Aesthetics of natural landscapes and the conservation of forest ecological integrity have received much attention because of the increasing public demand for aesthetic quality and the shift of forest conservation management objectives from single elements to multiple ecosystem services. However, existing research has not adequately addressed the relationship between forest scenic beauty with the color index and ecological integrity. This study aimed to evaluate and quantify the scenic beauty of forests and the vegetation color index using web questionnaires and Python color interpretation, with Jiuzhaigou World Natural Heritage and Giant Panda National Park in western Sichuan, China, as examples. The relationships between forest scenic beauty with vegetation color and ecological integrity were explored via correlation and linear regression analyses, respectively. The results showed that: (1) The overall scenic beauty of the autumn forests in the study area was at a “medium” level; (2) the scenic beauty of the autumn forest was significantly positively correlated with the saturation and value ratio; and (3) the scenic beauty was not significantly negatively correlated with ecological integrity. This research provides an important reference for the renovation of autumn foliage forests and ecotourism planning. This study also provides a theoretical basis for the transformation of forest conservation management objectives, offering the possibility for nature reserves to achieve the “win-win” management goal of ecological protection and local economic development.

A comprehensive understanding of the effects of mountain roads on plant diversity is critical to finding the most effective solutions for managing this particular driver. Little is known, however, about the simultaneous effects that road have on the multiple facets of biodiversity, although roads are considered to be one of the major disturbances in the Qionglai mountain range. In this study, we analyzed the impact of roads on the multiple facets of plant diversity (taxonomic, functional and phylogenetic diversity) in the study area using Hill numbers by comparing plant diversity between roadside and interior plots at the landscape scale, then, we used linear mixed models to analyze the effect of mountain roads on the multiple facets of plant diversity along an elevational gradient. The results showed that the roadside plots lacked 29.45% of the total number of species with particular functional traits (such as a relatively high specific leaf area (SLA), a relatively low leaf dry matter content (LDMC) and relatively old clades) and exclusively contained 14.62% of the total number of species. Compared with the interior community, the taxonomic, functional and phylogenetic diversity of roadside community decreased by no more than 26.78%, 24.90% and 16.62%, respectively. Taxonomic and functional diversity of dominant and common species showed greater changes to road disturbances, while rare species showed the greatest change in phylogenetic diversity. Taxonomic homogenization of roadside communities was accompanied by functional and phylogenetic homogenization. Additionally, the impact of roads on these three facets of plant diversity showed the characteristics of peak clipping along the elevation gradient. Our findings highlight the negative impact of roads on the taxonomic, functional and phylogenetic diversity of the Qionglai mountain range, as roads promote communities that are more similar in taxonomic, functional, and phylogenetic composition, and to a greater extent contributed to compositional evenness. These effects tend to be functionally and phylogenetically non-random, and species in some clades or with some functional traits are at higher risk of loss. Our results are important for the conservation and management of nature reserves, especially for local governments aiming to create new infrastructure to connect natural mountainous areas.

Human activities change the natural ecosystem and cause the decline of the intact ecosystem. Establishing an applicable and efficient human activity monitoring indicator system benefits China’s ambitious national park system construction. In this study, we established a refined technique for ecological intactness scores (EIS) and applied it in the area of Giant Panda National Park (GPNP) from 1980 to 2020 by quantifying four types of human interferences including land use and cover change (LUCC), road construction, water reservoir and hydropower construction, and mining. The results show the following: (1) Under the ecological intactness score range of 0–10, the GPNP with about 92.6% area of the EIS was above 6.0, and the mean baseline level of intactness was 7.1 when it was established in 2018. (2) The EIS in the east of Qionglaishan and south of Minshan were relatively lower than the rest of the study area. (3) During the past 40 years, 80% of the GPNP’s ecological intactness has remained stable. (4) In total, 14% of the GPNP was degraded mainly in the areas below 1200 m with severe human activities. (5) LUCC and road construction were the main driving factors for the decrease of ecological intactness in the GPNP. (6) The habitat of the giant panda is mainly distributed in the areas with an EIS above 6.0, and this is a key link between ecological intactness and habitat suitability. Our research proved that the ecological intactness score (EIS) is an effective indicator for monitoring and assessing the impact of human activities on the regional natural ecosystem and could be helpful for ecological restoration and human activities management GPNP in the future.

