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opencc-by-4.0Sep 2023View details →

Evaluating plant lineage losses and gains in temperate forest understories - data and scripts

## Raw data and code to accompany the research entitled "Plant lineage losses and gains in temperate forest understories" by Padullés Cubino et al. (2023). In preparation. # There are two folders with (1) "data" and (2) "scripts". # The "data" folder contains two additional folders ("Input" and "Output") with CSV files with all the data used for analysis and produced from them. These data files are accompanied by a "metadata.xlsx" file with data descriptions. # The "scripts" folder contains three scripts for the analyses described in the manuscript: # H1_H4_H5_H6_forestreplot.R -> tests for hypotheses 1, 4, and 6. # H2_H3_forestreplot.R -> tests for hypotheses 2 and 3. # node.mean_function_forestreplot.R -> R function necessary to test H2 (load before running the code in "H2_H3_forestreplot.R". # If anything is unclear, please contact the corresponding author for clarification (padullesj@gmail.com).

opencc-by-4.0Sep 2023View details →

SI_IV_3_Reverse chemical ecology to study the defense of the plant host Sextonia rubra and the chemical mediators of its endophyte Fusarium falciforme against phytopathogen Trametes versicolor

Ces travaux présentant les données supplémentaires générés lors de l'étude de la confrontation d'isolat identifiés comme des Fusarium falciforme contre Trametes versicolor.

The functioning of alpine grassland ecosystems: climate outweighs plant species richness

<ol> <li>The biodiversity–ecosystem functioning relationship has received significant attention in recent decades. It has been widely demonstrated that plant diversity plays a crucial role in enhancing the functioning of terrestrial ecosystems. However, few studies have tested the influence of plant species richness in mediating the impacts of climate on ecosystem functions at large spatial scales. </li> <li>To address this gap, we utilized data from field surveys across broad climatic gradients at the Qinghai-Tibetan Plateau, China. Our goal was to examine the importance of plant species richness for the functioning of alpine grassland ecosystems, specifically productivity and soil carbon sequestration. </li> <li>Our results showed strong positive correlations between ecosystem functioning and growing season precipitation as well as species richness. In contrast, there was a negative correlation with growing season temperature. Notably, the positive effect of growing season precipitation on ecosystem functioning outweighed the negative effect of growing season temperature. The indirect effects of growing season precipitation and temperature on ecosystem functioning through changes in species richness were weak. Furthermore, the inclusion of climate factors in the model weakened the relationships between species richness and ecosystem functioning.</li> <li>Synthesis. Our findings demonstrate that climate factors are more important than species richness for the provisioning of ecosystem functions at large spatial scales. In summary, our study underscores the importance of considering climate factors alongside species richness when assessing ecosystem functioning across extensive geographical areas.</li> </ol>

Field testing a 13C labeling method in an East African ant-plant

Tree carbon allocation is a dynamic process that depends on the tree's environment, but we know relatively little about how biotic interactions influece these dynamics. In central Kenya, the loss of vertebrate herbivores and the savanna's invasion by the ant Pheidole megacephala are disrupting mutualisms between the founational tree Acacia drepanolobium and its native ant defenders. Here we piloted a 13Carbon (C) pulse-labeling mathod to investigate the influece of these biotic interactions on C allocation strategies by adult trees in situ. Trees withstood experimental conditions and took up sufficient labeled 13CO2 for 13C to be detected in various C sinks, including ant mutualists. The 13C in ants collected shortly after labeling suggested that trees exposed to herbivores allocated relatively more newly assimilated C to native ant defenders. Our results demonstrate the viability of the pulse-labeling method and suggest the C allocation to ant partners depends on the biotic context of the tree, but further investigation with replication is needed to characterize such differences in relation to invasion and herbivore loss.

Data from: Root-exuded benzoxazinoids can alleviate negative plant-soil feedbacks

Plants can suppress the growth of other plants by modifying soil properties. These negative plant-soil feedbacks are often species-specific, suggesting that some plants possess resistance strategies. However, the underlying mechanisms remain largely unknown. Here, we investigated if and how benzoxazinoids, a class of dominant secondary metabolites that are exuded into the soil by maize and other cereals, influence plant-soil feedbacks. We find that three out of five tested crop species suppress maize (Zea mays) performance via negative plant-soil feedbacks relative to the mean across species. This effect is partially alleviated by the capacity of maize plants to produce benzoxazinoids. Soil complementation with purified benzoxazinoids is sufficient to restore the protective effect for benzoxazinoid-deficient mutants. Sterilization and re-inoculation experiments suggest that benzoxazinoid-mediated protection acts via changes in soil biota. Substantial variation of the protective effect between experiments and soil types illustrates that its magnitude is context-dependent. In summary, our study demonstrates that plant secondary metabolites can confer resistance to negative plant-soil feedbacks. These findings expand the functional repertoire of plant secondary metabolites and reveal a mechanism by which plants can resist negative soil feedbacks. The uncovered phenomenon may represent a promising avenue to stabilize plant performance in crop rotations in the future.

