Take The Path Less Ordinary

It’s easy to see why avid naturalists are so intrigued by rainforest’s multi-level ecology. Often touted as the “aerial frontier”, a zone that is difficult to access, it is where millions of species coexist in harmony. This is where earth’s biosphere meets the atmosphere.

For many, the word rainforest itself invokes a sense of mystery and a tad of excitement. Afterall, stepping into the world’s oldest ecosystem is like a walk into the time tunnel. It is a powerful place where one can stand in awe amongst giant lofty trees that bespeaks a never-ending evolution cycle of tropical flora and fauna since time began.

While most holidaymakers are not botanist, much less ecologist, it’s best to get to know a wee bit about rainforest’s interesting features before walking into it. Remember, it’s not good enough to trot the jungle and not knowing what you’ve seen. We have a term for that - it’s called an “uneducated” trip. It’s such a shame to let the most interesting things about the rainforest go un-noticed.

This article attempts to dissect the rainforest and describe its key features in simple holidaymaker’s term. No jargons and long scientific names. Read on and ace the Malaysian jungle like a seasoned trekker.

Why our jungles are called rainforest ?

We usually kiss people who ask that question.

The obvious fact is: It makes rain and has its own micro-climate. People who lived in the untouched rain forest will tell you that it rains everyday, especially late afternoon. It experiences a cycle of dampness and dryness daily.

Unique plants like the nepenthes, locals call “periuk kera” or monkey cup, helps retain water within the forest’s biomass

Moisture from rainforest biomass evaporates into the air as soon as dawn breaks and by afternoon, laden clouds above pour the same body of water back to the ecology. Simply put, it can produce 75% of its own rain and most importantly, the humidity of large rainforests contributes rainclouds that may travel to other region in need of rain.

With 1700-2000mm annual rainfall and temperatures between 23 - 27 deg C, the Malaysian jungle is classified as “tropical rainforest” and is further refined into this composition ..

1. Low land Dipterocarpaceae
2. Hillside Dipterocarpaceae
3. Mountain Dipterocarpaceae
4. Montane Oak
5. Montane Ericaceous

Besides inland rainforest, Malaysia also spot a unique type of jungle called the mangroves in coastal region. Read more about mangrove here …

One big happy family

The Malaysian rainforest trees are mostly from the Dipterocarpaceae family. The name Dipterocarp is derived from Latin meaning “two winged seed”. Once released into the air from lofty mature trees, seeds remain airborne for a long period of time, enabling them to reach far and wide to propagate.

The Dipterocarpaceae has 17 genera and approximately 580-680 tree species, typically reaching heights of 40-70 m tall, with the tallest known living specimen over 85 m tall. Recent genetic findings show that the Malaysian dipterocarps are related to the Sarcolaenaceae, a tree family that can only be found in Madagascar, East Africa. This suggests that Dipterocarps came from the southern supercontinent of Gondwana, an India-Madagascar-Seychelles land mass millions of years ago.

Looks may be deceiving

With huge trees and dense undergrowth, one would have imagined the forest to be fed by rich soil.

Wrong.

One of the distinctive feature of the Malaysian rainforest is it grows on ground with little nutrient. Millennia of weathering and torrential rains has left its top soil with little mineral content that’s important for botanical growth. Your trekking boots would most probably be muddled with clay.

So where do plants get nutrients from?

Recent research papers indicate nutrients are found above the ground, mainly in rainforest’s biomass and on the forest floor’s decomposing litter with comprises of fallen leaves, barks, twigs, fruits, dead animals … etc. Plants intercept and absorb nutrients as soon as they are generated by decomposition hasten by termites, bacteria, fungi and various organisms. So, the rainforest makes its own food and merely needs the ground for anchoring.

If someone argues that rainforest can be logged, burned and replanted to its natural state, it’s a huge fallacy. All nutrients that feed the ecosystem will be lost forever. What remains on the barren soil cannot support regrowth. This is why slash & burn agriculture and logging made very infertile land and growing new vegetation is difficult. The damage is permanent. Furthermore, with every tract of rainforest cut, mankind is bringing about the extinction of some species that we don’t even know about.

