1. Introduction
The properties of the landscape, such as patch size, edge quantity, distance between habitats, and connectivity between habitat patches, have a direct impact on the flora and fauna of the region [
1]. The analysis of landscape patterns can use specific landscape indices to describe abstract spatial patterns and deduce the mechanisms and causes of landscape patterns from seemingly disordered landscape elements [
2,
3,
4]. The factor that has a relatively large impact on the natural landscape pattern is human interference [
5,
6]. Due to human activities changing the landscape’s spatial structure, many species are usually confined to small, isolated, and degraded habitat patches, which affects the survival of animals. The mechanism of landscape fragmentation or animal extinction caused by landscape patterns has become a hot issue in conservation biology [
7,
8,
9,
10]. It is considered one of the main reasons for the endangerment and extinction of many species and the decline of biodiversity [
11]. Landscape pattern analysis, as the basic research content of landscape ecology, can quantitatively analyze the spatial distribution characteristics of landscape components and is the basis for further research on landscape functions and dynamics. Conducting these studies will help solve some important theories and key technical issues in the effective in situ conservation of biodiversity [
12].
Different species respond differently to habitat fragmentation. The Worm-eating Warbler (
Helmitheros vermivorus), Middle Spotted Woodpecker (
Dendrocopos medius), and Ovenbird (
Seiurus aurocapillus) in North America—all area-sensitive species that mostly inhabit forest interiors—appear more frequently in continuous landscapes, but their densities decrease in fragmented landscapes [
13]. In contrast, the Northern Cardinal (
Cardinalis cardinalis) and Indigo Bunting (
Passerina cyanea), which nest in edge habitats, secondary forests, or urbanized areas, exhibit higher densities in fragmented rather than in continuous landscapes [
14,
15]. Research on Amazon rainforest fragmentation further shows that species richness is positively correlated with patch size [
16,
17,
18]. Notably, responses to fragmentation vary substantially even within closely related taxa [
19]. For species of the genus Syrmaticus (to which this study’s focal species, Mrs. Hume’s pheasant, belongs) and their relatives—groups that have been intensively studied using molecular genetics, inbreeding analysis, and isolation effect assessments—habitat fragmentation often exerts taxon-specific pressure. Molecular genetic studies of Syrmaticus species (e.g.,
Syrmaticus humiae and
Syrmaticus reevesii) have revealed that population genetic diversity is closely linked to habitat connectivity: fragmented habitats reduce gene flow among subpopulations, leading to increased genetic differentiation [
19]. Recent inbreeding analysis of Syrmaticus populations further confirms that fragmented habitats elevate inbreeding levels, with inbreeding depression (e.g., reduced reproductive success and survival rates) becoming more pronounced in highly isolated patches [
20]. For insular Syrmaticus populations, such as those on Taiwan Island, geographic isolation (exacerbated by anthropogenic fragmentation) has driven significant genetic divergence from mainland conspecifics, highlighting the long-term evolutionary impacts of habitat disconnection [
21,
22]. In tropical regions, 65% of natural habitats have disappeared [
23]. In temperate regions, the original natural habitats no longer exist [
24]. In China, habitat fragmentation reduces the quality and area of habitats, having an important impact on the survival of animals [
25,
26,
27]. Habitat fragmentation, or fragmentation, has an important impact on the breeding success rate, population viability, dispersal behavior, habitat selection, genetic diversity of birds, and the resulting ecological effects (such as edge effects and isolation effects) [
28,
29,
30,
31].
Among avian species, edge responses also vary: Steller’s Jay (
Cyanocitta stelleri) and Swainson’s Thrush (
Catharus ustulatus) have higher densities in edge areas, while the Brown Creeper (
Certhia americana), Pacific-slope Flycatcher (
Empidonax difficilis), and Varied Thrush (
Ixoreus naevius) rarely occur in edge habitats [
20,
21,
22]. For other taxa, responses to fragmentation also diverge: some species are highly sensitive to area loss in fragmented forest habitats, while the species richness of taxa like frogs and butterflies remains stable or even increases after forest patch isolation [
19,
32,
33,
34]. However, it is important to note that amphibians (including frog species) often face hidden risks in fragmented landscapes: recent studies have documented inbreeding depression in amphibian populations in fragmented urban or agricultural areas, where reduced connectivity limits gene flow and increases the frequency of deleterious alleles [
34,
35,
36,
37]. Urbanization, in particular, intensifies such effects by creating permanent barriers to dispersal, further exacerbating genetic degradation in amphibian populations [
38,
39,
40,
41,
42,
43].