Data from: Successful recovery of native plants post-invasive removal in forest understories is driven by native community features

Temperate forest understories hold the majority of the plant diversity present in these ecosystems and play an essential role in the recruitment and establishment of native trees. However, the long-term persistence of healthy forest understories is threatened by the impacts of invasive plants. As a result, a common practice is the removal of the agent of invasion. Despite this, we know little about the success of these practices and lack a comprehensive understanding of what intrinsic and extrinsic factors shape the recovery. In a multi-year field experiment, we investigated (Q1) whether native propagule availability drove native community recovery, (Q2) what the characteristics of successfully recovering communities were, and (Q3) under which environmental conditions recovery rates were faster. After initial removal of invasives, we seeded native species to manipulate assembly history and mimic restoration practices, we also implemented a repeated, vs. once, removal treatment, all in a full-factorial design. We collected data on plant species composition and abundance (i.e., species level percent cover) and on environmental conditions (i.e., light and soil water availability) in the three subsequent summers. Our results show that native community recovery rates were independent of seeding additions or frequency of invasive plant removal. The fastest rates of recovery were associated with high native species richness, native communities with higher values of specific leaf area (SLA), and low drought stress years. Our results suggest that restoration practices post-invasive plant removal should be tailored to enhance natural dispersal, or artificial addition if the resident community is species-poor, of native species with traits compatible with high resource availability, such as species with high SLA. In addition to the importance of the native community characteristics, our results underscore the need for assessing environmental conditions, favoring management practices during years of low drought stress to maximize native community recovery.

Establishing peat-forming plant communities: A comparison of wetland reclamation methods in Alberta's oil sands region

The Sandhill Wetland (SW) and Nikanotee Fen (NF) are two wetland research projects designed to test the viability of peatland reclamation in the Alberta oil sands post-mining landscape. To identify effective approaches for establishing peat-forming vegetation in reclaimed wetlands, we evaluated how plant introduction approaches and water level gradients influence species distribution, plant community development, and establishment of bryophyte and peatland species richness and cover. Plant introduction approaches included seeding with a Carex aquatilis-dominated seed mix, planting C. aquatilis and J. balticus seedlings, and spreading a harvested moss layer transfer. Establishment was assessed six years after introduction at SW and five years after introduction at NF. A total of 51 species were introduced to the reclaimed wetlands, and 122 species were observed after five and six years. The most abundant species in both reclaimed wetlands was C. aquatilis, which produced dense canopies and occupied the largest water level range of observed plants. Introducing C. aquatilis also helped to exclude marsh plants such as Typha latifolia that has little to no peat accumulation potential. Juncus balticus persisted where the water table was lower and encouraged formation of a diverse peatland community and facilitated bryophyte establishment. Various bryophytes colonized suitable areas, but the moss layer transfer increased cover of desirable peat-forming mosses. Communities with the highest bryophyte and peatland species richness and cover (averaging 9 and 14 species, and 50% to 160% cover respectively) occurred where summer water level was between -10 and -40 cm. Outside this water level range, a marsh community of Typha latifolia dominated in standing water and a wet-meadow upland community of Calamagrostis canadensis and woody species established where the water table was deeper. Overall, the two wetland reclamation projects demonstrated that establishing peat-forming vascular plants and bryophytes is possible, and community formation is dependent upon water level and plant introduction approaches. Future projects should aim to create microtopography with water tables within 40 cm of the surface and introduce vascular plants such as J. balticus that facilitate bryophyte establishment and support development of a diverse peatland plant community.

