THE GROWTH OF PROTECTION FORESTS AGAINST SAND AND WIND IN COASTAL AREAS IN THANH HOA

Abstract

Results on the study of the development of protection forests against sand and wind in coastal districts and cities in Thanh Hoa (Nga Son, Hau Loc, Hoang Hoa, Sam Son and Tinh Gia) show that most of the protection forests against sand and wind are purebred Casuarina equisetifolia forests. Planted forest with initial density of 5000 trees/ha (planted forest in 2010 in Hau Loc district; in 1998, 2007 in Hoang Hoa; in 2015 in Quang Xuong; in 2014 in Tinh Gia) the current density ranged from 2180 plants/ha to 4820 plants/ha. The remaining forest was planted with initial density of 2500 trees/ha, the current density ranged from 480 plants/ha to 1840 plants/ha. In general, casuarinas grow well on sandy soil in coastal districts of Thanh Hoa. The average diameter and height was 17cm and 19,3m in planted forest in 1998; 4,6cm and 6,6m in planted forest in 2015; ranging from 14,1cm to 18,3cm and from 10,4m to 16,8m in planted forest in 2000, from 12,7cm to 14,3cm and from 12,7m to 14,6m in planted forest in 2007, from 10,5cm to 12,8cm and from 11,5m to 13,9m in planted forest in 2010, from 6,4cm to 8,9cm and from 8,3m to 10,8m in planted forest in 2014. Plants grew strongly in diameter and height in early years, then decreased with age.