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Plants display a range of temporal patterns of inter-annual reproduction, from relatively constant seed production to mast seeding, the synchronized and highly variable interannual seed production of plants within a population. Previous efforts have compiled global records of seed production in long-lived plants to gain insight into seed production, forest and animal population dynamics, and the effects of global change on masting. Existing datasets focus on seed production dynamics at the population scale but are limited in their ability to examine community-level mast seeding dynamics across different plant species at the continental scale. We harmonized decades of plant reproduction data for 141 woody plant species across nine Long-Term Ecological Research (LTER) or long-term ecological monitoring sites from a wide range of habitats across the United States. Plant reproduction data are reported annually between 1957 and 2021 and based on either seed traps or seed and/or cone counts on individual trees. A wide range of woody plant species including trees, shrubs, and lianas are represented within sites allowing for direct community-level comparisons among species. We share code for filtering of data that enables the comparison of plot and individual tree data across sites. For each species, we compiled relevant life history attributes (e.g., seed mass, dispersal syndrome, seed longevity, sexual system) that may serve as important predictors of mast seeding in future analyses. To aid in phylogenetically informed analyses, we also share a phylogeny and phylogenetic distance matrix for all species in the dataset. These data can be used to investigate continent-scale ecological properties of seed production, including individual and population variability, synchrony within and across species, and how these properties of seed production vary in relation to plant species traits and environmental conditions. In addition, these data can be used to assess how annual variability in seed production is associated with climate conditions and how that varies across populations, species, and regions. The dataset is released under a CC0 1.0 Universal public domain license.

In communities characterized by periodic pulses of food availability, the relationship between resource peaks and the timing of reproduction among consumers is of paramount importance for the survival of offspring. In certain instances, they may give birth to juveniles well before the peak of food availability, prioritizing optimal conditions for juveniles over mature females. The species that can cope with masting periods in temperate broad-leaved forests through different reproductive mechanisms is the edible dormouse. It can start reproduction long before the maturation of the main types of fattening foods – beech nuts or acorns. During this study, in an oak-dominated forest in the years when acorns are almost absent, dormice exhibited anticipatory reproduction in response to an alternative food source: hazelnuts. Through precise tracking of food availability during the early stages of maturation, dormice reproduced long before the ripening of nuts in mast years. Surprisingly, parturition occurred even earlier than during years with abundant acorn crops. No significant differences in litter size were observed. The nutritional value of hazelnuts for successful reproduction was indirectly validated through amino acid analyses of both food types. Any amino acid peculiar for any seeds or its extreme content was not found. Content of some of them was even higher in the nuts. This synchronization of the growth of offspring with seed ripening ensures maximal food abundance when litters disperse, a time when juveniles are most vulnerable. [ABSTRACT FROM AUTHOR]

Reproduction by perennial plants varies from being relatively constant over years to the production of massive and synchronous seed crops at irregular intervals, a reproductive strategy called mast seeding. The sources of interspecific differences in the extent of interannual variation in seed production are largely unknown. We conducted a global meta‐analysis of animal‐dispersed species to quantify how the interannual variability in seed crops produced by plants can be explained by the seed mass, dispersal mode, phylogeny, and climate. Phylogenetic analysis indicated that the interannual variations in seed production and seed mass tended to be similar in related species due to their shared evolution. The interannual variation in seed production was 1.22 times higher in synzoochorous species dispersed by scatter‐hoarders compared with endozoochorous species dispersed by frugivores. Furthermore, the production of small seeds was associated with higher interannual variation in seed production, although synzoochorous species produced larger seeds than endozoochorous species. Precipitation rather than temperature had a significant positive effect on the interannual variation in seed production. The seed mass and dispersal mode contributed more to the interannual variation in seed production than phylogeny, climate, and fruit type. Our findings support a long‐standing hypothesis that interspecific variation in the masting intensity is largely shaped by interactions between plants and animals. [ABSTRACT FROM AUTHOR]

Summary: Resource storage is a critical component of plant life history. While the storage of nonstructural carbohydrates in wood has been studied extensively, the multiple functions of mineral nutrient storage have received much less attention. Here, we highlight the size of wood nutrient pools, a primary determinant of whole‐plant nutrient use efficiency, and a substantial fraction of ecosystem nutrient budgets, particularly tropical forests. Wood nutrient concentrations also show exceptional interspecific variation, even among co‐occurring plant species, yet how they align with other plant functional traits and fit into existing trait economic spectra is unclear. We review the chemical forms and location of nutrient pools in bark and sapwood, and the evidence that nutrient remobilization from sapwood is associated with mast reproduction, seasonal leaf flush, and the capacity to resprout following damage. We also emphasize the role wood nutrients are likely to play in determining decomposition rates. Given the magnitude of wood nutrient stocks, and the importance of tissue stoichiometry to forest productivity, a key unresolved question is whether investment in wood nutrients is a relatively fixed trait, or conversely whether under global change plants will adjust nutrient allocation to wood depending on carbon gain and nutrient supply. [ABSTRACT FROM AUTHOR]

Understanding the diversity and causes of senescence patterns in the wild remains a challenging task, in particular among fast‐living species for which senescence patterns have been poorly studied. Early life environmental conditions can shape senescence by influencing trade‐offs between early and late life performance (disposable soma theory) or individual fitness through lifelong positive effects (silver spoon effects).Using a 23‐year‐long monitoring dataset of two populations of Siberian flying squirrels (Pteromys volans L.) in western Finland, we analysed the occurrence, onset and rate of senescence in female survival, body mass and reproductive performance. We also examined how early life pulsed resources (tree masting during the year of birth) influence age‐specific variations in these traits.Our results indicate that survival senescence occurs after sexual maturity from 3 years of age. Females experiencing high resource availability at birth tended to survive better, but the age‐specific trend was not affected by early life resource conditions. Maternal body mass declined slightly with age, starting at 4 years, regardless of early resource conditions. Similarly, among reproductive traits, we showed late‐onset senescence in both litter size and annual reproductive probability, with no evidence supporting an effect of early life resources on these trends. We found no decline in juvenile body mass or in the juvenile size‐number trade‐off with maternal age.Our findings suggest that pulsed resources experienced at birth have a limited long‐lasting impact on the life‐history traits of this fast‐living rodent, with no significant effect on senescence patterns. [ABSTRACT FROM AUTHOR]

Pollen limitation has a considerable influence on forest masting, the highly variable and synchronised seed production, on which forest regeneration and ecosystem dynamics largely rely. Depending on the various mechanisms possibly involved in pollen limitation, the consequences of climate change on masting could be very different. These mechanisms were investigated in 10 oak populations along a climatic gradient using surveys of airborne pollen and fruiting rate as a proxy of pollen limitation. We found no support for the widely accepted hypothesis of the intra‐annual synchrony of flower phenology when considered in isolation. Instead, the fruiting rate was largely explained by a combination of intra‐annual flower phenology synchrony, annual investment in flowering and the effects of weather on pollen maturation and diffusion. These findings highlight the need for a cohesive theoretical framework for pollen limitation to accurately predict the impact of climate change on oak‐dominated ecosystems. [ABSTRACT FROM AUTHOR]

