BSc., MPhil., FLS., AMSB.

Dept of Life Sciences,

University of the West Indies

Currently much attention is being paid to natural forests which are being cleared at an alarming rate on a global scale.

The importance of these forests to our environment and biodiversity cannot be disputed, but little attention is paid to the secondary forests that emerge when the primary forests are cleared. In this article I would like to focus on secondary forests, what they are, how they come about and the functions they carry out in our environment.

First of all, what is a secondary forest? Simply put, vegetation can be classified as secondary if the original or primary forest has been cleared for any purpose and afterwards the land is abandoned.

Secondary forests come to exist by a variety of ways, for instance when land is cleared for agriculture, both short crop and long-term tree crops. Therefore, when the land becomes unproductive due to constant cultivation, or the crop no longer brings in a large income on the international market, it is abandoned. This type of forest is also created when an area is subjected to selective logging, as this opens up large gaps in the natural forest which can be occupied by species not native to the surrounding natural forest. Secondary forests are also created when land is cleared for quarrying. Large forest fires also clear land and open it up to occupation by non-native species. But secondary forests can also be created by natural causes, for instance landslides, wind and in some countries, by volcanic eruptions.

Like primary forests, secondary forests can also be sources of timber products such as lumber for construction. Some of the tree species that produce wood that is soft and not suited for construction of buildings or furniture can be used for other purposes, such as, pulpwood for paper production.

But secondary forests provide non-timber forest products (NTFPs), which include oils, leaves, bark, fruit, juice and gums. These are used in a variety of sectors, for example, to make handicrafts, as building materials for houses, and as ingredients in cosmetics and pharmaceuticals. Some other NTFPs include the biodiversity and atmosphere in the forest.

In terms of biodiversity, studies have been conducted that compare the biodiversity of species found in natural forests with that found in secondary forests. The results of these vary with secondary forests holding more species than primary forests and vice versa. Also, when it comes to biodiversity, there is major concern about the number of rare or endemic species of both flora and fauna that may be lost when natural forests are cut down. This is of great concern since certain species of animals cannot or will not cross large gaps to another patch of suitable habitat. In these cases, there is a possibility of using secondary forest as corridors to fragments of primary forest.

Like natural primary forests, secondary forests also perform many important functions for our environment, for instance, carbon sequestration. Young secondary forests in particular can absorb more carbon dioxide than plantation forests; this is because a characteristic of the former is high growth rates.

Secondary forests also prevent against soil erosion. It does this by slowing down the amount of water that runs off the soil, so that less water and loose soil is washed into rivers and streams which can cause flooding and siltation of rivers.

From a social and economic aspect, secondary forests provide various forms of employment such as, materials for traditional healers, raw materials for craftsmen, a place to bring tourists for ecotourism thus providing jobs for tour guides, and others that depend on the tourism sector, like taxi drivers, restaurants, handicraft vendors, hotels and farmers that supply food to the hotels and restaurants.

An example of how secondary forests are being protected is the forest reserve La Sociere in nearby St. Lucia, consist of secondary forest. The secondary forest is being protected as most of the natural forest has been logged or disturbed in some way. Also since St. Lucia depends on tourism these areas are vital to ecotourism, not to mention they are also home to a few endemic species.

It is hoped that this brief overview has highlighted the importance of secondary forests and that they should not be regarded by land planners as worthless vegetation to be bulldozed to put urban areas, highways and other infrastructure. They play an important part in our environment, and if we are to gain independence from a fossil fuel-based society we need to work hand-in- hand with our natural resources and use them sustainably.