The worst drought in 50 years in the southwestern province of Yunnan has damaged local diversity, provincial forestry officials said.

The severe drought has affected about half a million hectares of natural reserves, with shrinking wetland and water shortages for wildlife, according to the latest figures from the Yunnan provincial forestry bureau.

Environmental protection experts said the damage caused by the drought cannot be quickly fixed and some is even irreversible.

The Yunnan provincial forestry bureau said the severe drought has caused many precious plants like the ancient cycad forests and the Dove trees to die in large numbers, and endangered wild animals like the Asian elephants, which have moved out of the area.

There are more than 186 natural reserve zones in the province, with 151 types of rare and endangered plants as well as 199 animals under State protection.

The drought, which began in September, has forced many animals in the natural reserves to look for water in nearby villages and some have even died of dehydration on their way, Yang Shaobing, director of the Nangunhe Environmental Protection Zone Administration, told China Daily.

Yang said at least five cases of animals entering villages have been reported in the past four months, equal to the total number of such cases in the past two years.

What worries Yang the most is that no one knows how many more animals will die of thirst in the coming months.

"So far, the impact of the drought to the natural reserve is not large, but its potential impact is threatening future generations of these wild animals and plants," Zi Shize, director of the wildlife protection office with the Yunnan provincial forestry bureau, told local media earlier.

In order to protect wildlife from thirst, the Nangunhe natural reserve has been filling 45 selected pools where wild animals frequently appear, Yang said.

The water level of the four rivers passing the reserve is about 0.3 meters lower than last year.