大沙鼠扰动对荒漠土壤微生物数量和水肥状况的影响

Effects of Rhombomys opimus on Microbial Quantity,Soil Moisture Content and Soil Nutrient Content in a Desert

对比分析古尔班通古特沙漠10组大沙鼠（Rhornbomysopimus）洞区和无沙鼠扰动对照区20-30cm土层微生物各类群（真菌、细菌和放线菌）的数量分布，并比较土壤理化性质的差异。结果表明：大沙鼠的活动改变了洞区土壤水肥状况，有利于土壤微生物，尤其是真菌的生长发育。洞区土壤细菌（3．40×10^5±6．79×10^4个／g）、放线菌（7．52×10^4±1．11×10^4个/g）、真菌（5．03×10^3±2．05×10^3个/g）的数量均高于对照区（3．14×105±1．05×10^5个/g，6．04×10^4±1．65×10^4个/g，1．01×100±6．98×100^5个/g），（t=0．67，P〉0．05；t=2．356，P〈0．05；t=5．861，P〈0．01）。大沙鼠洞区20-30cm土壤水分（1．40％±0．47％）、速效P（16．68±5．11mg／kg）和速效K（125．50±24．99mg／kg）含量显著高于对照区（0．90％±0．11％；1．59±0．55mg／kg；81．00±20．82mg／kg），（t=3．276，P〈0．01；t=5．268，P〈0．01；t=4．326，P〈0．01）。而土壤有机质含量（0．11％±0．02％）、全P（0．027％±0．002％）、全K（1．225％±0．053％）含量显著低于对照区（0．14％±0．03％，0．031％±0．004，1．293％±0．047％）（t=2．997，P〈0．01；t=2．857，P〈0．01；t=2．982，P〈0．01）。全N（0．009％±0．002％）和速效N（16．68±5．1lmg／kg）的含量均低于对照区（0．01％±0．003％，16．80±5．15mg／kg），但是差异不显著（t=0．87，P〉0．05；t=0．052，P〉0．05）。

In this paper the analyzed results of 10 soil samples collected at 20-30 cm in depth at the burrow sites of Rhombomys opimus are compared with that of 10 soil samples collected random in the same soil layer in surrounding areas without disturbance of Rhombomys opimus in the Gurbantonggut desert. The results show that the burrow systems of Rhombomys opimus are advantageous to form a favorable environment for the growth and development of microorganism, especially for fungil, because the activity of Rhombomys opimus can change the conditions of soil moisture and nutrients. The quantities of bacteria （3.40 × 10^5 ± 6.79 × 10^4 ind·g^-1 ）, actinomycete （7.52 × 10^4 ± 1.11 ×10^4 ind·g^- 1） and fungal colonies （5.03 × 10^3 ± 2.05 × 10^3 ind·g^-1 ） in soil with the burrow systems of Rhombomys opimus are higher than that at the random sites （3.14×10^5±1.05 × 10^5 ind·g^-1, 6.04 × 10^4 ±1.65 × 10^4 ind·g^-1 and 1.01 ×10^3 ±6.98 × 10^2 ind·g^-1 respectively） （ t = 0.67, p 〉 0.05 ; t = 2. 356, p 〈 0.05 ; t = 5. 861, p 〈 0.01 ）. Soil moisture content （ 1.40 % ± 0.47% ） and available phosphorus content （ 16.68 ± 5.11 mg·kg^- 1 ） and potassium content in soil （ 125.50 ± 24.99 mg·kg^- 1 ） at the sites with burrow systems are significantly higher than that at the random sites （0.90 % ± 0.11%, 1.59 ± 0.55 and 81.00±20.82 respectively）, （t=3.276, p〈0.01; t=5.268, p〈0.01; t=4.326, p〈0.01）. Organic matter content （0.11% ±0.02% ）, total phosphorus content （0. 027% ± 0. 002% ） and potassium content （1. 225 % ± 0. 053 % ） in soil at the sites with burrow systems of Rkomborrtys opimus are significantly lower than that at the random sites （0.14 % ± 0.03 %, 0. 031% ± 0. 004 and 1. 293 % ± 0. 047% respectively）, （ t = 2.997, p〈0.01; t=2.857, p〈0.01; t=2.982, p〈0.01）. Similarly, total nitrogen content （0.009% ± 0. 002% ） and available nitrogen content （16.68 ± 5.11 mg· kg^-1） in soil at the sites with burrow systems of Rhombomys opimus are lower than that at the random sites （0.01% ± 0. 003 % and 16.80 ± 5.15 mg· kg^- 1 respectively） （t=0.87, p〉0.05; t=0.052, p〉0.05）.