雷竹林集约经营过程中土壤磷库的变化特征研究

Research on the Characteristic of Change in Soil Phosphorus Pool of Lei Bamboo (Phyllostachys praecox) Forest Under Intensive Management

为了研究雷竹林集约经营中土壤磷素的演规律,采集集约经营下种植雷竹不同年限(1年、5年、10年和15年)的雷竹林土壤,用Hedley法分析土壤的不同形态磷素组分含量,并测定pH、有效磷和全磷、酸性磷酸酶活性等指标。结果表明:土壤pH随着集约经营时间增加而显著下降(P<0.05)。雷竹林土壤磷素随种植年限增长而增加,1年、5年、10年和15年的全磷含量分别是0.70、0.89、1.37、1.86g/kg;有效磷含量分别为46.6、137.3、225.1、283.1mg/kg。在1～15年集约经营过程中,雷竹林土壤磷素组分Resin-Pi和NaHCO3-Pi随着集约经营时间的增加而显著上升;组分NaHCO3-Po、NaOH-Pi、NaOH-Po和Residual-P在集约经营初期变化不大;集约经营10年后显著增加;而HCl-Pi在集约经营前10年随着集约经营时间的增加而显著上升,10年后无显著变化。雷竹林土壤酸性磷酸酶活性随着集约经营时间的增加而显著降低。相关性分析表明,雷竹林土壤酸性磷酸酶活性与土壤的有机磷组分(NaHCO3-Po和NaOH-Po)均呈显著的负相关。综上所述,长期集约经营措施会引起雷竹林土壤磷素超量积累,对林地周边水体存在较大的污染风险。

To investigate the change of soil P in the Phyllostachys praecox stands under intensive management, soils were sampled with 1 year, 5 years, 10 years, and 15 years of bamboo stands. Soil pH, acid phosphatase activity, available P, and total P were analyzed. Hedley ＇ s method was used to study the different fractions of soil P. The results showed that soil pH was decreased with the prolonging plantation time of Phyllostachys praecox stand, and soil P content was increased. Soil total P （TP） contents were 0.70, 0.89, 1.37, 1.86 g/kg, and soil available P （Olsen P） contents were 46.6, 137.3, 225.1, 283.1 mg/kg in 1 year, 5 years, 10 years, and 15 years soil respectively. Soil resin-P i and NaHCO 3 -P i contents were significantly increased with the process of 0-15 years ＇ intensive management. The contents of NaHCO 3 -P o , NaOH-P i , NaOH-P o and Residual-P were not significantly changed in the initial stage of intensive management, and significantly increased after 10 years ＇intensive management. The content of HCl-P i was significantly increased in the initial 10 years ＇ intensive management, and was not changed after 10 years. The acid phosphatase activity was significantly increased with the lasting of intensive management. Correlation analysis showed that the acid phsophatase acitivity was negatively correlated with soil organic P fractions, such as NaHCO 3 -P o and NaOH-P o . In summary, long-term intensive management would cause the excess phosphorus accumulation in the soil of Lei bamboo, which would probably induce a contamination to the water around the forests.