The Mrs. Hume’s pheasant (
Syrmaticus humiae) is listed as a globally near-threatened species by the IUCN Red List [
27] and is particularly vulnerable to habitat fragmentation due to its weak migration and dispersal abilities—traits that limit its capacity to colonize new habitats or connect isolated subpopulations [
30,
37]. Geographically, the species has a disjunct distribution across Southeast Asia and southern China, with core populations in Guangxi, Yunnan, and Guizhou provinces of China, as well as in northern Myanmar and northeastern India (GBIF, 2024.
Syrmaticus humiae (Hume, 1881). Available online:
https://www.gbif.org/species/2473479, accessed on 29 September 2025). Based on GBIF occurrence data and regional surveys, its global population size is estimated to be 10,000–19,999 mature individuals, with a declining trend: in China, local abundances range from 0.1 to 0.5 individuals per km
2 in moderately disturbed habitats to 1.0–2.0 individuals per km
2 in well-protected forest patches (e.g., in Jinzhongshan Nature Reserve, Guangxi) [
27]. Like other gallinaceous birds,
S. humiae faces severe threats from human activities and climate change—two primary drivers of galliform population decline and extinction globally [
27]. Human-induced habitat loss (e.g., deforestation for agriculture, logging) and fragmentation have reduced its suitable habitat by over 30% in the past three decades [
44,
45]. Climate change further exacerbates these threats by shifting the species’ climatic niche, leading to mismatches between its current distribution and suitable environmental conditions (e.g., increased drought frequency reducing understory vegetation cover, a key resource for foraging and nesting). A case in point is another Syrmaticus species, Reeves’s Pheasant (
Syrmaticus reevesii), which has experienced a more severe population collapse: its rapid decline due to habitat destruction and overhunting led to its elevation to China’s National First-Class Protected Animal status [
27,
45]. However, for many Syrmaticus species (including S. humiae), identifying the precise drivers of population decline and implementing effective conservation measures remain challenging, largely due to the lack of long-term, high-spatiotemporal-resolution data on population dynamics, habitat use, and threat impacts. To address this gap, the present study identifies potential ecological corridors for
S. humiae in Jinzhongshan using the Minimum Cumulative Resistance (MCR) model—a widely applied tool for prioritizing connectivity conservation [
20]. This approach provides actionable insights for mitigating fragmentation impacts and safeguarding the species’ long-term survival. Some scholars have reported on the habitat use and population distribution of the Mrs Hume’s pheasant in Thailand [
31,
32,
33,
34] and the characteristics and use of its spring habitat [
35]. The summer habitat selection of the re-introduced Mrs Hume’s pheasant in Cenwanglaoshan was also reported [
37,
38]. With the intensification of human interference, habitat loss and fragmentation have become some of the most significant threats to biodiversity [
39,
40]. Analyzing habitat fragmentation and conducting adaptability evaluations can provide a basis for the protection of endangered species [
44,
45,
46,
47]. In terms of the habitat evaluation of the Mrs Hume’s Pheasant, only one recent study on the suitability of its macro-habitat scale in the Nanhua section of Ailao Mountain, Yunnan, has been conducted [
48,
49]. The research results show that the suitable habitats have been fragmented.
