rene aguirrez has been involved in the forest project for two years now. >> firstly, because i like it. i like working with plants. i didn't know much about it, but i learned on the job, and i'm interested in working with plants. i like it. >> it takes decades for the little seedlings to grow into mighty trees. at present, the project employs about a hundred workers. so far, investors in germany have put a good 30 million euros into a very long-term project. >> i'm not so worried about it being a long-term project. it all goes with a whole attitude to life. and i have my experience from my first year here. i was always so worried about the little seedlings. you could hardly see them in the tall grass, and today, they've grown into a real forest, that gives you a lasting sense of fulfillment. >> stefan prostler has left his old life as an event technician far behind him. he's started a family in costa rica and taught himself the complexities of re-forestation. >> one of the most important aspects of a project like this is taking responsibility for what you do. that's one difference to o