海南昌江县海滨土地风沙化及其环境整治

昌江县海滨土地风沙化主要是由于昌化江、珠碧江两大河流及研究区其它西流水系源头及沿岸森林植被遭到严重破坏,水土流失日趋严重,生态环境恶化;恶劣的气候条件;盲目开发等原因所致。针对上述原因和研究区土地风沙化状况,海南省和昌江县林业部门开展了一系列治沙造林试验研究,主要技术措施是:①先固沙,后造林,为造林幼苗生长创造有利条件;②用木麻黄大苗、壮苗带营养袋深栽造林;③采用"旱天造林"新技术,确保造林质量。该试验研究已取得成功,但还是存在一些问题,如木麻黄枯梢较为严重;垂直于主风方向的露兜行成活率较低;治沙林树种单调;后期管理差等。为此,本文提出了有关解决问题的建议:①造林过程中施加稀土微肥,以增强治沙林的抗逆性等;②增加与主风方向垂直的露兜行行数,提高网格固沙露兜的成活率;③扩大藤本植物种植面积,以增强固沙能力;④尝试引进其它地区固沙效果较好的物种,以增强抵御自然灾害的能力;⑤在防风林中立体套种适于生长的经济作物,以林养林;⑥加大投入,加强管理,加强环保教育,以确保治沙造林任务的顺利进行和环岛海防林的早日保质保量合拢。

Desertification and Re-afforestation of the Coast Land in Changjiang County, Hainan Island

Changjiang county is located to the northwest of the tailing range of Wuzhi Mountains in the Hainan Island.It faces the sea and is backed by the Mountains.From southeast to northwest,the relief is gradually descends from Mountains,hill,tableland,terrace to coastal plain.There are 44.85 km long sandy and 7.15 km rocky coast in 52 km long coastline in the county.The desertification coastal land is about 61.15 km² in size and from hundreds meters to 3 km in width,in which the active sand land accounts for 5.333 km² and semi active sand land 7.333 km².The dunes move at 10~30 m from the seashore to hinterland annually.The forest sectors of Hainan Province and Changjiang countuy have done a series of sand control experiments.The chief technological measures are as following:(1) Stabilize the drift sand firstly to create the adequate condition for afforestation.(2) Plant the big and strong sapling of Casuarin equisetifolia with nutrient bag in deep pit.(3) Apply the new technique of "planting in dry season" to guarantee the quality of afforestation.The above experiments are successful.However there still exists some problems such as quite serious wilting shoot,lower survival rate of Pandanus tectorius in the vertical lines to the usual wind direction,monotonous tree species in the afforestation and poor management in later stage.Thus the suggestions are offered in this paper for future extension:(1) Apply the fertilizer of rare earth elements in the process of afforestation to increase the resistance of the plants.(2) Add the vertical lines of Pandanus tectorius to the usual wind direction to raise the survival rate of them in the network of sand stabilization.(3) Enlarge the area of liana planting to enhance the stability of sand.(4) Try to induce the tree species from the other regions,which have good performance in sand stabilization.(5) Interplant the adaptable economic crops to provide support of afforestation with economic benefits.(6) Make more investments,better management and more extensive environmental education to ensure the connection of the protection forest belt around the island earlier.