Threats to the Cirio
Blowdown is very common. Trees that root into rock are less vulnerable to blowdown. Epiphytes in the cirios might make them more vulnerable to blowdown.
Infrequent germination. The trees apparently reproduce only in certain years with favorable conditions, possibly after very infrequent heavy rains. After searching for very many hour, in scores of locations, I only found a few trees under a foot tall.
Grazing. Cattle graze over much of Baja, even within the Biosphere Reserve. However, I haven't seen any signs that the cattle harm the cirios, which are well-protected with spines. ILt's possible that cattle may eat the very young cirios.
Collecting. Just N of Catavina, I found one cirio about a foot tall that had been dropped on the ground, with its taproot clearly cut by a knife. This was within half a mile of the highway. Evidence of stones disturbed, plus lack of small cirios in very favorable habitats, was further evidence that they were being collected there. There is a 5000 peso fine for collecting cirios.
