The tropics – which include a plethora of habitats between the Tropics of Cancer and Capricorn – are the perma-balmy home to more than 75 percent of all known species, including 90 percent of terrestrial birds, pretty much all shallow-water corals, and three-quarters of all amphibians. They act as a barometer for the state of biodiversity on the planet, which is why a new Nature review makes for such a profoundly disheartening read.
The international endeavor – led by Lancaster University – aimed to quantify the global importance of biodiversity in the tropics, while assessing their vulnerability to current antagonizing factors. These include climate change, pollution, deforestation, weak governance, overfishing, unsustainable product demands, poaching, and an increasingly large and affluent population.
From the forests and savannahs to the coastlines, the team not only found that they are likely to be more richly diverse than we’ve previously estimated, but that without urgent action, those antagonizing factors will likely trigger a collapse in biodiversity.
The review’s lead author, Jos Barlow – a professor of conservation science at Lancaster University – doesn’t hold out much hope for the future either.
“Unfortunately, over the coming 20 years I suspect we'll see more of the same – an increasingly warm and unpredictable climate, ongoing land-use change, growing pressure on protected areas, and woefully insufficient investment in socially-just and sustainable development pathways,” he told IFLScience.
Describing the prognosis as “sobering,” he added that he’d “love to be wrong.”
Between 15,000 and 19,000 new species are classified in the tropics every single year. That’s around 47 new species per day. One researcher suggests it would take three centuries to properly catalog all the biodiversity, which hints at what’s at stake here.
Even if how we describe it is up for some debate, the precipitous decline in biodiversity levels all over the planet is increasingly well documented. As every living thing is connected with intricate ecological strands, a speedy decline in biodiversity, particularly in the areas surrounding the Equator, is decidedly unwelcome but increasingly probable.
It cannot be overstated that the tropics also provide, as the team’s paper phrases it, “incalculable benefits to humanity.” They are where the fields of ecology, biogeography, and evolutionary biology sprang from, and provide much of the planet with vital, economy-driving natural resources.