Plant Size Research Articles

SARS-CoV-2 surveillance in US wastewater: Leading indicators and data variability analysis in 2023–2024

Wastewater-Based Epidemiology (WBE) has become a powerful tool for assessing disease occurrence in communities. This study investigates the coronavirus disease 2019 (COVID-19) epidemic in the United States during 2023–2024 using wastewater data from 189 wastewater treatment plants in 40 states and the District of Columbia. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and pepper-mild mottle virus normalized SARS-CoV-2 RNA concentration data were compared with COVID-19 hospitalization admission data at both national and state levels. We further investigate temporal features in wastewater viral RNA abundance, with peak timing and cross-correlation lag analyses indicating that wastewater SARS-CoV-2 RNA concentrations precede hospitalization admissions by 2 to 12 days. Lastly, we demonstrate that wastewater treatment plant size has a significant effect on the variability of measured SARS-CoV-2 RNA concentrations. This study highlights the effectiveness of WBE as a non-invasive, timely and resource-efficient disease monitoring strategy, especially in the context of declining COVID-19 clinical reporting.

SPL13 controls a root apical meristem phase change by triggering oriented cell divisions.

Oriented cell divisions are crucial for determining the overall morphology and size of plants, but what controls the onset and duration of this process remains largely unknown. Here, we identified a small molecule that activates root apical meristem (RAM) expression of SQUAMOSA PROMOTER BINDING PROTEIN-LIKE13 (SPL13) a known player in the shoot's juvenile-to-adult transition. This expression leads to oriented cell divisions in the RAM through SHORT ROOT (SHR) and cell cycle regulators. We further show that the RAM has distinct juvenile and adult phases typed by morphological and molecular characteristics and that SPL factors are crucially required for this transition in Arabidopsis and rice (Oryza sativa). In summary, we provide molecular insights into the age-dependent morphological changes occurring in the RAM during phase change.

Wolffia globosa, a novel crop species for protein production in space agriculture.

Space agriculture, pivotal for sustainable extraterrestrial missions, requires plants that can adapt to altered gravitational conditions. This study delves into the adaptive responses to altered gravity of Wolffia globosa, an aquatic plant known for its rapid growth and high nutritional value. The research aimed to analyse the effect of simulated microgravity and hypergravity on relative growth rate (RGR), morphological characteristics, protein content, and the correlation between plant size and growth rate of Wolffia globosa. The study highlighted the responses of the species to altered gravity, uncovering inherent variability among seven different clones of W. globosa. Results show a base variability among clones in terms of RGR, size and protein content. Furthermore, some clones are affected by simulated microgravity, showing a decrease in RGR. Differently, under hypergravity, clones showed RGR higher than in 1g control, therefore revealing a novel plant response to hypergravity. Morphological adaptations to gravity alterations were also evident. Among the studied clones, significant morphological changes were observed, further underlining the peculiar adaptation to the hypergravity environment. Differently, under simulated microgravity, morphology was generally stable across clones. A key finding of the study was the significant negative correlation between RGR and the physical dimensions of the plants: the fastest growth was associated with the smallest dimensions of the plants. This correlation might have practical implications in selecting clones for space cultivation, that leads to compact yet highly productive clones. The analysis of the protein content of all the clones revealed mostly no significant changes under hypergravity. Otherwise, a general decrease in protein content was observed under simulated microgravity. Overall, the study confirms the suitability of W. globosa for space agriculture and provides new insights into the perspective of using W. globosa as an alternative crop species for protein production for manned Space missions. Furthermore, it underscores the need for focusing on the clones and the selection of the W. globosa plants that are best adapted to the environmental conditions of space; therefore, selecting those with the best combination of biomass production (by means of growth rate, size), and protein content.

Functional differences between herbs and woody species in a semiarid Mediterranean plant community: A whole‐plant perspective on growth, nutrient‐use and size

