Forests represent one of the most highly diverse and productive ecosystems on earth, accounting for 80 per cent of the world’s terrestrial biodiversity. While definitions of forests vary globally and are influenced by location and primary use, the simplest definition of the word ‘forest’ is land with a tree canopy cover and area greater than 10 per cent and 0.5 hectares respectively. This includes natural forests and forest plantations.
Forests are rich in natural resources and have historically been a source of indigenous knowledge, sustenance and income to people around the world. They provide a natural habitat for wildlife including small and large mammals, birds, reptiles, amphibians and insects which all play important roles in the ecosystem. Trinidad and Tobago is home to several forest types, including tropical and semi-deciduous rain forest, littoral and deciduous seasonal woodland and mangrove forests, each with its own unique biodiversity and species interactions. Pollination, seed dispersal and maintenance of soil fertility are three major areas in which forest sustainability is closely entwined with wildlife.
The process of pollination is a vital step in the reproduction of plants. Bees are often recognized as the primary agents of pollination. However, in spite of their importance, numerous other species such as bats, butterflies, and birds such as hummingbirds, for example, contribute substantially to pollination (Ministry of Planning and Development 2020). Neotropical bats are considered a keystone group in forests (Avila-Cabadilla et al. 2012) and are presumed to pollinate approximately 573 species of plants (Lobova, Geiselman and Mori 2009). A keystone species is one which has a high impact within its ecosystem relative to its population size. Keystone species are credited with the existence of many ecosystems as system failure may occur in their absence. Snow and Snow (1972) suggest that some forest plants may have adapted their flowers over time to specifically appeal to hummingbirds as pollinators. Adaptations such as this highlight the significance of pollination mechanisms and plant-pollinator relationships.
Another important aspect of the plant life cycle is the production of seeds via fruit. Many plants rely on the support of wild animals to feed on their fruit and subsequently aid in the distribution of their seeds. Rostant (2018) emphasizes the role of bats in maintaining local forest ecosystems through fruit and seed dispersal, attributing them as essential in the recolonization of forest clearings. He highlights their contribution to repairing fragmented areas of forest due to their nature of foraging which involves traversing these areas. Known to bury and hoard food (Ramdial and Ramdial 1974), the red-rumped agouti holds an essential role in the cultivation of seeds in forests (Silvius and Fragoso 2003), as their scatter-hoarding behaviour is beneficial to forest growth (Lall, Jones and Garcia 2018). Agoutis often forget where some of their caches of seeds are located and it is these forgotten seeds which have a chance to germinate and grow some distance away from their parent trees.
Birds tend to feed on small whole fruit whose seeds pass easily through their digestive systems and are dispersed through their excrement (Herre 2001). Channel-billed toucans are identified as important seed dispersers in rainforests (Joyce 2013).
Orange-winged Amazon parrots have been observed to inadvertently drop intact seeds onto the forest floor while feeding (Keeler-Wolf 1988), while primates such as monkeys are also regarded as another important keystone species in our forests, for their role in seed dispersal (Chapman 1989) and forest regeneration based on their dietary range and mobility (Nunez-Iturri and Howe 2007). In a study by Giraldo et al. (2007), red howler monkeys were found to be responsible for enriching less diverse forest areas by transporting seeds to them. The Trinidad Piping-Guan or Pawi is a cracid (turkey-like bird) endemic to the island of Trinidad (found only on the island of Trinidad) and is identified on the International Union for Conservation of Nature’s Red List of Threatened Species, as a critically endangered species (BirdLife International 2020). These birds are valuable in the dispersal of large seeds (Naranjit 2012) despite their alarmingly low population size on the island.
Forest soil fertility is greatly enhanced by the activities of wildlife, particularly those inhabiting the forest floor. Animals such as peccaries (wild boar or quenk) contribute dung and urine to the ecosystem and their trampling behaviour as they forage helps to release and redistribute nitrogen which is essential for plant growth (Julião 2021). In mangrove forests, fiddler crabs have been found to improve soil structure and aeration by creating burrows, which in turn boosts the growth and production of white mangrove (Smith, Wilcox and Lessmann 2009). The role of microorganisms in nutrient cycling is often highlighted in discussing the fertility of forest soils. However many insects are also effective specialists in breaking down leaf litter and in some cases even carrion. Termites feed on dead leaves and rotting wood while carrion flies and beetles aid in the decomposition of animal carcasses.
The exotic pet trade and changes in hunting practices over the years are but two of many factors which have placed wildlife at great risk both locally and globally with many ecologically significant species being targeted. Removal of such species directly disrupts their pivotal roles, threatening ecosystem balance and overall forest health and productivity.
For example, in the absence of primates, many species of plants would suffer from seed dispersal pattern changes with the possibility of local extinction for some tree species (Eisenberg and Redford 1999). The long-existing mutualistic relationship between plants and wild animals for fruit eating and seed dispersal is a crucial element of forest sustainability (Fabiani 2020).
Many countries are adopting a community forestry approach to forest conservation and livelihood preservation of which wildlife is an integral component. Our country has several active community forestry projects such as the Fondes Amantes Community Reforestation Project, the National Reforestation and Watershed Rehabilitation Programme in Trinidad and Tobago and the work of the Grande Riviere Tourism Development Organization to name a few. The success of these ventures however depends on the conservation of wildlife populations. In some areas it is first necessary for the value of wildlife in situ to be recognized as greater than its market value before this step can be taken. Public education is the key to building awareness and ensuring that all stakeholders are knowledgeable in the aspects of any wildlife conservation approach.
Forests and the resources within are of infinite value to us as humans. They are home to thousands of wildlife species which all play a significant role in the functioning of the ecosystem. As biological indicators, the presence or absence of wildlife species may provide invaluable information to us about the overall health of our forests. It is our duty to ensure that our practices regarding them are responsible. To sustain our biodiversity is to preserve our future. The fate of the human race depends on the fate of our forests which ultimately lies in our hands.