Limestone habitats

Limestone landscapes – also known as karst – are formed over millennia as soluble rocks dissolve and erode, leaving behind striking towers and cave systems.

The often-isolated nature of these unique features, and the extreme soil and water conditions found within them, have created the perfect conditions for a highly biodiverse landscape, rich in endemic species.

The steep, inaccessible nature of karst landscapes means that many limestone hills have retained their forest cover, even while the surrounding areas have been deforested. As a result, these striking towers act as natural refuges for species that have been wiped out from much of their range.

What species live in limestone habitats?

In Vietnam’s karst hills, a number of primate species thrive in the haven of forest cover, including the Tonkin snub-nosed monkey, cao vit gibbon and Delacour’s langur, which has specially adapted pads on its hands, feet and rump to allow it to run, jump and sit on the razor-sharp limestone.

Limestone caves are extraordinary environments, each with its own unique light, heat, moisture and nutrient conditions, and their own community of species that have evolved to cope with these conditions.

Bats are among the most abundant and familiar species that live in limestone caves. In many cases, it is their guano – deposited on the cave floor – that supports entire food webs made up of weird and wonderful creatures. These include blind fish and crickets, hairy earwigs, long-legged centipedes and beetles, ghost snails, cave-adapted whip scorpions, trapdoor spiders, crabs, geckos and a highly specialised bat-eating snake, the cave racer.

Tonkin snub-nosed monkey. © Le Khac Quyet / Fauna & Flora

Tonkin snub-nosed monkey.

What are the threats to limestone environments?

Although karst caves and towers can take millions of years to form, they can disappear very quickly— taking entire ecosystems with them when they go.

Limestone is very valuable to humans; it’s a key ingredient in the manufacture of cement, concrete and mortar, and a commonly used material for buildings and stonework. Industrial-scale quarrying continues to represent a serious threat to limestone environments around the world.

Many species found in limestone ecosystems are so precisely adapted to their habitat that they cannot withstand changes, and they cannot survive outside their own small range, which may be as restricted as a single cave. The existence of such species is already precarious, which is why it’s so important to protect their habitat from degradation and destruction.

Fauna & Flora’s work in limestone habitats

Fauna & Flora works in many areas where limestone rock formations are a dominant feature of the landscape, including in Myanmar, Sulawesi and Vietnam.

Our work in these environments ranges from identifying priority sites and developing best practice management plans, to working with corporate partners to minimise and take responsibility for, their impact on these precious habitats.

Amelia McKinlay (Fauna & Flora staff) on a boat among karst limestone hills, looking to observe Delacour's langur. © Steph Baker / Fauna & Flora

Amelia McKinlay (Fauna & Flora staff) on a boat among karst limestone hills, looking to observe Delacour's langur.