Pebble Beach. In its native range, P. radiata is a principal host for the dwarf mistletoe Arceuthobium littorum. The habitat of the pines on Cedros Island contrasts greatly with the desert scrub on other parts of the island, forming zones of abrupt transition. The numerous groves form a mostly-monotypic forest of the species, with very few other plants besides seedlings emerging in the understory. In some areas, the edges of the forest form a zone that supports chaparral species, including Malosma laurina, Diplacus stellatus, and the endemic Eriogonum molle. With their large surfaces to condense fog, the pines create irrigation for themselves and their associates. Towards the far northern end of the island, a succulent community mostly consisting of Dudleya is found, and the endemic Dudleya pachyphytum can sometimes be found growing under the pines in the ecotone. A remnant P. radiata stand in Pacific Grove is a prime wintering habitat of the monarch butterfly. In South Africa, the tree is a threat to already scarce water resources. The tree has remarkable roots. Monterey pine roots will reach downward as far as physically permitted by subterranean conditions. Roots have been discovered up to long. Efforts to remove large quantities of the non-native tree in areas of South Africa have resulted in significant increases in accessible water. Conservation status Fungal disease The three remaining wild stands of var. radiata (Monterey pine proper) are infected and under threat of extirpation from pine pitch canker caused by Fusarium circinatum, a fungal disease native to the southeast United States and found (in 1986) to have been introduced to California. When trees begin to die of the disease, they attract bark beetles which provide a pathway for infection of other trees. In some stands, 80–90% of trees are infected. If the disease is introduced in agroforestry areas dependent upon P. radiata, such as New Zealand, it could have catastrophic effects in those countries as well. Sphaeropsis blight (Diplodia pinea) infects P. radiata in California and causes serious damage to plantations of the species in New Zealand, Australia and South Africa, especially after hail damage to growing tips. Baja California On Guadalupe Island, var. binata is critically endangered. Most of the population was destroyed as tens of thousands of feral goats ate binata seedlings and caused soil erosion from the mid-19th century until just a few years ago. The older trees gradually died off until by