Welcome to the Jungle

Millions of distinctive ecosystems give rise to the biome of tropical rainforest that can be both the terrifying Jungle of our imagination or our myth’s Eden (Rainforest Alliance). Rainforests now only cover less than 6% of the Earth’s land, yet it is estimated by scientists that more than half of the world’s biodiversity resides there. It is astonishing that 40% of the Earth’s oxygen is produced by the rainforests(Blue Planet).

The Earth’s most diverse ecosystem is located between the tropics of Cancer and Capricorn at 3 main geographical sites. As the map of Figure 1 shows, they are located in the Amazon basin in Central and South America, in Africa at the Zaire basin and the eastern part of Madagascar and in Southeast Asia from India’s west coast to Queensland, Australia.

Figure 1: Map of the Tropical Rainforest of the World-indicates by the bright yellow colour (NatGeo)

Their proximity to the equator is key to their existence. Due to their location, rainforests have uniformly high temperatures ranging from 20°C to 30°C and receive annually ≥2 m/yr of rainfall (WWF). These factors in addition to the direct sunlight all year round contribute to the high net primary productivity (Rainforest Conservation).

Plants

The types of plants that exist in a rainforest are more than any other area on Earth. It is astounding that as much as 70% of the flora or the rainforests are trees. The rainforest generally consists of 4 distinct layers: forest floor, understory, upper canopy and emergent. These characteristics allow them to have close resemblance to on another.  They have straight smooth trunks up to the height of 100ft where there, they develop branches creating the canopy layer. At that layer, it is where all the fun happens. It is full of food and animals. Their trunks have a thin bark due to their adaptation to the tropical climate where there is no need for protection over water loss of freezing. Below that layer the understory layer there is not much light penetration through and thus there only very few trees and shrubs growing up to 60 ft. In addition to this the environment there is very humid as there is little air movement.  The lowest level at the forest floor only a few herbs are grown there. The topsoil or rainforests is very thin and poor in quality. It astonishes that Due to the humidity and micro fauna litter is broken where a leaf in an ordinary climate would decompose in 1 year, in the forest floor will only need 6 weeks. The top layer is the emergent where trees are quite spaced and can reach up to 240ft they are distinct since they grow above the canopy. Their trunks are very smooth and to support their gigantic size they grow the famous buttress roots for support over the thin topsoil (Blue Planet).

Figure 2: The Four Layers of the Rainforest (IHMC)

Animals

The colour pallet and patterns of all the types of animals living in rainforests is wonderful. Mammals and birds dominate the canopy .In the rainforest it is never quiet. The vocalizations of the animals are very distinct. Their diet is dependant heavily on fruits. The largest group of animals in the rainforest are insects that have developed various adaptations to camouflage from predation. These include butterflies with bright colours and ant colonies. Rainforests have the highest biodiversity of all biomes. It is estimated that in 1 hectare there could be 40-100 different species.

Even though they are very similar, each on the main rainforest areas around the world are home for different species of animals and trees. There are many species of monkeys that are endemic only to that particular rainforest and thus do not exist in the other 2 rainforests. There are also variations within a particular rainforest. In the Amazon Brazil, there are species of trees that only grow in the mountains and do not grow in the lowlands of the basin. This implies that the destruction of even a small part of such a rich and diverse biome will have an irreversible effect on biodiversity (Blue Planet).

The difference in their location and the species of each particular rainforest makes them special for our survival through the services that they provide to human kind. On the following blogs, I will be discussing the ecosystem services that the rainforest provide and you will be surprised on the amount as well as types of services provided.