Search

In this paper, we examine intraspecific variation in the quantity of alkaloid chemical defence in field collected individuals of the polymorphic ladybird beetle Adalia decempunctata (10-spot ladybird). Like its more widely studied relative Adalia bipunctata (2-spot ladybird), A. decempunctata possesses the alkaloids adaline and adalinine, which are, respectively, the major and minor alkaloids of A. bipunctata. We focused especially on alkaloid concentration in relation to colour pattern morph, sex, and the relationship between female and egg parameters. There was a marked sexual dimorphism in the balance of the two alkaloids, with adaline predominating in females and adalinine predominating in males: in males, on average, over 70% of total alkaloid was adalinine. Females had a lower proportion of adalinine (< 10%) than their eggs (> 15%) and relationships between egg alkaloid and female alkaloid or fecundity were weak or non-existent. Colour pattern morph had a borderline (although not) significant relationship with adaline concentration and total alkaloid concentration, which could be further explored with laboratory reared individuals. The sexual dimorphism in alkaloid content, which seems likely due to differences in synthesis, might be related to their relative costs to the two sexes and might provide insight into the evolution of alkaloid diversity in ladybirds. [ABSTRACT FROM AUTHOR]

Males in polygynous systems may be facing a trade‐off between the traits that enhance reproductive success and the need to cope with environmental change. To secure mates, males invest into large bodies, lavish ornaments and costly activities, but these investments may be incompatible with future environments. As climatic change intensifies, thermal stressors could be disrupting the energy‐intensive pathways that historically have yielded mating opportunity. We evaluated how traits associated with social dominance interacted with environmental conditions to shape mating behaviour and opportunity in moose (Alces alces), a heat‐sensitive species in which southern populations live at the edge of their thermal tolerance. We anticipated that males with favourable characteristics (e.g. age, weaponry) would allocate more to reproduction, resulting in increased mating opportunity. We expected that warm temperatures would limit reproductive effort, especially as age and weapon size increased. We quantified mating tactics, effort, and opportunity for male moose ranging in age from 1.5 to 11.5 years. We used hidden Markov models to detect mating tactics, accelerometer data to quantify movement effort, and proximity to females as a proxy for mating opportunity. We modelled these mating dynamics as a function of age, weapon size, and ambient temperature. Warm temperatures exaggerated age‐related differences in time and effort allocated to reproductive movement. Heat disproportionately limited reproductive effort in old males, the ages that also had the greatest mating opportunity. Even though warm temperatures altered mating behaviour, they did not reduce mating opportunity. Across temperatures, mating opportunity was highest in prime‐age and old males, yet time and effort devoted to reproductive movement decreased with age. Climate change, which is increasing autumn temperatures, may increase variation in reproductive effort across ages and depress the movement of old males, who are typically the primary breeders. The discrepancy between behaviour and opportunity suggests that movement is not a reliable pathway to reproduction and emphasizes the advantages of energy‐saving strategies, especially as environments become more taxing for heat‐sensitive species. We reveal the limitations of movement effort in polygynous mating strategies and the susceptibility of this critical life history stage to environmental change. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Evolutionary fitness is determined by how an organism allocates energy, or other limited resources, to reproduction during its lifetime. For iteroparous organisms, two alternative patterns of lifetime reproductive allocation are terminal investment and reproductive restraint. Terminal investment maximizes an individual's current reproductive output by allocating all available resources to current reproduction at the cost of future reproduction. In contrast, the reproductive restraint strategy allocates the individual's resources toward future survival and reproductive events. We used dynamic state variable modeling to investigate the conditions under which the burying beetle, Nicrophorus orbicollis, would balance between reproductive restraint and terminal investment over their lifetime. Our model provides a formal extension, specific to burying beetle biology, of the dynamic terminal investment threshold conceptual model. For young females, we show that delayed reproduction and reproductive restraint are the optimal tactic for all individuals except for those in the highest condition. However, as age increases, terminal investment becomes the optimal tactic over an increasingly broader range of individual conditions. Surprisingly, manipulation of a variety of factors, such as survival rate, resource availability, and metabolic costs, causes only minor changes in the general pattern observed. We suggest that in burying beetles, and other similar organisms, age plays a dominant role in determining the pattern of reproductive allocation over a lifetime. Individual energetic condition is important in changing the boundaries between alternative reproductive strategies, but it does not change the overall pattern of dominance of delayed reproduction or reproductive restraint at early ages and dominance of terminal investment with increasing age. Significance statement: In this model of the dynamic terminal investment threshold, age is the dominant determinant of reproductive allocation over a lifetime. Differences in survival rate, resource availability, and metabolic costs result in only slight adjustments to the optimal reproductive allocation strategy. Our model predicts the coexistence of multiple reproductive strategies and suggests that patterns of reproductive allocation identified for burying beetles may be broadly applicable across diverse taxa (e.g., insect parasitoids, altricial birds) that share similar life history characteristics and constraints with burying beetles. Furthermore, even in species that exhibit dramatically different life histories from burying beetles (e.g., long-lived, indeterminate growth, absence of reproductive senescence) this approach of dynamic state variable modeling shows potential for characterizing and comparing lifetime reproductive allocation patterns. [ABSTRACT FROM AUTHOR]

This article is a Commentary on Barman et al. (2024), 244: 1013–1023. [ABSTRACT FROM AUTHOR]

Plants can adapt to environmental changes by adjusting their functional traits and biomass allocation. The size and number of flowers are functional traits related to plant reproduction. Life history theory predicts that there is a trade‐off between flower size and number, and the trade‐off can potentially explain the adaptability of plants. Elevation gradients in mountains provide a unique opportunity to test how plants will respond to climate change. In this study, we tried to better explain the adaptability of the alpine plant Gentiana lawrencei var. farreri in response to climate change. We measured the flower size and number, individual size, and reproductive allocation of G. lawrencei var. farreri during the flowering period along an elevation gradient from 3200 to 4000 m, and explored their relationships using linear mixed‐effect models and the structural equation model. We found that with elevation increasing, individual size and flower number decreased and flower size increased, while reproductive allocation remained unchanged. Individual size positively affected flower number, but was not related to flower size; reproductive allocation positively affected flower size, but was not related to flower number; there is a clear trade‐off between flower size and number. We also found that elevation decreased flower number indirectly via directly reducing individual size. In sum, this study suggests that G. lawrencei var. farreri can adapt to alpine environments by the synergies or trade‐offs among individual size, reproductive allocation, flower size, and flower number. This study increases our understanding of the adaptation mechanisms of alpine plants to climate change in alpine environments. [ABSTRACT FROM AUTHOR]

Earth system models must predict forest responses to global change in order to simulate future global climate, hydrology, and ecosystem dynamics. These models are increasingly adopting vegetation demographic approaches that explicitly represent tree growth, mortality, and recruitment, enabling advances in the projection of forest vulnerability and resilience, as well as evaluation with field data. To date, simulation of regeneration processes has received far less attention than simulation of processes that affect growth and mortality, in spite of their critical role maintaining forest structure, facilitating turnover in forest composition over space and time, enabling recovery from disturbance, and regulating climate-driven range shifts. Our critical review of regeneration process representations within current Earth system vegetation demographic models reveals the need to improve parameter values and algorithms for reproductive allocation, dispersal, seed survival and germination, environmental filtering in the seedling layer, and tree regeneration strategies adapted to wind, fire, and anthropogenic disturbance regimes. These improvements require synthesis of existing data, specific field data-collection protocols, and novel model algorithms compatible with global-scale simulations. Vegetation demographic models offer the opportunity to more fully integrate ecological understanding into Earth system prediction; regeneration processes need to be a critical part of the effort.