Data from: Photodegradation modifies microplastic effects on soil properties and plant performance

Microplastics in soil affect plant-soil systems depending on their shape and polymer type. However, previous research has not yet considered the effects of degraded plastics, which are the plastic materials actually present in the environment. We selected 8 microplastics representing different shapes (fibers, films and foams) and polymer types, and exposed them to UV-C degradation. Each microplastic was mixed with soil at a concentration of 0.4% (w/w). The phytometer Daucus carota grew in each pot. At harvest, soil properties and plant biomass were measured. Photodegradation altered microplastics physical and chemical properties, impacting plant-soil systems. Microplastics degradation effects on plant and soil were observed with fibers and foams, but there were negligible effects with films. The latter could be explained by the polymer structure of films and manufacturer's additives, potentially delaying their degradation. Degraded fibers increased soil respiration more than their non-degraded counterparts, as photodegradation increased the positive effects of fibers on soil water retention. The emergence of oxygenated groups during degradation may have increased the hydrophilicity of fibers, enhancing their ability to retain water. Degraded foams increased soil respiration, which could be related to the possible leaching of organic substances with lower partition coefficients, which may promote soil microbial activity. By contrast, degraded foams decreased soil aggregation, likely as degradation produced larger holes increasing their permeability. Also, the increase of hydrophilic molecules could have decreased soil particle cohesiveness. Degraded fibers and foams increased shoot and root mass as a result of microplastic effects on soil properties. Photodegraded microplastics affected root traits, which could be linked to microplastic effects on soil water status and plant coping strategies.

Data from: Plant-derived environmental DNA complements diversity estimates from traditional arthropod monitoring methods but outperforms them detecting plant-arthropod interactions

Our limited knowledge about the ecological drivers of global arthropod decline highlights the urgent need for more effective biodiversity monitoring approaches. Monitoring of arthropods is commonly performed using passive trapping devices, which reliably recover diverse communities, but provide little ecological information on the sampled taxa. Especially the manifold interactions of arthropods with plants are barely understood. A promising strategy to overcome this shortfall is environmental DNA (eDNA) metabarcoding from plant material on which arthropods have left DNA traces through direct or indirect interactions. However, the accuracy of this approach has not been sufficiently tested. In four experiments, we exhaustively test the comparative performance of plant-derived eDNA from surface washes of plants and homogenized plant material against traditional monitoring approaches. We show that the recovered communities of plant-derived eDNA and traditional approaches only partly overlap, with eDNA recovering various additional taxa. This suggests eDNA as a useful complementary tool to traditional monitoring. Despite the differences in recovered taxa, estimates of community α- and β-diversity between both approaches are well correlated, highlighting the utility of eDNA as a broad scale tool for community monitoring. Last, eDNA outperforms traditional approaches in the recovery of plant-specific arthropod communities. Unlike traditional monitoring, eDNA revealed fine-scaled community differentiation between individual plants and even within plant compartments. Especially specialized herbivores are better recovered with eDNA. Our results highlight the value of plant derived eDNA analysis for large-scale biodiversity assessments that include information about community level interactions.

Identifying Mozambique's most critical areas for plant conservation: An evaluation of protected areas and important plant areas

Successful protected area networks must represent biodiversity across taxonomic groups. However, too often plant species are overlooked in conservation planning, and the resulting protected areas may, as a result, fail to encompass the most important sites for plant diversity. The Mozambique Tropical Important Plant Areas project sought to promote the conservation of Mozambique's flora through the identification of Important Plant Areas (IPAs). Here, we use the Weighted Endemism including Global Endangerment (WEGE) index to identify the richest areas for rare and endemic plants in Mozambique and subsequently evaluate how well represented these hotspots are within the current protected area and IPA networks. We also examine the congruence between IPA and protected areas to identify opportunities for strengthening the conservation of plants in Mozambique. We found that high WEGE scores, representing areas rich in endemic/near‐endemic and threatened species, predict the presence of IPAs in Mozambique, but do not predict the presence of protected areas. We also find that there is limited overlap between IPAs and protected areas in Mozambique. We demonstrate how IPAs could be an important tool for ensuring priority sites for plant diversity are included within protected area network expansions, particularly following the adoption of the "30 by 30" target agreed within the post‐2020 Convention on Biological Diversity framework, with great potential for this method to be replicated elsewhere in the global tropics.

opencc-by-4.0Sep 2023View details →

Fig. 6 in The Australian issid planthopper genus Orinda Kirkaldy, 1907: New subgenera, new species, host plant and identification key (Hemiptera: Fulgoromorpha: Issidae)

Fig. 6. Orinda spp., distribution map.

