Vegetation Restoration Mechanism Study On Coal Waste Piles

The study investigated the soil physical and chemical property and vegetation distribution of the waste piles of Didao and Chengzihe coal mine of Jixi city by the means of investigating and sampling and typical experiment. The result showed that the soil nutrients are all being improved with the increasing of discarded ages and the pH value is dropping. When the waste ages are over 25 years, the nutrients and pH value can facilitate the vegetation growth and the vegetation are growing more and better gradually. And at same time the soil structure and texture of the waste piles are improved without human disturbance and the changes are becoming steady gradually when the ages are over 30 years. When the ages are over 50 years old, the piles can be completely covered by vegetation. So it will take from 50 to 100 years at least to reach more ideal state. Because the natural process is very long, man must promote it in the process to restore the vegetation as soon as possible.The study divides the waste piles into four site types by cluster analysis according to the soil physical and chemical property and the characteristic of vegetation distribution:The first type is those whose ages are less than 7 years; the second type is between 8 and 25 years; the third type is between 26 and 40 years; the fourth type is above 41 years.The study also designed the vegetation recovering types based on the different site types by studying their soil and vegetation:The first type is to mainly seed those pioneer plants which are growing on the waste piles, in order to cover it rapidly. The second type is to chiefly seed pioneer plants and some bushes properly, that is still to cover it rapidly and improve the soil property properly. The third type is to plant bushes and herbages, but mostly bushes, mainly to improve the soil property and brought about a little economic benefit. The fourth type is to plant bushes and arbors, the main purpose is to utilize the waste piles.At same time the study designed different recover measures fordifferent types and vegetations: The waste piles of the first type took the measure of being covered with folium soil to recover it, but the other types did not cover with soil. Take mixture measure to seed herbage while bush and arbor were planted by covering with new soil.