Abstract Despite decades of research, a comprehensive understanding of trait coordination at the whole‐plant level remains elusive. Furthermore, while the link between above‐ground growth rates and leaf traits related to nutrient use is well established, much less is known about the below‐ground compartment. Herbs and woody species exhibit distinct above‐ground growth and nutrient‐use strategies, but whether these differences extend to root traits below‐ground remains unclear. We carried out a common garden experiment with 23 perennials (7 herbs and 16 woody species) coexisting in a Mediterranean shrubland and measured 17 above‐ground and below‐ground traits related to growth, nutrient use and size. We analysed the links between growth rate and nutrient use focusing especially on roots and considering potential differences between herbs and woody species. We also combined plant size data from experimental juveniles and field‐sampled adults to determine the effects of life stage on whole‐plant phenotypic integration. We found a significant relationship between growth rates (both above‐ground and below‐ground) and root nutrient‐use strategies. Root diameter was negatively associated to growth rate only in herbs. Specific root area and root tissue density were positively and negatively correlated with growth rate, respectively, in both herbs and woody species. Moreover, we found significant differences in roots traits between herbs and woody species. Plant growth rate and root nutrient‐use strategies were both positively associated to plant size (height and above‐ground diameter) in juveniles, while a negative relationship was observed in adults. Our work provides insights on the links between whole‐plant growth rate and nutrient‐use strategies in species from a dry Mediterranan shrubland. Specifically, we show that whole‐plant growth rate is strongly associated to root traits, with more acquisitive root nutrient‐use strategies related to faster growth rates, which in turn translated to greater plant size in juveniles but smaller in adults. Our results also highlight root functional differences and contrasting patterns of whole‐plant phenotypic integration between herbs and woody species, offering deeper insights into species coexistence in species‐rich dry Mediterranean environments. Read the free Plain Language Summary for this article on the Journal blog.

Eelgrass (Zostera marina) Trait Variation Across Varying Temperature-Light Regimes

Seagrass trait variation, which results from both local genetic adaptation and phenotypic plasticity, has important effects on ecosystems. Physical drivers underlie these processes and are important determinants of trait variation. Despite this, few studies examine multivariate predictive relationships between sets of physical drivers and sets of seagrass traits. Here, we use redundancy analysis to define this relationship for eelgrass Zostera marina, using traits that represent bed structure, morphology, and physiology and physical drivers that emphasize light conditions and temperature variability on different time scales. We found a relationship between plant size (i.e., leaf length and width, rhizome width, number of leaves) and shoot density that dominated the trait variation. Specifically, as temperatures became warmer, more variable, and light was less limiting, plants became smaller (shorter, narrower, and fewer leaves, thinner rhizomes) but beds became denser. Plant biomass (leaf area index), which increased with decreasing temperature variability and bottom light, further refined this relationship. Overall, temperature variability (i.e., daily temperature range, heat accumulation, time in the optimal temperature range, and tidal and meteorological variability), as well as bottom light, were important predictors of eelgrass traits. We further identified three distinct temperature-light regimes across which traits differed; these included the cool low variability temperature regime with low light, the warm high variability temperature regime with high light, and the intermediate case between these endpoints. Our study identifies specific temperature and light drivers that define certain eelgrass traits and provides a multivariate statistical model that can be used to predict eelgrass trait values from known physical conditions.

Inter-row cover crops influencing the development of conilon coffee

The use of forage as a cover crop is an alternative for the sustainable management of conilon coffee (Coffea canephora Pierre ex Froehner) crops. The objective of this study was to evaluate the herbage accumulation and nutritive value of forages used as cover crops and their effect on the productivity and physiology of conilon coffee plants. The inter-row management assessed were 1- Congo grass [Urochloa ruziziensis (R. Germ. & C.M. Evrard) Crins], 2- Mombaça guineagrass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs], 3- Marandu palisadegrass [Urochloa brizantha (Hochst. ex A.Rich.) R.D.Webster], 4- weeds, 5- weeding and herbicide application. The experiment was conducted in 2020 and 2021 using a randomized block design (split-plot) with four replications and a plot size of 24 m2. Herbage accumulation of Congo grass, Mombaça guineagrass and Marandu palisadegrass (1.12 to 3.81 t/ha) were higher than weeds (0.18 to 1.95 t/ha) in seven periods evaluated. Mombaça guineagrass had the highest average herbage accumulation (1.47 to 3.81 t/ha). The forage cover crops did not differ among themselves for dry matter concentration, crude protein and C:N ratio in three periods evaluated. The inter-rows management with cover crops did not reduce productivity, grain/fruit ratio, grain size, vegetative vigour and physiology of the coffee plants compared to the management with weeding and herbicide in 2021. In 2022, they stagnated or reduced productivity by up to 49%, with changes in plant physiology. Adjustments in the management of cover crops are needed for the development of competitive and sustainable coffee crops.

