Zong-Xin Ren

Bumblebees (Bombus spp.) are key high-elevation pollinators, yet their nest-level activity patterns and their synchronization with community-level floral visitation remain poorly understood. In previous studies, bumblebees showed bimodal floral visitation patterns in wild high-elevation communities, with activity peaks in the morning and afternoon. However, it is unknown whether nest activity mirrors these patterns in the field. Understanding this relationship is important for linking colony-level behaviour with pollination dynamics in natural communities. In this study, we investigated the daily departure and return behaviour of a natural colony of Bombus lepidus in the Hengduan Mountains, southwestern China, and their coordination with floral visitation in the nearby communities during the 2019 flowering season. We also examined associations between environmental factors and nest activity across the day. During the observation period, overall activity declined over the season, whereas the proportion of returning bees carrying pollen increased. Daily nest departures and returns exhibited pronounced bimodal patterns that closely paralleled floral foraging activity, albeit with slight temporal offsets between the independently sampled activity distributions. Colony activity was associated with nest-entrance environmental conditions, showing unimodal (non-linear) responses: activity peaked at a nest entrance air temperature of approximately 24 °C and nest entrance relative humidity of 50–55%. Morning activity was relatively insensitive to environmental variation, whereas afternoon behaviour was more responsive to microclimatic fluctuations. Our results suggest that nest-entrance microclimate may be linked to daily activity patterns and their temporal alignment with floral resources at a local scale.

Background and Aims: Floral trait influences on pollination performance have been extensively studied in monandrous orchids (one anther). Diandrous orchids (two anthers) introduce a new hierarchical level because removing two pollen smears requires at least two visits, potentially indicating more attractive flowers and greater opportunities for pollination performance via male function. We studied trait–performance relationships in diandrous orchids using a threatened hoverfly-pollinated Phragmipedium that mimics oviposition sites by resembling aphids. Methods: We measured flower size and height and quantified male and female performances (i.e. pollen smear removal and deposition) across two flowering seasons. Because the influence of different traits is not always independent in trait–performance relationships, we applied commonality analyses to decompose the unique and shared explained variances of traits. Key Results: Larger and taller flowers exhibited higher male and female performances, suggesting positive pollinator-mediated selection. This pattern remained consistent when performance types were combined, particularly for flowers with two removals and one deposition (2♂/1♀), representing the maximum performance. Although individual trait effects explained more variance, reaching up to 15 % in the case of flower height on female performance, the combined effects of flower size and height were also relevant, reaching up to 6 % in the case of 1♂/1♀ performance. This indicates that even non-correlated traits can have a shared effect. Conclusions: Despite oviposition-site mimicry being widespread in angiosperms, this is the first investigation on the effects of floral trait variation on performance in this system, corroborating general patterns observed in other rewarding and non-rewarding systems. We also demonstrate positive effects of attractive traits in diandrous orchids when male and female functions are considered separately and jointly, especially in the maximum performance type (2♂/1♀), corroborating theoretical predictions for this system where two anthers are an additional level of complexity.

Two new species of Orchidaceae, Neottia minutiflora J. D. Ya and Gastrochilus alpinus J. D. Ya, are described and illustrated from Yunnan, China. Bulbophyllum bisetum Lindl. is recorded for the first time in the country. Neottia minutiflora is unique in its tiny flowers, rectangular undulate-margined labellum auricles, and linear-falcate lateral lobes longer than the broadly triangular mid-lobe. Gastrochilus alpinus differs by its bilobed leaf apices, 2–6-flowered racemes, glabrous erose-margined labella with two median ridges, and shortly bifid saccate-subconical hypochilia. All these species are derived from the Gaoligong Mountains. Specifically, Neottia minutiflora is distributed in Tengchong County; Bulbophyllum bisetum and Gastrochilus alpinus are native to Gongshan County.