Aim: The assembly of species into communities and ecoregions is the result of interacting factors that affect plant and animal distribution and abundance at biogeographic scales. Here, we empirically derive ecoregions for mammals to test whether human disturbance has become more important than climate and habitat resources in structuring communities. Location: Conterminous United States. Time Period: 2010–2021. Major Taxa Studied: Twenty‐five species of mammals. Methods: We analysed data from 25 mammal species recorded by camera traps at 6645 locations across the conterminous United States in a joint modelling framework to estimate relative abundance of each species. We then used a clustering analysis to describe 8 broad and 16 narrow mammal communities. Results: Climate was the most important predictor of mammal abundance overall, while human population density and agriculture were less important, with mixed effects across species. Seed production by forests also predicted mammal abundance, especially hard‐mast tree species. The mammal community maps are similar to those of plants, with an east–west split driven by different dominant species of deer and squirrels. Communities vary along gradients of temperature in the east and precipitation in the west. Most fine‐scale mammal community boundaries aligned with established plant ecoregions and were distinguished by the presence of regional specialists or shifts in relative abundance of widespread species. Maps of potential ecosystem services provided by these communities suggest high herbivory in the Rocky Mountains and eastern forests, high invertebrate predation in the subtropical south and greater predation pressure on large vertebrates in the west. Main Conclusions: Our results highlight the importance of climate to modern mammals and suggest that climate change will have strong impacts on these communities. Our new empirical approach to recognizing ecoregions has potential to be applied to expanded communities of mammals or other taxa. [ABSTRACT FROM AUTHOR]

Following a resource pulse, animals may finance reproduction by consuming concurrently available resources (income breeding) or by storing resources for future reproduction (capital breeding). Understanding how these reproductive strategies are used is important for determining the ecological mechanisms that structure timing of reproduction and that drive interannual population fluctuations in animals.We gathered a reproductive dataset for five small mammal species over a 12‐year period in Northeastern USA during which six masting events of American beech (Fagus grandifolia) and eastern hemlock (Tsuga canadensis) occurred. Masting created alternate years where seeds were either available late (masting year) or early (cached from the previous year) in the breeding season. The small mammal species differed in reliance on seeds and overwintering strategies. We quantified the diet using stable isotopes and recorded reproduction timing, proportion breeding and litter size in females and testes size in males.Timing of seed availability minimally affected litter size but strongly affected proportion breeding and timing of reproduction. During masting years (late seed availability), a higher proportion of females reproduced, with breeding taking place later in the season (lactation timed with peak seed availability), although the delay was restricted in Napaeozapus insignis, an obligate hibernator. After a fall mast, cached seeds were used as capital in the following spring (early seed availability) to support a litter that, depending on the species, occurred 24–79 days sooner than a mast year. No late‐season reproduction occurred in years with early seed availability except for Myodes gapperi which produced a second litter, likely financed by fungal consumption. Males also showed strong responses to seed availability, mirroring female reproduction with testes size staying constant in years with late seed availability and sharply decreasing over the breeding season in years with early seed availability.Our results highlight that although photoperiod and temperature broadly set bounds of the breeding season in temperate environments, resource availability influences the reproductive strategies that species use, which in turn alters reproductive timing and can drive large inter‐annual population fluctuations. Differences in overwintering strategies and diet may further modulate reproductive timing and output relative to resource pulses. [ABSTRACT FROM AUTHOR]

Acorn production in oaks (Quercus spp.) shows considerable inter-annual variation, known as masting. The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculate oak (Quercus robur L.) in an ancient mixed woodland during two moderate masting years. Comparisons were made between natural pollination, hand pollinations with out-of-stand pollen, in-stand pollen or a 1:1 combination of the two pollen sources, and for bagged flowers left unpollinated. After all treatments, > 85% of the flowers or developing acorns were aborted between May and August of both years. When flowers were protected with pollen bags and no pollen added, no acorns were produced. In contrast, hand pollination with out-of-stand pollen produced the most acorns both years and significantly more than within-stand pollen or natural pollination in 2022. Hand pollination with out-of-stand or within-stand pollen provided significantly more acorns than natural pollination in 2023. In 2022, hand pollination with a 1:1 mixture of out-of-stand and within-stand pollen yielded an intermediate number of mature acorns between those for the out-of-stand and within-stand pollination treatments. The study provides clear evidence of maternal choice during acorn development in pedunculate oak and of the benefits of pollen supplementation. It also confirms that pedunculate oak is a fruit-maturation masting species; abortion of pollinated flowers and immature acorns determines a mast year (rather than the number of flowers produced) at this site. [ABSTRACT FROM AUTHOR]

Plants display a range of temporal patterns of inter‐annual reproduction, from relatively constant seed production to “mast seeding,” the synchronized and highly variable interannual seed production of plants within a population. Previous efforts have compiled global records of seed production in long‐lived plants to gain insight into seed production, forest and animal population dynamics, and the effects of global change on masting. Existing datasets focus on seed production dynamics at the population scale but are limited in their ability to examine community‐level mast seeding dynamics across different plant species at the continental scale. We harmonized decades of plant reproduction data for 141 woody plant species across nine Long‐Term Ecological Research (LTER) or long‐term ecological monitoring sites from a wide range of habitats across the United States. Plant reproduction data are reported annually between 1957 and 2021 and based on either seed traps or seed and/or cone counts on individual trees. A wide range of woody plant species including trees, shrubs, and lianas are represented within sites allowing for direct community‐level comparisons among species. We share code for filtering of data that enables the comparison of plot and individual tree data across sites. For each species, we compiled relevant life history attributes (e.g., seed mass, dispersal syndrome, seed longevity, sexual system) that may serve as important predictors of mast seeding in future analyses. To aid in phylogenetically informed analyses, we also share a phylogeny and phylogenetic distance matrix for all species in the dataset. These data can be used to investigate continent‐scale ecological properties of seed production, including individual and population variability, synchrony within and across species, and how these properties of seed production vary in relation to plant species traits and environmental conditions. In addition, these data can be used to assess how annual variability in seed production is associated with climate conditions and how that varies across populations, species, and regions. The dataset is released under a CC0 1.0 Universal public domain license. [ABSTRACT FROM AUTHOR]

Quantifying how global change impacts wild populations remains challenging, especially for species poorly represented by systematic datasets. Here, we infer climate change effects on masting by Joshua trees (Yucca brevifolia and Y. jaegeriana), keystone perennials of the Mojave Desert, from 15 years of crowdsourced observations. We annotated phenophase in 10,212 geo‐referenced images of Joshua trees on the iNaturalist crowdsourcing platform, and used them to train machine learning models predicting flowering from annual weather records. Hindcasting to 1900 with a trained model successfully recovers flowering events in independent historical records and reveals a slightly rising frequency of conditions supporting flowering since the early 20th Century. This reflects increased variation in annual precipitation, which drives masting events in wet years—but also increasing temperatures and drought stress, which may have net negative impacts on recruitment. Our findings reaffirm the value of crowdsourcing for understanding climate change impacts on biodiversity. [ABSTRACT FROM AUTHOR]

Climate change effects on tree reproduction are poorly understood, even though the resilience of populations relies on sufficient regeneration to balance increasing rates of mortality. Forest‐forming tree species often mast, i.e. reproduce through synchronised year‐to‐year variation in seed production, which improves pollination and reduces seed predation. Recent observations in European beech show, however, that current climate change can dampen interannual variation and synchrony of seed production and that this masting breakdown drastically reduces the viability of seed crops. Importantly, it is unclear under which conditions masting breakdown occurs and how widespread breakdown is in this pan‐European species. Here, we analysed 50 long‐term datasets of population‐level seed production, sampled across the distribution of European beech, and identified increasing summer temperatures as the general driver of masting breakdown. Specifically, increases in site‐specific mean maximum temperatures during June and July were observed across most of the species range, while the interannual variability of population‐level seed production (CVp) decreased. The declines in CVp were greatest, where temperatures increased most rapidly. Additionally, the occurrence of crop failures and low seed years has decreased during the last four decades, signalling altered starvation effects of masting on seed predators. Notably, CVp did not vary among sites according to site mean summer temperature. Instead, masting breakdown occurs in response to warming local temperatures (i.e. increasing relative temperatures), such that the risk is not restricted to populations growing in warm average conditions. As lowered CVp can reduce viable seed production despite the overall increase in seed count, our results warn that a covert mechanism is underway that may hinder the regeneration potential of European beech under climate change, with great potential to alter forest functioning and community dynamics. [ABSTRACT FROM AUTHOR]

