Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark; Büsgen-Institute, Soil Science of Temperate Ecosystems, Georg August University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany.
Department of Agricultural Soil Science, Georg August University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany.
Sci Total Environ. 2018 Sep 1;634:963-973. doi: 10.1016/j.scitotenv.2018.03.391. Epub 2018 Apr 11.
Initial changes in soil structure and C stocks were studied under short-rotation coppices (SRC) planted on former cropland near Göttingen, Central Germany. Plantations were established either as monocultures with willow (Willow-SRC) or poplar (Poplar-SRC), or as an agroforestry system with willow strips and grassland alleys in between (Willow-AF). A neighbouring cropland served as a control. Three sampling campaigns were applied in this study. The first sampling was conducted at a fine scale to reveal the differences in soil C with depth (i.e. 0-3, 3-6, 6-9, 9-12, 12-15, 15-20, 20-30cm). Here, results indicated the main differences between plantations in 0-3, 3-20 and 20-30cm layers. These soil depths were therefore chosen for the second sampling campaign to reveal differences in aggregate composition, C accumulation in aggregates and density fraction, and microbial biomass carbon (MBC) between plantations. Furthermore, quality of soil organic matter and amount of C mineralised by microorganisms were estimated by an incubation experiment. Results here indicated two times higher CO emissions from the top layer than from the lower layers under SRCs, as well as higher MBC in SRCs (490-788.7μgCg) than in cropland (266.4μgCg). The results of the third sampling on the texture of respective soil horizons indicated a significant correlation (R=78%) of soil clay to C at 0-3cm depth. It was concluded that aggregation and C in microbial biomass and free light fractions were the first indicators of soil quality improvement after conversion of arable land to SRC plantations.
本研究以德国中部哥廷根附近的耕地为立地条件，对短轮伐期林（SRC）下土壤结构和碳储量的初始变化进行了研究。林分分别采用单一树种（柳树 SRC 和杨树 SRC）或农林复合系统（柳树条带和草地中间的林带）建立。相邻的耕地作为对照。本研究进行了三次采样。第一次采样在细尺度上进行，以揭示不同深度（即 0-3、3-6、6-9、9-12、12-15、15-20 和 20-30cm）下土壤碳的差异。结果表明，林分之间的主要差异存在于 0-3、3-20 和 20-30cm 土层。因此，选择这些土壤深度进行第二次采样，以揭示林分之间团聚体组成、团聚体中碳积累和密度分数以及微生物生物量碳（MBC）的差异。此外，通过培养实验估计了土壤有机质质量和微生物矿化的碳量。结果表明，SRC 表层的 CO 排放是下层的两倍，而 SRC 中的 MBC（490-788.7μgCg）高于耕地（266.4μgCg）。第三次采样对各土壤层质地的结果表明，土壤粘粒与 0-3cm 深度碳之间存在显著相关性（R=78%）。研究得出结论，团聚体以及微生物生物量和自由轻组中的碳是耕地转为 SRC 林分后土壤质量改善的第一个指标。
