The field on the left was used as pasture in the past, but the cows were recently excluded by the fence — sometime in the past 10 years — in an effort to reforest the field. Some of the plants that are sprouting up didn’t need any assistance at all. Their seeds were either already in the soil or got there with the assistance of animals (or wind, to a lesser degree). However, within this natural regrowth there are hundreds of young trees that have been planted in an effort to create a forest that is more beneficial for wildlife conservation. Without this active reforestation effort, it will probably take a lot longer for a forest to develop that resembles what was there decades ago … before the trees were cleared for pasture to produce beef.
In Costa Rica, like many other Central American countries, the pace of forest clearing sped up quickly in the 1950s and 60s when the market for meat provided a good source of income for landowners. People cleared forests at a staggering rate in order to raise animals as well as sell its timber. Between 1940 and 1980, at least 50% of the forests in Costa Rica were cut and the rate of forest clearing topped 3% per year.
This pattern continued through the 1980s, but it started to slow when people began valuing the landscape in different ways. Meat didn’t necessarily retain it’s high economic rewards (and there were few forests to cut anyway). At the same time, intact forests were recognized as important habitat — for both the unique diversity of plants and animals in the region as well as for the thousands of people that began travelling to see it. These new “ecotourists” hired guides, stayed in hotels, and played on ziplines. Now, the region seems to be reaching a point where some of the pastures aren’t as valuable for raising meat as for attracting people.
Since the 1980s, much more attention has been placed on reforestation. Several large areas of land were set aside to allow the forest to regrow naturally. Today, about a quarter of the land in Costa Rica is protected in some way. The forests within these areas are regrowing, though only a small portion of the forests are being actively replanted with the the kinds of trees that used to grow there in the past.
Scientists and conservationists are now faced with a tricky question: “What is the best way to regrow a forest that we don’t completely understand?” You might think that we would know by now how to grow the kind of forest that we want. However, botanists barely have names for all of the trees in some tropical regions, let alone the details of their natural history. Some of the most basic and essential information about how to grow the forest you want — tree seedling survival rates, growth rates, fertilizer requirements, seed germination practices — is unknown. Amazing, huh?
So, the “edge” of our knowledge about tropical reforestation is simply an understanding of how to help it along.