Pollination syndromes are widely used to infer pollination modes from floral traits, yet increasing evidence suggests that similar trait combinations can lead to different reproductive outcomes. Compared with herbaceous plants, the reproductive flexibility of trees remains poorly understood. We investigated the reproductive ecology of Lithocarpus elizabethae and L. echinophorus (Fagaceae), traditionally regarded as insect-pollinated, to test whether floral traits reliably predict reproductive outcomes. We hypothesized that if insect- or wind-mediated pollen transfer contributes substantially beyond geitonogamy, reproductive success would be higher under open (insect pollination, airborne pollen transfer, and geitonogamy) and mesh-bagging (airborne pollen transfer plus geitonogamy) treatments than under paper-bagging treatments (geitonogamy). We combined floral and fruit morphology observations, flower visitor surveys, and pollination exclusion experiments using three treatments: paper-bagging, mesh-bagging, and open controls. Fruit set, fresh acorn mass, sound seed occurrence, seed abortion, and insect infestation were analyzed using generalized linear mixed models. Fruit set and acorn mass did not differ among treatments, indicating that reproductive output was maintained despite restricting insect visitation and/or airborne pollen transfer. In contrast, seed quality varied significantly between species and among treatments, suggesting that reproductive outcomes are shaped by species identity, pollination environment, and post-pollination processes rather than floral traits alone. Fruit production under paper-bagging treatments indicates substantial geitonogamous reproduction, although the genetic contribution of selfed versus outcrossed pollen remains unresolved. Our findings challenge simple syndrome-based predictions and demonstrate that reproductive strategies in Lithocarpus are more flexible and context-dependent than floral traits alone would predict.

Evolutionary trees are of central importance in biology to develop explanatory frameworks for many kinds of studies, including studies of behaviour, ecology, and conservation. Since the last major estimate of evolutionary relationships among many bumblebee species two decades ago, there have been revisions to their taxonomy, descriptions of new species, and sequencing of many rarer species. By combining: (1) earlier data mostly from slow-evolving nuclear genes as a backbone tree; with (2) new data from fast-evolving mitochondrial COI barcodes to resolve more of the twigs on the tree, including sequences obtained from rare old specimens with ancient DNA techniques; as well as (3) the results from broader genomic data for resolving deep relationships, we make a Bayesian estimate of evolutionary relationships with BEAST 2 among all 289 published and accepted extant bumblebee species, an increase of more than 29% of the species on the previous largest tree. The new tree will serve as a framework for future comparative studies that should enable broader insights into the evolution and ecology of all bumblebees. We illustrate this with an analysis of the evolution of some male morphological characters related to male mate-searching behaviour. We also present a novel map of spatial variation in net diversification rates among bumblebee species world-wide, which indicates an especially rapid net diversification within the more recent Mesoamerican and South American faunas.

An experimental manipulation of ray florets in Knautia arvensis (Caprifoliaceae) carried out in 2001 originally yielded results that were hard to reconcile with a hypothesis about floral attraction. Reframed as a test of florivory the archived data reveal that cutting ray florets left pollinator visitation and seed set essentially unchanged, but altered plant resource economics. Nectar concentration (and consequently available sugar after accounting for volume) declined under the large cutting treatment, while individual seed weight was consistently lower in the cut inflorescences. Together, these patterns suggest that simulated florivory can leave pollination largely intact yet reduce nectar quality and seed provisioning, producing lighter seeds without reducing seed set. More broadly, the study shows how re-examining archived “inconclusive” experiments through alternative perspectives can generate new ecological insights beyond those originally sought.

We provide the first global review of edibility in the large, diverse and evolutionarily complex pantropical plant family Apocynaceae. Our survey reveals edible representatives in all major lineages and including all plant parts, with multivariate analyses illustrating the global differences in phylogenetic, geographic and use preferences. A surprising 440 edible species are listed, although comparatively, this is a significant general under‐representation of the family as a human food source. This is likely, at least in part, because the family is better known for its vast array of bioactive defense compounds and wide use in traditional medicine than as a food source. Using IUCN Red List data, we show that edible Apocynaceae are generally less threatened than the family overall, although most species remain unevaluated. At the same time, many taxa depend on pollinators to produce edible fruit and seeds, yet pollination data are missing for most species, highlighting linked knowledge gaps relevant to conservation and future crop development. In addition, we illustrate these patterns with four case studies of edible Apocynaceae from North America, South America, and China. In a phylogenetic analysis the edible Chinese species Dregea sinensis grouped with neither other species of Dregea nor with any of its closer related genera. Therefore, a new genus, Kushengia , is established and the transfer of D. sinensis and D. yunnanensis , as well as D. corrugata , which is here treated as a variety, is made, and all necessary new combinations are provided.