Abstract Plants can adapt to environmental changes by adjusting their functional traits and biomass allocation. The size and number of flowers are functional traits related to plant reproduction. Life history theory predicts that there is a trade‐off between flower size and number, and the trade‐off can potentially explain the adaptability of plants. Elevation gradients in mountains provide a unique opportunity to test how plants will respond to climate change. In this study, we tried to better explain the adaptability of the alpine plant Gentiana lawrencei var. farreri in response to climate change. We measured the flower size and number, individual size, and reproductive allocation of G. lawrencei var. farreri during the flowering period along an elevation gradient from 3200 to 4000 m, and explored their relationships using linear mixed‐effect models and the structural equation model. We found that with elevation increasing, individual size and flower number decreased and flower size increased, while reproductive allocation remained unchanged. Individual size positively affected flower number, but was not related to flower size; reproductive allocation positively affected flower size, but was not related to flower number; there is a clear trade‐off between flower size and number. We also found that elevation decreased flower number indirectly via directly reducing individual size. In sum, this study suggests that G. lawrencei var. farreri can adapt to alpine environments by the synergies or trade‐offs among individual size, reproductive allocation, flower size, and flower number. This study increases our understanding of the adaptation mechanisms of alpine plants to climate change in alpine environments.

Investment of resources in reproduction can be based on individual state, environmental conditions, and perceived mate quality. Changing climates impact many aspects of the environment by increasing temperature, decreasing precipitation, and altering resource availability. Access to high-quality resources is known to improve survival under elevated temperatures, but its effects on reproduction in warming environments are largely unexplored. Here, we investigate the effects of elevated temperature and sugar resources on reproductive output within and between E- and Z-pheromone strains of the European corn borer moth [Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae)]. Corn borers prefer mates from their own strain, with reproductive output being highest for within-strain pairs. In this experiment, mating pairs were provided with a 20% sugar solution while exposed to either ambient (23 °C) or elevated (28 °C) temperatures. We measured reproductive investment as the total number of egg clusters laid 3 days after pairing. We found that at ambient temperature, sugar supplementation resulted in high investment across all pairs, including with usually unpreferred mates. However, when sugar was provided at elevated temperature, more egg clusters were laid in pairs with preferred (within-strain) mates as compared to less preferred (between-strain) mates. These results differ from temperature effects in the absence of sugar and suggest that the effects of sugar on reproductive investment in less preferred mates depend on temperature. Changes in investment may be due to differences in the allocation of extra resources to thermoregulation at elevated temperatures. Our results suggest the possibility of interactive effects of temperature and resources on sexual selection. [ABSTRACT FROM AUTHOR]

Invasive plant transformers substantially change the abiotic environment of invaded ecosystems and thus habitat suitability to resident species. Post‐invasion environmental alteration can also modify the selective pressure acting on native plants. Here, I explored whether the decrease in light availability due to an invasion of Heracleum mantegazzianum drives evolution of reproductive strategies of Veronica chamaedrys, a perennial plant combining sexual and clonal reproduction.Using a common garden experiment with plant material of V. chamaedrys from 23 sites with distinct invasion history and light conditions, I searched for changes in reproductive allocation. I also asked whether evolution of the two modes can be constrained by the genetic trade‐off between them. Furthermore, the phenotypic trade‐off between the two modes was explored in a field experiment.I found that invaded populations increased investments in clonal reproduction, a shift that was driven by decreased light availability, particularly in the early invasion phases. However, as light availability rebounded in the more advanced phases of invasion, so decreased allocation to clonal structures. In terms of relative allocation, increased investment in ramets was paralleled by reduced seed production, and the changes were underpinned by genetic trade‐off. Finally, the phenotypic trade‐off was demonstrated in the field experiment by showing that plants producing more ramets were also less likely to flower.These results suggest that an exotic plant invasion can drive evolution of reproductive allocation, here observed on a timescale of tens of years. This knowledge is important not only for the prediction of long‐term invasion impacts, but also, more generally, for the provision of novel insights into the process of adaptation of plants to changing abiotic conditions. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

It is difficult to assess the relative variability or stability of chasmogamous (CH) and cleistogamous (CL) reproduction in perennial herbs with mixed mating because long-term data in natural populations are unavailable. Here, the aim was to quantify and compare spatial (between-habitat) and temporal (among-year) variation in CH and CL reproduction over 5 years in two subpopulations of the native perennial grass Danthonia compressa. This species produces CH spikelets on terminal panicles in early summer, while axillary CL spikelets, including a basal cleistogene, mature into the autumn. Flowering tillers were collected from a sunny woodland edge and an adjacent shady interior habitat for 5 consecutive years (2017–21). Seed set, fecundity, seed mass and biomass allocation were recorded for the two floral types along with tiller vegetative mass. Bivariate line fitting was used for allometric analysis of CH and CL fecundity. Seed set, fecundity, mass per seed and allocation to seeds differed between floral types and showed significant variation between habitats and among years. Seed set and fecundity in CH panicles were greater than that of axillary CL panicles in most years. Tiller mass positively affected axillary CL seed production and mass of the basal cleistogene. Fecundity and allocation among years were more variable for CH compared to CL reproduction. High seed set and fecundity of CH spikelets suggest that pollination does not limit reproduction via chasmogamy. Late maturation of axillary CL spikelets provides additional fecundity, especially in larger plants along sunny woodland edges. The heavy cleistogene at the tiller base could be important to population persistence, analogous to the axillary bud bank of other perennial grasses that are not cleistogamous. The spatiotemporal stability of CL reproduction underscores the ecological significance of cleistogamy to reproductive fitness. [ABSTRACT FROM AUTHOR]

An understanding of the drivers of individual fitness is a fundamental component of evolutionary ecology and life‐history theory. Reproductive senescence, mate and mating tactic choice and latent heterogeneity in individual quality interact to affect individual fitness.We sought to disentangle the effects of these fitness drivers, where longitudinal data are required to understand their respective impacts.We used reproductive allocation and success data from a long‐term (1989–2018) study of white‐throated dippers Cinclus cinclus in Switzerland to simultaneously examine the effects of female and male age, mating tactic, nest initiation date and individual heterogeneity on reproductive performance.We modelled quadratic and categorical effects of age on reproductive parameters. The probability of polygyny increased with age in both sexes before declining in older age classes. Similarly, hatching probability in monogamous pairs and the number of nestlings hatched in both monogamous and polygynous pairs increased with female age before declining later in life. As predicted, offspring survival in monogamous pairs increased with male age before declining in older age classes, but male age had no effect on offspring survival in polygynous nesting attempts.Our results demonstrate that parental age, mating tactic and individual heterogeneity all affect reproductive success, and that the impacts of senescent decline are expressed across different demographic components as a function of sex‐specific senescent decline and mating tactic. [ABSTRACT FROM AUTHOR]

