| 华南桉树人工林芒萁层片的生态筛效应 |
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| 引用本文： | 刘美洁,孙中宇,耿守保,温美丽,戴佳玲,杨龙.华南桉树人工林芒萁层片的生态筛效应[J].热带地理,2021,41(6):1338-1346. |
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| 作者姓名： | 刘美洁 孙中宇 耿守保 温美丽 戴佳玲 杨龙 |
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| 作者单位： | 1.广东省遥感与地理信息系统应用重点实验室//广东省地理空间信息技术与应用公共实验室//广东省科学院广州地理研究所，广州 510070;2.广东工业大学 环境科学与工程学院，广州 510006 |
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| 基金项目： | 国家自然科学基金(31770473);国家重点研发计划(2018YFC1800304);广东省科学院百名青年人才培养专项(2019GDASYL-0104002) |
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| 摘 要： | 芒萁是华南退化坡地上最具代表性的先锋种、优势种和关键种，能够快速形成密集的单优种层片结构。与传统阻碍更新的观点不同，野外观察发现芒萁层片内仍有少数物种能够成功定居，被认为具有生态筛效应。文章通过设置4种芒萁层片处理（芒萁层片完全剔除-UR；仅保留地上层-AF；仅保留根毯层-AR；芒萁层片全部保留-CK），分别在不同处理下移植目标种幼苗并结合土壤性状，探究芒萁层片生态筛效应及其潜在机理。结果发现：1）桉林芒萁根毯层中土壤有机质、全氮、碱解氮、有效磷、速效钾、交换性钠、交换性钙、交换性镁和阳离子交换量均显著高于芒萁红壤层和裸地红壤；2）多数乔木种和草本种在芒萁根毯层保留时无法存活，仅荷木、桃金娘、梅叶冬青和野牡丹等目标种幼苗在保留芒萁根毯层处理（AR和CK）下能够存活与生长。这表明芒萁层片确实具有生态筛效应，且其关键在于根毯层的作用而并非土壤养分改善作用。理论上，芒萁层片（尤其是根毯层）与生态恢复的生物阈值突破密切相关，未来需要进一步解析芒萁根毯层的结构与功能。应用上，华南地区存在大量以芒萁为单优林下植物的人工林类型（如桉林等），在进行结构优化与林分改造时需注意芒萁的生态筛效应。
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| 关 键 词： | 幼苗生长 林下植被 蕨类 幼苗移植 群落演替 根毯层 |
| 收稿时间： | 2021-05-07 |
Ecological Filtering Effect of Dicranopteris Synusia under Eucalyptus Plantation in South China |
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| Meijie Liu,Zhongyu Sun,Shoubao Geng,Meili Wen,Jialing Dai,Long Yang.Ecological Filtering Effect of Dicranopteris Synusia under Eucalyptus Plantation in South China[J].Tropical Geography,2021,41(6):1338-1346. |
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| Authors: | Meijie Liu Zhongyu Sun Shoubao Geng Meili Wen Jialing Dai Long Yang |
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| Institution: | 1.Key Lab of Guangdong for Utilization of Remote Sensing and Geographical Information System//Guangdong Open Laboratory of Geospatial Information Technology and Application//Guangzhou Institute of Geography, Guangdong Academy of Sciences, Guangzhou 510070, China;2.School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. |
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| Abstract: | Dicranopteris is the most representative pioneer species, dominant species and key species in degraded slope land in South China. Dicranopteris could quickly form dense synusia of a single and dominant species. In contrast to the traditional view that Dicranopteris hinders forest regeneration, we found that there are a few species that could settle down in Dicranopteris synusia. We proposed a hypothesis that Dicranopteris synusia could act as an ecological filter. In this study, we transplanted 12 target species seedlings under Dicranopteris synusia with 4 treatments to explore the ecological filtering effect of Dicranopteris synusia, and analyzed the mechanism with soil characteristics. The 4 treatments included the understory removal treatment (UR), the aboveground of Dicranopteris synusia were kept (AF), the root blanket of Dicranopteris synusia were kept (AR) and all of the Dicranopteris were kept (CK). The results showed that: 1) Compared with the red soil under Dicranopteris synusia of Eucalyptus plantation and bare ground, the contents of soil organic matter, total nitrogen, hydrolyzed nitrogen, available phosphorus, available potassium, and exchangeable base ions in the root blanket of Dicranopteris synusia were significantly higher. 2) The majority of the tree species and all of the herbaceous species could not survive with the root blanket of Dicranopteris synusia kept (AR and CK). The species that could survive with the root blanket of Dicranopteris synusia kept were Schima superba, Rhodomyrtus tomentosa, Ilex asprella and Melastoma candidum. The results indicated that Dicranopteris synusia could act as an ecological filter. The key lies in the role of root blanket of Dicranopteris synusia, and not in the improvement of soil nutrients. Theoretically, Dicranopteris synusia, especially the root blanket of Dicranopteris synusia, is closely related to the breakthrough of biological threshold for ecological restoration. In the future, it is necessary to further analyze the structure and function of the root blanket of Dicranopteris synusia. In terms of application, there are a large number of plantation types (such as Eucalyptus plantation) that Dicranopteris occupied as a single dominant understory species in South China. Therefore, we should pay more attention to the ecological filtering effect of Dicranopteris synusia in structural optimization and stand transformation. This study could provide a reference for the restoration and reconstruction of degraded slope land in South China. |
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| Keywords: | seedling growth understory vegetation fern transplant seedlings community succession root blanket synusia |
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