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作 者 ：王江*,张崇邦

期 刊 ：生态学报 2009年 29卷 3期 页码：1636~1646

关键词：退化裸地；植被恢复；土壤微生物量；土壤基础呼吸；功能多样性；

Keywords:degraded barren land, re-vegetation, soil microbial biomass, soil basal respiration, functional diversity,

摘 要 ：研究了重金属污染裸地植被恢复4、5、6a和7a后的植物凋落物积累量、土壤化学特征、重金属含量与土壤微生物特征。结果表明：与未恢复裸地相比，植被恢复显著地提高了根际土壤中的有机碳（18.6~31.1 g·kg-1）、总氮（0.88~1.56 g·kg-1）和总磷（0.34~0.39 g·kg-1）含量（P < 0.05）；上述指标以及植物凋落物积累量没有随植被恢复年龄增加而提高。植被恢复地土壤pH、重金属铅、锌、铜的总量和DTPA（diethylenetriaminepentaacetic acid）可提取量均显著地高于未恢复裸地（P < 0.05），并且随植被恢复年龄增加呈现出一致提高的趋势。土壤微生物量碳和氮在5个研究样地中的变化趋势基本一致，即最大值均出现在样地RV（恢复5a）（127.34 mg·gdw-1和2.45 mg·gdw-1），然后在样地RVI(恢复6a)和RVII（恢复7a）均有不同程度地下降。微生物量氮在4个恢复样地中变化显著（P < 0.05）。土壤微生物基础呼吸和功能多样性最大值发生在样地RVI（5910 mg·gdw-1和3.14），随后在样地RVII中略有下降（P > 0.05）。未恢复裸地的土壤微生物对羧酸和胺类化合物利用率显著大于4个恢复样地（P < 0.05），对碳水化合物、氨基酸、聚合物和杂合物的利用率显著低于4个恢复样地（P < 0.05）。主成分分析结果表明，未恢复裸地的CLPP（community level physiological profiles）指纹与恢复样地存在显著差异（P < 0.05），4个恢复样的CLPP指纹相似。

Abstract:Litter accumulation, soil-chemical parameters, heavy metal contents and soil-microbial properties after the re-vegetation of the barren land contaminated with heavy metals were investigated. The results showed that, the re-vegetation could significantly increase soil organic carbon (18.6-31.1 g·kg-1), total nitrogen (0.88-1.56 g·kg-1) and total phosphorus (0.34-0.39 g·kg-1) in rhizosphere soils compared with the barren land. However, the litter accumulation and the above indicators did not consistently increase with the re-vegetation ages. Soil pH, the total amount of Pb, Zn and Cu and DTPA-extractable Pb, Zn and Cu in the re-vegetated soils were significantly (P < 0.05) higher than those in the barren land, and linearly increased with the re-vegetation age. The RV site had the highest levels in both soil-microbial biomass carbon and nitrogen (127.34 mg·gdw-1 and 2.45 mg·gdw-1). There was a significantly (P < 0.05) different decline in microbial biomass nitrogen in the RVI and RVII sites. The RVI site had the highest levels in soil basal respiration and functional diversity (59.10 mg·gdw-1 and 3.14) and there was a decline in the RVII site. Both the basal respiration and functional diversity had no significant difference among the four re-vegetated sites. Soil-microbial community in the barren land had a greater utilization in carboxylic acids and amines/amides, and lower utilization in carbohydrates, amino acid, polymers and miscellaneous than those in the four re-vegetated sites (P < 0.05). The PCA (principal components analysis) showed that CLPP (community level physiological profiles) in the barren land was significantly (P < 0.05) distinct from the re-vegetated sites, but had no significant difference among the four re-vegetated sites.

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