Background and Aims We examined the relationship between reproductive allocation and vegetative growth in three monoicous sexual systems of bryophytes. The sexual systems show a gradient of increasing distance between the sexes, from gonioautoicous to cladautoicous to rhizautoicous. Here, we investigated the following two hypotheses: (1) reproductive allocation differs between sexes and sexual systems, and male reproductive allocation increases with increasing distance between male and female gametangia; and (2) reproductive allocation is negatively related to vegetative growth. Methods We sampled the three sexual systems, represented by three moss species of the genus Fissidens in the Atlantic Forest of Southeastern Brazil. Ramets were washed in the laboratory; the reproductive structures were detached from the vegetative ramets and sorted regarding sex and individual, dried at 70 °C for 72 h, and weighed in an ultramicrobalance. We calculated the mean reproductive and vegetative mass and reproductive allocation and used generalized linear models to test our predictions. Key Results Reproductive allocation differed between species and sexes. It was higher in the rhizautoicous than in the cladautoicous and gonioautoicous species. Mean reproductive allocation was greater in males than in females of the rhizautoicous species, greater in females than males of the cladautoicous species, and did not differ between the sexes in the gonioautoicous species. Estimates of reproductive and vegetative mass were positively related in females of the rhizautoicous species. Vegetative mass was not related to reproductive allocation in the gonioautoicous species, but negatively related to reproductive allocation in the male and female branchlets of the cladautoicous species and in the female ramets of the rhizautoicous species. Conclusions The reproductive allocation patterns differ between the rhizautoicous species and the 'truly' monoicous species, with shorter intersexual distances, which implies that our hypotheses were supported only in part. We suggest that the hypotheses should be reformulated and tested further by comparing 'truly' monoicous species with dioicous species and by including other genera. [ABSTRACT FROM AUTHOR]

To compete effectively, living organisms must adjust the allocation of available energy resources for growth, survival, maintenance, and reproduction throughout their life histories. Energy demands and allocations change throughout the life history of an organism, and understanding their energy allocation strategies requires determination of the relative age of individuals. As most scleractinian corals are colonial, the relationship between age and mass/size is complicated by colony fragmentation, partial mortality, and asexual reproduction. To overcome these limitations, solitary mushroom corals, Herpolitha limax from Okinawa, Japan and Fungia fungites from Okinawa and the Great Barrier Reef (GBR), Australia, were used to investigate how energy allocation between these fundamental processes varies as a function of age. Measurements of the relative growth, biochemical profiles, fecundity of individuals of different sizes, and the settlement success of their progeny have revealed physiological trade-offs between growth and reproduction, with increasing body mass ultimately leading to senescence. The importance of energy allocation for reproduction led us to examine the reproductive strategies and sex allocation in the two studied species. In the present study, the smallest individuals of both species studied were found to invest most of their energy in relative growth, showing higher lipid and carbohydrate content than the later stages. In medium-sized corals, this pattern was overturned in favour of reproduction, manifesting in terms of both the highest fecundity and settlement success of the resulting brooded larvae. Finally, a phase of apparent senescence was observed in the largest individuals, characterized by a decrease in most of the parameters measured. In addition, complex reproductive plasticity has been revealed in F. fungites in the GBR, with individual females releasing eggs, embryos, planulae, or a combination of these. These data provide the most direct estimates currently available for physiological, age-related trade-offs during the life history of a coral. The unusual reproductive characteristics of the GBR F. fungites indicate previously unknown layers of complexity in the reproductive biology of corals and have implications for their adaptive potential across a wide geographical scale.

Life-history traits, such as reproductive allocation, sexual expression, sex ratio, and reproductive success, are central aspects of a species' ecology and evolution. For example, bias in male and female sex expression may play a large role in determining the viability of populations in the face of environmental pressures, such as population fragmentation, climate change and habitat occupancy. Thus, in this study, we investigated reproductive traits in 10 meta-populations of Fissidens flaccidus Mitt. From each meta-population, 30 patches were randomly selected, and 1 cm2 samples were collected form each patch. A total of 20,173 ramets were analyzed and classified into male, non-sporophytic female, sporophytic female, and non-sex expressing. In addition, population density in each patch was quantified. Our results showed that relative reproductive allocation in perigonia and sporophytes is greater than perichaetia. Trade-off between sexual relative reproductive allocation and asexual gemma production was observed, suggesting an important role of female ramets in asexual reproduction. The number of male ramets does not influence the reproductive success observed in each patch, and ramet density may induce male sex expression. Thus, we concluded that reproductive allocation in male function is efficient, since fewer male ramets can assure a considerable reproductive success. Furthermore, our results suggest that there may be a habitat preference between the sexes, since male ramets are found in patches with high density and mostly below female ramets, suggesting an avoidance of direct sunlight by male ramets. [ABSTRACT FROM AUTHOR]

Reproductive strategies in lichens are a rarely studied field, and little is known about which variables affecting the production of reproductive structures are most important. Here, we investigated how lichen size and cardinal direction affected the density of apothecia in the cyanolichen Leptogium marginellum. We hypothesized that larger thalli and thalli facing south (towards the pole) would have a higher density of apothecia. Individuals with larger body sizes may store more resources that can be invested in sexual reproduction, and thalli facing south in the southern hemisphere could be exposed to more favorable abiotic conditions, similar to the north in the northern hemisphere. We collected L. marginellum thalli along a stream in a protected southeast Brazil area. Cardinal directions and the largest diameter of each thallus were registered with a GPS and a digital pachymeter, respectively. We observed the thalli with a stereomicroscope, delimited a region of 1×1 cm, and photographed it to count the number of apothecia with ImageJ. We found that cardinal direction did not affect the body size or the density of apothecia. However, lichen size was an important variable in the density of apothecia, explaining almost 60% of the variation observed. According to our findings, reproduction can be considered an allometric process, and reproductive patterns can vary with the hemisphere where the lichen is found. To our knowledge, this is the first research studying reproductive allocation in a tropical lichen. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungus (AMF) can mediate physiological adaptation of higher plants to drought stress, including wheat. Yet, it is unclear how AMF affects reproductive output via mediating crop physiological vitality at the evolutionary scale. To clarify this issue, a growth environment-controlled experiment was conducted using four primitive wheat genotypes and four modern ones with or without AMF (Funneliformis mosseae) inoculation. Two water regimes (80 % and 40 % field water capacity, FWC80 (well-watered) and FWC40 (drought stress)) were included. The data indicated that AMF inoculation significantly improved leaf area, photosynthetic rate, stomatal conductance and water use efficiency under drought stress, compared to the non-AMF group (CK). Regardless of soil moisture, the relationship between reproductive biomass vs. vegetative biomass (R-V), and between leaf biomass vs. shoot biomass, all fell into a typical allometric pattern (α>1, P <0.001) in primitive wheat. In contrast, in modern wheat, the R-V relationship tended to an isometric pattern (α≈1, P <0.001), showing lower α values in all treatments relative to primitive ones. Furthermore, AMF inoculation significantly promoted the maintenance rate of yield and biomass under drought stress, suggesting greater drought tolerance as induced by AMF in modern wheat compared to primitive ones. These findings illuminated a key evolutionary strategy to enhance reproductive allocation via activating physiological activities under drought stress from primitive to modern wheat. [Display omitted] • AMF activates wheat physiological vitality under drought stress across wheat species. • AMF induces stronger yielding in modern wheat than primitive ones. • The results are mechanistically driven by distinct R-V relationships between species. • The study reveals a key evolutionary strategy to enhance wheat reproductive. [ABSTRACT FROM AUTHOR]