Herbivory and elevated levels of CO2 and nutrients separately, rather than synergistically, impacted biomass production and allocation in invasive and native plant species

Large parts of the Earth are experiencing environmental change caused by alien plant invasions, rising atmospheric concentration of carbon dioxide (CO2), and nutrient enrichments. Elevated CO2 and nutrient concentrations can separately favour growth of invasive plants over that of natives but how herbivory may modulate the magnitude and direction of net responses by the two groups of plants to simultaneous CO2 and nutrient enrichments remains unknown. In line with the enemy release hypothesis, invasive plant species should reallocate metabolites from costly anti-herbivore defences into greater growth following escape from intense herbivory in the native range. Therefore, invasive plants should have greater growth than natives under simultaneous CO2 and nutrient enrichments in the absence of herbivory. To test this prediction, we grew nine congeneric pairs of invasive and native plant species that naturally co-occurred in grasslands in China under two levels each of nutrient enrichment (low-nutrient vs. high-nutrient), herbivory (with herbivory vs. without herbivory) and under ambient (412 ± 0.6 ppm) and elevated (790.1 ± 6.2 ppm) levels of CO2 concentrations in open-top chambers in a common garden. Elevated CO2 and nutrient enrichment separately increased total plant biomass, while herbivory reduced it regardless of the plant invasive status. High-nutrient treatment caused the plants to allocate a significantly lower proportion of total biomass to roots, while herbivory induced an opposite pattern. Herbivory suppressed total biomass production more strongly in native plants than invasive plants. The plants exhibited significant interspecific and intergeneric variation in their responses to the various treatment combinations. Overall, these results suggest that elevated CO2 and nutrients and herbivory may separately, rather than synergistically, impact productivity of the invasive and co-occurring native plant species in our study system. Moreover, interspecific variation in resource-use strategies was more important than invasive status in determining plant responses to the various treatment combinations.

Artificial light at night (ALAN) decreases plant diversity and performance in experimental grassland communities – Data on species biomass and traits

Artificial light at night (ALAN) affects many areas of the world and is increasing globally. To date, there has been limited and inconsistent evidence regarding the consequences of ALAN on plant communities as well as the fitness of their constituent species. ALAN could be beneficial for plants as they need light as an energy source, but they also need darkness for regeneration and growth. We created model communities composed of 16 plant species sown, exposed to a gradient of ALAN ranging from 'moonlight only' to conditions like situations typically found directly underneath a streetlamp. We measured plant community composition and its production (biomass), as well as functional traits of three plant species from different functional groups (grasses, herbs, legumes) in two separate harvests. We found that biomass was reduced by 33% in the highest ALAN treatment compared to the control, Shannon diversity decreased by 43% and Evenness by 34% in the first harvest. Some species failed to establish in the second harvest. Specific leaf area, leaf dry matter content and leaf hairiness responded to ALAN. These responses suggest that plant communities will be sensitive to increasing ALAN, and they flag a need for plant conservation activities that consider impending ALAN scenarios.

Dataset: Plant-mediated effects of fire and fragmentation drive plant–pollinator interaction β-diversity in fire-dependent pine savannas

Interaction β-diversity is a measure essential for understanding and conserving species interactions and ecosystem functioning. Interaction β-diversity explains the variation in species interactions across spatial and temporal gradients, resulting from species turnover or interaction rewiring. Each component of interaction β-diversity has different ecological implications and practical consequences. While interaction β-diversity due to species turnover is related to assembly processes and fragmentation, rewiring can support high biodiversity and confer resilience to ecological networks. However, it is unclear whether both components respond to the same or different ecological drivers. Here, we assessed the ecological drivers of plant–pollinator interaction β-diversity and its components across 24 sites in 9 longleaf pine (LLP) savannas in north and central Florida. We evaluated the effects of flowering plant composition and flower abundance, vegetation, fire regime, soil moisture, terrain characteristics, climate, spatial context and geographic location. We used path analysis to evaluate the drivers of spatial interaction β-diversity and its main components. We then used generalized linear mixed models to assess the temporal patterns of spatial β-diversity among sites within preserves. We found that plant–pollinator networks in LLP savannas are highly variable across space and time, mainly due to species turnover and possibly in response to abiotic gradients and dispersal boundaries. Flower abundance and flowering plant composition, geographic location, fire seasonality, soil moisture, and landscape context were the main drivers of plant–pollinator β-diversity, highlighting the role of fire management and habitat connectivity in preserving plant–pollinator networks.

opencc-by-4.0Oct 2023View details →

Images of plants at harvest timepoint of Mini5SynCom Screen and Validation Experiments

pictures of plants at harvest timepoint (14 days post infection) of all experiments and data shown in publication titled "Identifying microbiota community patterns important for plant protection using machine learning in synthetic community experiments" by B. Emmenegger, J. Massoni, C.M. Pestalozzi, M. Bortfeld-Miller, B.A. Maier and J.A. Vorholt. The picture name is unique to be able to link to data presented in supplemental data 1.

