互花米草入侵对胶州湾潮滩湿地硫素时空分布的影响

选择胶州湾互花米草潮滩(入侵前为光滩)和光滩为研究对象,研究了互花米草入侵下胶州湾潮滩湿地土壤总硫(Total sulfur, TS)、有效硫(Available sulfur, AS)及互花米草各器官TS含量的时空分布特征及其影响因素.结果表明,互花米草入侵后湿地0～60 cm土壤TS((1.53±0.24) g·kg~(-1)))和AS((0.75±0.04) g·kg~(-1))的平均含量明显高于入侵前光滩湿地TS((1.13±0.09) g·kg~(-1))和AS((0.53±0.02) g·kg~(-1))的平均含量(n=54,p0.05),增幅分别为35.40%和41.51%.其中,互花米草入侵后湿地30～50 cm土层TS含量和20～60 cm土层AS含量较入侵前的光滩湿地大幅增加(n=9,p0.05).与光滩相比,6、10、12月互花米草潮滩土壤TS含量增幅分别为14.53%、67.86%、22.52%,AS含量增幅分别为48.72%、39.06%、50.98%.逐步线性回归分析结果表明,互花米草入侵后导致土壤EC、有机质的改变是影响其土壤AS含量分布的关键因素.互花米草TS含量均值为(2.73±0.39) g·kg~(-1),6月植物TS含量与10月、12月植物TS含量之间均存在显著性差异(n=9,p0.05),硫(S)累积量最高值出现在10月,同种器官内6月根、茎、叶的硫累积系数(Accumulation Factor of sulfur, AF_S)均高于10月、12月.研究表明,互花米草入侵总体增加了土壤硫库储量,提高了湿地土壤AS的供给能力,但增加了其时空变异性,AS在不同季节差异较大.

Effects of Spartina alterniflora invasion on sulfur content temporal and spatial variation in tidal flat wetland of Jiaozhou Bay

The temporal and spatial distributions of soil total sulfur (TS), soil available sulfur (AS) and TS in different organs of Spartina alterniflora contents in tidal flat wetland of Jiaozhou Bay were studied based on the S. alterniflora invasion. The results showed that the average contents of TS, AS in soils of S. alterniflora zone (0~60 cm) were (1.53±0.24) g·kg^-1 and (0.75±0.04) g·kg^-1, which were much higher than those in bare flat zone with the content of (1.13±0.09) g·kg^-1 and (0.53±0.02) g·kg^-1(n=54, p<0.05), with the increase of 35.40% and 41.51%, respectively. There was a significant increase on TS at 30~50 cm and AS at 20~60 cm soil layers in S. alterniflora zone compared with the bare flat zone (n=9, p<0.05). The amplification of soil TS were 14.53%, 67.86% and 22.52% in June, October and December, meanwhile, the amplification of soil AS were 48.72%, 39.06% and 50.98%, respectively. Stepwise regression equations showed that EC and organic matter were critical factors on content of soil AS after S. alterniflora invasion. The average content of TS of the whole plants was (2.73±0.39) g·kg^-1. TS content of S. alterniflora in June was significantly different from that of October and December (n=9, p<0.05). Sulfur accumulation was highest in October, and the AF_S values of roots, stems and leaves in June were higher than those in October and December. The results showed that the soil sulfur reserves increased and AS supply capacity was enhanced due to the S. alterniflora invasion. However, it varied greatly in different seasons.