塔克拉玛干沙漠公路防护林带不同林分的凋落物贮量及土壤性质研究

Study on Litter Standing Biomass and Soil Properties under Different Shelterbelts along the Tarim Desert Highway

以塔克拉玛干沙漠腹地塔中地区不同林龄(5 a生、10 a生、13 a生、16 a生)沙漠公路防护林为研究对象,选取林带内滴头处和滴头外两个不同位置,对3种植物林带地表凋落物和对应0~10 cm的土壤进行收集、取样和化学分析。结果表明:防护林带内凋落物平均厚度沙拐枣(Calligonum mongolicum)10.9~14.8 cm,贮存量6.6~23.0 t hm-2;柽柳(Tamarix chinensis)9.2~11.8 cm,贮存量5.0~16.5 t hm-2;梭梭(Haloxylon ammodendron)6.3~11.0 cm,贮存量4.6~12.7 t hm-2。三树种对应土壤全N、全P、全K含量表现出不同的动态过程,其中全N全P均随定植年限的增加总体上属于富集过程,全K含量随定植年限的增加呈波浪式变化。三种土壤微生物数量随着土壤深度的增加而呈递减趋势。不同林龄防护林带内蔗糖酶、蛋白酶以及脲酶的活性变化趋势基本呈现滴头处大于滴头外。由此可见该地区的浇灌模式会对土壤各营养物质的积累与生物活性的表达产生一定影响。

Taking the desert highway shelter forest with different ages in the hinterland of Tarim Desert as research objects, three kinds of plant litters and the corresponding soil samples(0-10 cm) were collected and tested at the dripper and outside the dripper. The results showed that the average ranges of the litter thickness of Calligonum mongolicum, Tamarix chinensis Lour. and Haloxylon ammodendron. were 10.9-14.8 cm, 6.3-11.0 cm and6.3-11.0cm, respectively. The litter storages of Calligonum mongolicum., Tamarix chinensis Lour. and Haloxylon ammodendron. were 6.6-23.0 t hm-2, 5.0-16.5 t hm-2and 4.6-12.7 t hm-2, respectively. The contents of soil total N and P increased with the increase of plantation time of the shelter-belt, while the content of soil total K changed slightly. The enzyme activities of invertase, urease and protease at the dripper were bigger than that outside the dripper in the different Shelter-belts. In this case, the irrigation model in this area had an impact on soil nutrient accumulation and the expression of biological activity.