Forest nutrient availability, foliar nutrient concentrations, and primary productivity across the globe have been previously investigated to understand large-scale biogeochemical and ecosystem processes. While previous studies have focused on nitrogen (N) and phosphorus (P) concentrations and fluxes of foliage, the concentrations and fluxes of these elements in reproductive organs have not yet been synthesized at the global scale despite the importance of fecundity and fitness in biogeochemical cycles. Here, we tested three hypotheses related to trends in reproductive and leaf litterfall at the global scale, including two hypotheses related to concentrations of N and P, and a third hypothesis related to fluxes of N and P. The temperature/precipitation hypothesis posits that N and P availability is greatest in warm and wet climates and the substrate-age hypothesis suggests young high-latitude soils are more N limited compared to older, highly weathered soils at low latitudes that are more P limited. The productivity and fecundity hypothesis posits that both rates of primary productivity and allocation to reproductive tissues decrease from tropical to temperate and boreal latitudes, resulting in greater fluxes of N and P in tropical than temperate and boreal ecosystems. To test these hypotheses and elucidate patterns of reproductive allocation of nutrients in forest ecosystems, we present a global-scale data synthesis of both reproductive and leaf litterfall concentrations and fluxes of N and P. We found that reproductive litterfall N and P concentrations both increased with mean annual temperature and most closely aligned with the temperature/precipitation hypothesis. In support of the productivity and fecundity hypothesis, we found that reproductive litterfall fluxes of N and P also increased toward lower latitudes. Our global median estimates of the percent contribution of reproductive litterfall to leaf plus reproductive litterfall for N were 13.0% (interquartile range: 4.6–20.0%) and for P were 16.1% (6.8–25.9%). Our results demonstrate that reproductive litterfall fluxes of N and P are important components of litterfall and contribute to our understanding of the mechanisms that limit both N and P across the globe. [ABSTRACT FROM AUTHOR]

Inundation shifts plant growth, species diversity and ecosystem stability, but it remains unclear how inundation depth shapes the phenotypic variability of clonal plants in an estuary wetland. To reveal the response of clonal plant populations to inundation depth, we calculated the variation of Phragmites australis using shoot height, leaf length, leaf width, leaf biomass and panicle length in the Liaohe estuary wetland. Reproductive allocation was defined by the ratio of panicle length to shoot height. Linear regression showed that shoot height, leaf length, leaf width, leaf biomass and panicle length were negatively correlated with inundation depth, while the ratio of panicle length to shoot height was negatively correlated with inundation depth (p < 0.0001). Based on data regarding the statistical differences of plant phenotypic traits among P. australis, we recognized populations had generated variation differentiation. Compared with other functional traits, the coefficient of variation of leaf-related traits were at a high level. Therefore, leaf parameters would be the most suitable, and they increased the area and weight to support the action of plants during floods. Multivariate statistical analysis suggested that P. australis populations in the Liaohe estuary wetland were divided into two phenotypic clusters, consistent with geographical distance and morphological similarity. Our results provide a novel perspective on the ecological strategy of cloned plants under inundation change and offer theories for the conservation and restoration of estuarine wetland ecosystems. [ABSTRACT FROM AUTHOR]

The bidirectional dynamics between species and their biotic and abiotic environments, known as eco‐evolutionary feedbacks, may shift the direction of evolution and alter the ecological role of species. Alewife, Alosa pseudoharengus, is an exemplary species to study reciprocal feedbacks between ecology and evolution, owing to repeated independent derivations of a landlocked life history from an ancestral anadromous form. In this study we analysed the reproductive allocation during the spawning season in a landlocked Alewife population in the context of eco‐evolutionary feedbacks. We also compared our findings with previous results from a neighbouring anadromous population of the species. Similarities were found between the two Alewife populations in relation to their ovarian development, oocyte release strategy and fecundity type, but also differences in seasonal patterns of energy investment. Anadromous Alewives invested more in the size of the first oocyte batch of the season and subsequently tapered their reproductive allocation, while spawning batch in landlocked Alewife was invariant as the spawning season progressed. The evolutionary change from ancestral tapering to equitability of seasonal reproductive investment can be explained with reference to eco‐evolutionary changes that occurred upon landlocking related to the availability of zooplankton prey and feeding opportunity. [ABSTRACT FROM AUTHOR]

Studies investigating the trade‐off between current and future reproduction often find that increased allocation to current reproduction is associated with a reduction in the number or quality of future offspring. In species that provide parental care, this effect on future offspring may be mediated through a reduced future ability to provide care. Here, we test this idea in the burying beetle Nicrophorus vespilloides, a species in which parents shift the cost of reproduction toward future offspring and provide elaborate parental care. We manipulated brood size to alter the costs females experienced in association with current reproduction and measured the level of parental care during a subsequent breeding attempt. Given that these beetles breed on carcasses of small vertebrates, it is important to consider confounding effects due to benefits associated with resource access during breeding. We, therefore, manipulated access to carrion and measured the level of parental care during a subsequent breeding attempt. We found that females provided the same level of care regardless of previous brood size and resource access, suggesting that neither affected future ability to provide care. This may reflect that parents feed on carrion during breeding, which may buffer against any costs of previous breeding attempts. Our results show that increased allocation to current reproduction is not necessarily associated with a reduction in future ability to provide care. Nevertheless, this may reflect unique aspects of our study system, and we encourage future work on systems where parents do not have access to a rich resource during breeding. [ABSTRACT FROM AUTHOR]

Abstract Previous studies have demonstrated changes in plant growth and reproduction in response to nutrient availability, but responses of plant growth and reproduction to multiple levels of nutrient enrichment remain unclear. In this study, a factorial field experiment was performed with manipulation of nitrogen (N) and phosphorus (P) availability to examine seed production of the dominant species, Stipa krylovii, in response to N and P addition in a temperate steppe. There were three levels of N and P addition in this experiment, including no N addition (0 g N m−2 year−1), low N addition (10 g N m−2 year−1), and high N addition (40 g N m−2 year−1) for N addition treatment, and no P addition (0 g P m−2 year−1), low P addition (5 g P m−2 year−1), and high P addition (10 g P m−2 year−1) for P addition treatment. Low N addition enhanced seed production by 814%, 1371%, and 1321% under ambient, low, and high P addition levels, respectively. High N addition increased seed production by 2136%, 3560%, and 3550% under ambient, low, and high P addition levels, respectively. However, P addition did not affect seed production in the absence of N addition, but enhanced it under N addition. N addition enhanced seed production mainly by increasing the tiller number and inflorescence abundance per plant, whereas P addition stimulated it by decreasing the plant density yet stimulating height of plants and their seed number per inflorescence. Our results indicate seed production is not limited by P availability but rather by N availability in the temperate steppe, whereas seed production will be increased by P addition when N availability is improved. These findings enable a better understanding of plant reproduction dynamics in the temperate steppe under intensified nutrient enrichment and can inform their improved management in the future.