Jinzhongshan, Guangxi, is a key distribution area of the Mrs Hume’s pheasant in China, according to previous studies of Mrs. Hume’s pheasant by Jiang et al. (2012) and Yuan et al. (2024). Twenty (20) ecological variables were considered as potential factors affecting the habitat selection of Mrs. Hume’s pheasant [
27,
45], and the main habitat types of the Mrs Hume’s pheasant are Pinus yunnanensis var. tenuifolia forests, coniferous broad-leaved mixed forests, and evergreen–deciduous broad-leaved mixed forests, but it can also be active in tung oil forests and artificial Chinese fir forests [
45]. There are currently no reports on relevant habitat fragmentation and habitat evaluation. Therefore, analyzing the landscape pattern and fragmentation degree of the habitat of the Mrs Hume’s pheasant and evaluating the habitat suitability to explore the spatial utilization pattern of the habitat of the Mrs Hume’s pheasant in fragmented habitats are highly necessary [
46,
47,
48]. At the same time, understanding the current situation of habitat interference and damage of the Mrs Hume’s pheasant provides a theoretical basis for corridor restoration and connectivity improvement. The research results are of great significance for the design and management planning of nature reserves.
3. Results and Analysis
3.1. Area Characteristics of Landscape Components
The 2012 survey by the Guangxi Forestry Bureau indicated that the reserve hosted 200 individuals with a patchy distribution. The results indicated that the habitat characteristics were as follows: 200 m to 400 m distance to habitat edge, less than 200 m distance to water, over 400 m distance to human habitation, over 601 m to the road, over 60% tree cover, less than 40% shrub cover, less than 20% herb cover, over 60% leaf litter cover, over 10.1 m high trees, over 20 (individuals/per quadrat) tree density, over 2.1 m high shrubs, less than 10 (individuals/per quadrat) density of shrubs, over 0.5 m high herb species, less than 10 (individuals/per quadrat) density of herbs, over 30 cm diameter trees, and abundant food (
Table 2) [
44,
45].
The proportion of a landscape type in the total landscape area represents the relative contribution of this landscape to the entire landscape. As can be seen from
Table 3, the proportions of landscape types in the total landscape area, in descending order, are CKL > LKL > YT > NT > ML > SL > CLKL > SY > JJL > YNL > CZ. In the entire landscape, the area of evergreen broad-leaved forest accounts for the largest proportion of the total area, while the proportion of villages is the smallest. The areas of deciduous broad-leaved forest, evergreen broad-leaved forest, and evergreen–deciduous broad-leaved mixed forest account for 55.25% of the entire landscape. Broad-leaved forest is the matrix of the entire landscape, and coniferous forest, tung tree forest, economic forest, and other landscape components are mosaically distributed within it (
Table 5).
The order of the average area of patches of each landscape component is SY > LKL > CLKL > CKL > YT > YNL > JJL > ML > SL > NT > CZ. In particular, the average areas of masson pine forest, Chinese fir forest, farmland, and villages are all smaller than the average area of patches in the entire landscape, indicating a high degree of fragmentation. The area proportion of Pinus yunnanensis var. tenuifolia forest is relatively small, but its average patch area is close to that of evergreen broad-leaved forest and tung tree forest, suggesting a relatively low degree of fragmentation. The water area is on the edge of the study area, accounting for a small proportion in the entire landscape and having little impact on other landscapes.
3.2. Perimeter of Landscape Components
The order of the perimeters of each landscape component is CKL > LKL > NT > YT > ML > SL > CLKL > JJL > SY > YNL > CZ. The general trend is slightly different from that of the landscape component area. In the study area, the evergreen broad-leaved forest has the highest proportion of the total perimeter, reaching 25.32%, followed by the deciduous broad-leaved forest, and the proportions of the rest are all less than 15%. The proportion of the perimeter of each landscape type to the total landscape perimeter is of great significance for the study of some species distributed at the boundaries. The evergreen broad-leaved forest and deciduous broad-leaved forest have large areas and can accommodate more boundary species.
3.3. Number of Landscape Component Patches
The number of patches of each landscape component in the study area is extremely unbalanced. Farmland has the largest number of patches, with 406 patches, accounting for 23.77% of the total number of patches. It is followed by evergreen broad-leaved forest, Chinese fir forest, masson pine forest, deciduous broad-leaved forest, and tung tree forest, and the proportions of the rest are all less than 10%. However, the water area, which has the largest average patch area, only has three patches. The number of farmland patches is much larger than that of evergreen broad-leaved forest and deciduous broad-leaved forest, but its total area is much smaller than the two. The proportion of the area of farmland in the total area is similar to that of masson pine forest, and the average patch areas are not very different, but the number of farmland patches is also much higher than that of masson pine forest patches, indicating that farmland has a large number of small-sized patches and a high degree of fragmentation.