Summary: Many trees exhibit masting – where reproduction is temporally variable and synchronous over large areas. Several dominant masting species occur in tropical cyclone (TC)‐prone regions, but it is unknown whether TCs correlate with mast seeding.We analyzed long‐term data (1958–2022) to test the hypothesis that TCs influence cone production in longleaf pine (Pinus palustris). We integrate field observations, weather data, satellite imagery, and hurricane models to test whether TCs influence cone production via: increased precipitation; canopy density reduction; and/or mechanical stress from wind.Cone production was 31% higher 1 yr after hurricanes and 71% higher after 2 yr, before returning to baseline levels. Cyclone‐associated precipitation was correlated with increased cone production in wet years and cone production increased after low‐intensity winds (≤ 25 m s−1) but not with high‐intensity winds (> 25 m s−1).Tropical cyclones may stimulate cone production via precipitation addition, but high‐intensity winds may offset any gains. Our study is the first to support the direct influence of TCs on reproduction, suggesting a previously unknown environmental correlate of masting, which may occur in hurricane‐prone forests world‐wide. See also the Commentary on this article by Pearse & Wion, 242: 8–9. [ABSTRACT FROM AUTHOR]

European beech (Fagus sylvatica L.) is characterized by inter-annual cycles of seed production (masting), with synchronized high seed production between sites in some years. The importance of both seed quantity and quality monitoring stems from its role in sustaining the ecological balance, promoting biodiversity, and ensuring the long-term viability of forest ecosystems. This study aimed to (1) describe seed production from 2015 to 2022, (2) identify the potential factors that could affect the yield appearance and seed quantity, and (3) compare the quality of beechnuts from different crop years in Croatia. At each of the six forest seed objects located in the area of forest administrations Bjelovar, Karlovac, Ogulin, Požega, and Delnice, we selected 5 trees for seed collection. Seeds were collected with large PVC nets covering total projection area of the tree crowns. Seed quality testing was performed according to the International Rules for Seed Testing (ISTA Rules). Our results indicate a consistent biennial beechnut cycle. The crop was completely absent in 2015, 2017, 2019 and 2020, while 2016, 2018, 2020 and 2022 were fruitful years. Weather plays a key role in triggering masting. We found that beechnut production is influenced by summer weather conditions (from June to August) in the previous two years. Abundance of beechnut production varies on an annual level, population level and on individual trees. Factors that partially explain the variability in yield are tree height and crown size. No significant differences in viability were found across different years and sites, though the results should be approached with caution due to limited sample representation. The study identified a positive correlation between seed weight and viability, as well as the impact of precipitation on moisture content. The results emphasize the need for continued monitoring and further research to understand the factors influencing beechnut production and quality, crucial for sustainable forest management in the face of climate change.

Many plant species worldwide are dispersed by scatter-hoarding granivores: animals that hide seeds in numerous, small caches for future consumption. Yet, the evolution of scatter-hoarding is difficult to explain because undefended caches are at high risk of pilferage. Previous models have attempted to solve this problem by giving cache owners large advantages in cache recovery, by kin selection, or by introducing reciprocal pilferage of 'shared' seed resources. However, the role of environmental variability has been so far overlooked in this context. One important form of such variability is masting, which is displayed by many plant species dispersed by scatterhoarders. We use a mathematical model to investigate the influence of masting on the evolution of scatter-hoarding. The model accounts for periodically varying annual seed fall, caching and pilfering behaviour, and the demography of scatterhoarders. The parameter values are based mostly on research on European beech (Fagus sylvatica) and yellow-necked mice (Apodemus flavicollis). Starvation of scatterhoarders between mast years decreases the population density that enters masting events, which leads to reduced seed pilferage. Satiation of scatterhoarders during mast events lowers the reproductive cost of caching (i.e. the cost of caching for the future rather than using seeds for current reproduction). These reductions promote the evolution of scatter-hoarding behaviour especially when interannual variation in seed fall and the period between masting events are large. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.

Abstract Biology has an increasing need to reconsider the tools used to assess the variability of measurements, in addition to their central tendency. More than 100 years after Pearson's publication, most biologists still use the “good old” Pearson's coefficient of variation, PCV, despite its documented flaws such as sensitivity to excess zero values and/or irrelevant low mean values, which may compromise its use in some biological applications. A new statistic was developed in 2017 by Kvålseth, KCV, which is easy to implement. Unlike PCV, KCV is bounded (between 0 and 1), and it can be computed from PCV, ensuring backward compatibility with past studies. In addition to simulated data, we used the recent MASTREE+ database comprising the time series of the fruiting dynamics of perennial plants worldwide to compare the properties of PCV and KCV. Using as a benchmark the loose hump‐shaped relationship between the interannual variability of fruiting and latitude, KCV led to significant increase in statistical power as it required almost half as many time series as PCV to detect the relationship. Perhaps most importantly, simulated data showed that KCV allows huge reductions in the length of time series required to estimate the population true variability, saving more than half the duration of long‐term monitoring if fruiting fluctuations are very large, which is common in perennial plant species. Compared to the widely used PCV, KCV has great accuracy for estimating and analysing variability in biology, while strongly increasing statistical power. Selecting appropriate tools to assess the variability of measurements is crucial, particularly where the variability is of primary biological interest. Using Kvålseth's KCV is a promising avenue to circumvent the well‐known issues of the former Pearson’ PCV, its properties remain to be explored in other fields of biology, for purposes other than purely statistical ones (e.g. estimating heritability or evolvability of traits).

Mast seeding is the episodic, massive production of plant seeds synchronized over large areas. The resulting superabundance of seeds represents a resource pulse that can profoundly affect animal populations across trophic levels. Following years of high seed production, the abundance of both seed consumers and their predators increase. Higher predator abundance leads to increased predation pressure across the trophic web, impacting nonseed consumers such as the wood warbler Phylloscopus sibilatrix through increased nest predation after tree mast years. Over the past 30 years, the frequency of tree seed masts has increased, while wood warbler populations have declined in several regions of Europe. We hypothesized that increasing mast frequencies may have contributed to the observed population declines by creating suboptimal breeding conditions in years after masting. We measured reproductive output in four study areas in central Europe, which was between 0.61 and 1.24 fledglings lower in the years following masting than nonmasting. For each study area, we used matrix population models to predict population trends based on the estimated reproductive output and the local mast frequencies. We then compared the predicted with the observed population trends to assess if the frequency of mast years had contributed to the population dynamics. In Wielkopolska National Park (PL) and Hessen (DE), masting occurred on average only every 4 years and populations were stable or nearly so, whereas in Jura (CH) and Białowieża National Park (PL), masting occurred every 2 and 2.5 years, respectively, and populations were declining. The simple matrix population models predicted the relative difference among local population trends over the past 10–20 years well, suggesting that the masting frequency may partly explain regional variation in population trends. Simulations suggest that further increases in mast frequency will lead to further declines in wood warbler populations. We show that changes in a natural process, such as mast seeding, may contribute to the decline in animal populations through cascading effects. [ABSTRACT FROM AUTHOR]