Assessing vertical seed dispersal through seed oxygen isotope ratios of Japanese larch (Larix kaempferi)

AbstractVertical seed dispersal, involving seed movement to higher or lower elevations, plays a vital role in plant adaptation to rising temperatures. However, its assessment has been limited owing to labor‐intensive processes. A recently developed method exploits the negative correlation between elevation and seed oxygen isotope ratios (18O/16O; hereafter δ18O) for efficient evaluation of vertical seed dispersal. Nevertheless, it remains unclear whether this method is suitable for conifers and whether plant size and age introduce noise into δ18O values, which would affect vertical seed dispersal estimations. In this study, we investigated the association between elevation and seed δ18O values of Japanese larch (Larix kaempferi) and explored the relationship among these oxygen isotope ratios, tree height, diameter at breast height (DBH), and age. Notably, we found a negative correlation between elevation and seed δ18O values of L. kaempferi but failed to detect any influence of tree height, DBH, and age on these oxygen isotope ratios. These findings suggest this method's potential for accurately estimating vertical seed dispersal across diverse plant lineages.

Shoot facilitation contributes more than root facilitation to plant size inequality under environmental stress: theoretical insights from a two-layer zone-of-influence model

Shoot facilitation contributes more than root facilitation to plant size inequality under environmental stress: theoretical insights from a two-layer zone-of-influence model

Design of a hybrid solar and biomass-based energy system integrated with near-zero energy building: Techno-environment investigation and multicriteria optimization

The current research aims to meet the energy needs of a group of residential buildings in Norway with the least amount of carbon dioxide emission and the greatest amount of renewable energy. The supply side based on the renewable renewable-based energy system is planned and scaled using the real-time data use of domestic hot water (DHW), heating and electricity necessary for the buildings. PVT panels are used in the hybrid solar and biomass-based energy systems to produce both the DHW requirements and the electricity production. The digester is used with the heat pump, which generates heat. A double-effect absorption refrigeration system is also utilized to provide the necessary cooling requirements. On the supply side, the management of the heat streams and the redirection of flows are done using a rule-based regulating system. The whole plant's size is supplied, and the dynamic energy simulation is run. The primary deciding criteria for heating the buildings are the costs of electricity and biomass. The whole system is then optimized depending on operating circumstances, and the outcomes are compared to the design point. PVT may be used to create more than 80% of the yearly DHW. Furthermore, summertime radiation accounts for 64.8% of cooling output since it is more intense and may be converted into cooling energy. Digester/CC also contributes 66.55% of the building's heating, showing that the designers should rely on biomass as wintertime energy costs are higher. The parametric study demonstrates that increasing PVT time and tank capacity has varied effects on efficiency and emissions. Also, On winter days, there was a significant drop in renewable energy generation from summer to autumn, from 82.7 MWh to 28.52 MWh. The optimization results show that at the TOPSIS point, the total cost, efficiency, and emission index are 9.73 $/hr, 36.8%, and 7.75kg/MWh, respectively.

Remotely Sensed Variables Predict Grassland Diversity Better at Scales Below 1,000 km as Opposed to Abiotic Variables That Predict It Better at Larger Scales

AbstractGlobal spatial patterns of vascular plant diversity have been mapped at coarse grain based on climate‐dominated environment–diversity relationships and, where possible, at finer grain using remote sensing. However, for grasslands with their small plant sizes, the limited availability of vegetation plot data has caused large uncertainties in fine‐grained mapping of species diversity. Here we used vegetation survey data from 1,609 field sites (>4,000 plots of 1 m2), remotely sensed data (ecosystem productivity and phenology, habitat heterogeneity, functional traits and spectral diversity), and abiotic data (water‐ and energy‐related, characterizing climate‐dominated environment) together with machine learning and spatial autoregressive models to predict and map grassland species richness per 100 m2 across the Mongolian Plateau at 500 m resolution. Combining all variables yielded a predictive accuracy of 69% compared with 64% using remotely sensed variables or 65% using abiotic variables alone. Among remotely sensed variables, functional traits showed the highest predictive power (55%) in species richness estimation, followed by productivity and phenology (48%), spectral diversity (48%) and habitat heterogeneity (48%). When considering spatial autocorrelation, remotely sensed variables explained 52% and abiotic variables explained 41%. Moreover, Remotely sensed variables provided better prediction at smaller grain size (<∼1,000 km), while water‐ and energy‐dominated macro‐environment variables were the most important drivers and dominated the effects of remotely sensed variables on diversity patterns at macro‐scale (>∼1,000 km). These findings indicate that while remotely sensed vegetation characteristics and climate‐dominated macro‐environment provide similar predictions for mapping grassland plant species richness, they offer complementary explanations across broad spatial scales.

