Diversity

The lasca Protochondrostoma genei is an endemic freshwater fish of high conservation concern, listed in Annex II of the Habitat Directive and classified as Endangered in Italy. This study investigates the ecology, population structure, and habitat use of P. genei in the Chiarò di Cialla Creek (Northeast Italy), a biodiversity hotspot recently designated as a Special Area of Conservation (SAC IT3320041). Particular regard is given to the issue represented by the presence of the common nase Chondrostoma nasus, which competes with the lasca for habitats and trophic resources. Fish assemblages were surveyed by electrofishing during 2023 and 2024, coupled with detailed hydromorphological characterization of mesohabitats. Results highlighted that the lasca showed preference for glides and especially pools, characterized by moderate depths, low to moderate current velocities, high shading, and abundant shelters such as boulders, roots, and woody debris. However, P. genei extensively overlapped in habitat use with the invasive common nase C. nasus, whose density increased markedly during the study period, suggesting ongoing colonization and potential issues for the lasca conservation. Despite moderate river functionality scores and localized anthropogenic pressures, the Chiarò di Cialla Creek remains a key refuge for P. genei. These findings provide essential ecological information to support targeted conservation actions, including habitat management and invasive species control, within protected riverine systems.

Pinus yunnanensis, an endemic tree species in southwest China, is regarded as a suitable candidate for afforestation. However, long-term disturbances have led to forest degradation and structural simplification. This study evaluated taxonomic and phylogenetic alpha (α) and beta (β) diversity across three P. yunnanensis vegetation types: evergreen coniferous forests (ECFs), evergreen coniferous and broad-leaved mixed forests (ECMFs), and deciduous and coniferous broad-leaved mixed forests (DCMFs), aiming to identify their optimal ecological configurations. A total of 120 vascular plant species from 33 families and 55 genera were recorded, with Ericaceae, Fagaceae, Pinaceae, and Adoxaceae as the co-dominant families. In the tree layer, species richness was significantly higher in DCMFs than in ECFs (p < 0.05), likely due to improved winter light availability resulting from seasonal canopy shedding. Both ECMFs and DCMFs supported significantly higher phylogenetic α diversity than ECFs, indicating a broader evolutionary history and potentially greater functional resilience. In contrast, taxonomic β diversity was lower in ECFs, suggesting a more homogeneous species composition dominated by closely related shrubs. Among the vegetation types, the P. yunnanensis–Pinus armandii community in ECFs showed the highest species richness and a stable microenvironment, making it particularly suitable for ecological restoration at high altitudes. Within ECMFs, the P. yunnanensis–Lyonia ovalifolia community appeared to be the most optimal, potentially reducing competition and promoting species coexistence through resource complementarity. In DCMFs, the P. yunnanensis–Alnus nepalensis community, with its strong nitrogen-fixing capacity, emerged as the preferred configuration for restoring degraded forests at lower elevations. These findings suggest that future vegetation restoration projects centered on P. yunnanensis should adopt tailored combinations of vegetation types based on specific environmental conditions.

The obligate symbiosis between aphids and their primary bacterial symbionts (Buchnera) is ecologically and evolutionarily significant, yet the genetic patterns underlying these associations require further clarification. This study investigated the coevolutionary relationships of two aphid species, Cinara formosana and Tuberolachnus salignus, with their Buchnera symbionts using COI (mitochondrial cytochrome c oxidase subunit I) and bacterial 16S rRNA (16S ribosomal RNA) markers revealed substantial genetic divergence between the two aphid species, with interspecific genetic distances ranging from 0.131 to 0.138. In contrast, populations of T. salignus from different regions showed minimal intraspecific variation (genetic distance 0.006). Phylogenetic analyses confirmed that populations of each aphid species formed distinct, monophyletic clusters. Crucially, the phylogenetic relationships inferred from the aphid COI gene were fully congruent with those derived from the Buchnera 16S rRNA gene sequences. This concordance further supports the application of the COI gene as a reliable marker for species identification within the studied Lachninae aphids. Our findings provide novel insights into the coupled genetic divergence and coevolution of aphids and their obligate symbionts, offering a molecular framework for the precise identification and population monitoring of these aphids, which can inform sustainable management strategies.