我国的古树资源非常丰富,树种繁多,遍布林区、居民区、庙宇、宫苑、游览胜地或自然保护区内。古树是活的历史文物,是进行植物区划、研究植物地理学、古气候、古植被的宝贵资料。近些年来,各地古树有愈来愈减少的趋势。出现这种现象主要是社会上还没有完全认识保护古树的重要意义。由于基建、兴修水利、环境污染、水土流失、病虫害或迷信(砍剥树皮“治病”)等原因,很多古树被砍伐或衰老死亡。此外,也有由于生长地土壤板结、营养面积小、土 China’s ancient tree resources are very rich, many species, all over the forest, residential areas, temples, gardens, tourist attractions or nature reserves. Old trees are living historical relics and are valuable materials for plant zoning, plant geography, paleoclimate and ancient vegetation. In recent years, ancient trees have been declining more and more everywhere. The main reason for this phenomenon is that the society has not yet fully understood the significance of protecting ancient trees. Many old trees have been deforested or aged for death due to infrastructure construction, water conservation, environmental pollution, soil erosion, pests or superstitions (“culling bark”). In addition, due to the growth of soil compaction, nutrient area is small, soil