川南笔架山丹霞孤立生境地表光谱特征研究

Land Surface Spectral Characteristics of Danxia Isolated Biotope in Bijia Mountain, Southern Sichuan

丹霞顶部“孤岛”系统具备高异质化生境,是景观和生物多样性集聚地,富含丰富的生态与地理信息,具有很高的研究价值。受样地可进入性问题影响,前人针对丹霞顶部“孤岛”系统的研究存在一定片面性。本研究利用无人多载具协同调查技术,在四川南部笔架山开展针对丹霞顶部小型“孤岛”系统的地表光谱采集实验,并综合运用数据处理、对比、定性分析等方法,对系统中的地物类型、地物水平方向变化特征,以及水平方向上土壤有机质变化特征进行了探讨。结果表明,“孤岛”上的地物包括土壤、裸露的红色砂岩、绿叶植物和苔藓4类,且未发现明显的地物分带特征。“孤岛”中部可见裸露砂岩,而边部可见土壤,与传统观点存在差异,说明小型“孤岛”系统可能比经典的丹霞山顶系统更为复杂。此外还发现“孤岛”中部土壤的有机质含量高于边部土壤的有机质含量,即中部土壤比边部土壤更“肥沃”。

The “isolated island” systems on the top of some Danxia landforms contain highly heterogeneous biotopes and are gathering places for landscape and biodiversity. They are rich in ecological and geographic information and are of great research value. Due to accessible problem, previous studies focused on these systems are usually one-side. This study presents surface spectrum acquisition experiment for the small-scale “island” system on the top of Danxia landform in the Bijiashan area of southern Sichuan using unmanned multi-vehicle collaborative surveying technology. Based on the acquired spectral data, several data processing, data comparison, and qualitative analysis methods were used to investigate the ground feature types, the horizontal variation of ground feature, and the horizontal variation of soil organic matter content for the system. The results showed that the ground features on the “isolated island” included soil, bare red sandstone, green leafy plants and moss. No obvious zoning has been found for the ground features. Exposed sandstone can be found in the middle of the “island”, while soil can be found on the edge, which is disagreement with the traditional view, indicating that small-scale “isolated island” system may be more complicated than classic isolated system on the top of Danxia landforms. In addition, it was found that the soil organic matter content in the middle of the “island” is higher than that of the soil on the edge, that is, the soil in the middle is more “fertile” than the soil on the edge.