摘要
为提高沙棘林生产力和合理经营沙棘林 ,以黄土丘陵区吴旗、安塞试验区多年的观测数据为依据 ,对沙棘群落特性及林地水分、养分进行了分析 .结果表明 ,沙棘生长迅速 ,适应性强 ,4～ 5年可形成林茂草丰的灌木 草本群落 .1～ 8龄生物量增长迅速 ,8～ 11龄生物量增长相对较缓 ,11龄后通过自然稀疏沙棘能维持较合理的群落结构和较高初级生产量 .沙棘对林地土壤水分的利用可分为根系微弱利用层 (0～2 0cm)、根系利用层 (2 0～ 30 0cm)、土壤水分补充调节层 (30 0～ 40 0cm)和微调节层 (40 0～ 5 0 0cm) .由于沙棘的改土作用及林地枯枝、落叶的蓄水作用 ,沙棘林地 1～ 1.5m土层土壤水分恢复较好 ,可超过或接近荒山天然草地 .沙棘可通过根瘤固氮及枯枝、落叶等凋落物的分解维持林地养分平衡 .6～ 9龄沙棘 ,土壤全N量可由农地、草地的 0 .0 5 %～ 0 .1%提高到 0 .2 % .
To improve the productivity of Hippophae rhamnoides forest and to manage the forest reasonably, the community characteristics of Hippophae rhamnoides and the water and nutrient condition of the woodland were analyzed. The results showed that Hippophae rhamnoides grew fast and its adaptability was strong. 4～5 years old Hippophae rhamnoides could form shrubs-grass community. The biomass 1～8 years old Hippophae rhamnoides increased rapidly, but that of 8～11 years old increased more slowly. Hippophae rhamnoides older than 11 years could keep reasonable community structure and higher primary productivity by natural thinning. The utilization of soil moisture by Hippophae rhamnoides could be classified into four layers as faint utilization layer of root system (0～20 cm), utilization of root system (20～300 cm), adjustment layer supplied by soil moisture (300～400 cm), and faint adjustment layer (400～500 cm). Due to the soil improvement by Hippophae rhamnoides and the water retaining by litter, the soil moisture of 1～1.5 m layer could be easy to restore. Hippophae rhamnoides could keep the balance of nutrition in the woodland through the fixation of nitrogen by root nodule and the decomposition of litter. In the 6～9 years old Hippophae rhamnoides plantation, the total nitrogen content of soil might be improved from 0.05～0.1% to 0.2%.
出处
《应用生态学报》
CAS
CSCD
2002年第9期1061-1064,共4页
Chinese Journal of Applied Ecology
基金
科技部中俄国际合作项目
水利部"948"引进项目 ( 975 15 4) .
关键词
黄土丘陵区
沙棘
群落特性
林地水分
养分分析
Hippophae rhamnoides, Community characteristics, Water, Nutrition, Loess Hilly Region.
