NEW IDEA ON THE BOTANOGEOCHEMICAL EXPLORATION IN DAXINGANLING FOREST COVERED AREA

Betula and larix are broadly distributed in the forest covered area in northern Daxing'anling Mts.The botanogeochemical study by taking betula and larix samples is operatable and versatile.The outer barks and fallen leaves of plants are the best sampling media for botanogeochemical survey.The sampling for larix and betula leaves should be done in September,when the leaves have just fallen down.The interval of sampling is between 100 and 600 m.The best sampling periods for larix and betula barks are June and September.The sampling interval should be 10~200 m.The sampled barks would be 0.2 m above the ground.Dry ashing is suggested.The best ashing temperature is around 450℃.