ABSTRACT. Parasite infections may contingency different aspects of the hosts’ lives, and are usually expected to directly or indirectly compromise host reproduction. However, although amphibians have historically been study models in parasite ecology, the effects of parasitism on amphibians’ reproduction remain unknown. Thus, we investigated how the parasite load varies as a function of climatic seasonality (rainy and dry season) and intrinsic host characteristics (size and sex), as well as the relationship between parasite load and reproductive investment in males and females of a small frog (Pseudopaludicola pocoto Magalhães, Loebmann, Kokubum, Haddad & Garda, 2014) in the Brazilian semiarid region. The parasitological parameters of the studied population were not influenced by the season of the year or by the hosts’ body size, but females of P. pocoto had a higher prevalence and intensity of infection than males. The number of oocytes and the volume of the testes were not related to the parasite load, revealing that the parasitism did not negatively impact the gonadal investment in P. pocoto. Our findings suggest that short-lived species, such as the tiny Pseudopaludicola species, have a high reproductive investment independent of their parasitic interactions. In addition, this should be true mainly in those species that live in seasonally dry environments, such as P. pocoto, in which reproduction is even more constrained by the shortened and unpredictable rainy period.

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• In the dioecy Idesia polycarpa Maxim species, the males and females exist a significant difference in the reproductive allocation, and the number of inflorescences on architecture differs. • Annual reproduction of I. polycarpa , the inflorescence cluster production was 8.85% higher in females than males. • This is a new attempt to demonstrate that the impact of floral development on the architecture of male and female individuals and the allocation relationship between branch architecture (tier of branches, branch sections) and tree reproductive parts (fruiting spurs, short branches, and lateral terminal buds). Several studies have reported females of dioecious species often have higher reproductive effort than males because they produce fruits and seeds. We examined the relative reproductive allocation of the inflorescences at the shoot and whole plant levels of the sexes. The number of inflorescence clusters in the shoot following the tier of branches and reproductive parts (fruiting spurs, short branches, and lateral terminal buds) of females and males was compared. In addition, the reproductive allocation in the per shoot, fruit growth, weight variation, fruit diameter, and fruit numbers counted and the annual reproductive variations were examined. The study was found a female-biased annual reproductive allocation of this species. The inflorescence cluster production was 8.85% higher in females than males. Fruiting spurs produced the highest number of inflorescence clusters in both sexes. The highest 64% and 51% of inflorescence clusters allocation were in the second tier of branches (2Y) of females and males, respectively. Fruits were the highest in numbers from June to July and produced in the 2Y, besides, the highest fruit loss occurred by 56.92% from September to October in females. The results suggest that the architecture of females and males in Idesia polycarpa invests differently in their reproductive allocation and quantity depending on branch type. [ABSTRACT FROM AUTHOR]

Premise: We investigated sex‐specific differences in the life‐history traits of a metapopulation of the dioicous moss Weissia jamaicensis. Field observations revealed high rates of fertilization, which is uncommon for most dioicous bryophytes. We raised four hypotheses associated with the way the reproductive traits are related to the fertilization rate in this metapopulation. Methods: We sampled 10 patches of the metapopulation and quantified sexual expression, sex ratio, reproductive success, and reproductive allocation. The ramets were classified as male, non‐sporophytic female, sporophytic female, or non‐sex‐expressing. Thirty ramets from each of the categories expressing sex were placed for regeneration to test the effect of reproductive allocation on this trait. Results: We found greater expression of the female function in all patches, implying a female bias in the metapopulation. The number of male ramets was variable in each patch and did not affect reproductive success. At the prezygotic level, the allocation of resources to the male function was higher. However, the large allocation of resources to sporophyte development in sporophytic females, which exceeded allocations at prezygotic levels, was related to the higher mortality rate of these ramets, suggesting reproductive cost. Conclusions: The prezygotic ramets that allocated the greatest amount of resources to reproduction expressed sex less frequently, biasing the sex ratio toward the sex that allocated the least amount of resources to reproduction. Overall, the ramets that allocated the greatest amount of resources to reproduction had the lowest regeneration rate, suggesting reproductive cost. [ABSTRACT FROM AUTHOR]

The forage yield and quality of artificial grasslands typically decline rapidly over time after planting. Moreover, the reason for this decline of artificial grassland remains unclear. Here, we evaluated the relationship between years since planting and annual net primary productivity (ANPP), seed yield, and reproductive allocation (ie., the ratio of seed yield to annual net primary productivity) for eight common gramineous species separately planted in monoculture artificial grasslands in the Qinghai-Tibetan Plateau. We utilized T50 values (the time when ANPP or seed yield drop to 50% of their maximum values) to quantify the decline rates of eight artificial grasslands respectively, and additionally evaluated the influence of evolutionary history and other plant attributes on T50 (ANPP) and T50 (seed yield). We found that both ANPP and seed yield decreased linearly over time following planting for all species. ANPP generally declined more rapidly than did seed yield. The reproductive allocation of Deschampsia cespitosa, Festuca kirilowii, Festuca kryloviana, and Festuca sinensis increased significantly over time after planting. We did not observe any association of evolutionary history, seed mass, plant height, reproductive allocation, ANPP (second year), seed yield (second year) with T50 (ANPP) and T50 (seed yield). In addition, clonal propagation mode may influence declines of artificial grassland, and evolutionary history may shape shifts in reproductive allocation with plant population aging. This study was the first to utilize T50 values for the study of artificial grassland declines. Our research framework thus has the potential to guide future quantitative studies of artificial grassland declines.

Ulva prolifera green tides, one of the greatest marine ecological disasters, originate in the southern Yellow Sea of China and obtain the highest biomass in Haizhou Bay (latitude around 35° N) during northward drift. U. prolifera shows different morphologies from southern Haizhou Bay (SH) to northern Haizhou Bay (NH). Owing to the distinct nutrient environments between SH and NH, we hypothesized that thalli in NH with poor nutrients increased the surface area to volume ratio (SA:VOL) to better absorb nutrients. Here, we tested this hypothesis by comparing the SA:VOL of thalli in SH and NH. The results showed that the thalli in NH had a lower SA:VOL than those in SH, and SA:VOL had positive relationships with temperature and nutrients, contrary to the general hypothesis. The novel results suggested that morphological differences of U. prolifera were the result of developmental state rather than environmental acclimation. Indicators of reproduction (reproductive allocation ratio) were negatively related to variation in tissue contents of C, N, P, and crude protein, whereas indicators of growth (tissue contents of C, N, P, and crude protein) showed significant positive influences on SA:VOL. The results indicated that a trade‐off relationship between reproduction and growth existed in the northward drift. All the results suggested that physiological functional traits affected morphological variation of U. prolifera in different environmental conditions during the drifting of green tides. This study presents new insights into the opportunist species nature of U. prolifera through morphological variation and associated functional consequences. [ABSTRACT FROM AUTHOR]