Understanding how habitat heterogeneity influences the structure and stability of ecological networks is critical for predicting ecosystem responses to environmental change. In alpine ecosystems, open meadows and forests represent contrasting habitats with distinct vegetation structures, resource availability, and microclimatic conditions. In this study, we integrated spatial and temporal data on pollinator-plant interactions to investigate network structure, species roles, and diurnal foraging dynamics across meadow and surrounding forest habitats during two flowering seasons on Yulong Snow Mountain, Yunnan, China. A total of 11,094 plant-pollinator interactions were recorded, involving 229 pollinator and 89 flowering plant species. Meadows supported significantly higher interaction frequencies, species richness, and α-diversity for both plants and pollinators, although they showed a striking numerical dominance of a single key pollinator, Bombus friseanus. Network dissimilarity analyses revealed substantial differences between habitats, with both species turnover and rewiring contributing to interaction dissimilarity. Diurnal foraging dynamic analysis revealed that some key species, such as Bombus lepidus, displayed distinct foraging patterns across habitats indicating behavioral adaptation and temporal niche partitioning to microclimate. Our findings highlight the strong influence of habitat type on pollination network architecture and reveal many shared pollinator species, indicating some degree of cross-habitat linkage. These results underscore the importance of habitat heterogeneity and spatial coupling in shaping pollination services and sustaining biodiversity in mountain ecosystems under environmental change.

Animal pollination underpins plant reproduction and biodiversity across most terrestrial ecosystems1,2,3,4, yet the global relationships between plant and pollinator diversity remain poorly understood. Here we demonstrate, for the first time at a global scale, a consistent positive relationship between local flowering plant richness and pollinator species richness, observed across a wide range of environments and geographic gradients. This relationship is strongly shaped by human influence: relatively undisturbed or semi-natural communities support higher pollinator diversity per plant species than anthropogenic habitats. However, contrary to expectation, restored and even some novel ecosystems can approach the pollinator richness of more pristine systems. These findings support recent studies challenging long-held assumptions that degraded habitats are inevitably poor in biodiversity, and highlight the potential for ecological restoration to recover functional pollination networks. We also refine global estimates of the prevalence of animal pollination among flowering plants, finding that while the overall proportion remains high, it varies predictably with geography and habitat context. Together, these results underscore the central role of diverse plant communities in sustaining pollinator diversity and offer hope for the recovery of degraded habitats in maintaining this vital ecological function.

Summary: Understanding the relationship between temperature and genome size (GS) is crucial for predicting plant performance under global warming. Smaller‐GS species are hypothesized to be favored in warmer climates, while larger‐GS species may thrive in cooler environments. To test this hypothesis, we analyzed data from temperate grasslands spanning four decades (1982–2021), examining species composition, phenology, and productivity in response to rising temperatures. With rising temperatures, larger‐GS species exhibited earlier phenological events but slower growth rates, leading to a decline in biomass production. By contrast, smaller‐GS species, though initiating growth later, demonstrated accelerated growth rates, resulting in increased biomass. This dynamic has driven a shift in community structure, with smaller‐GS species becoming increasingly dominant. Phylogenetically informed models revealed a negative interaction between GS and temperature on species' biomass, underscoring the constraint of larger genomes under warming conditions. This is reflected in a community‐wide reduction in GS over time, despite relatively stable overall productivity. Our research highlights the pivotal role of GS in mediating plant community responses to climate warming, offering insight into the distinct growth strategies employed by species with different GS. Our findings underscore the importance of considering GS in predicting plant community dynamics in response to ongoing global climate change.