Restoring valuable timber trees is a necessary part of regaining many ecosystem services and products provided by degraded tropical forests. However, knowledge of seed production, a regeneration prerequisite, is limited for many tropical timber tree species. We studied the fruit production of African mahogany (Khaya anthotheca) in a semi-deciduous rainforest in East Africa, to provide information for ecological restoration programs. First, we quantified population variability and synchrony in fruit production. Then, we assessed how reproductive status and output were influenced by tree size, neighbourhood crowding, exchangeable cations, liana presence, and crown exposure. We found fruit production at the population level was weakly synchronised, with high interannual variability at the population and individual levels. Tree size determined reproductive status. Individual quantity of fruit produced increased with tree size but decreased with neighbourhood crowding. Our results indicate that K. anthotheca does not meet the criteria for mast fruiting. Our findings suggest that reproductive output in mahogany is regulated by tree size and competition. In addition to active protection, thinning to reduce competition around seed trees may boost fruit production at the individual tree level to provide seed for forest enrichment. [ABSTRACT FROM AUTHOR]

Increasing evidence indicates that tree growth processes, including reproduction, can be either sink- or source-limited, or simultaneously co-limited by sink and source, depending on the interplay between internal and environmental factors. We tested the hypothesis that the relative strengths of photosynthate supply and demand by stem growth and reproduction create variable competition for substrate that is imprinted in the tree-ring isotopes (C and O) of stone pine (Pinus pinea L.), a masting gymnosperm with large costs of reproduction, under warming-induced drought. Across five representative stands of the Spanish Northern Plateau, we also identified reproductive phases where weather drivers of cone yield (CY) have varied over a 60-year period (1960–2016). We found that these drivers gradually shifted from winter–spring conditions 3 years before seed rain (cone setting) to a combination of 3- and 1-year lagged effects (kernel filling). Additionally, we observed positive regional associations between carbon isotope discrimination (Δ13C) of the year of kernel filling and CY arising at the turn of this century, which progressively offset similarly positive relationships between Δ13C of the year of cone setting and CY found during the first half of the study period. Altogether, these results pinpoint the increasing dependence of reproduction on fresh assimilates and suggest sink and source co-limitation superseding the sink-limited functioning of reproduction dominant before 2000. Under climate warming, it could be expected that drier conditions reinforce the role of source limitation on reproduction and, hence, on regeneration, forest structure and economic profit of the nutlike seeds of the species. [ABSTRACT FROM AUTHOR]

The natural regeneration of the temperate oak forests is often insufficient. Acorns of the oak serve as the basis of the recruitment and key food resources in these ecosystems, thus the crop size, the germination success and seed predators have crucial roles in the process. Wild boar (Sus scrofa) is often considered as one of the main mitigating agents in oak regeneration. Therefore, in our study we analyzed and compared the spatial patterns of the acorn density and the patches rooted by wild boar within and among the different examined time intervals in a 28 ha Turkey-sessile oak (Quercus cerris, Q. petraea) forest stand. Data were collected between 2016 October and 2019 December. In the acorn density patterns, intra-annual similarities were recognized mainly, regardless of the crop size. Meanwhile, rooting patterns showed inter- and intra-annual similarities in mast years and intra-annual overlaps in non-mast years, indicating that masting is a fundamental driver of wild boar foraging behavior. However, a direct local connection between the rooting intensity and the acorn density could not be shown, as wild boars never fully depleted the acorns, even in intensively used patches. This study can help in predicting the intensively rooted forest patches, providing opportunities to manage wildlife conflicts. [ABSTRACT FROM AUTHOR]

Soluble sugars have multiple functions in plants and both their absolute and relative abundances may vary in association with diverse physiological processes and life‐history events. Some also have specific functions in different organs that vary seasonally. Therefore, studying the dynamics of sugar compositions in woody species would further our understanding of their functions, which has been mainly analyzed en bloc. In order to elucidate the functions of specific soluble sugars and the effects of reproduction on their profile, we monitored the soluble sugar composition in "new" (current‐year) and "old" (1–3 years old) branches of Fagus crenata for 7 years, which included three reproduction ("masting") events. As well as the generally predominant sugar species (sucrose, glucose, and fructose), substantial amounts of raffinose (accounting for up to 42% of the total sugars) were found in both new and old branches during winter hardening. In addition, myo‐inositol (which plays important roles in cell growth and development) was detected mainly during the early growing season and fluctuated interannually in both new and old branches. Furthermore, the only clear change in soluble sugar contents associated with reproduction events was in myo‐inositol concentrations in the new branches, which were lower in fruiting trees than in non‐fruiting trees, possibly due to the growth reduction in fruiting tree branches identified in previous studies. The results show the importance of considering the dynamics of each sugar component, rather than en bloc, in attempts to elucidate their roles in physiological processes and responses to environmental changes. [ABSTRACT FROM AUTHOR]

Biology has an increasing need to reconsider the tools used to assess the variability of measurements, in addition to their central tendency. More than 100 years after Pearson's publication, most biologists still use the "good old" Pearson's coefficient of variation, PCV, despite its documented flaws such as sensitivity to excess zero values and/or irrelevant low mean values, which may compromise its use in some biological applications.A new statistic was developed in 2017 by Kvålseth, KCV, which is easy to implement. Unlike PCV, KCV is bounded (between 0 and 1), and it can be computed from PCV, ensuring backward compatibility with past studies. In addition to simulated data, we used the recent MASTREE+ database comprising the time series of the fruiting dynamics of perennial plants worldwide to compare the properties of PCV and KCV.Using as a benchmark the loose hump‐shaped relationship between the interannual variability of fruiting and latitude, KCV led to significant increase in statistical power as it required almost half as many time series as PCV to detect the relationship. Perhaps most importantly, simulated data showed that KCV allows huge reductions in the length of time series required to estimate the population true variability, saving more than half the duration of long‐term monitoring if fruiting fluctuations are very large, which is common in perennial plant species. Compared to the widely used PCV, KCV has great accuracy for estimating and analysing variability in biology, while strongly increasing statistical power.Selecting appropriate tools to assess the variability of measurements is crucial, particularly where the variability is of primary biological interest. Using Kvålseth's KCV is a promising avenue to circumvent the well‐known issues of the former Pearson' PCV, its properties remain to be explored in other fields of biology, for purposes other than purely statistical ones (e.g. estimating heritability or evolvability of traits). [ABSTRACT FROM AUTHOR]

Bambusoideae is a taxon of mass‐flowering monocarpic perennials with a long life cycle. Forest ecosystems are affected by Bambusoideae seeding and death events in various ways, including an increased abundance of Apodemus spp. The utilization and preference of dwarf bamboo seeds over tree seeds by field mice remain elusive. Therefore, we aimed to determine whether field mice prefer dwarf bamboo to tree seeds. We examined one dwarf bamboo species (Sasa borealis) against four tree species with varying acorn/fruit traits (Castanea crenata, Quercus crispula, Fagus crenata, and Lindera triloba). The seeds were placed in a container in a forest among dead S. borealis culms, with an automatic camera monitoring the setup. The examined seeds were mainly foraged by two field mouse species, Apodemus speciosus and Apodemus argenteus, with preference in the following order: C. crenata, L. triloba, S. borealis, F. crenata, and Q. crispula. Our findings indicated that during S. borealis mast seeding years, predation pressure on F. crenata and Q. crispula seeds could be considerably reduced. This suggests that mast seeding might disrupt the normal pattern of survival, and seed dispersal patterns, potentially altering the forest vegetation composition. [ABSTRACT FROM AUTHOR]

