Objective Wilderness has important ecological functions and conservation values, and in the face of the current global climate change and the severe situation of rapid decline of biodiversity, the construction of wilderness protection system plays a key role in maintaining the integrity and authenticity of ecosystems, sustaining biodiversity, and enhancing human well-being. The quantitative and visual analysis of the spatial distribution characteristics of wilderness in Heilongjiang Province, an important ecological security barrier in the northern part of China, can not only comprehensively reflect the degree of human interference with nature, but also determine the reasonableness of the delineation of the scope of nature reserve, while contributing to the formulation of local wilderness protection strategy.

Methods Taking wilderness in Heilongjiang as the research object, this research selects the four indicators of remoteness from settlements, remoteness from accessible roads, population distribution density and biophysical naturalness to prepare the wilderness quality index map by the classical wilderness mapping method, Normalization is carried out using ArcGIS, and hierarchical analysis method (AHP) is applied to calculate the weights of the above four wilderness evaluation indicators with the four indicators being superimposed. Through the natural breakpoint method, the 10 grades of wilderness in Heilongjiang Province are classified into the following 5 categories: Other land (grade 1−2), low-quality wilderness (grade 3−4), medium-quality wilderness (grade 5−6), wilderness with relatively high quality (grade 7−8), and high-quality wilderness (grade 9−10). Additionally, The spatial distribution pattern of the wilderness land in Heilongjiang Province and the driving factors thereof are mapped and analyzed.

Results 1) The spatial pattern of wilderness in Heilongjiang Province shows an axial distribution, which is overall “low in the southwestern and southeastern areas, and high in the central axis belt area”. High-quality wilderness is mainly concentrated in Daxing’anling, Heihe, Mudanjiang and their surrounding areas, and within the long and narrow region, Daxing’anling borders Heihe, and Mudanjiang borders Yichun, forming a confrontation pattern of high-quality wilderness in the northwestern and southeastern parts of the province. In the southeastern and southwestern parts of Heilongjiang Province, the distribution area of low-grade wilderness centered on Harbin, Shuangyashan and other cities and counties is formed, showing a “cluster-type” distribution pattern. 2) In the research area, the area of wilderness above the low quality grade accounts for 79.79% of the total area of the research area, and that of wilderness above the relatively high quality grade accounts for 53.53% of the total area, indicating a large wilderness reserve in Heilongjiang Province. In the Daxing’anling region, the quality of wilderness is the highest, and the area of high-quality wilderness is the largest, amounting to 21,560 km²; the area of wilderness with relatively high quality is 35,900 km², and the area of medium-quality wilderness is 8,300 km², which is closely related to such factors as high density of forested land, high degree of naturalness, low degree of interference from human activities, and good quality of the ecological environment in the region. 3) The larger the average patch area in the horizontal spatial distribution pattern of wilderness, the lower the density of patch edge, the lower the degree of influence of the edge effect, and the higher the resistance to external interference. 4) In the research area, the area of high-quality wilderness and that of wildness with relatively high quality are respectively 30,728 km² and 371 km², and only 41.73% of the high-quality wilderness is in nature reserves, indicating that the existing nature reserves fail to fully cover the wilderness in the province. 5) By using Gross Demostic Product (GDP) to represent the economic development level of each prefecture-level city, the degree of coupling is calculated by coupling each city’s GDP ranking with its non-wilderness ranking, and by coupling the degree of climate comfort with the degree of wilderness. Economic development and climate comfort are found to be important drivers for the distribution of wilderness landscape pattern.

Conclusion The wilderness resources in Heilongjiang Province are rich and of high quality, while high-quality wilderness, although distributed in a concentrated manner, has not been completely and effectively protected at present. It is possible to consider establishing a clear hierarchical management mechanism for zoning protection; constructing a spatial protection axis of wilderness in Heilongjiang Province based on the spatial distribution characteristics of such wilderness for hierarchical protection; and strengthening public education on the wilderness environment to enhance the aesthetics of wilderness for citizens, so as to encourage them to appreciate the wilderness landscape and participate in the protection of wilderness lands on their own initiative. At the policy and legal levels, permanent and systematic protection of wilderness lands will be carried out, and a wilderness space protection system will be established in Heilongjiang Province. In the nature protection system, wilderness is recognized and spatially protected on the basis of the national park protection system and the delineation of ecological function zones and protection red lines. Economy and climate are important driving factors affecting the spatial distribution pattern of wilderness, and economic development inevitably requires urban development activities. In the future, Heilongjiang Province needs to balance the relationship between economic development and ecological protection, and realize the sustainable development of green economy.