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mutually beneficial symbiosis system formed between arbuscular mycorrhizal fungi(AMF)and host plants is one of the representative types of symbiosis systems widely distributed in various ecosystems. In addition to promoting the growth and development of host plant, AMF can also have various effects on the reproduction process of host plants. Studying the changes of reproduction strategies of host plants infected by AMF has important theoretical significance for in-depth understanding of changes in plant reproductive fitness. In this article, we review the related researches on the effects of AMF on the reproduction of host plant, including the effects of AMF infection on reproductive allocation, floral characteristics, insect-pollination and anthesis of host plants. Although current studies have found that AMF can promote the increase of host plant reproduction input, increase the size and number of flowers, increase the number of pollen and nectar secretion, affect the behavior of flower visitors, and cause early flowering and prolonged flowering, the specific mechanism of AMF affecting reproduction of flowering plant is still unclear, and there is currently no unified conclusion due to differences between host plants. However, due to the ubiquity of AMF symbiosis with plant, its important role in the process of plant reproduction cannot be ignored. In the future, more researches should be conducted to investigate the influence mechanism of AMF on the reproductive traits of host plants, the resource allocation of male and female functions in the process of plant sexual reproduction, asexual reproduction and offspring fitness in addition to conducting more in-depth studies in the above-mentioned aspects. [ABSTRACT FROM AUTHOR]

Abstract Ulva prolifera green tides, one of the greatest marine ecological disasters, originate in the southern Yellow Sea of China and obtain the highest biomass in Haizhou Bay (latitude around 35° N) during northward drift. U. prolifera shows different morphologies from southern Haizhou Bay (SH) to northern Haizhou Bay (NH). Owing to the distinct nutrient environments between SH and NH, we hypothesized that thalli in NH with poor nutrients increased the surface area to volume ratio (SA:VOL) to better absorb nutrients. Here, we tested this hypothesis by comparing the SA:VOL of thalli in SH and NH. The results showed that the thalli in NH had a lower SA:VOL than those in SH, and SA:VOL had positive relationships with temperature and nutrients, contrary to the general hypothesis. The novel results suggested that morphological differences of U. prolifera were the result of developmental state rather than environmental acclimation. Indicators of reproduction (reproductive allocation ratio) were negatively related to variation in tissue contents of C, N, P, and crude protein, whereas indicators of growth (tissue contents of C, N, P, and crude protein) showed significant positive influences on SA:VOL. The results indicated that a trade‐off relationship between reproduction and growth existed in the northward drift. All the results suggested that physiological functional traits affected morphological variation of U. prolifera in different environmental conditions during the drifting of green tides. This study presents new insights into the opportunist species nature of U. prolifera through morphological variation and associated functional consequences.

Abstract Plants generally adopt different reproductive strategies to adapt to their environments and increase their fitness. Here, we studied the effects of enclosure cultivation on the reproductive allocation of a wheatgrass species Agropyron mongolicum in the Desert steppes of Northern China. The results showed that: (a) after enclosure cultivation, the height, clump width, coverage, and clump biomass of A. mongolicum significantly increased by 78.96% (p = .040), 63.50% (p = .013), 50.89% (p = .032), and 205.38% (p = .022), respectively, whereas density did not show a significant change (p = .330). (b) Enclosure cultivation significantly affected the biomass of A. mongolicum. Compared with cultivation outside the fence, root, leaf, and spike biomass of A. mongolicum inside the fence significantly increased by 183.52% (p = .020), 334.09% (p = .011), and 381.25% (p = .005), respectively. In addition, root biomass was the highest among the components (38.53 and 13.59 g inside and outside the fence, respectively) and spike biomass was the lowest (6.16 and 1.28 g inside and outside the fence, respectively). (c) Enclosure cultivation affected elemental nutrient allocation and the caloric values of various components of A. mongolicum, and the caloric values are positively correlated with carbon, nitrogen, and phosphorus contents. Enclosure cultivation significantly reduced carbon, nitrogen, and phosphorus in the roots, as well as nitrogen and phosphorus in the spikes, but significantly increased nitrogen in the spikes by 9.78%. The caloric values of A. mongolicum inside and outside the fence in decreasing order were as follows: spikes > leaves > stems > roots. Comparison of cultivation effects between inside and outside the fence showed that the caloric values of the spikes and roots significantly increased by 0.92% and 1.60%, respectively, whereas those of the leaves significantly decreased by 0.70%. Our results demonstrate that the reproductive allocation of elemental nutrients and caloric values in nonreproductive and reproductive organs are plastic to arid environments.

Previous studies have demonstrated changes in plant growth and reproduction in response to nutrient availability, but responses of plant growth and reproduction to multiple levels of nutrient enrichment remain unclear. In this study, a factorial field experiment was performed with manipulation of nitrogen (N) and phosphorus (P) availability to examine seed production of the dominant species, Stipa krylovii, in response to N and P addition in a temperate steppe. There were three levels of N and P addition in this experiment, including no N addition (0 g N m−2 year−1), low N addition (10 g N m−2 year−1), and high N addition (40 g N m−2 year−1) for N addition treatment, and no P addition (0 g P m−2 year−1), low P addition (5 g P m−2 year−1), and high P addition (10 g P m−2 year−1) for P addition treatment. Low N addition enhanced seed production by 814%, 1371%, and 1321% under ambient, low, and high P addition levels, respectively. High N addition increased seed production by 2136%, 3560%, and 3550% under ambient, low, and high P addition levels, respectively. However, P addition did not affect seed production in the absence of N addition, but enhanced it under N addition. N addition enhanced seed production mainly by increasing the tiller number and inflorescence abundance per plant, whereas P addition stimulated it by decreasing the plant density yet stimulating height of plants and their seed number per inflorescence. Our results indicate seed production is not limited by P availability but rather by N availability in the temperate steppe, whereas seed production will be increased by P addition when N availability is improved. These findings enable a better understanding of plant reproduction dynamics in the temperate steppe under intensified nutrient enrichment and can inform their improved management in the future. [ABSTRACT FROM AUTHOR]

Patterns of resource allocation reflect the plastic strategies that result from different selective pressures imposed by the environment. However, biomass allocation can be limited by architectural restrictions that change with the plant size. Our knowledge about sex allocation in heterosporous aquatic ferns remains scarce and studies on the reproductive strategies of these plants may yield valuable information regarding the evolutionary history of heterospory. Here, we investigate resources allocation, both in number and in biomass, to produce megasporangia and microsporangia among three species of Salvinia with different body sizes. Salvinia oblongifolia, S. auriculata and S. minima were collected in temporary ponds on the floodplain of the Pandeiros River in Brazil. We counted megasporangia and microsporangia, and measured their dry mass in each ramet. We also measured the total vegetative biomass and total reproductive biomass of each ramet in each species. Resource allocation to megasporangia production is associated with the specific body size of each species. However, the allocation for microsporangia production was higher in the species with intermediate size, which probably may be related to the drought event. The total reproductive biomass of each species was not dependent on the total vegetative biomass, but despite a similar reproductive effort, species differ on which sex is prioritized in the allocation process. Our results provide the first data about the processes underlying the sex allocation of Salvinia in the floodplains. The production of sori is size dependent in each Salvinia species and is shaped by drought, an intense selective pressure in temporary wet habitats. [ABSTRACT FROM AUTHOR]