The timing of flowering and fruiting plays a critical role in the reproduction, population size, and range of fruit-eating animals. The Hainan Tropical Rainforest National Park, China, hosts one of the world's most endangered primate species, the Hainan gibbon (Nomascus hainanus). Understanding the phenological patterns of the principal food sources of the Hainan gibbon is crucial for the effective management of their habitats and the conservation of this threatened population. To that end, we conducted a regression analysis to better understand how climate may impact the timing and availability of fruits known to support the Hainan gibbon. We observed significant seasonal and inter-annual variations in the reproductive phenology of these fruiting species, with most species flowering from March to June and fruiting from August to December. Importantly, we found that Hainan gibbons face severe food scarcity between January and April. We show that sunshine exerts a significant effect on the flowering time, while fruiting phenology is most sensitive to temperature. We suggest that the restoration of the Hainan gibbon habitat should include planting more tree species which that produce fruit in the time of low food availability between January-April, including the species Memecylon ligustrifolium, Wrightia pubescens, Sarcosperma laurinum, Eurya ciliata, and Pouteria annamensis. [ABSTRACT FROM AUTHOR]

Abstract Pulsed resources have prominent effects on community and ecosystem dynamics; however, there is little research on how resource pulses affect human–wildlife interactions. Tree masting is a common type of pulsed resource that represents a crucial food for many species and has important bottom‐up effects in food webs. In anthropogenic landscapes, years of food shortage after mast years can have negative outcomes for both people and wildlife, for instance when an increased use of anthropogenic foods by animals exacerbates human–wildlife conflicts. Here, we used novel remote sensing indicators of forest productivity and phenology, together with weather cues and ground measures of mast production, to assess whether years of masting and crop failures lead to changes in human–wildlife conflict occurrence. We used a unique 14‐year dataset including the production of European beech Fagus sylvatica seeds and brown bear Ursus arctos damage in the northeastern Carpathians as our model system. Linking these data in a panel regression framework, we found that temporal fluctuations in damage occurrence were sensitive to the year‐to‐year variation in beechnut production. Specifically, the number of damages during bear hyperphagia (i.e., September to December, when bears need to accumulate fat reserves prior to hibernation) was significantly higher in years with low beechnut production than in normal or mast years. Furthermore, we provide evidence that beech masting and failure can be predicted through a combination of remote‐sensing, weather, and field indicators of forest productivity and phenology. We demonstrate how pulsed resources, such as tree masting, can percolate through food webs to amplify human–wildlife conflict in human‐dominated landscapes. Given the recent range expansion of large carnivores and herbivores in many regions, including Europe, predicting years of natural food shortage can provide a pathway to proactive damage prevention, and thus to foster coexistence between wildlife and people.

Trees must allocate resources to core functions like growth, defense, and reproduction. These allocation patterns have profound effects on forest health, yet little is known about how core functions trade off over time, and even less is known about how a changing climate will impact tradeoffs. We conducted a 21‐year survey of growth, defense, and reproduction in 80 ponderosa pine individuals spanning eight populations across environmental gradients along the Colorado Front Range, USA. We used linear mixed models to describe tradeoffs among these functions and to characterize variability among and within individuals over time. Growth and defense were lower in years of high cone production, and local drought conditions amplified year‐to‐year tradeoffs between reproduction and growth, where trees located at sites with hotter and drier climates showed stronger tradeoffs between reproduction and growth. Our results support the environmental stress hypothesis of masting, which predicts that greater interannual variation in tree functions will be associated with more marginal environments, such as those that are prone to drought. With warming temperatures and increased exposure to drought stress, trees will be faced with stronger interannual tradeoffs, which could lead to further decreases in growth and defensive efforts, ultimately increasing risks of mortality. [ABSTRACT FROM AUTHOR]

Summary: Interannual variability of seed production, known as masting, has far‐reaching ecological impacts including effects on forest regeneration and the population dynamics of seed consumers. Because the relative timing of management and conservation efforts in ecosystems dominated by masting species often determines their success, there is a need to study masting mechanisms and develop forecasting tools for seed production. Here, we aim to establish seed production forecasting as a new branch of the discipline. We evaluate the predictive capabilities of three models – foreMast, ΔT, and a sequential model – designed to predict seed production in trees using a pan‐European dataset of Fagus sylvatica seed production. The models are moderately successful in recreating seed production dynamics. The availability of high‐quality data on prior seed production improved the sequential model's predictive power, suggesting that effective seed production monitoring methods are crucial for creating forecasting tools. In terms of extreme events, the models are better at predicting crop failures than bumper crops, likely because the factors preventing seed production are better understood than the processes leading to large reproductive events. We summarize the current challenges and provide a roadmap to help advance the discipline and encourage the further development of mast forecasting. [ABSTRACT FROM AUTHOR]

Tabernaemontana rotensis (Kaneh.) P. T. Li is an attractive small tree that is endemic to the islands of Guam and Rota. Conservation efforts of the threatened population are constrained by lack of research. Understanding the ecology of flower and fruit development is fundamental to successful conservation of threatened angiosperms. This study determined the extent of flower induction following tropical cyclone defoliation, tested the efficacy of 10% urea sprays as a defoliant to induce flowering, and quantified the resulting fruit expansion to determine ontogeny traits. A total of 512 inflorescences were observed, half following tropical cyclones and half following defoliation with urea. Fruit length was measured every five to seven days until seed dispersal. The mean length of time between defoliation and initial flower anthesis was 29 days, and did not differ between tropical cyclone defoliation and urea solution aerosol defoliation. Four stages of observable fruit development were identified following anthesis. Linear increases in ovary length occurred for two weeks, maximum ovary length occurred at about day 30, color break from green to orange began at about day 60, and seed dispersal occurred at about day 90. Defoliation treatment did not influence the timing of these stages. The results indicated that tropical cyclone and urea solution defoliation consistently generated mast flowering after about one month with mast seeding about three months later. Conservationists may use this new knowledge to predictably schedule seed harvests at about four months following a natural or anthropogenic defoliation event. Many Tabernaemontana species are exploited for traditional medicine, and the use of defoliation to manipulate phenology of these species may benefit the practitioners of this trade. [ABSTRACT FROM AUTHOR]

Bambusoideae are well-known for their large-scale flowering, seeding, and death events that occur after a vegetative phase that can often last for decades. These events are a valuable resource for many animals. Their mast seeding, in particular, affects rodent populations although the causal relationship between them is speculative. Moreover, the species of animals that utilize this resource also remains unclear. Therefore, this study aimed to examine the interaction between mast seeding plants and animals by conducting a feeding test using the seeds of a dwarf bamboo species (Sasa borealis) at different seasons and in different forest types. The results revealed that two mouse species, Apodemus speciosus and A. argenteus, utilized the seeds. They both predated as well as removed and sometimes buried the seeds, exhibiting small-seed caching behavior. Furthermore, A. speciosus was found to exhibit higher seed predation at covered sites and switching to removal behavior at the more exposed, open sites, while A. argenteus showed no distinguishable trends. Additionally, A. speciosus utilized the seeds less frequently in fall than in summer, suggesting a shift in diet towards acorns when available. Collectively, the results of this study provide novel insights into the interaction between mast seeding plants and the animals that utilize them.

Reproduction in an uncertain world is fraught. The consequences of investing in too many offspring in a resource poor season can be disastrous but so too is missing the opportunity of a resource rich year. We consider a simple population and individual growth model and use Lyapunov exponents to find analytical results for the optimum brood size under stochastic environmental conditions. We show that if the environment shows dramatic changes between breeding seasons choosing a smaller brood size is more likely to be successful but the best strategy is to synchronize your reproduction to the food availability. Finally, we show that if the cost of having offspring is high it can be better to live in a highly varying world with a plastic strategy that synchronizes to the environment than to live in a deterministic world with a constant strategy, a finding with implications for invasive species and climate change.

