Effect of the Method Combining Cutting with Machine Boat on Controlling Spartina alterniflora and Its Impact on Wetland Soil Characteristics
- 生命科学－已发表论文 
在福建泉州湾开展了刈割+机耕船方法(机械法)治理互花米草(Spartina alterniflora)试验,调查了该法治理互花米草的效果,并对互花米草治理迹地土壤的理化性状进行了监测,为互花米草治理迹地的再利用提供依据。2006年7月初对互花米草进行刈割,待其新萌生株生长至10～15cm后,用机耕船对滩涂进行高强度耕作,以充分破坏其根系,其后,如仍有零星新萌生株,则用人工踩踏使其深埋淤泥之中。近一年多的治理效果监测表明,该法治理迹地在第二年以后没有发现新萌生植株,治理效果理想;与未治理互花米草的草滩相比,治理一个月后,治理迹地的土壤容重减小了21.2%～23.5%,之后,土壤容重逐渐增大,但在治理后一年时的土壤容重仍小于未治理互花米草的滩涂;随着互花米草根系的逐渐死亡和分解,治理迹地中根系生物量呈明显下降趋势,且下降速率在治理后第二年的4月开始明显增大,至10月时残存根系基本分解完毕;在治理后13个月,治理迹地0～20cm和20～40cm土层土壤中水解氮比治理前分别提高了16.2%和11.7%,有效磷含量分别提高了11.9%和16.7%,全氮含量分别提高了16.4%和17.5%。由此可见,机械法治理互花米草效果十分理想,2006～2007年的治理成本约为7500～9000元/hm2,该方法为红树林等乡土植被的恢复及滩涂的再利用创造了条件。Since Spartina alterniflora was introduced to China in 1979, it began to colonizing and formatting populations in China’s costal tidal flat for the optimum temperature, humidity, salinity, soil, moisture, nutrient, and other environmental conditions. In last decade, Spartina alterniflora had became a salt marsh plant that has the largest distribution area (over 5×104 hm2) in China’s coastal tidal flat. The outbreak of Spartina alterniflora had formed severity threat to biodiversity and ecological safety of China’s coastal tidal flat, and Spartina alterniflora had become one of the most important invasive species. Last a few years, many efforts had been done in China on Spartina alterniflora controlling technology and method, such as herbicide, replacing biology, cutting and watering, and acquired some achievements. In the paper, the method combining cutting with machine boat was used to control Spartina alterniflor in Quanzhou estuary, the controlling effect was investigated, and the wetland soil characteristics were monitored. In July 2006, Spartina alterniflora was cut, thereafter, mechanized-farming boat, whose rear consists of rotary tiller, was used to fully destroy the root system when new sprouted plants grew at 10 to 15 cm. If there were still some new sprouted plants, they would be trampled and embedded into the soil. The monitoring result showed that the controlling effect was wonderful. Compared with the non-controlled Spartina alterniflora tidal flat, the soil bulk density of controlled area decreased about 21.2% to 23.5% after controlled one month, then, it increased gradually, but it was still less than that in the non-controlled Spartina alterniflora tidal flat after controlled one year. With the death and decomposition of roots, the root biomass of the controlled area obviously decreased, and the decreasing rates had obviously been accelerated since the April in 2007. The residual roots were basically decomposed up in October. 2007. In August. 2007 (after controlled 13 months), compared with non-controlled Spartina alterniflora tidal flat soil, hydrolytic nitrogen increased 16.2% (in 0 to 20 cm soil layer) and 11.7% (in 20 to 40 cm soil layer), and available phosphorus increased 11.9% (in 0 to 20 cm soil layer) and 16.7% (in 20 to 40 cm soil layer). In short words, the controlling effect was very well, and the controlling cost was about 7 500 to 9 000 RMB per hectare from 2006 to 2007, for which created condition recovering the native mangrove forest.