Final answer:
It is true that the Rapanui began using agricultural practices such as manavai and pu in response to deforestation on their island. These innovations helped protect crops from harsh conditions and maintain sustainability.
Step-by-step explanation:
In response to the loss of forests, the Rapanui began the agricultural practices of manavai and pu is true. Facing environmental changes such as deforestation, societies like the Rapanui, the Kayapó, and the Bantu adapted their agricultural practices to sustain their communities. The Rapanui developed manavai, which are circular stone enclosures for cultivating plants, protecting them from the harsh wind and salt spray. The pu were planting pits with rocks placed around them. These techniques helped maximize the fertility of the soil and protect the crops from the elements, aiding in their survival despite the challenges caused by deforestation and the subsequent lack of resources used for essential items like boats.
Such innovations are examples of how communities adapt and develop intricate knowledge of the local environment to ensure sustainability. In other parts of the world, similar agricultural strategies were adopted. For example, the Kayapó enhance biodiversity by planting diverse crops and managing apêtê, or "forest islands", while Bantu communities adjusted their cultivation techniques to various conditions of the tropical rainforest. These tactics illustrate the potential for human societies to adapt to and mitigate environmental changes.