Explaining variation in plant-herbivore associational effects in a tree biodiversity experiment

Within biodiversity-ecosystem function research, a major outstanding question is how herbivory, a critical ecosystem function at the base of the food web, changes along gradients of plant biodiversity. Neighborhood-level associational effects are hypothesized to be a strong driver of biodiversity-herbivory relationships, but we lack a successful framework that explains the wide variation observed in the sign and magnitude of plant-herbivore associational effects, particularly in systems with mainly generalist herbivores. In this study, we combine measurements from a tree biodiversity field experiment with simulation to provide a framework for explaining variation in plant-herbivore associational effects, particularly when herbivores that feed on many different species (e.g., generalists) cause most damage. We show that monoculture herbivory levels of focal species and their neighbors predict the direction and strength of associational effects. We provide evidence that this may be due to a "spillover effect", in which some insect herbivores attracted to focal individuals ultimately end up feeding on neighboring individuals. With an empirically parameterized simulation, we explain how spatial organization modifies biodiversity-ecosystem function relationships when associational effects operate. We suggest a set of experiments to test the generality of our conceptual framework, to elucidate the underlying mechanisms that produce the patterns we find, and to ultimately increase the predictability of plant-herbivore associational effects. We conclude by discussing how our results might inform pest management in diversified agroecosystems and reforestation sites. Synthesis Our results provide a potential framework for explaining why positive and negative plant-herbivore associational effects are often balanced in systems with primarily generalist herbivores and point to a path forward for predicting when increased plant biodiversity will be associated with increased, decreased, or unchanged levels of insect herbivory on individual plant species in such systems.

Data from: Revealing biogeographic patterns in genetic diversity of native and invasive plants and their association with soil community diversity in the Chinese coast

Within-species genetic diversity is shaped by multiple evolutionary forces within the confines of geography, and has cascading effects on the biodiversity of other taxa and levels. Invasive species are often initially limited in genetic diversity but still respond rapidly to their new range, possibly through 'pre-adapted' genotypes or multiple sources of genetic diversity, but little is known about how their genetic structure differs from that of native species and how it alters the genetic-species diversity relationship. Here, we selected a widespread native species (Phragmites australis) and its co-occurring invasive competitor (Spartina alterniflora) as our model plant species. We investigated the genetic structure of P. australis using two chloroplast fragments and ten nuclear microsatellites in 13 populations along the Chinese coastal wetlands. We discovered a distinct geographical differentiation, showing that the northern and southern populations harbored unique genotypes. We also found a significant increase in genetic diversity (allelic richness and expected heterozygosity) from south to north. Combined with previous studies of S. alterniflora, the Mantel tests revealed a significant correlation of genetic distances between P. australis and S. alterniflora even when controlling for geographic distance, suggesting that the invasive species S. alterniflora might exhibit a phylogeographic pattern similar to that of the native species to some extent. Furthermore, our results suggest that the S. alterniflora invasion has altered the relationship between the genetic diversity of the dominant native plant and the associated species richness of soil nematodes. The reason for the alteration of genetic-species diversity relationship might be that the biological invasion weakens the environmental impact on both levels of biodiversity. Our findings contribute to understanding the latitudinal patterns of intraspecific genetic diversity in widespread species. This work on the genetic diversity analysis of native species also provides significant implications for the invasion stage and ecological consequences of biological invasions.

