Facing the demands of biodiversity conservation and ecosystem service improvement, the spatial pattern optimization of nature reserves has always been a research topic of interest. However, there remains a lack of methodological guidance in the planning of nature reserves and the surrounding areas. To promote the landscape sustainability of nature reserves, we constructed ecological security patterns (ESPs) with two scenarios as a case study in Wenchuan, China. In detail, the ecological sources were identified by ecosystem service evaluation, and the resistance surface was characterized by the habitat quality. The ecological corridors were determined based on circuit theory and the minimum cumulative resistance model. The ecological sources were mainly aggregated in the protected areas, with an area of more than 1000 ha; the high-resistance values were mainly in the area with dense roads or high elevation. There were 21 corridors in the scenario of only optimizing the nature reserve, while 31 corridors were identified when considering non-nature reserves, and the landscape connectivity was enhanced accordingly. The result supported constructing the ESPs between nature and non-nature reserves in Wenchuan to further protect pandas, and a methodological contribution was made to understand the differences of ESPs between them, thus supporting a methodological formulation of sustainable landscape patterns.

The study of natural suitability of human settlements environment aims at objectively revealing the human settlements under the influence of natural geographic elements, which to quantitatively characterize the pattern of regional population distribution under natural limitations or suitability. Based on the kilometer grid, the study establishes the Human Settlements Index (HSI), which includes Relief Degree of Land Surface (RDLS), Temperature-Humidity Index (THI), Land Surface Water Abundance Index (LSWAI) and Land Cover Index (LCI). The main conclusions are as follows: (1) The RDLS of Qinghai-Tibet Plateau is dominated by high values (high elevation, sharp topographic undulation), with great regional differences. It is obviously different that the THI of the region, which shows an increasing trend from the northwest arid region to the southeast. However, both the high LSWAI and the LCI distribute on intensively and zonally. (2) Supposed that the auxiliary elements (hydrology, vegetation) enhance dominant elements (topography, climate), the conclusion shows that the HSI between 0.07~1 in the study area, averages 0.45. According to the grading judgment of the topographic and climatic suitability, with the restriction of physiological elements on human habitation, there defines the 7 types of human settlements environment suitability. (3) The unsuitable type account for 32.48% of the total area, and only 1.87% of the corresponding population, mainly distributed in the Kunlun mountains, the Gangdis mountains and the western side of the Himalayas. As an important basis, human settlements suitability provides scientific basis for resources and environment carrying capacity, moreover, it supports the regional planning and population distribution.

1. Cities are increasingly expected to become greener, more resilient, and more inclusive in response to rapid urbanization, climate change, and growing pressure on urban infrastructures. Urban gre...