Why does the Chihuahuan Desert contain such a large variety of cactus species?

The Chihuahuan Desert’s remarkable diversity of cacti—which includes more than 400 species and accounts for nearly one-fourth of the world’s total—is primarily driven by the region's highly varied environmental conditions.12

The desert features an extremely diverse landscape that encompasses mountains, valleys, plateaus, and lowlands. This complex topography creates a wide range of elevations, soil types, and microclimates across the region. Because plant life in the North American Desert is heavily influenced by local environmental factors and moisture availability, these variations allow for a vast array of specialized plant communities to thrive. Higher elevations, for instance, tend to be cooler and receive more precipitation than the lower plains and valleys, further contributing to the region's status as one of the most biologically diverse deserts in North America.23