Range boundaries are long‐term biogeographic features of species distributions and abundance. However, many species demonstrate dynamic range boundaries, reflecting strong seasonal and annual variability in migratory behaviour.As a form of facultative migration, irruptions involve the movement of many individuals outside of their resident range in response to climate variability, resource availability, and demographic processes. Many species have experienced range shifts and altered phenology in response to modern climate change, but spatiotemporal changes in irruption dynamics are less well known.We quantified changes in the geography and periodicity of boreal bird irruptions across eastern North America from 1960 to 2021. Using data from Audubon's Christmas Bird Count for nine finch species, including several exhibiting recent population declines, we evaluated latitudinal trends in southern range and irruption boundaries and characterized irruption periodicity using spectral wavelet analysis.Six boreal birds exhibited significant northward shifts in their southern range boundaries and three species displayed shifts in their southern irruption boundaries.Irruption periodicity across multiple species was consistent across the 1960s and 1970s, culminating in frequent and synchronized irruptions of multiple species (superflights) during earlier decades. Coherence between species dampened beginning in the early 1980s as superflight periodicity became increasingly unstructured, finally reforming in recent decades, after 2000.Boreal birds are considered important sentinels of the boreal forests, and northward shifts and altered periodicity of irruptions may indicate broad‐scale changes in climate‐ and resource‐associated drivers operating across the boreal forests. [ABSTRACT FROM AUTHOR]

Bamboos are known for flowering simultaneously over a wide geographic range at long intervals of more than several decades. Florivory by Dicraeus phyllostachyus and D. nartshukae causes severe damage to bamboo seed production. However, the nature of the life history of the two Dicraeus species, particularly how they sustain populations during non-masting years of bamboos such as their host plant range, is poorly explored. We hypothesised that the two Dicraeus species host on other plant species and/or on non-floral organs of bamboos and move to bamboo florets during masting years. We tested whether the two Dicraeus species oviposit and develop on florets of grasses excluding bamboos (other grasses), and on non-floral organs of bamboos, including branch buds and bamboo shoots, by conducting a natural population survey and laboratory experiments. We found that the two Dicraeus species utilise short, slender shoots of Phyllostachys nigra var. henonis and a few other grass florets in the natural populations. Laboratory experiments also showed that the two Dicraeus species oviposited and fed on non-floral organs of bamboos and several species of other grass florets, although the oviposition rate and number of eggs varied among organs and the survival rate was low on most other grass florets. The generalised feeding ability may have enabled the two Dicraeus species to utilise the bamboo florets during masting years and become the dominant florivorous insect of bamboos. Unravelling their life history strategies may contribute to understanding adaptation in florivorous insects of masting plants as well as their impact on the evolution of masting in plants. [ABSTRACT FROM AUTHOR]

Allocation strategies of carbon (C), nitrogen (N), and phosphorus (P) are key to the reproductive processes of plants. Nutrient allocation to seeds depends on defensive traits of seeds and fruit because greater nutritional contents attract more seed predators. To compare resource allocation strategies for reproductive and defensive traits across species, we calculated the cost of resource investment in reproductive organs for nine species from four genera and defensive traits for seven species from two genera of Fagaceae. The results showed that no single element is the common resource currency across species, but that the reproductive strategy of each species is regulated by C, N, or P. Reproduction in Fagus crenata was limited by N but not by C, whereas in Quercus serrata it was co‐limited by C and N. Among the seven Fagaceae species, there was a negative correlation between the thickness of the pericarp and the concentration of the total phenolics in the seed and pericarp, suggesting alternative strategies for developing defensive traits in ripening seeds with limited C‐based resources. Overall, our results highlighted the diversity of resource allocation strategies to reproduction and defensive traits of Fagaceae species. To better understand the masting phenomenon at the population or community levels, comprehensive consideration of the diversity of resource allocation strategies among species is worth exploring in the future. [ABSTRACT FROM AUTHOR]

• Synchronized biennial-bearing prevails olives in the Levant. • A nonlinear dynamical model is developed to explain the phenomena. • Coupling individual fruit trees by anemophily is not essential for synchronization. • The model represents bounded chaos, reflecting socio-political factors in Syria. • Bifurcation diagrams show the versatility of the model. We develop and analyze a temporally continuous spatially lumped resource budget model to explain the dynamics of synchronized biennial-bearing olives in the Levant, specifically focusing on Syria, the region's foremost olive-producing country. The model is a time-continuous counterpart of the celebrated resource budget model. It consists of a Duffing oscillator coupled with a dynamical model of pollination with an external force propelling olive growth by photosynthesis. The reference data are obtained from statistical databases of international organizations and our own observation systems in Jordan, a country neighboring Syria, providing a wealth of information to refine the model structure. An intensive review of Syria's modern history involving significant shifts in agricultural policy and social stability leads to a conclusion that the model should comprehend the anomaly of olive yield interacting with socio-political factors as an autonomous behavior. The conventional mathematical methodology analyzes the model's characteristics, such as solutions' non-negativity, boundedness, and stability. The system is stable during pollination off-season but may become unstable and unbounded during pollination on-season, which is a property that the time-discrete resource budget model cannot reproduce. A significant finding is that coupling individual fruit trees by anemophily is not essential in synchronization, overturning earlier studies in the literature. The values of model parameters that best fit the historical data of olive yield in Syria result in bounded chaos. With alternative parameter values, the model could exhibit periodic oscillation, instability, or blowing up, as clearly shown in bifurcation diagrams. [ABSTRACT FROM AUTHOR]

Pulsed resources have prominent effects on community and ecosystem dynamics; however, there is little research on how resource pulses affect human–wildlife interactions. Tree masting is a common type of pulsed resource that represents a crucial food for many species and has important bottom‐up effects in food webs. In anthropogenic landscapes, years of food shortage after mast years can have negative outcomes for both people and wildlife, for instance when an increased use of anthropogenic foods by animals exacerbates human–wildlife conflicts. Here, we used novel remote sensing indicators of forest productivity and phenology, together with weather cues and ground measures of mast production, to assess whether years of masting and crop failures lead to changes in human–wildlife conflict occurrence. We used a unique 14‐year dataset including the production of European beech Fagus sylvatica seeds and brown bear Ursus arctos damage in the northeastern Carpathians as our model system. Linking these data in a panel regression framework, we found that temporal fluctuations in damage occurrence were sensitive to the year‐to‐year variation in beechnut production. Specifically, the number of damages during bear hyperphagia (i.e., September to December, when bears need to accumulate fat reserves prior to hibernation) was significantly higher in years with low beechnut production than in normal or mast years. Furthermore, we provide evidence that beech masting and failure can be predicted through a combination of remote‐sensing, weather, and field indicators of forest productivity and phenology. We demonstrate how pulsed resources, such as tree masting, can percolate through food webs to amplify human–wildlife conflict in human‐dominated landscapes. Given the recent range expansion of large carnivores and herbivores in many regions, including Europe, predicting years of natural food shortage can provide a pathway to proactive damage prevention, and thus to foster coexistence between wildlife and people. [ABSTRACT FROM AUTHOR]