As an increasingly prevalent form of human activity, roads drive the taxonomic homogenization of mountain plant assemblages, threatening global biodiversity. However, little is known about how mountain roads impact functional and phylogenetic beta diversity and how these effects are related to taxonomic homogenization. To understand the mechanism of taxonomic homogenization triggered by mountain roads, we used species absence/presence data from 76 plots (2 m*50 m) and values for 12 traits measured on 978 species from the interior and roadside communities in the Qionglai mountain range, one of the temperate regions with the highest plant species richness in the world. We used a structural equation modeling approach (SEM) to consider several surrogates of road disturbance (changes in soil physicochemical properties and the presence or absence of roads) and the causal relationship between three facets of beta diversity (taxonomic beta diversity, TBD; functional beta diversity, FBD and phylogenetic beta diversity, PBD). The results suggest that TBD, FBD and PBD respond inconsistently to mountain roads, despite strong positive correlations between the three facets of plant beta diversity in the study area. Compared with the interior community, the βtotal.tax and βtotal.func of the roadside community decreased by 2.54% and 2.22%, respectively, which were related to the reduction of species and trait richness differences and replacements; however, we did not find the same results when assessing the changes in βtotal.phy, which represents tip-weighted PBD (twPBD). Furthermore, the largest effect of roads on beta diversity was reflected in basal-weighted PBD (bwPBD), which decreased by 9.97%, indicating that those species with fewer extant relatives and longer evolutionary histories are more sensitive to mountain roads. Therefore, it is necessary to take targeted protection measures for ancient species in roadside communities. In addition, we believe that it is still necessary to take measures to prevent the further dispersal of nonnative species, although the presence of non-native species in roadside plots has led to small changes in three facets of beta diversity. There were causal relationships between the three facets of beta diversity, but their intensity and sign different in the SEM of different components of beta diversity (i.e., richness difference and replacement). Our findings suggest that the homogenization of community species composition at the landscape scale arises by a combination of adaptive responses of the functional traits of organisms to environmental consistency (e.g., reduced the differences in soil variables) caused by roads and resorting or reassembly of community clades composition due to environmental filtering. These results contribute to our comprehensive understanding of the impact of mountain roads on plant diversity, which highlights the complex relationship between human pressure and biodiversity loss.

In the Anthropocene, global change is reshaping biological communities, potentially leading to widespread biotic homogenization—a worrying erosion of biological distinctiveness. However, the extent to which human activities have homogenized plant communities worldwide remains a pivotal unresolved question. To address this gap, we conduct a global meta-analysis of 1604 experimental and observational comparisons from 256 studies to assess the impacts of major global change drivers on plant β-diversity across its taxonomic, functional, and phylogenetic dimensions. The findings indicate no significant net change in plant β-diversity globally, with responses varying markedly across global change factor types, biogeographic regions, ecosystems, and plant life forms. Specifically, climate change and biological invasions are consistently associated with reduced β-diversity, while land management (e.g., ecological restoration, reduced grazing, and controlled burning) is associated with increased β-diversity. The effects of land-use change (e.g., urbanization, habitat fragmentation, and infrastructure development) and multiple interacting factors are variable. Crucially, impacts differ across biodiversity dimensions. For instance, climate change is associated with reduced taxonomic and functional β-diversity but is associated with increased phylogenetic β-diversity. Our study calls for a shift in conservation focus from solely preventing species extinctions to addressing compositional changes in communities. It emphasizes the importance of functional and phylogenetic processes and the need to integrate all three biodiversity dimensions into monitoring and planning to maintain ecosystem resilience and evolutionary potential.