The patch density PD1 of each landscape component (number of patches of the landscape component/area of the landscape component) directly reflects the degree of fragmentation of the landscape component. The village has the highest patch density, which is much higher than the average patch density of the entire landscape (total number of patches/total area), and has a greater impact on other landscapes. However, its area accounts for only 0.9% of the total area (PLAND), so it does not play a leading role in the fragmentation of the entire landscape. The patch density of the tung tree forest is similar to that of the economic forest, indicating that their degrees of fragmentation are similar. However, the area of the tung tree forest is much larger than that of the economic forest, so it has the greatest impact on the entire landscape.
The ratio of the number of patches of a type to the total landscape area represents the degree to which the landscape matrix is divided by the patches of this type, that is, the patch density PD2 (also known as porosity) of this landscape component in the entire landscape. This index has an important impact on biological protection and the distribution of matter and energy. The order of the patch density of each landscape component is NT > CKL > SL > ML > LKL > YT > CLKL > CZ > JJL > YNL > SY. The farmland has the largest patch density of 1.0 patch/km2, which means that the broad-leaved forest, the landscape matrix, is highly divided by farmland. The sum of the areas of the deciduous broad-leaved forest, evergreen broad-leaved forest, and evergreen–deciduous broad-leaved mixed forest, which have relatively large areas, accounts for more than 50% of the entire landscape area. And the patch density of the evergreen broad-leaved forest is greater than that of other broad-leaved forests, indicating that the evergreen broad-leaved forest plays a leading role among the broad-leaved forests. The patch density of the tung tree forest is similar to that of the deciduous broad-leaved forest, but the area of the tung tree forest is only half of that of the deciduous broad-leaved forest. It can be seen that the tung tree forest has a greater impact on the entire landscape than the deciduous broad-leaved forest.
3.4. Result of Landscape Fragmentation
Fragmentation is an important characteristic of landscape quality. The fragmentation index can quantify the degree of landscape fragmentation well. A larger value indicates a stronger degree of fragmentation and more severe interference. The fragmentation index (F) of the entire Nature Reserve is 0.9887, the patch fragmentation degree is 0.1732, the connectivity is 1.861, and the area-weighted shape index (AWS) is 425.3024. This indicates that the patches in the habitat of the Mrs Hume’s pheasant are relatively large in area and have a low degree of fragmentation. Therefore, the overall habitat in Jinzhongshan is suitable for the survival of the Mrs Hume’s pheasant. However, the connectivity of the patches is not high, and there are small-area patches that are not suitable for survival, resulting in a relatively high fragmentation index and a relatively high area-weighted shape index. The population of the Mrs Hume’s pheasant may still communicate through corridors or roads, etc., to reduce the impact of edge effects, thus forming an adaptation to fragmentation (
Table 6).
Note: PLAND is the proportion of the landscape in the total area, NP is the number of patches, PD1 is the patch density of the landscape component, PD2 is the patch density of the entire landscape, LPI is the proportion of the largest patch in the landscape area, LSI is the landscape shape index, PAFRAC is the perimeter–area fractal dimension, and CONNECT is the connectivity.
3.5. Result of Landscape Diversity
Fractal dimension (PAFRAC) can be intuitively understood as the non-integer dimension of irregular geometric shapes. This index is used to reveal the degree of boundary folding of each landscape component, and all landscape components follow the same fractal dimension rule. Since the number of farmland patches is less than 10, which has no practical significance, its fractal dimension is not calculated. The fractal dimensions of each landscape component do not differ much, indicating that the degrees of patch boundary folding are similar. The landscape component with the largest fractal dimension is the Pinus yunnanensis var. tenuifolia forest, followed by villages, while the masson pine forest has the smallest fractal dimension. This shows that the patch boundaries of the Pinus yunnanensis var. tenuifolia forest are the most tortuous and complex, while the fractal dimension indices of artificial forests such as Chinese fir forests, tung tree forests, and masson pine forests are relatively low because they are always reclaimed more neatly during artificial planting. The perimeter–area fractal dimension at the whole-landscape level is 1.337 (as shown in
Table 5,
Table 6 and
Table 7), which is much less than 2, indicating that the degree of folding of the entire landscape boundary is low.
