摘要
本文以烟台海岸沙地为试验地,通过对不同生态断带(取样地距高潮线10,30,50 m)植被、土壤水溶性盐分离子(Na^+,K^+,Cl^-,SO_4^(2-))含量、土壤养分(土壤速效P,速效K,速效N,全K,全P)含量、土壤酶(脲酶、蔗糖酶、磷酸酶)活力的分析,以了解海岸不同生态断带土壤盐度和养分空间异质性与植物分布的关系和作用机理.结果表明,近高潮线10 m处土壤Na^+,K^+,Cl^-,SO_4^(2-)含量最高,尤其是Na^+和Cl^-分别较远离高潮线30 m和50 m处土壤高9.7,2.7倍和22.3,2.8倍.同时,近高潮线10 m处土壤酶脲酶、蔗糖酶、碱性磷酸酶活力和土壤有效养分含量最低,随远离高潮线土壤酶活力上升、土壤有效养分含量增加.与近高潮线10 m相比,50 m处土壤Na^+和Cl^-含量下降了95.7%,73.7%;土壤有效N,有效K,有效P含量分别升高69.1%,32.7%,6.0%;土壤蔗糖酶、脲酶、磷酸酶活力分别提高204.7%,388.1%,455.1%.而且不同生态断带植物种类不同,10 m处只有抗沙埋耐盐性强的滨麦(Leymus mollis)生长形成单一种群,30 m处出现了抗旱抗盐的以肾叶打碗花(Calystegia soldanella)为优势种的草本植物群落,在50 m处出现了以小灌木刺槐(Robinia pseudoacacia)为优势种的草灌群落.研究表明,由于距海岸高潮线距离和受海水侵蚀强度的不同使不同生态断带土壤酶活力和养分含量随远离高潮线土壤盐度的降低而呈梯度增长趋势,不同生态断带土壤酶活力和养分呈空间异质性分布,其中盐分起主导作用.同时海岸生态环境的异质性是诱发植物种分布不同的生态诱因,而植物对沙埋、盐胁迫、土壤瘠薄的适应生态幅不同可能是诱发其分布不同的生物诱因.因此利用海岸带环境盐度和养分的空间异质性,合理布局和栽种抗逆性不同的植物种类将有助于快速恢复海岸带环境和维持海岸生态系统的稳定.
This experiment was conducted on Yantai coastal dune. The vegetation grown on the different area of10 m,30 m,50 m far from high tide line was surveyed,and the mineral ions（ Na^＋,K^＋,Cl^-,SO4^2-）,soil nutrients（ available nitrogen,available potassium,available phosphorus,whole potassium,whole phosphorus）,and soil enzyme activities（ invertase,urease,phosphatase） were measured from the soil of 10 m,30 m,50 m far from high tide line to understand the relationship between spatial heterogeneity of soil nutrients and salt concentration and distribution of plant species and the mechanism is involved on the sand dune. The results showed that contents of Na^＋,K^＋,Cl^-,SO4^2-were the highest in the soil closed to the high tide line（ 10 m）,especially the contents of Na^＋and Cl^-were higher with 9. 7 and 2. 7 time than that in the 30 m location with 22. 3 times,2.8 times than that in the 50 m location. At the same time,the soil closed to high tide ling（ 10 m） had the lowest activities of soil invertase,urease,phosphatase and the content of available nutrient. With far away from high tide line,the contents of water-soluble ions of the soil tend to decrease,while the soil available nutrients and soil enzyme activities tend to increase. Compared with the soil closed to high tide line（ 10 m）,the contents of Na^＋and Cl^-decreased by 95. 7% and 73. 7%,the contents of available nitrogen,available potassium,available phosphorus increased by 69. 1%,32. 7% and 6. 0%,while activities of invertase,urease,phosphatase increased by 204. 7%,388. 1%,455. 1% in the soil far away 50 m from high tide line. With far away from high tide line,the dominated species of coastal vegetation changed and species diversity increased. At 10 m,there was only one species（ Leymus mollis） grown there. At 30 m location,there was a community of Calystegia soldanella,which was a dominated species with resistance to drought and salt. At 50 m location,there was a community of Robinia pseudoacacia,which was also a dominated species with resistance to drought and salt. It indicated that the distance from coastal high tide and strength subject to seawater erosion affected on the activity of soil enzymes and nutrition content. Both the activity of soil enzymes and nutrition were lowest on high tide line,and increased as the distance from high tide line increased and the salt content of soil decreased. The salt played an important role in soil enzyme activity and nutrient heterogeneity distribution. At the same time,the spatial heterogeneity of nutrient content was a ecological factor inducing the different spatial heterogeneity of plant species distribution. But it was a biological factor that plant species had different amplitude of ecological adaptation to sand burial,salt stress,and barren soil. Therefore,taking advantage of spatial heterogeneity of nutrient distribution and soil salt contents to reasonably arrange and plant species with different ability of resistance to adversity environment,will be helpful to promote the environment recovery of coast and maintain the stable of coastal ecological system.
作者
宋玉
周瑞莲
张婷凤
杨润亚
SONG Yu, ZHOU Ruilian, ZHANG Tingfeng, YANG Runya(College of Life Science, Ludong University, Yantai 264025, China)
出处
《鲁东大学学报（自然科学版）》
2018年第3期217-227,共11页
Journal of Ludong University:Natural Science Edition
基金
国家自然科学基金资助项目(31770762)
关键词
盐度
土壤酶
土壤养分
植被分布
空间异质性
soil salinity
soil enzyme activities
soil nutrients
vegetation distribution
patial heterogeneity
