Integrating ecosystem services and complex network theory to construct and optimize ecological security patterns: a case study of Guangdong-Hong Kong-Macao Greater Bay Area, China.

The urban agglomerations' rapid expansion and population growth have led to the fragmentation of landscape patterns and the degradation of ecosystems, seriously threatening regional ecological security. Ecological security pattern (ESP) is a spatial planning approach to effectively balance the development of urbanization and ecological protection. However, previous studies have ignored the difference in the importance of ecosystem services and the spatial compactness of ecological sources. The quantitative management objectives for maintaining the resilience of ESP are also rarely discussed. In this study, taking the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) as an example, ecological sources were identified by simulating multiple ES weight assignment scenarios through GeoSOS area optimization. Ecological corridors and strategic points were extracted by Linkage Mapper. The robustness analysis based on complex network theory was performed to quantify the management objectives of ESPs. The results showed that ESPs include 26,130.61 km2 ecological sources (accounting for 46.6% of the area of GBA), 557 ecological corridors, and 112 ecological strategic points. In more detail, ecological sources are mainly distributed in the western and eastern mountainous areas, and ecological corridors primarily link peripheral edge areas of GBA in a circular radial shape. Compared with the current nature reserves, the identified ecological sources are more compact in landscape pattern. According to the robustness analysis, at least 23% of the important ecological sources should be strictly restricted from development activities to maintain the ESP's ability to resist ecological risks. This study also proposed corresponding differentiated ESPs management strategies. By optimizing the existing ESPs construction method and clarifying the ESPs management strategies, this study provides a completely scientific framework for the construction and management of ESPs in urban agglomerations.

Ecological network construction and optimization in Guangzhou from the perspective of biodiversity conservation.

Rapid urbanization has resulted in fragmentation and decreased connectivity in urban landscapes, endangering regional biodiversity conservation and high-quality, sustainable development. networks (ENs) construction and optimization is a critical technique to enhance landscape connectivity effectively, promote species interaction and dispersal, and thereby hence urban biodiversity., most existing studies on ENs construction have been undertaken from the perspective of ecosystem service functions or the value of landscape structure, with regional species still being overlooked. on the distribution data of critical species in this study, the maximum entropy model (MaxEnt), wilderness mapping model, and granularity reverse method were integrated to identify ecological sources. the habitat quality (HQ) index was utilized to construct a resistance surface modified by landscape connectivity and ecological sensitivity. findings indicate that: (1) a grid scale of 1700 m is the relatively optimal minimum threshold for ecological source sites in Guangzhou; (2) 35 crucial ecological sources in Guangzhou are identified, with a total area of 1100.42 km2, mainly woodlands, distributed in mountain systems in the northern and central parts of the city; and (3) 59 ecological corridors are identified, with a total length of 817.4 km, with a relatively high density in the central part of the city. some extent, this study offers fresh ideas for constructing urban ENs from the standpoint of biodiversity conservation. contributes to the city achieving a win-win economic development and ecological protection situation.

Benign optic nerve gliomas in an adult: A case report.

RATIONALE: Benign optic nerve gliomas were rarely found in adults, and total resection of these lesions seems impossible. We aimed to share a rare clinical case with an unusual and instructive treatment process. PATIENT CONCERNS: A 52-year-old woman complained of a 4-month history of visual disturbance. Automated perimetry revealed visual field defect in her both eyes. DIAGNOSIS: This patient was diagnosed with optic nerve glioma. We found its pathological features consistent with the pilocytic astrocytomas (WHO grade I). INTERVENTIONS: A total resection of the tumor was smoothly performed. OUTCOMES: Repeat MRI 3 months after the surgery demonstrated no recurrence of the lesion. Two years of postoperative telephone follow-up showed a stable status of improved vision. LESSONS: We reported this interesting case to show a rare kind of condition regarding optic nerve gliomas in adults, which might help neurosurgeons like us to diagnose and treat these "invisible" tumors.