Shallow soil with low water availability, poor nutrition, and limited living space is the key limiting factor of plant growth and reproduction in vulnerable karst regions. As pioneers adapted to these areas, little is known about the reproductive responses of annual herbs to these limited soil resources. In this study, we, therefore, investigated the reproductive strategies ("fight or flight") of two annual Asteraceae herbs (Xanthium sibiricum and Bidens pilosa) growing in the harsh karst soil environment, by comprehensively considering biomass allocation, reproductive phenology, and seed production. X. sibiricum and B. pilosa were grown under three soil depths and three water availability levels in a full two-way randomized block design, then biomass allocation, initial flowering time, fruiting stage, life span and seed number and mass were examined. In X. sibiricum, reproductive allocation decreased with decreasing water availability, soil depth, and water availability + soil depth. Meanwhile, the initial flowering time, fruiting stage and life span were all delayed with moderate decreases in resources. However, in B. pilosa, reproductive allocation increased with decreasing soil resources, while initial flowering time, fruiting stage and life span remained unchanged under moderate resource decline. Under severe resource decline, both species showed a reduction in fruiting stage and life span. These results support the hypothesis that X. sibiricum tends to adopt a "fight" reproductive strategy in response to declining resources via changes in biomass allocation, reproductive phenology and seed production. In contrast, B. pilosa tends to adopt a "flight" strategy in terms of biomass allocation, while maintaining a relatively stable reproductive phenology and seed size to cope with the harsh living conditions. However, neither species coped well under severe declines in water availability, nutrition and living space. These findings help our understanding of how herbaceous plants can adjust their reproductive strategies to support their regeneration in harsh karst soil environments. [ABSTRACT FROM AUTHOR]

The sand-stabilising, xeric shrub Artemisia ordosica Krasch. has experienced widespread decline decades after being widely distributed through seeding in the Mu Us Sandy Land in China. The role of biocrusts in the decline of A. ordosica populations has received attention but has not been directly confirmed. To clarify the effects of biocrusts on shrub decline, a field study was conducted with different biocrust treatments (bare sand, lichen biocrust, moss biocrust, biocrust removed) in August 2019 in the Mu Us Sandy Land in North China. In each biocrust treatment, the age structure, dynamic indices, and reproductive allocation patterns of the A. ordosica population were determined, in addition to soil characteristics. A separate laboratory study was conducted to determine the effects of soil moisture and nutrients on seed germination. With the development of biocrust, the age structure of A. ordosica populations began to decline, but when the biocrust was removed, A. ordosica seedlings re-established. Soil moisture and nutrient contents were higher under lichen biocrust (earlier stage of biocrust development) and biocrust removal than under moss biocrust (later stage of biocrust development). In response to the adverse conditions under biocrust, A. ordosica increased reproductive output while reducing vegetative growth, thereby increasing the possibility for offspring dispersal and colonisation of new habitats. By contrast, with biocrust removal, A. ordosica reduced reproductive allocation. In addition, with the development of biocrust, soil moisture was reduced, and seed germination was limited. Thus, biocrusts are important in the decline of A. ordosica in sandy lands because of reductions in seed germination, which further suggests that moderate removal of biocrusts to improve seed germination can be key in the sustainable development of sandy land vegetation.

A central principle in trait‐based ecology is that trait variation has an adaptive value. However, uncertainty over which plant traits influence individual performance across environmental gradients may limit our ability to use traits to infer ecological processes at larger scales. To better understand which traits are linked to performance under different precipitation regimes, we measured above‐ and belowground traits, growth, and reproductive allocation for four annual and four perennial species from a coastal sage scrub community in California under conditions of 50%, 100%, and 150% ambient precipitation. Across water treatments, annual species displayed morphological trait values consistent with high rates of resource acquisition (e.g., low leaf mass per area, low root tissue density, high specific root length), and aboveground measures of resource acquisition (including photosynthetic rate and leaf N concentration) were positively associated with plant performance (reproductive allocation). Results from a structural equation model demonstrated that leaf traits explained 38% of the variation in reproductive allocation across the water gradient in annual species, while root traits accounted for only 6%. Although roots play a critical role in water uptake, more work is needed to understand the mechanisms by which root trait variation can influence performance in water‐limited environments. Perennial species showed lower trait plasticity than annuals across the water gradient and were more variable as a group in terms of trait–performance relationships, indicating that species rely on different functional strategies to respond to drought. Our finding that species identity drives much of the variation in trait values and trait–performance relationships across a water gradient may simplify efforts to model ecological processes, such as productivity, that are potentially influenced by environmentally induced shifts in trait values. [ABSTRACT FROM AUTHOR]

Body size has fundamental impacts on animal ecology and physiology but has been strongly influenced by recent climate change and human activities, such as size‐selective harvesting. Understanding the ecological and life history consequences of body size has proved difficult due to the inseparability of direct effects of body size from processes connected to it (such as growth rate and individual condition). Here, we used the cnidarian Hydra oligactis to directly manipulate body size and understand its causal effects on reproduction and senescence. We found that experimentally reducing size delayed sexual development and lowered fecundity, while post‐reproductive survival increased, implying that smaller individuals can physiologically detect their reduced size and adjust life history decisions to achieve higher survival. Our experiment suggests that ecological or human‐induced changes in body size will have immediate effects on life history and population dynamics through a growth‐independent link between body size, reproduction and senescence. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lack of fitness costs has been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N)mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. RESULTS: G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: (i) 16–60% higher reproductive allocation; (ii) longer reproduction phase through early flowering (2–7 days); (iii) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; (iv) ‘winged’ seeds with 30–70% longer sepals that facilitate long-distance seed dispersal. CONCLUSION: The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which poses challenges to contain the spread of resistance. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Much empirical data obtained across taxa is necessary to evaluate how variation in migratory costs and benefits can play a role in shaping the phenotypic and genetic patterns of reproductive investment between populations. Reproductive resources are allocated to both the size and number of eggs, and females may vary their allocation to each of these traits in response to increased movement capacity. In central regions of Japan, the rice plant skipper Parnara guttata guttata migrates in a southwesterly direction every year during late summer and early autumn ('migratory' population), but this migration is not observed in populations in southern or parts of western Japan ('resident' population). If migratory costs and benefits vary between these populations, they may cause their reproductive strategies to differ. Moreover, migration combined with a shift of reproductive allocation that evolved in one generation may influence the flight ability and patterns of reproductive allocation in the other generation in which migration has not evolved. In this study, a common-garden experiment was conducted to compare reproductive traits (egg size and number of eggs), flight ability and body size between these populations under two daylength regimes, at which different forms of adult P. g. guttata emerge. Under both daylength regimes the female adults of migratory populations had greater flight ability and tended to lay a greater number of eggs, which were on average smaller than the eggs laid by resident population females. A population-level difference in reaction norm elevation for flight ability and number of eggs was detected, but no interactions between population and daylength. The effects of the energetic cost of flight, adaptive constraints (e.g., genetic correlations and trade-offs), and the optimal strategy may explain the difference between populations of this species in the patterns of reproductive allocation to egg size and number of eggs. [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Extreme events such as extreme drought and precipitation are expected to increase in intensity and/or duration in the face of climate change. Such changes significantly affect plant productivity and the biomass allocation between reproductive and vegetation organs (i.e., reproductive allocation). Our aims are to test the effects of water addition on the trade-offs in allocation of plant biomass and whether such effects are modified by species. A manipulative experiment was conducted from May 2000 to October 2001, where four dominant plant species (i.e., Leymus chinensis, Stipa grandis, Artemisia frigida, and Potentilla acaulis) in the Inner Mongolia steppe in China were treated with 8 levels of water addition. Results demonstrated that water addition significantly affected the reproductive allocation of plants, and such effects were modified by species. Specifically, with increasing water availability, L. chinensis was not impacted, while A. frigida allocated more biomass to reproductive organs than to vegetative organs, while such allocation in S. grandis and P. acaulis first decreased, and then increased after reaching a peak. Our results indicated that plant species can adjust their reproductive allocation patterns to deal with water availability gradients. Climatic factors such as rainfall and temperature usually co-appearing, thus future research should explore the joint effects of several climate change factors on grasslands in order to maintain the health and sustainability of grasslands.

