What are"debt for nature"swaps? how can they be used to encourage
the protection of tropical rain forest

"Debt-for-nature swaps" are just "financial transactions"  from which a part of a nation's (Developing nation) foreign debt is forgiven. This is done in exchange of "local investments" for the purpose of environmental conservation measures.

Explanation:

The model for "debt-for-nature swaps", was outlined in  the EAI (Enterprise for the Americas Initiative), was extended  in the "Tropical Forest Conservation Act" (TFCA) to include the countries  present around the world  with 'tropical forests'.With the help of the program, "debt can be restructured" only in eligible  countries, and 'funds' generated through this transactions are used to support programs for "conserving  tropical forests" within the 'debtor country'.124.8 million dollars has been spent under the 'TFCA' to restructure loan agreements in '13  countries' and nearly 218.4 million dollars in 'local currency' will be generated in the  next 12-26 years for 'tropical forest conservation projects'.Thus, "debt for nature swaps" encourages  the protection of "tropical rain forest".

Very minute and important evidence needs to be collected in order together detail and figure out what had happened