5 facts you might not know about why forest biodiversity matters

The Earth’s forests are some of the richest and most biodiverse habitats we have.

Not only do they serve as important carbon sinks, but up to 350 million people living in or near them rely on their ecosystems for a range of basic needs, from food and shelter, to energy and medicine.

March 3 is World Wildlife Day and this year's theme is Forests and Livelihoods: Sustaining People and Planet. The theme is focused on forest biodiversity - a forest's many life forms and ecological roles. The observance this year is a reminder of the critical impact forests have in our lives.

With that in mind, here are five facts about the roles forests play in sustaining the health of people and the planet.

1. Primary forest is still disappearing

Globally, a UK-sized area of tropical forest was lost every year between 2014 and 2018, on average, according to a report from the New York Declaration on Forests (NYDF). And data from Global Forest Watch suggests that we lost a football pitch of primary rainforest every 6 seconds in 2019. The same data showed that primary forest loss was 2.8% higher in 2019 than in 2018, and has remained high for the last two decades.

2. Soil is key to healthy forests - and a healthy planet

Just one teaspoon of healthy soil is home to more living organisms than there are people on the planet. These microscopic organisms are the building blocks that enable the vast trees and everything else within forest ecosystems to thrive. Without healthy soil, life would struggle. There is also more carbon in forest soils in Great Britain than in the trees themselves, so if we look after the soil, the soil will help to look after the forests. In this way, forests can be an important tool in reducing atmospheric carbon and a route to mitigating climate change.

3. The green desert effect and forest complexity

Forest ecosystems are diverse and complex – simply planting trees won’t automatically create healthy forest biomes. In fact, new forests can become green deserts, with low levels of biodiversity, according to a 2010 study by two US academics. Those experts found that planting trees on degraded lands is likely to have a greater positive effect on biodiversity, especially if indigenous tree species are used. In existing forests, grasslands, and shrublands, such benefits are likely to be less pronounced.

4. Growing emissions problems

Global annual tropical tree losses between 2014 and 2018 have been responsible for 4.7 gigatons CO2 emissions per year, according to the NYDF report. That equates to more than all the CO2 emissions from the European Union’s member states in 2017.

But it’s not just tropical forest that should capture our attention. Mangroves and peatlands are also being lost as land is given over to farming. Together with agriculture’s effects on tropical forest areas, this destruction is contributing around 13% of total human CO2 emissions and is exacerbating the effects of climate change, according to the World Economic Forum’s Nature Risk Rising: Why the Crisis Engulfing Nature Matters for Business and the Economy report.

5. Nature’s medicine cabinet

There are currently 107 Amazonian species endangered by the ongoing loss of biodiversity. That includes several that are important to the pharmaceutical industry, such as the cinchona tree, the source of the malaria drug quinine. At the heart of a substantial number of key advances in drug therapies lies a continued reliance on the natural world. This can be seen in the field of cancer treatment in particular, where 75% of approved anti-tumour pharmaceuticals are non-synthetic. More precisely, almost half (48.6%) are either natural products or were directly derived from natural sources.