The highly scented needles of the Pine contain tannins, making them quite bitter to the taste, and the whole tree contains a volatile oil which can cause mouth, throat and stomach irritation if ingested, so it isn't one to have in an area where tortoises might nibble on fallen needles. Trees and shrubs from the Pinaceae family contain the substance terpene, an extremely sticky resin which is difficult to remove without using harsh cleaning agents, and this is a good reason not to have these conifers near tortoise enclosures where the resin could get on their shells. For identification purposes, the needles of Pine are attached to the twig in bundles of 2, 3 or 5 and have a brown sheath at the base. See also Cedar and Fir.
Pine chips or shavings are sometimes sold as substrate for tortoise enclosures, but when heated they can emit highly toxic fumes and there is also a serious risk of impaction if eaten, so we advise against using them.