The landscape shape index reflects the complexity of landscape component patches. The larger the shape index, the more irregular and tortuous the patch shape is. The average shape index of Pinus yunnanensis var. tenuifolia forest patches, as the constructive species, is relatively high, indicating that its shape is complex. Among the shape indices of the entire forest landscape, the evergreen–deciduous broad-leaved forest has the largest value. The average shape indices of economic forests and evergreen broad-leaved forests are similar, but the area of economic forests is much smaller than that of evergreen broad-leaved forests, indicating that the evergreen broad-leaved forest landscape is more complex and its ecosystem is more stable.
The diversity index is a measure of the complexity and variability of various patches in the landscape. Generally, as the diversity index increases, the complexity of the landscape structural components also tends to increase. The landscape diversity index of Jinzhongshan is shown in
Table 3,
Table 4 and
Table 5. From the perspective of the landscape interior, its Shannon’s evenness index (SHEI) is 0.845 (close to 1), indicating that the areas of each landscape component are relatively similar. The landscape contagion index (CONTAG) reflects the non-randomness or aggregation degree of different patch types in the landscape. If a landscape consists of many discrete small patches, its value is small; when the landscape is dominated by a few large patches or when patches of the same type are highly connected, its value is large. The landscape contagion value is 55.340, indicating that the proportions of different landscape types vary greatly, and the distribution of landscape components is uneven. In particular, the large differences between the three types of broad-leaved forests and farmland and villages result in a relatively large evenness index. Shannon’s diversity index (SHDI) is 2.03 (greater than 1), indicating that the landscape fragmentation in the study area is relatively serious (
Table 7).
3.6. Result of Habitat Suitability Evaluation
Finally, based on the Sj values, habitats with Sj values greater than 0.333 are considered suitable habitats; those with Sj values between 0 and 0.333 are moderately suitable habitats; and those with Sj values equal to 0 are unsuitable habitats. By using the analytic hierarchy process, the overlay method, and geographic information system auxiliary software such as ArcView, it was determined that deciduous broad-leaved forests, deciduous–evergreen broad-leaved mixed forests, evergreen broad-leaved forests, and coniferous broad-leaved mixed forests are suitable habitats; coniferous forests and tung tree forests are moderately suitable habitats; and other woodlands are unsuitable habitats.
The area of Jinzhongshan is 38,716.605 hm
2. The area of suitable habitats is 21,391.93 hm
2, accounting for 55.25%; the area of moderately suitable habitats is 8160.343 hm
2, accounting for 21.07%; and the area of unsuitable habitats is 9164.334 hm
2, accounting for 23.67%. The area of the Jinzhongshan Nature Reserve is 20,924.4 hm
2. The area of suitable habitats is 13,469.03 hm
2, accounting for 64.31%; the area of moderately suitable habitats is 3521.10 hm
2, accounting for 16.83%; and the area of unsuitable habitats is 3934.27 hm
2, accounting for 18.81% (
Table 8). From the results, it can be seen that after the establishment of the Guangxi Jinzhongshan National Nature Reserve, the proportion of habitats suitable for the Mrs Hume’s pheasant has increased significantly, rising from 76.32% in the Jinzhongshan area to 81.19% in the Jinzhongshan Nature Reserve.
The habitat suitability pattern map of Hume’s pheasant in Jinzhongshan area (
Figure 2) was drawn using the Geographic Information System (GIS 9.3)-assisted software ArcMap. Deciduous broad-leaved forests, mixed deciduous and evergreen broad-leaved forests, evergreen broad-leaved forests, and coniferous broad-leaved mixed forests are suitable habitats. Coniferous forests and tung tree forests are moderately suitable habitats. Water areas and other forested areas in blank spaces are unsuitable habitats. It can be seen from the map that the proportion of suitable habitats for Hume’s pheasant in the Jinzhongshan area is relatively large. However, it has already become fragmented, especially in areas outside the reserve, where the fragmentation is more severe, which has an impact on the survival of Hume’s pheasant.