Although lowland tree species in the ever-wet regions of Southeast Asia are characterized by the supra-annual cycle of reproduction, the reproductive phenology of montane tree species remains poorly understood. In this study, we investigated the reproductive phenology of montane tree species using litter samples that were collected every 2 weeks from six rainforest sites, consisting of three elevations (1700, 2700, and 3100 m), on Mount Kinabalu, Borneo. At each elevation, one site was on infertile ultrabasic soil and one was on relatively fertile non-ultrabasic soil. We used a composite sample from 10 or 20 litter traps per site and sorted it by species. Therefore, the obtained data captured reproductive phenology in the population of each species rather than in an individual tree. Ten-year time series of flower and fruit litterfall were obtained for 30 and 39 tree species, respectively. Fourier analysis was used to identify the dominant cycle of each time series. The most abundant cycle across species was supra-annual, followed by sub-annual, and annual cycles. Many species at higher elevations showed supra-annual cycles of flower litterfall, whereas species in the 1700 m sites often showed annual or sub-annual cycles regardless of soil types. No systematic differences were found among sites for fruit litterfall. Mechanisms underlying these elevational patterns in reproductive cycle remain unclear but may include more severe El Niño droughts, lower primary productivity, lower soil fertility, and the absence of some sub-annually or annually reproducing families at higher elevations. [ABSTRACT FROM AUTHOR]

Background and aims – Where one or several tree species come to dominate patches of tropical forest, as many masting ectomycorrhizal legumes do in Central Africa, ecological theory predicts they may be prone to herbivory, which might alter their reproductive output. This was indirectly investigated in lowland rainforest in Cameroon for Tetraberlinia korupensis, whose crowns were attacked in 2008 by an outbreaking black caterpillar—identified as an Achaea sp., probably A. catocaloides—in Korup National Park. Material and methods – Field-collected data on tree-level seed and fruit (pod) production of T. korupensis in its 2008 masting event were compared with that of its two co-dominant neighbours (T. bifoliolata, Microberlinia bisulcata), whose populations masted in 2007 (and 2010). To do this, bivariate regression models (linear, polynomial, ZiG [zero-inflated gamma model]), contingency table analysis, and non-parametric measures of dispersion were used. Key results – Assuming T. korupensis is prone to Achaea caterpillar attacks, empirical data support the hypothesized lower proportion of adults participating in its masting (54% in 2008) than for either masting population of M. bisulcata (98% in 2007, 89% in 2010) or T. bifoliolata (96% in 2007, 78% in 2010). These fruiting T. korupensis trees were about one-third larger in stem diameter than conspecific non-fruiters and produced as many pods and seeds per capita as T. bifoliolata. However, regressions only modestly support the hypothesis that the positive tree size–fecundity relationship for T. korupensis was weaker (i.e. lower adj. R2 ) than for M. bisulcata (whose leaves are morphologically similar) or T. bifoliolata, with mostly similar dispersion about the median among these species. Conclusion – Altogether, the findings suggest a role for tolerance in nutrient-poor forests. It is postulated that instead of conferring resistance to herbivores, the ectomycorrhizas associated with these trees may enable them to more quickly recover from potential yet unpredictable insect outbreaks. [ABSTRACT FROM AUTHOR]

Mass flowering (masting) has been hypothesized to be an adaptive strategy to satiate florivores/granivores. However, few studies have corroborated this by examining seed predation in multiple flowering patches of varying sizes across a wide geographical range over multiple years. Moreover, the trophic consequences of masting for the parasitoids of florivores/granivores and their feedback effects are poorly understood. Here, we used the nationwide masting of two bamboo species, Sasamorpha borealis var. borealis and Phyllostachys nigra var. henonis , in Japan and compared florivory and seed sets in multiple flowering patches during the masting year and the following sporadic flowering years. We found lower florivory damage in both bamboo species and higher seed set for Sasamorpha borealis var. borealis in patches with massive and spatiotemporally isolated flowering. Additionally, the relative level of parasitism of florivores increased considerably in the sporadic flowering year, particularly in large flowering patches of Sasamorpha borealis var. borealis. Our results indicate the importance of spatiotemporal isolation during masting for satiating two dipteran florivores and suggest that parasitoids might rapidly suppress the extent of florivory in the sporadic flowering years after masting. Collectively, our study highlights the importance of considering multi-trophic consequences in understanding the adaptive significance of masting. [ABSTRACT FROM AUTHOR]

Australia is home to a diverse assemblage of plant species that display marked population-level variation in inter-annual flower or seed output (i.e. masting). These include a semelparous bamboo with an estimated inter-crop period of 40–50 years, numerous iteroparous masting gymnosperms, angiosperms that include landscape-dominant eucalypts, arid-zone wattles and spinifex (Triodia spp.) grasses, and a rich selection of species that display disturbance-related forms of masting such as pyrogenic flowering and environmental prediction. Despite the prevalence of masting in the Australian flora, there has been a paucity of research on these plants. Nevertheless, from the literature available, it appears that, similar to other parts of the world, a continuum of inter-year reproductive variability exists, with a small number of species displaying extreme–high inter-annual seeding variability. From experimental studies and many anecdotal reports, most of the fitness benefits associated with masting evident overseas also operate in Australia (e.g. predator satiation, improved pollination efficiency, and environmental prediction). Additionally, some Australian masting species offer periodically important food resources for Aboriginal nations in the form of seed or fruit. These include the bunya pine (Araucaria bidwillii), members of the cycad genera Cycas and Macrozamia , spinifex (Triodia) grasses, and mulga shrubs (Acacia aneura). Key future research areas for effective conservation of Australian masting plants include (1) improved understanding of how management interventions such as burning and silvicultural thinning influence regeneration dynamics and higher-order trophic interactions, (2) further longitudinal monitoring across a range of habitats to identify other, as yet unknown, species that display reproductive intermittency, and (3) elucidation of how changes to temperature, precipitation and fire regimes under climate change will affect reproduction and regeneration dynamics of the Australian masting flora. Australia is home to a diverse assemblage of plant species that display synchronised inter-annual variation in flower or seed output (i.e. masting). These plants include a semelparous masting bamboo, numerous iteroparous gymnosperms and angiosperms, and a diverse assemblage of species with fire-related forms of masting such as pyrogenic flowering and environmentally predictive masting. Here, we review the ecology and evolution of these species and provide recommendations for conservation and management of the systems they occur in. [ABSTRACT FROM AUTHOR]

In plants, processes from flowering to seed maturation are influenced by various factors, including weather conditions, resource supply, and damage inflicted by seed predators, that collectively contribute to annual variability in seed production. To identify the important factors associated with sound acorn production in Quercus serrata, from 2014 to 2020, we investigated the demographic processes from flowering to acorn maturation in six individual trees within a stand in a warm‐temperate secondary forest in western Japan. We found that the annual production of female flowers was positively correlated with the difference in April temperatures between successive years. However, their fluctuation was low and unaffected by either seed or flower production in the previous year. Compared with those of female flowers, the annual variability in sound acorn production within an individual was significantly higher and more synchronized. Key factor analyses revealed that reproductive losses due to the oviposition and sap‐sucking activities of Mechoris ursulus were the most prominent factors contributing to the observed annual variation in total predispersal losses at an individual level, and their effects were synchronized among individuals within a population. Survival from female flowering to sound acorn maturation was strongly predicted by the temperature in June, which corresponds to the period of adult M. ursulus emergence. Our findings indicate that the damage inflicted by the main seed predator during the predispersal stage can sufficiently regulate the sound acorn production patterns in Q. serrata that appear to resemble masting behavior (the highly variable and synchronized production of acorns within individuals). [ABSTRACT FROM AUTHOR]

