Parts I, II, and III. Among the societies you can choose to analyze to write about are Rapa Nui, otherwise known as Easter Island, Medieval Greenland, societies in China, Indigenous North Americans, the Mayans, Mesopotamia, the Inca Empire, Rwanda, and several others. Some of what is available online refers to the society on Rapa Nui, so let's look briefly at that as an example.
Rapa Nui, or Easter Island, is a very unusual Polynesian island in the southeastern Pacific in that it is devoid of most of its plant species. Deforestation led to the extinction of its forests, which contained may different types of plants,grasses and trees. Among the species of flora that are now extinct is the palm tree Paschalococos disperta. Plus, the island was once used for sheep grazing, leaving the island mostly covered in reeds. Easter Island stands in great contrast to the lush South Pacific islands that surround it, such as Tahiti and even the Hawaiian Islands. Since Easter Island has become so barren, authors Terry Hunt and Carl Lipo point out that it has become known as the "'poster' child for what happens when societies squander their resources and destroy their environment" (p. 21). Diamond particularly ran with this interpretation of what happened to Easter Island and blames on the islanders the "ecological catastrophe" that led to the society's "destruction." One of the island's unique features is that between 1100-1680 AD, the islanders carved 887 gigantic stone statues out of volcanic ash. Diamond asserts that it was the islanders' choice to build the statues that led to their ecological problems and their own destruction, since he assumes they cut down the trees to use the timber to haul and erect the statues.
In great contrast to Diamond, authors Hunt and Lipo argue researchers are newly aware that Europeans arrived on the island, bringing with them their diseases and their propensity to enslave natives to add to the slave market. Hence, they argue that the real reason for the island's fall was the wrongful death and enslavement of its people. Working on the island with a team of other researches and scientists, Hunt and Lipo were also able to prove the island's deforestation happened over a period of 400 years, and the island even still contained some forest as late as the 18th and 19th centuries. This contradicts earlier theories that the island was completely deforested by 1250 AD. The authors conclude the islanders were not guilty of foolish decisions that resulted in their own destruction; rather, they were a very "ingenuous" and "successful" people whose small population was sadly diminished due to European diseases and enslavement (p. 41).