Guilin

Ninety-eight per cent of the world's monk fruit grows within a few mountain counties of one city. Guilin — known globally for the karst peaks on China's ¥20 banknote — is also the sole meaningful production base for luohanguo, the natural zero-calorie sweetener now found in health drinks, protein bars, and tabletop sweeteners worldwide. The same limestone mountains that draw over 100 million tourists a year create the specific microclimate where monk fruit thrives, and no other region on Earth replicates those conditions at commercial scale.

Guilin's karst is Devonian-era limestone eroded into tower peaks, each separated by isolated valleys with distinct temperature, humidity, and soil chemistry. Monks first documented cultivating luohanguo in these valleys in the 13th century. More than 13,000 hectares of monk fruit are planted across Yongfu and Lingui counties, yielding over 100,000 metric tonnes annually — exports exceeded 700 million yuan in a recent twelve-month period.

Guilin's karst functions like an archipelago — each valley an island with its own microclimate, isolating monk fruit in conditions no competitor can replicate. This is competitive exclusion through geography: the same specificity that makes orchids endemic to single mountaintops makes luohanguo endemic to Guilin.

The global sweetener market exceeds $100 billion annually, yet natural alternatives account for less than half a per cent. As demand for plant-based sweeteners accelerates, Guilin's geographic monopoly grows more valuable — and more fragile. The prefecture of 4.9 million people holds a chokepoint on a commodity that most consumers never trace back to a specific place.

Apply different economic pressures to the same karst and it expresses different phenotypes — expose it to tourism policy and it produces a visitor economy drawing over 100 million travellers; expose it to agricultural investment and it produces the world's monk fruit supply chain. One geological genotype, two economic phenotypes, zero substitutes for either.