Environment versus biodiversity. Who will win?

There are many different factors which impact on the biodiversity within rainforests. The one we are going to be focusing on in this blog post is the climate.

A recent study by Nehren et al (2013) discusses the impact of natural climate change on an area of rainforest in South East Brazil in the late Holocene (the most recent geological epoch which began approximately 11500 years ago at the end of the last ice age). Their studies concluded that natural climate change can have a huge impact on the vegetation cover and composition of rainforests. The rainforest in SE Brazil expanded under warm and humid conditions in the late Holocene. This expansion in turn affected the local environmental conditions and could have also had an impact on a global climate system. Locally, soil development, weathering intensity and geomorphic processes where enhanced. More globally speaking, an expansion of the rainforest would lead to a larger area of land acting as a carbon sink reducing the impacts of rising carbon dioxide levels (more on this in a future blog post).

So why is the climate so important for rainforests? Well, the extreme amount of rainfall (>1500mm/year), the lack of seasonal variation (due to the proximity to the equator) and the high temperatures all contribute to an environment which encourages high rates of growth. We all know that plants need sunlight, water and nutrients to grow and the rainforest provides all of these (Gaughan, 1998).

But what dangers might the rainforest face relating to its biodiversity and climate? We can safely say that it is not just one climatic factor that is responsible for the diversity seen in the rainforest but say that one of these climatic factors were to change rapidly. Let's say, an increase in temperature, this would force an organism, which remember, is specifically adapted to thrive in its current environment, away from the equator in order to stay within its optimum temperature range. As this species moves away from the equator (if it can, plants don't have legs), it will experience a greater variation in temperature range which it would then need to adapt to. Essentially in order to survive this species would need to win the race of adaptation versus environmental change. If we have more losers in the race to beat the environment, certainly biodiversity will be an overall loser.

I'll leave you with something some of you might be wondering. Why does it rain so much in a rainforest? The link to some great basic information can be found here.

That's all for now.