Data from: Promoting plant diversity and habitat heterogeneity through vineyard terracing

Questions: Viticulture on steep slopes has shaped landscape and biodiversity in many regions, but insufficient profitability has led to management cessation and shrub encroachment. A solution to maintain cultivation economically viable could be vineyard terracing. We aimed to identify the potential of terracing to enhance plant diversity and habitat heterogeneity in vineyards, analyse effects of management intensity on vineyard vegetation, and assess how plant communities change after vineyard abandonment. Location: Wine-growing region of the Upper Middle Rhine Valley in Hesse (50.042342°N, 7.814533°E) and Rhineland-Palatinate (50.119139°N, 7.719275°E), Germany. Methods: We recorded vascular plant species and local vineyard parameters in vertically oriented vineyards with vegetated and tilled open inter-rows, in terraced vineyards with tilled terrace inter-rows and extensively managed embankments and in vineyard fallows in a total of 45 study sites. We used plant species richness, Ellenberg indicator values and Grime's strategy types to describe how traits and ecological requirements respond to distinct vineyard management. Results: Plant species richness and composition were determined by management-derived disturbance intensities. Extensively managed embankments had a distinct plant community, the highest plant species richness, more perennial and indicator species, and lower nitrogen indicator values compared to inter-rows. In contrast, highly disturbed open and terrace inter-rows revealed plant communities associated with annuals and ruderals, but species richness did not differ between terrace inter-rows and embankments. Plant communities of fallows were completely different with lower plant diversity. Conclusions: Our results highlight the potential of terraced vineyards for plant diversity with nutrient-poor, extensively managed embankments providing conditions that have become rare in modern agricultural systems. A long environmental gradient from terrace inter-rows to embankments created habitat heterogeneity at a narrow space. In contrast, intensive inter-row management in vertically oriented vineyards hampers high plant diversity and abandonment fosters the spread of woody species at the expanse of plant diversity.

Spatial patterns of phylogenetic and species diversity of Fennoscandian vascular plants in protected areas

Protected areas are one of the main strategic means for conserving biodiversity. Yet, the design of protected areas usually neglects phylogenetic diversity, an important diversity measure. In this paper, we assess the phylogenetic diversity and species richness of vascular plants in Fennoscandian protected areas. We evaluate how much species richness and phylogenetic diversity is found within and outside protected areas, and the differences in diversity between different categories of protected areas. We also assess the differences in the diversity-area relationship of the different protected area categories in terms of both species richness and phylogenetic diversity. We build a multi-locus phylogeny of 1,519 native vascular plants of Norway, Sweden, and Finland. We estimate the phylogenetic diversity and species richness by combining the phylogeny with publicly available occurrence data and the currently protected area system of Fennoscandia. Our results indicate that protected areas in Fennoscandia hold more diversity when larger, and that phylogenetic diversity increases faster with area than species richness. We found evidence for more diversity outside of protected areas of the different countries of Fennoscandia than inside of protected areas, but no evidence for diversity differences between areas with different protection status. Hence, our results indicate that the current protected area system in Fennoscandia is no more effective in conserving phylogenetic diversity and species richness of vascular plants than a random selection of localities. Our results also indicate that planning conservation strategies around phylogenetic diversity, rather than species richness, might be more effective in protecting vascular plant diversity.

Nectar robbing by bees affects the reproductive fitness of the distylous plant Tirpitzia sinensis (Linaceae)

Nectar robbing can affect plant reproductive success directly by influencing female and male fitness, and indirectly by affecting pollinator behavior. Flowers have morphological and chemical features that may protect them from nectar robbers. Previous studies on nectar robbing have focused mainly on homotypic plants. It remains unclear how nectar robbing affects the reproductive success of distylous plants, and whether defense strategies of two morphs are different. Nectar robbing rates on the long- and short- styled morph (L-morph, S-morph) of the distylous Tirpitzia sinensis were investigated. We compared floral traits, the temporal pattern of change in nectar volume and sugar concentration, nectar secondary metabolites and sugar composition between robbed and unrobbed flowers of two morphs. We tested direct effects of nectar robbing on female and male components of plant fitness and the indirect effects of nectar robbing via pollinators. Nectar robbing rates did not differ between the two morphs. Flowers with smaller sepals and petals were more easily robbed. The floral tube diameter and thickness were greater in L-morphs than in S-morphs, and the nectar rob holes were significantly smaller in L-morphs than in S-morphs. Nectar robbing significantly decreased nectar replenishment rate but did not affect nectar sugar concentration or sugar composition. After robbery the quantities and diversity of secondary compounds in the nectar of S-morphs increased significantly and the total relative contents of secondary compounds in L-morphs showed no obvious changes. Nectar robbing could decrease female fitness by decreasing pollen germination and thus decreasing seed set. Nectar robbing had no significant effects on male fitness. Robbed flowers were less likely to be visited by hawkmoth pollinators, especially in S-morphs. These results suggest that nectar robbing could directly and indirectly decrease the female fitness of T. sinensis, and different morphs have evolved different defense mechanisms in response to nectar robbing pressure.