加拿大一枝黄花入侵对杭州湾湿地围垦区土壤养分及活性有机碳组分的影响

加拿大一枝黄花(Solidago canadenis)是我国危害最严重的外来入侵植物之一,为了阐明其对入侵地生态系统的影响,以浙江省慈溪市杭州湾湿地围垦区内自然分布的加拿大一枝黄花群落和3种土著植物群落:束尾草(Phacelurus Griseb)群落、白茅(Imperata cylindrica)群落和芦苇(Phragmites australis)群落为研究对象,采用野外样地实验的方法,研究了加拿大一枝黄花入侵对土壤氮、磷和钾含量以及有效性和活性有机碳组分含量的影响。结果表明加拿大一枝黄花的入侵显著降低了土壤的p H(P0.05),对土壤全氮、全磷、全钾、有效磷、速效钾和钾含量没有显著影响(P0.01),但显著提高了碱解氮、铵态氮和硝态氮的含量(P0.01),其中加拿大一枝黄花0~10 cm土层碱解氮含量分别是束尾草、白茅和芦苇的1.72倍、2.35倍和2.00倍。加拿大一枝黄花入侵对土壤总有机质含量无显著影响(P0.01),但是却改变了活性有机碳组分,与束尾草、白茅和芦苇相比,加拿大一枝黄花群落0~10 cm表层土壤中微生物生物量碳的含量分别提高了196.72%、180.21%和41.47%;可溶性碳0~10 cm土层分别降低了27.27%、40.78%和4.00%,10~20 cm土层分别降低了41.36%、39.49%和29.63%;易氧化碳含量在两个土层中均显著降低(P0.01)。上述结果表明加拿大一枝黄花的入侵降低了土壤p H,提高了土壤氮素的有效性,改变了活性有机碳组分。

Invasion Effects of Solidago Canadensis on Soil Nutrients and Active Organic Carbon Components in Reclamation District of Hangzhou Bay Wetland

Solidago canadenis is one of the worst hazardous invasive plantsin China, in order to clarify its influence on the ecological system of invaded land, this experiment tookSolidago canadenis communitiesand three kinds of native plant communities:Phacelurus Griseb communities, Imperata cylindricall communitiesandPhragmites australis communities naturally distributed in the reclamation district of Cixi city of Hangzhou Bay wetland as the research object, studied the invasion effects of Solidago canadensis on soil nitrogen, phosphorus and potassium contents and their available component contents as well as active organic carbon components on wild sample plots.The results showed that the invasion ofSolidago canadenis significantly reduced soil pH value (P<0.05), had no significant influence on contents of soil total nitrogen, total phosphorus, total potassium, available phosphorus and available potassium (P>0.01), but significantly increased the contents of available nitrogen, ammonium nitrogen and nitrate nitrogen (P<0.01), soil available nitrogen content inSolidago canadenis in 0–10 cm soil layerwere 1.7 times, 2.4 times and 2.0 times of Phacelurus Griseb, Imperata cylindricalandPhragmites australis,respectively. The invasion of Solidago canadensis had no significant influence on soil total organic matter content (P>0.01), but changedsoil active organic carbon components. Compared with thePhacelurus Griseb, Imperata cylindricalandPhragmites australis, soil microbial carbon content in 0–10 cm soil layer inSolidago canadenis increased by 196.72%, 180.21% and 41.47%, respectively; soil soluble carbon reduced by 27.27%, 40.78% and 27.27%, respectively, and reduced by 41.36%, 39.49% and 29.63% in 10–20 cm layer, respectively; soil readily oxidized carbon reduced significantly in the two layers (P<0.01). The above results showed that theinvasion of Solidago canadenis could reduce soil pH value, increase the effectiveness of soil nitrogen andchange soil active organic carbon components.