The Process of Speciation

Although tropical rainforest covers roughly 6% of the earth’s surface area, it contains 50% of the world’s species. What causes this concentration of diversity?

Although scientists don’t fully understand why more species are formed in one place than another, they summarised that geographical isolation of small populations for a long time promotes species formation. It’s called “The Process of Speciation” - isolated populations become independent genetic and hence independent evolutionary units. Some botanists think high year round productivity due to lack of seasonal changes - Malaysia is a land of eternal summer - caused the process of speciation to be more active and resulting more species found here today.

Bio-diversity world record holder

Not many know that Malaysia has one of the oldest jungles in the world. Compared to the world’s rainforest, Malaysia’s is a great grandmother, dating back to the Pleistocene Epoch 130 million years ago and far older than those in Latin America and Africa. During the Ice Ages, Malaysia’s forest was spared from glaciers and crushing cold due to its location near the sunny and warm equator. And so we have a massive variety of flora and fauna that have not stopped growing and evolving long before the existence of dinosaurs and mankind.

In 1997, a group of international researchers found an astounding 1175 tree species within a small plot of 52 hectares in Lambir Hills National Park, setting new standard for diversity.

The Malaysian rainforest is home to roughly 8,000 species of flowering plants, 200 species of mammals, 600 species of birds, 115 species of snakes, 80 species of lizards and thousands of insect species, many still undiscovered. For a list of wildlife, see these links … Mammal, Reptile, Avian, Amphibian and Insect.

Every layer you peel, you reveal more

As show on the picture above, the rainforest is a “forest on top of another forest”. Every layer has its specialty and own ecosystem. Everything happens above ground level.

Emergent Level

As mentioned earlier, the Malaysian rainforest kingdom is dominated by one family of trees - the Dipterocarpaceae. All family members can reach heights up to 40 m with their crowns, or popularly known as canopies, supported by large skyward trunk. World’s 3rd tallest tree, the Malaysian Tualang (Koompassia excelsa), can reach up to 80 m and almost impossible to axe down.

Every once a while, rare few trees soar above the canopy level and they are called emergents. With plentiful of sunlight, these giants experience a quantum spur of growth until it is too tall to withstand storm and windy conditions. When an emergent tree falls, it creates a wide gap for sunlight to reach the forest floor, hence enabling smaller trees below a chance to grow and fill up the gap.

Canopy level

The canopy is the key feature of the rainforest.

It seals the jungle’s humidity, control the temperature and ensure its ecology is intact. It is often an uneven ‘sea’ of close knitted tree crowns, and if a gap appears somewhere, nearby trees will very fast plug up the gap in their competition for light.

Although the canopy level is so-called “sealed”, tree canopies rarely intertwine or even touch. Instead they avoid each and other by a few feet. No one knows why but botanists suggest this feature serves as protection from infestations from tree-eating caterpillars and diseases. Due to this, wildlife that inhabits this level developes the ability to cross these gaps by hopping, leaping, gliding, or flying.

Sub-Canopy or Understory level

Underneath the main canopy are different levels or strata of trees flourishing in sub-canopy and understory layers. This level retains much of the forest’s moisture and with low light, plants have larger leaves to gather in existing sunlight. Epiphytes like orchids, ferns and vines cling on tree trunks and have adapted to growing in the shade and don’t need much light for photosynthesis.

Forest Floor level

Lastly, since very little sunlight reaches the forest floor, plant life is quite sparse in this level of the rainforest. With hardly any sun ray reaching the floor and under damp conditions, things begin to decay quickly. A leaf that might take months to decompose in a regular climate will perish in weeks. This process in turn feeds surrounding trees with all the nutrient they need.

Rainforest trees’ root network grow on or just beneath the forest floor because this is where the nutrients are concentrated.

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Besides wildlife and plants, human evolution isn’t spared by the Process of Speciation either.

Native settlements tucked in rainforest pockets have evolved into a variety of tribes, each honed by niche ecology which they live in. Today, Malaysian Orang Asli jungle natives come in almost 30 genetic orders. Due to isolation for thousands of years, the tribes maintain a DNA pool so pure it can be trace back to the Adams and Eves that first walked out of Africa.

Everyone is beautiful - if you squint a bit. Read about Orang Asli in this post.