Optimal dimensioning of renewable energy generation and storage systems

With high energy demand and large available area, agricultural farms offer significant potential for renewable energy investments, like photovoltaic systems and electrical energy storages. However, the profitability of such investments depends strongly on self-consumption, so accurate planning requires computation-intensive simulation and optimization considering local consumption. This study presents a novel methodology for the optimal dimensioning and configuration of photovoltaic systems and electrical energy storages using efficient techniques from continuous non-linear optimization. Combining physical and economic models with measured consumption data, an investment’s net present value over 20 years is maximized. Using gradient-based solver WORHP, the simulation, optimal control, and optimal dimensioning of the local energy system are calculated simultaneously, allowing for efficient computation over an entire year of hourly data to capture both daily and seasonal variations.The approach is demonstrated with simple use cases, including an exemplary day of a dairy farm’s consumption, for which optimal systems with and without storage achieve 77% and 43% of autarky, respectively. Saturation effects of optimal plant size can be observed when sizes are large enough for optimal self-consumption but not expanded further for grid export. With energy storage, this saturation is reached at higher values. Optimizing photovoltaic plants with different orientations to match the specific consumption patterns characteristic of the dairy farm achieves similar autarky as a single plant while reducing investment costs by more than 20%. While thorough validation and comparison against heuristic methods predominantly used in the field is part of ongoing research, the presented use cases demonstrate the flexibility and efficiency of the proposed method and highlight its promise as a planning tool in the agricultural domain and beyond.

Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area.

Climate and environment strongly influence the size, shape, and toothiness (physiognomy) of plants' leaves. These relationships, particularly in woody non-monocotyledonous angiosperms, have been used to develop leaf-based proxies for paleoclimate and paleoecology that have been applied to reconstruct ancient terrestrial ecosystems for the last ~120 million years of Earth's history. Additionally, given that these relationships have been documented in living plants, they are important for understanding aspects of plant evolution and how plants respond to climatic and environmental changes. To conduct these types of analyses on modern and fossil plants, leaf physiognomy must be measured accurately using a reproducible methodology. This protocol describes a computer-based method for measuring and analyzing a variety of leaf physiognomic variables in modern and fossil leaves. This method allows for the measurement of leaf physiognomic traits, in particular variables related to leaf serrations, leaf area, leaf dissection, and linearity that are used in the digital leaf physiognomy proxy for reconstructing paleoclimate, as well as petiole width and leaf area, which are used for reconstructing leaf mass per area, a paleoecological proxy. Because this digital leaf trait measurement method can be applied to fossil and living plants, it is not limited to applications related to reconstructing paleoclimate and paleoecology. It can also be used to explore leaf traits that may be informative for understanding the function of leaf morphology, leaf development, phylogenetic relationships of leaf traits, and plant evolution.

Highest Occurring Vascular Plants from Ladakh Provide Wood Anatomical Evidence for a Thermal Limitation of Cell Wall Lignification.

As an evolutionary achievement of almost all terrestrial plants, lignin biosynthesis is essential for various mechanical and physiological processes. Possible effects of plant cell wall lignification on large-scale vegetation distribution are, however, not yet fully understood. Here, we present double-stained, wood anatomical stem measurements of 207 perennial herbs (Potentilla pamirica Wolf), which were collected between 5550 and 5850 m asl on the north-western Tibetan Plateau in Ladakh, India. We also measured changes in situ root zone and surface air temperatures along the sampling gradient and applied piecewise structural equation models to assess direct and indirect relationships between the age and size of plants, the degree of cell wall lignification in their stems, and the elevation at which they were growing. Based on the world's highest-occurring vascular plants, the Pamir Cinquefoils, we demonstrate that the amount of lignin in the secondary cell walls decreases significantly with increasing elevation (r = -0.73; p < 0.01). Since elevation is a proxy for temperature, our findings suggest a thermal constrain on lignin biosynthesis at the cold range limit of woody plant growth.

