The study, led by Stephen Blake of SLU, focused on the effects of elephant foraging and movement patterns on the diversity of plant species in their habitats. The researchers found that elephants help to maintain the diversity of plant species by creating openings in the vegetation, which allows for the growth of new plants. Additionally, their foraging habits help to spread the seeds of various plants, promoting the growth of new trees and shrubs. The researchers estimate that elephants are responsible for the growth of up to 60% of the woody plants in some areas.

However, as elephant populations decline due to hunting and habitat loss, this important ecosystem service is being lost. Stephen Blake explained that “the decline of elephants is likely to have cascading effects on the functioning of ecosystems, including changes to the composition of plant communities and the carbon sequestration potential of the land.”

The study also found that elephant dung plays a crucial role in the carbon cycle. Elephants ingest large amounts of carbon-rich vegetation as they forage, and when they defecate, this carbon is returned to the soil in the form of dung. This dung can then be used by other plants for growth, a process known as carbon sequestration. This helps to remove carbon from the atmosphere, which can have a cooling effect on the planet.

The researchers estimate that if elephants were to go extinct, it would result in a loss of about 361 million metric tons of carbon sequestration per year. This is a significant amount and highlights the importance of protecting elephant populations in order to maintain the health of ecosystems and preserve the services they provide.

The study’s findings have important implications for conservation efforts. The authors argue that it is crucial to protect elephant populations in order to maintain the health of ecosystems and preserve the important services they provide. They also highlight the need for more research on the impacts of elephant extinction on the planet’s atmosphere, and call for the inclusion of carbon sequestration in conservation management plans.

The loss of elephants would also mean a loss of cultural heritage for many people in Africa and Asia. Elephants are culturally and symbolically important in many societies, and their extinction would represent a loss of a connection to the natural world and a loss of traditional knowledge.

The researchers emphasize the need to consider the broader impacts of elephant extinction and the importance of protecting elephant populations for the sake of both biodiversity and the Earth’s atmosphere. The results also underline the importance of holistic conservation management plans that consider the different ecosystem services that animals like elephants provide.

“The implications of our study extend beyond just forest elephants in Africa,” lead author Fabio Berzaghi said. “As we show that leaves from low carbon density trees are less palatable to herbivores, those findings imply that other large herbivores, such as primates or the Asian elephant, could also contribute to the growth of high carbon density trees in other tropical forests. Our aim is to expand on this by investigating those other species and regions.”

Source: Saint Louis University
Featured image: Silvia Ribeiro

The post Elephants play a key role in creating forests which store carbon and protect biodiversity appeared first on African Conservation Foundation.

The world’s most famous tropical forests found on lowlands, like those of the Amazon or Borneo, are celebrated for their ability to store carbon. The Amazon rainforest itself holds up to twenty years’ worth of fossil fuel carbon emissions in its trees and soil.

While tropical forests can also be found on tropical mountains such as Mount Kinabalu in Borneo, these have long been assumed to store much less carbon. On mountains, temperature decreases with increasing elevation, negatively affecting tree growth. Also, common mountain features such as thick fog, wind and steep slopes tend to constrain tree height.

If trees are smaller, and grow slower, then mountain forests should contain less carbon sequestered from the atmosphere through growth processes: a hypothesis which has been reflected in studies of tropical mountains in the Andes and southeast Asia.

But our research, recently published in Nature, shows that tropical mountain forests in Africa actually store as much carbon per hectare as those found in African lowlands – a finding specific to the continent.

This is because, although African tropical mountain forests have fewer trees (about 450 per hectare compared to 600 in other continents) than their lowland counterparts, they have a greater abundance of large trees (over 70 cm in diameter), whose increased mass means they hold on to more carbon.

We wondered if this unusual finding was thanks to elephant populations resident in many African tropical mountain regions, who eat and destroy smaller tree stems – creating room for others to grow larger – and also transport nutrients which are limited in mountain soils.

But we didn’t find significant differences in tree height between forests with and without elephants, although unfortunately our data only showed us if elephants were present in a given area and not how many were around. Other explanations could include the low frequency of tropical cyclones or active volcanoes in Africa, making it less likely for trees to be destroyed before they grow tall.

Carbon storage

A group of 101 researchers working at different institutions across Africa, Europe, North America, Asia and New Zealand measured 72,336 trees with trunks of over 10cm diameter on 44 mountains in 12 countries within the African continent. For each tree we recorded trunk diameter, species and height.

We used an equation to estimate the carbon stored in these forests, since actually cutting, drying and weighing trees – technically the most accurate method for analysing carbon capture – would rather undermine our aim to mitigate climate change.

We then calculated how much tropical mountain forest had been lost in the African continent over the past 20 years, using data from satellites. We estimated that 0.8 million hectares had been lost, mostly in DRC, Uganda and Ethiopia.

Unexpectedly, given the steep terrains which make logging operations or large-scale farming challenging, we found that in many African countries deforestation rates were higher in the mountains than the lowlands.

So if these mountain forests store more carbon than expected, we are releasing more carbon dioxide into the atmosphere than previously assumed. In fact, the 0.8 million hectares of mountain forest destroyed since 2001 has emitted more than 450 million tonnes of carbon dioxide into the planet’s atmosphere, accelerating global warming.

Biodiversity loss

African tropical mountain forests are not only carbon-rich: they are also rich in biodiversity. Among their huge trees live elephants, mountain gorillas, chimpanzees, and numerous species of birds, amphibians and snakes found nowhere else in the world. Continued deforestation will push many of these creatures further towards extinction.

These forests also act as “water towers” (like giant water tanks), irrigating agricultural land and supplying numerous vital river systems including the Congo and the Nile. This makes them crucial for local and regional crop growth, hydropower systems providing renewable energy, and inland fisheries supporting nutritious diets and livelihoods for local communities.

Mountain forests often collect water droplets from fog in a process known as “occult precipitation”. This makes local landscapes much more humid than if the forests were not present. Destroying these forests is therefore not only terrible for our global climate, but also for regional weather and biodiversity, since many species require the specific conditions created by this humidity to thrive.

But our study also provides some hope. If these forests store more carbon than previously assumed, it could allow us to increase the economic benefits awarded to developing countries who successfully decrease deforestation, meaning greater incentives for forest conservation – and better futures for those who call the mountain forests home.

Aida Cuní Sanchez, honorary fellow, University of York; Martin Sullivan, Lecturer in Statistical Ecology, Manchester Metropolitan University, and Phil Platts, Research Fellow, University of York

This article is republished from The Conversation under a Creative Commons license. Read the original article.
Featured photo by Hamsavani Raja Komaraim/Scopio

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