Plants upon plants upon plants

There are a couple of reasons that cloud forests can look so magical; one being the daily mid-afternoon mist rolling in to settle heavily upon the mountains so that you often find that you are wandering through the clouds on your way home for dinner, another being the strangely primeval-appearing flora; crowds of epiphytic orchids, bromeliads, ferns, mosses and lycopods who have casually draped themselves over what appears to be any available surface, be it tree trunk, crown or yourself, if you were to stand still for long enough.

Epiphytes are found in every major group of the plant kingdom, with the most commonly known species being orchids and bromeliads, as those of you with a penchant for easily maintained houseplants will likely be very familiar with. The word ‘Epiphyte’ is derived from the Greek Epi ‘Upon’ and Phyton ‘Plant’. They are aerial dwellers who firmly entangle their roots on branches or trunks of other plants, capturing water and nutrient-rich soil blown into the canopy to aid their survival.They may sound parasitic as they ‘use’ other plants as a physical support on which to grow, however in a lot of cases they can indirectly benefit their host, rarely impacting them negatively. In fact, over time the accumulated organic mass captured by the epiphytic roots can become dense, allowing fungi called ‘Mycorrhizae’ to populate their newly fashioned soil terrace. This may be for another lengthier blog post but ultimately the mycorrhizae fungi majorly aid in the uptake of scarce minerals and can be of huge importance to many trees and their forests globally.

The aforementioned soil terraces cocooned in the epiphytic roots not only aid the trees, but also provide a safe haven for many animals, such as squirrels and hummingbirds. Additionally, as epiphytes need their own water source – being too far from the soil to extract it in the ‘usual’ plant method – they can be quite ingenious with their solutions, once again indirectly benefitting a whole host of creatures. For example, some bromeliads have evolved to arrange their leaves to capture water and detritus material in a cuplike vessel, which creates an aquatic habitat allowing tree frogs, snails, flat-worms, mosquitoes, salamanders, and even crabs to complete their life cycles ‘aerially’.

For instance, there is a tree directly opposite the Reserva Las Tangaras cabin’s back porch which is so laden with hangers-on that it’s incredibly difficult to identify where the epiphytes end and the tree begins. A quick root around in some of the leaves and I find some vivacious dragonfly larvae, two different species of tree frogs, a number of grasshoppers and crickets who had likely spent their nymph-phase here, not to mention the dreaded thousands of mosquito larvae thoroughly enjoying the nooks & crevices of this crafted aquatic habitat.

In Europe, we don’t have any of these typical ‘tropical’ epiphytic rooted flora to gaup at and scrabble around looking for frogs in, but what we have a lot of, especially where Jack & I are from (the UK) are mosses and lichen. Much less striking but equally as fascinating in what they can do. They are so seemingly inconsequential, yet they cover just about everything in the small villages tucked into Northern England. The structures in these settlements are largely made up of different varieties of stone, which moss & lichen are particularly attracted to in the damper climates. They like to cling, not only onto our local pub’s outside wall, but to all vegetation surrounding us here in the cloud forest too.

Mosses & liverworts appear under the family Bryophytes however their true extent (both diversity and magnitude) is unknown. Much of their biomass is concentrated in the canopies of trees so as such their species diversity is rarely included in forest inventories, having primarily relied on tree falls to obtain such knowledge in the past.

As you climb higher and higher into the cloud forest the appearances of bryophytes increases with your ascent. Perhaps this indicates that they play an integral role in this environment, you wonder. You thought correct! They are infinitely useful within this habitat. One of their main capabilities being to retain water. Their water holding capacity can actually exceed total annual rainfall by 50-90%, the additional moisture derived from fog that settles upon the slopes. This function is especially important for areas that vary more in their seasons (such as the sub-alpine cloud forest at more than 3500 metres above sea level) because the mosses slowly release their harboured moisture to the forest floor and surrounding vegetation during the drier periods.

Now, you may have been here in the wet season but for those of you who haven’t, the wet season is WET. We have actually had 114mm of rain, in a single day! It is difficult to imagine 50-90% more water within the environment, but if one day all the mosses all just got up and said ‘adios’, there’d be a colossal increase in landslides and unstable ground. Not to mention, flooding would become substantial on the heavier rain days and the Reserva Las Tangaras bridge would almost certainly be wiped out. We’d be trapped, albeit happily.

Now we all have a deep newfound respect for epiphytes, here’s the sad truth – deforestation of the lowland forests surrounding the cloud forest is predicted to lead to large reductions in cloud generation. This would lead to an irreversible loss of the epiphytes that rely on these hydrological systems. Subsequently, due to the classic ‘snowballing’ ecological effect – that which we have come to know too well in this era – much of the ecosystem in these magical areas will be damagingly impacted with the loss of the epiphytes. Unfortunately, epiphytes play a hugely vital role here not only helping to define the cloud forest but by preventing erosion and landslides, managing flood control, releasing precipitation, sheltering hundreds of species of animals throughout their life cycles, looking beautiful at dawn with glistening dew, adding to the carbon cycle, capturing essential vitamins for the trees they reside on, and much more. So, the next time someone comes up to you and tells you that they’re about to deforest an area adjacent to a cloud forest you can scream ‘But the EpiPHytES!!’ in their face and immediately bombard them with all of this interesting information and they’ll maybe think twice.

(And yes, epiphytes can also harbour their own epiphytes, adding just another dimension to the biodiversity of these lush cloud forests.)