Aboveground and belowground sizes are aligned in the unified spectrum of plant form and function

Understanding the global variation of plant strategies is essential for unravelling eco-evolutionary processes and ecosystem functions. Variation in ten fundamental aboveground and fine-root traits is summarised in four dimensions, the first of which relates to aboveground plant size. However, there is no consensus about how root size fits within this scheme. Here, we add rooting depth and lateral spread, compiling a set of twelve key traits that define the fundamental investments of plants in growth, reproduction, and survival. We examine whether the inclusion of root size alters the dimensionality and structure of trait correlations defining plant functional strategies. Our results show that including root size traits does not alter the fundamental structure and dimensionality of the plant functional space, regardless of trait completeness and phylogenetic relatedness. Plant size defines a single continuum of allometric investments at the global scale, independent from leaf and root economic strategies.

Zooming in on the temporal dimensions of plant–soil feedback: Plant sensitivity and microbial dynamics

Abstract The magnitude of plant–soil feedback (PSF) can depend on the time of conditioning as well as the length of feedback. Understanding the temporal variation in PSF requires insight in the response of both soil characteristics and the plant. We examined how conspecific PSF varies with the length of conditioning and the size of the response plant using Jacobaea vulgaris, a species known to experience negative conspecific PSF. Together with reanalysis of an existing microbial sequence dataset, we tested whether the temporal variation in PSF is due to size‐dependent plant sensitivity to conditioned soil or due to compositional changes in microbial communities of conditioned soil. Further, by reanalysing another existing dataset, we examined temporal dynamics of the relative growth rates (RGR) of J. vulgaris during the feedback phase. Testing varying conditioning lengths, uncovered that J. vulgaris exhibited the strongest negative PSF at 5 weeks of conditioning, after which PSF gradually attenuated. Plant sensitivity to conditioned soil decreased with increasing plant age/size of the response plant. In the feedback phase, the RGR of J. vulgaris was first higher, then lower and at the end similar in ‘away’ soil compared to ‘home’ soil. The dissimilarity in bacterial and fungal communities in ‘home’ and ‘away’ soil significantly decreased during the feedback phase. When J. vulgaris grew in ‘away’ soil, the relative abundance of 10 (out of 80) bacterial OTUs that positively correlated with plant growth decreased over time, while 5 (out of 86) OTUs that negatively correlated with plant growth the relative abundance increased over time. Additionally, only one (out of 10) fungal OTU that negatively associated with plant growth increased over time in ‘away’ soil. Synthesis. Our findings illustrate that PSF varies with the duration of soil conditioning and of the feedback phase. During the feedback phase, changes in PSF can be attributed to both the size‐dependent plant sensitivity to conditioned soil and temporal changes in the microbial community of conditioned soil. This highlights the importance of considering the reconditioning of soil microbial communities by the test plants during the feedback phase for understanding temporal variation in PSF.

Is reinforcement a viable conservation strategy for the endangered perennial herb, Astragalus applegatei?

Reinforcing imperiled plant populations with transplanted individuals is a conservation tool that is increasingly used to counter the negative effects of land use change and habitat fragmentation. A reinforcement project's success is dependent on the survival of planted individuals and the support of the extant population's growth; thus, demographic comparisons of planted and extant individuals within the same population are critical to quantify success. We assessed long‐term demographic data from planted (9 years) and extant (7 years) individuals of a rare perennial herb, Astragalus applegatei, to quantify the success of a reinforcement project. We compared cumulative survival among extant and planted cohorts and constructed generalized mixed‐effect models to understand how age affected survival, flowering, and plant size of both planted and extant individuals. Overall, 9.7% of planted individuals survived after 9–11 years. Although young planted individuals had higher flowering percentages than extant individuals, our models for survival, flowering, and plant size were similar in planted and extant individuals as they aged. Cumulative survival curves among planted cohorts varied while they were similar among extant cohorts. Furthermore, there was evidence of recruitment by planted individuals, an essential benchmark of successful translocation projects. Combined, these results suggest that reinforcement can be a successful conservation tool for A. applegatei under the right conditions and may be used to inform conservation strategies for other imperiled herbaceous perennials.

