Que Liu and his wife Si En spend their mornings picking pu'er leaves in a forest not far from their village in the highlands of southwest China.Pu'er is a kind of tea that is famous for its complex taste. The taste changes with each successive steeping, tea lovers say.But the crop this year has been small at Nannuoshan, one of the six major pu'er mountains in Yunnan Province.The hottest weather and lowest rainfall totals in years have reduced production."Drought has cut production by about half this spring," said Zi Sai, the son of Que Liu and Si En.Local officials blame climate change for an increase in drought-like conditions in recent years. The dry weather has worsened over the past 20 years, with this year's drought breaking some records."The entire precipitation pattern has changed due to global warming," said Xiao Chan, head of weather services at China's National Climate Center in Beijing.Pu'er trees grow in the cloud-covered forests of Yunnan. The trees require no fertilizer or pesticides, unlike tea grown on large farms elsewhere.The adult plant normally reaches a height of four meters. Spring produces the highest-quality leaves from the trees.The summer harvest, with a higher percentage of water, is considered to be lower in quality. Summer leaves are sold for mass consumption, said Zi Sai.The drought conditions hurt the economy of the 32 villages of Nannuoshan."My family depends wholly on tea for survival, earning about 200,000 yuan a year," said Zi Sai's uncle, Si Da, who is 44. That represents just over $29,000."This year...our income has been cut by tens of thousands of yuan," he said.While one ancient tree, said to date from before the time of the Mongol invader Genghis Khan 800 years ago, survived the drought, other younger trees did not.If the trees survive, they may need three to five years for a full recovery, Si Da said."They are quite pitiful, these trees," he added. "They should be protected, like children are."