Key Laboratory of Resources and Utilization of Bamboo of State Forestry Administration, China National Bamboo Research Center, Wenyi Road 310, Hangzhou, 310012, China.
National Long-Term Observation and Research Station for Forest Ecosystem in Hangzhou-Jiaxing-Huzhou Plain, Zhejiang, Hangzhou, 310012, Zhejiang, People's Republic of China.
Environ Sci Pollut Res Int. 2020 Jan;27(2):2301-2310. doi: 10.1007/s11356-019-06750-2. Epub 2019 Nov 27.
Bamboo forests are one of the most important forest resources in subtropical China. A pure, single-layer bamboo forest is considered an optimal habitat for intercropping medicinal herbs. Soil microorganisms have an important role in various ecological processes and respond quickly to environmental changes. However, changes in soil nutrients and microbial communities associated with agroforestry cultivation methods remain poorly documented. In the present study, a pure moso bamboo (Phyllostachys edulis) forest (Con) and three adjacent moso bamboo-based agroforestry (BAF) systems (moso bamboo-Paris polyphylla (BP), moso bamboo-Tetrastigma hemsleyanum (BT) and moso bamboo-Bletilla striata (BB)) were selected; and their soil chemical properties and bacterial communities were studied and compared to evaluate the effects of agroforestry on soil bacterial communities and the relationship between soil properties and bacterial communities in BAF systems. Results showed that compared with soils under the Con, soils under the BAF systems had more (p < 0.05) soil organic carbon (SOC) and available nitrogen (AN) but lower (p < 0.05) pH and available potassium (AK). In addition, compared with the Con system, the BB and BT systems had significantly greater (p < 0.05) available phosphorus (AP). Compared with that in the Con system, the Shannon index in the BAF systems was significantly greater (p < 0.05), but the Chao1 index not different. On the basis of relative abundance values, compared with the Con soils, the BAF soils had a significantly greater abundance of (p < 0.05) Bacteroidetes and Planctomyces but a significantly lower abundance of (p < 0.05) Verrucomicrobia, Gemmatimonadetes and Candidatus Xiphinematobacter. Moreover, compared with the Con system, the BB and BT systems had a greater (p < 0.05) abundance of Actinobacteria, Rhodoplanes, Candidatus Solibacter and Candidatus Koribacter. Redundancy analysis (RDA) revealed that soil pH, SOC and AP were significantly correlated with bacterial community composition. Results of this study suggest that intercropping medicinal herbs can result in soil acidification and potassium (K) depletion; thus, countermeasures such as applications of K fertilizer and alkaline soil amendments are necessary for BAF systems.
竹林是中国亚热带最重要的森林资源之一。单一纯竹林被认为是间作药用植物的最佳栖息地。土壤微生物在各种生态过程中起着重要作用，并能迅速响应环境变化。然而，与农林复合经营方式相关的土壤养分和微生物群落的变化仍记录甚少。本研究选择了一片纯毛竹（Phyllostachys edulis）林（Con）和三个相邻的毛竹农林复合系统（BAF）（毛竹-重楼（BP）、毛竹-三叶崖爬藤（BT）和毛竹-白芨（BB）），对其土壤化学性质和细菌群落进行了研究和比较，以评估农林复合经营对土壤细菌群落的影响，以及 BAF 系统中土壤性质与细菌群落之间的关系。结果表明，与 Con 下的土壤相比，BAF 系统下的土壤具有更多的（p < 0.05）土壤有机碳（SOC）和有效氮（AN），但更低的（p < 0.05）pH 值和有效钾（AK）。此外，与 Con 系统相比，BB 和 BT 系统的有效磷（AP）显著增加（p < 0.05）。与 Con 系统相比，BAF 系统的 Shannon 指数显著增加（p < 0.05），而 Chao1 指数没有差异。基于相对丰度值，与 Con 土壤相比，BAF 土壤中厚壁菌门和浮霉菌门的丰度显著增加（p < 0.05），而疣微菌门、芽单胞菌门和拟杆菌门的丰度显著降低（p < 0.05）。此外，与 Con 系统相比，BB 和 BT 系统中的放线菌门、Rhodoplanes、Candidatus Solibacter 和 Candidatus Koribacter 的丰度显著增加（p < 0.05）。冗余分析（RDA）表明，土壤 pH 值、SOC 和 AP 与细菌群落组成显著相关。本研究结果表明，间作药用植物会导致土壤酸化和钾（K）耗竭；因此，BAF 系统需要采取施用钾肥和碱性土壤改良剂等对策。