Elevation can greatly affect both intensity and duration of flooding in riparian areas, and may thus affect the performance of plants distributed therein. However, few studies have examined the performance of riparian plants over elevation difference.This study compared growth and reproductive traits of populations of the riparian species Polygonum hydropiper distributed at low and high elevations of 10 different riparian locations in the hydro-fluctuation belt of the Three Gorges Reservoir Region, China.Both the location and the interaction between location and elevation had significant effects on almost all growth and reproduction traits of P. hydropiper, suggesting that the effects of elevation varied greatly among different locations. Across all locations, high-elevation plants had significantly higher total biomass, stem biomass, root biomass, and plant height than low-elevation plants. Correspondingly, high-elevation plants also had significantly higher stem starch concentrations. In comparison, low-elevation plants had significantly lower biomass, shorter height, and thinner leaves; while they had significantly higher reproductive allocation, as well as faster germination and higher germination rate at a number of locations. Therefore, low energy consumption and high reproductive capacity could be a survival adaption of low-elevation plants to frequent and deep flooding.Local conditions and/or flooding might impose strong selection pressure on P. hydropiper, thus resulting in intra-specific differentiation. Across all locations, low- and high-elevation populations exhibit different growth and reproduction responses to different flooding regimes.

The effect of grazing on patterns of reproduction in trees has been little reported. We explored the effects of grazing intensities on reproductive growth, allocation patterns, and duration in elm trees (Ulmus pumila L.) at the Horqin Sandy Land, a degraded area in northern China. Current-year shoots were selected from branches and harvested from individual elm trees subjected to one of four grazing intensities (heavy, moderate, light, and no grazing). Shoots, flower buds, flowers, seeds, leaf buds, and leaves were collected, dried, and weighed. Results showed that the biomass in heavy, moderate and light grazing treatments is significantly higher than in no grazing treatment (P

Chile is one of five global regions exhibiting a mediterranean-type climate regime characterized by evergreen sclerophyll shrublands. These matorral shrublands which dominate the foothills and slopes of the Coastal Mountains and foothills of the Andes in central Chile have received much less study than evergreen shrublands in other mediterranean-type climate regions of the world. Phenological development, growth, and nutrient dynamics of the four widespread matorral shrub species, Lithrea caustica (Anacardiaceae), Colliguaja odorifera (Euphorbiaceae), Kageneckia oblonga (Rosaceae), and Retanilla trinervia (Rhamnaceae), were monitored in central Chile from 1971 to 1975. The four study species all demonstrated growth dynamics and nutrient relations similar to chaparral shrub species of southern California. The species exhibited a sequential development of phenological stages in leaf components following fall precipitation. Colliguaja with relatively shallow root systems showed a sharp peak of new leaf production at the beginning of summer, dropping quickly as summer drought occurred. Another shallow- rooted species while Retanilla initiated leaf production in the late winter, earlier than the other two species, and presented a growth pattern dependent on soil moisture availability. Lithrea and Kageneckia, a more deep-rooted species, initiated leaf production in late spring and continued through the summer. Overall, Chilean shrubs exhibited higher nutrient contents than those of chaparral shrubs in California, suggesting a difference in soil nutrient availability. Reproductive tissues represent a significant portion of the new biomass and nutrient allocation in all four matorral shrubs. Biomass allocation of new tissues (i.e. new leaves, new stems and reproductive tissues) ranged from 8.2% in Retanilla to 16.7% in Colliguaja. Overall, the phenology and nutrient relations of matorral shrubs were similar to those found in chaparral, shrubs indicating that the similar climate regimes can lead to convergence in leaf traits, phenology, and nutrient relationships.

The cost of reproduction hypothesis suggests that allocation to current reproduction constrains future reproduction. How organisms accrue reproductive costs and allocate energy across their lifetime may differ among species adapted to different resource types. We test this by comparing lifetime reproductive output, patterns of reproductive allocation, and senescence between two species of burying beetles, Nicrophorus marginatus and N. guttula, that differ in body size, across a range of carcass sizes. These two species of burying beetles maximized lifetime reproductive output on somewhat different–sized resources. The larger N. marginatus did better on large and medium carcasses while the smaller N. guttula did best on small and medium carcasses. For both species, reproduction is costly and reproduction on larger carcasses reduced lifespan more than reproduction on smaller carcasses. Carcass size also affected lifetime reproductive strategies. Each species’ parental investment patterns were consistent with terminal investment on carcasses on which they performed best (optimal carcass sizes). However, they exhibited reproductive restraint on carcass sizes on which they did not perform as well. Reproductive senescence occurred largely in response to carcass size. For both species, reproduction on larger carcasses resulted in more rapid senescence. These data suggest that whether organisms exhibit terminal investment or reproductive restraint may depend on type and amount of resources for reproduction.

Extreme events such as extreme drought and precipitation are expected to increase in intensity and/or duration in the face of climate change. Such changes significantly affect plant productivity and the biomass allocation between reproductive and vegetation organs (i.e., reproductive allocation). Our aims are to test the effects of water addition on the trade-offs in allocation of plant biomass and whether such effects are modified by species. A manipulative experiment was conducted from May 2000 to October 2001, where four dominant plant species (i.e., Leymus chinensis , Stipa grandis , Artemisia frigida , and Potentilla acaulis) in the Inner Mongolia steppe in China were treated with 8 levels of water addition. Results demonstrated that water addition significantly affected the reproductive allocation of plants, and such effects were modified by species. Specifically, with increasing water availability, L. chinensis was not impacted, while A. frigida allocated more biomass to reproductive organs than to vegetative organs, while such allocation in S. grandis and P. acaulis first decreased, and then increased after reaching a peak. Our results indicated that plant species can adjust their reproductive allocation patterns to deal with water availability gradients. Climatic factors such as rainfall and temperature usually co-appearing, thus future research should explore the joint effects of several climate change factors on grasslands in order to maintain the health and sustainability of grasslands. [ABSTRACT FROM AUTHOR]

Rapid evolution of traits and of plasticity may enable adaptation to climate change, yet solid experimental evidence under natural conditions is scarce. Here, we imposed rainfall manipulations (+30%, control, −30%) for 10 years on entire natural plant communities in two Eastern Mediterranean sites. Additional sites along a natural rainfall gradient and selection analyses in a greenhouse assessed whether potential responses were adaptive. In both sites, our annual target species Biscutella didyma consistently evolved earlier phenology and higher reproductive allocation under drought. Multiple arguments suggest that this response was adaptive: it aligned with theory, corresponding trait shifts along the natural rainfall gradient, and selection analyses under differential watering in the greenhouse. However, another seven candidate traits did not evolve, and there was little support for evolution of plasticity. Our results provide compelling evidence for rapid adaptive evolution under climate change. Yet, several non‐evolving traits may indicate potential constraints to full adaptation. [ABSTRACT FROM AUTHOR]