A value chain modeling approach for upscaling the production of fine flavor cocoa in Arauca (Colombia)

AbstractThe fine flavor cocoa (FFC) market offers additional income for small farmers. Despite the potential of several Latin American countries to produce FFC, their lack of standardized postharvest processes hinders compliance with high‐quality standards demanded by the FFC market, as these processes have a direct impact on cocoa's organoleptic characteristics. This work supports the design of a collective postharvest transformation model that coordinates the main steps in the cocoa agri‐food chain: transport of the cocoa harvest, classification, fermentation, drying, storage, and commercialization. Our methodology includes a modeling scheme combining optimization and simulation models, considering variability in the processes, and covering operational (transport and resource allocation), tactical (design and sizing of the processing plant), and strategic (sales dynamics) decisions across the cocoa value chain. We illustrate this methodology in a case study in Arauca, Colombia. Our findings emphasize the importance of combining these operational and strategic models since their inputs and outputs are interconnected influencing the decision‐making within the cocoa value chain. Our study also identifies key determinants for the postharvest design, highlighting the postharvest center capacity, FFC prices, and the market selling mode (export or local).

Techno-economic Analysis Conversion of Empty and Partially Filled Paddy Grain Waste into Glucose through Bioconversion Route

Waste generated from Malaysia’s paddy milling factories, known as empty and partially filled paddy grain (EPFG), has been improperly managed as it can be further utilized for sustainable resources such as feedstock via biorefinery. However, the critical driver for a biorefinery is whether the proposed design is profitable. In this study, the conversion of EPFG into glucose as an alternative to sustainable management was analysed in terms of their economic performance as feedstock. The process design involved the production of non-concentrated glucose from EPFG using hydrothermal pre-treatment and enzymatic process, which led to the 76% conversion yield. The economic performance for the plant is at 1.04 million USD, 46.9%, and 34.3% for net present value (NPV), return on investment (ROI), and internal rate return (IRR), respectively. The minimum sugar selling price (MSSP), when zero NPV, is at 0.42 $/kg when the co-product revenue is considered. Sensitivity analysis results indicate that the MSSP is highly sensitive to plant size. This economic evaluation serves as an introductory guide to assess the economic performance of paddy milling waste to glucose via enzymatic hydrolysis. The results of the present study could provide insight for the Malaysian paddy industry in managing the EPFG, hence increasing their market potential.

A New Species of Crepidium (Orchidaceae: Epidendroideae: Malaxideae): From Assam, North East India

ABSTRACTA new species of the tribe Malaxideae (Orchidaceae), Crepidium assamicum, is described and illustrated here as new species from Assam, North East India. The new taxon is superficially similar to Crepidium purpureum but differs in its habitat, plant size, long floral bract, very densely flowered inflorescences, leaf number, larger petiole size, both winged throughout and flower color. This species is confined to grow in open grassland near river bank of Dibru‐Soikhowa, Dibrugarh district of Assam, in a huge population comprising 500–600 individuals. The threat status of this new species is provisionally assessed here as “Threatened” following the IUCN Red List Categories and Criteria version 16 (2024).

Vegetative traits, floral biology, and mutualistic interactions in the tropical mountain shrub Ribes ciliatum (Grossulariaceae)

Plant species in tropical mountain ecosystems experience significant environmental variation across short spatial distances. These systems offer an opportunity to assess geographic variation in plant traits in relation to biotic and abiotic environments. We examined plant vegetative and reproductive traits in the shrub R. ciliatum across two native conifer forests in central Mexico. We measured plant height, number of branches, leaf size, flower production, floral morphology, floral longevity, and plant reproductive success in R. ciliatum populations found in fir forests (3100 m) and Hartweg's pine forests (subalpine habitat, 3700 m). We also quantified the level of pollinator dependence, pollinator visitation rates, and fruit consumption rates by frugivorous birds in both populations. Plants were shorter and had smaller leaves in the subalpine forest than in the fir forest. Floral longevity decreased in the subalpine forest, but flower production, flower size, and fruit weight remained similar across populations. Fruit set and pollinator visitation rates were higher in the subalpine forest; however, seed weight and fruit consumption rates did not differ between sites. Hummingbirds and bumblebees were the primary pollinators of R. ciliatum, and the bird Ptiliogonys cinereus was the most important fruit consumer at both sites. Fruit set was entirely dependent on pollinators. Reduced plant size in the subalpine forest coincides with a general pattern associated with high mountain environments. In contrast, reproductive characters had a closer relationship to the pollination environment. The absence of variation in flower size and shape was consistent with the similarity in the composition of the pollinator community. Meanwhile, compared to lower-elevation forests, the subalpine forest exhibited shorter-lived flowers and increased fruit set, associated with higher pollinator visitation rates. Ribes ciliatum is a key resource for pollinators and frugivores at a time of year when few other floral resources are available in these high-elevation mountain forests.