Zooming in: on Africa's tropical rainforests.

This post is one of three that will focus on tropical rainforests in different regions. Africa is home to the world's second largest rainforest, located in the Congo Basin, like other rainforests around the world it has suffered the consequences of direct human disturbances and the indirect influences of climate change (Zhou et al., 2014). The diagram below is helpful for visualising the change in forest abundance around the world over the past decade, of particular concern is the extreme loss of rainforest area in Africa.

Map of Global Rainforest Area Loss and Gain Since 1990

A few points about Africa's rainforests:

• Research has reported that compared to Amazonian rainforests, Africa's are lower in biodiversity, although the exact reasons for this are not clear. Africa experiencing a higher number of 'dry months' in the year, the lower impact of tectonic movements, isolation of the continent and the long history of human inhabitation, are all reasons that have potentially attributed to the lower biodiversity of this region.
• One of the most problematic origins of resource extraction in Africa's rainforests is through hunting wildlife for 'bushmeat'. Hunting for bushmeat is a practice that has existed for hundreds of years in African rainforests, and evidence exists to suggest that this trade is growing - an activity that increases the vulnerability of rainforest species and decreases sustainability.
• Recently published research highlights the role that the cocoa industry has to play in African rainforest deforestation. Together, the Ivory Coast and Ghana cultivate over half of the world's cocoa - out of the top seven producers, African countries make up four of them. Although forest clearance for the growth of cocoa is not the only reason for deforestation, nor are African rainforests the only tropical rainforests affected, due to the high rates of cocoa farming, it is an especially real and growing threat for the region.

Map of Global Cocoa Production

What is evident from the information in this post is that all rainforests are at risk, and although tropical rainforests share many of the same characteristics, as is clear through the designation of the 'tropical rainforest biome', the histories and pressures each region has experiences will differ somewhat. In summary, conservation and research efforts for rainforests need to be tailored specifically for combating each regions most critical threats.

From sink to source?

In 3 years, how did the world's rainforests go from carbon sink to carbon source? I know it isn't a credible scientific study to measure climate problems by newspaper headlines - but these Guardian headlines (2014 and 2017) are completely contradictory, and they were published only three years apart. The articles, based on two scientific papers (Asner et al., 2014 and Baccini et al., 2017), are essentially suggesting that the world's rainforests have gone from being heralded as storing more CO2 than the US emits in a year, to being lambasted for releasing MORE carbon than all of the US traffic does in a year - is it true? Have our rainforests turned from carbon stores to carbon sources?

Unsurprisingly, it is not a straightforward matter. From reading the papers it becomes clear that the authors each have different measures for carbon sequestration. The results from each study have been analysed/manipulated carefully in order to prove/disprove the carbon storage abilities of rainforests. An important point to note is that Baccini et al do not consider non-woody or herbaceous species, nor do they take into account soil carbon storage properties, they are strictly focusing on trees in rainforests. Asner et al however, use completely different measures for carbon storage, their approach of 'high-resolution carbon mapping' helped them target carbon stocks in Peru that are vulnerable to degradation. From delving into these papers a little further, it is clear that due to their contrasting methodologies, they aren't directly comparable - however - it appears that the authors from the Guardian articles have interpreted the results in similar ways in order to create shocking headlines, enticing the eco-aware-Sunday-browsing reader (me). Regardless of their direct comparability, what is obvious from the two papers and related literature in the field (Fisher et al, 2013 & Alamgir et al., 2016), is that it is not clear what the exact state of the world's rainforests are in when it comes to carbon sequestration.

Logging activities in Indonesian rainforest, 2010. 

What both papers do provide, is evidence for the fact that land degradation activities and deforestation pose huge risks to the potential longevity of rainforests as carbon sinks. The role of rainforests as carbon sinks/regulating GHG emissions is just one of the ecosystem services that rainforests provide. Harking back to my first blog post, the potential symbiosis between humans and the rainforest is threatened by the ongoing degeneration they are experiencing. As rainforests continue to be ravaged by land use change, clearing and logging (all human activities), ecosystem services that humans rely on will be damaged. The articles discussed in this post bring an important topic to their readers attention: if we want biodiversity, if we want to limit the effects of climate change - we've got to start protecting our rainforests!

The Rainforest. An Introduction.

Rainforests? I'm a big fan, I think they're great and significantly, I think they're important. But, it's not just me that thinks they're important - it's actually just a fact. Planet earth's tropical rainforests take up less than 5% of the world's surface area, yet it is estimated that they still hold around 50% of all earth's flora and fauna. They're pretty diverse to say the least - in fact, they're extremely BIOdiverse. According to the Convention on Biological Diversity, biodiversity means:

'The variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.'

Rainforests, in today's current climate (both environmentally and politically), are vulnerable. As mentioned above, rainforests as ecosystems are extremely biodiverse, and not only that, but they provide extremely important ecosystem services that are vital for the survival of the human race. The world's rainforests, their locations highlighted on the map below, provide services such as fuel wood, stabilisation of soils protecting from soil erosion and regulate the global climate by reducing greenhouse gas concentrations.

Map displaying locations of the world's rainforests

The over-extraction and over-exploitation of rainforests that we see today is paradoxically self-destructive. There is a strong body of scientific research that recognises how the loss to ecosystem services reduces the resilience of the human race (Hooper et al., 2005). The diagram below, taken from the European Commission's paper on the 2020 EU biodiversity strategy, clearly illustrates the reciprocal nature of the relationship between protecting biodiversity in ecosystems (i.e. rainforests) and human well-being.

Through the following  posts on this blog, I hope to explore the current state of our world's tropical rainforests and fully understand exactly how important they are and to what extent, through our actions, we as humans are jeopardising our own futures. To end this short introductory post, below are some pictures I've taken when visiting a part of the most amazing Costa Rican rainforest. The month I spent living in Tortuguero National Park helped me start to appreciate just how vital rainforests are to planet earth (hence the choice of topic for my blog was an obvious and easy one). Perhaps looking at the photos below you might think I am a part of the problem that I've been describing above... and that's definitely something I've considered - hmm!