Increasing evidence indicates that plants respond to maltreatment in addition to physical abuse. Plants are trimmed, torn up, cut down, pruned and treated in brutal ways without consciousness on the part of the people doing the destruction. The rootstock of some plants attempts to regrow after the part above the ground has been removed. Others die, as the millions of Christmas trees every year. Ringbarking of trees (incising a deep circular groove through the bark and underlying cambium layer) was used an effective way to kill individual trees prior to land clearance, which is now more commonly achieved by "chaining" (ripped out of the ground with chains attached to tractors), chainsaws and burning. Living trees are scarred by removal of bark and limbs, and impaled with nails out of wanton vandalism or in using them as signposts or telegraph poles. Ornamental trees and fruit trees are pruned and coppiced for human convenience. Bonsai plants have their growth intentionally stunted and the bodies shaped in outlandish ways. Flowering plants have their reproductive organs plucked before their function is fulfilled. Vegetables are torn from the ground even before they have a chance to flower. Grain producing plants are cut down just as their seeds ripen, ready to fall to the ground. Perhaps more brutal is the indifference and neglect of householders. House and garden plants are left unwatered and unfed during vacations and periods of forgetfulness. Some are brought from special ecological niches and forced to live and die in some living room at the wrong temperature and humidity and fed the wrong nutrients. Each new year millions of plants are dug up and thrown out because their natural annual cycles do not suit the gardener.