Mast seeding – the pronounced inter-annual variability and synchrony in seed production – can have profound local ecological impacts. We explore the potential for generating long (centuries to millennia) proxy records of tree mast seeding, from pollen deposited in lake sediments. This proxy record uses pollen recovered from annually-banded (varved) sediments from a core collected from Lake Ohau, South Island, New Zealand to reconstruct masting events for two genera of Southern Beech, Fuscospora spp. and Lophozonia spp. We find average mast frequencies inferred from Fuscospora pollen from a 43-year sediment core collected from Lake Ohau comparable to seed fall expected for the catchment using a differential-temperature (ΔT) statistical model for the period 1974–2016. In contrast, Lophozonia pollen mast frequency in the 1974–2016 timeseries was consistently lower than that predicted by the ΔT model, although the patterns of variability were broadly similar. We explore this approach in a second 32-year pollen timeseries from Lake Ohau, spanning the pre-instrumental period 1833–1864. During this interval, average air temperature was ~1°C cooler than the late 20th century, and interannual variability of air temperature was subdued, such that mast frequency predicted by the Δ T model is the lowest in 200 years. We find mast frequency in our pollen records reflects this pattern for Fuscospora, with a minima of mast frequency from 1850, compared to the 1974–2016 record, but not for Lophozonia. This paper demonstrates that a centuries-long pollen record from the Lake Ohau sedimentary sequence has the potential to form a valuable proxy for Fuscospora masting that would supplement existing seedfall records. Long records of this type could significantly enhance our understanding of the environmental drivers of mast seeding. [ABSTRACT FROM AUTHOR]

Abstract Mast seeding, the synchronized interannual variation in seed production of trees, is a well‐known bottom‐up driver for population densities of granivorous forest rodents. Such demographic effects also affect habitat preferences of the animals: After large seed production events, reduced habitat selectivity can lead to spillover from forest patches into adjacent alpine meadows or clear‐cuts, as has been reported for human‐impacted forests. In unmanaged, primeval forests, however, gaps created by natural disturbances are typical elements, yet it is unclear whether the same spillover dynamics occur under natural conditions. To determine whether annual variation in seed production drives spillover effects in naturally formed gaps, we used 14 years of small mammal trapping data combined with seed trap data to estimate population densities of Apodemus spp. mice and bank voles (Myodes glareolus) on 5 forest sites with differing disturbance history. The study sites, located in a forest dominated by European beech (Fagus sylvatica), Norway spruce (Picea abies), and silver fir (Abies alba), consisted of two primeval forest sites with small canopy gaps, two sites with larger gaps (after an avalanche event and a windthrow event), and a managed forest stand with closed canopy as a control. Hierarchical Bayesian N‐mixture models revealed a strong influence of seed rain on small rodent abundance, which were site‐specific for M. glareolus but not for Apodemus spp. Following years of moderate or low seed crop, M. glareolus avoided open habitat patches but colonized those habitats in large numbers after full mast events, suggesting that spillover events also occur in unmanaged forests, but not in all small rodents. The species‐ and site‐specific characteristics of local density responding to food availability have potentially long‐lasting effects on forest gap regeneration dynamics and should be addressed in future studies.

Mast seeding, a phenomenon observed in numerous perennial plant species, is highly variable reproduction across years, synchronized among individuals within a population. One major fitness advantage of masting is the reduced seed predation rates, achieved through alternating seed scarcity and abundance that starve and subsequently satiate seed consumers. Proximately, the variability in seed production frequently correlates with weather conditions. Convergent responses among species to weather fluctuations often lead to synchronized masting events across species, which may help with predator satiation, but this hypothesis has rarely been tested. Here, we address this gap by using 23 years of seed production and pre-dispersal seed predation monitoring in three North American oak species (Quercus rubra , Quercus alba , Quercus montana). We found that spring and summer weather patterns correlated with masting events in all three species, resulting in intraspecific synchrony levels ranging from 0.21 to 0.38, depending on the species pair. Intraspecific masting synchrony facilitated efficient insect starvation in Q. rubra and Q. alba , while community-wide mast years were necessary for satiation in Q. montana. Our findings present a rare empirical test supporting the hypothesis that intraspecific masting synchrony enhances reproductive efficiency by minimizing seed losses to generalist pre-dispersal seed predators. Improved seed survival via community-wide masting implies that stands with diverse oak species may have improved regeneration potential, suggesting management options for increased seed supply. • Mast seeding is variable reproduction over years, synchronized in populations. • Masting reduces seed predation by alternating seed scarcity and abundance. • Weather impacts seed production, synchronizing masting events across species. • A 23-year study shows intraspecific masting synchrony aids predator satiation. • Stands with diverse oak species may have improved regeneration potential [ABSTRACT FROM AUTHOR]

Large solitary carnivores need to correspond to spatial and temporal variations in food resources, and therefore are expected to change their movement strategies seasonally and annually. Movement strategy of an animal is also mediated by internal factors such as sex. We investigate movement strategy of Asian black bears (Ursus thibetanus) in two biological periods (mating and hyperphagia periods), by fitting random walk models including Brownian walks (BWs), Lévy walks (LWs), and composite Brownian walks (CBWs). We explored the best random walk models approximating the movement paths of 59 trajectories performed by 29 Asian black bears, obtained in years with different food availability. The results strongly supported the occurrence of CBW patterns over scale‐free LW patterns for their movements. We found some differences in composition of the best CBW models between mating and hyperphagia periods, though no distinctive differences were found among the best models regarding sex and food availability. Our findings demonstrated that the CBW is the best model to describe the movement of the Asian black bears among the random walk models tested, and indicate the importance of understanding multiple modes of their activity or movement. [ABSTRACT FROM AUTHOR]

Information on the allergenic pollen season provides insight on the state of the environment of a region and facilitates allergy symptom management. We present a retrospective analysis of the duration and severity of the allergenic pollen season and the role of meteorological factors in Istanbul, Turkey. Aerobiological sampling from January 2013 to June 2016, pollen identification and counting followed current standard methodology. Pollen seasons were defined according to 95% of the Annual Pollen Integral (APIn) and the season start date was compared with the first day of 5 day consecutive non-zero records. Generalized additive models (GAMs) were created to study the effect of meteorological factors on flowering. The main pollen contributors were taxa of temperate and Mediterranean climates, and neophytic Ambrosia. Cupressaceae, Poaceae, Pinaceae, Quercus and Ambrosia had the greatest relative abundance. The pollen season defined on 95% of the APIn was adequate for our location with total APIns around 10.000 pollen*day*m−3. Woody taxa had generally shorter seasons than herbaceous taxa. In trees, we see precipitation as the main limiting factor for assimilate production prior to anthesis. A severe tree pollen season in 2016 suggests intense synchronous flowering across taxa and populations triggered by favourable water supply in the preceding year. GAM models can explain the effect of weather on pollen concentrations during anthesis. Under the climatic conditions over the study period, temperature had a negative effect on spring flowering trees, and a positive one on summer flowering weeds. Humidity, atmospheric pressure and precipitation had a negative effect on weeds. Our findings contribute to environmental and allergological knowledge in southern Europe and Turkey with relevancy in the assessment of impacts of climate change and the management of allergic disease. [ABSTRACT FROM AUTHOR]

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long‐lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time‐series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population‐level time‐series from 974 species in 66 countries. The mean and median time‐series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well‐studied species, MASTREE+ includes extensive replication of time‐series across geographical and climatic gradients. Here we describe the open‐access data set, available as a.csv file, and we introduce an associated web‐based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long‐lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics. [ABSTRACT FROM AUTHOR]

Summary: Forest ecology traditionally focuses on plant growth and survival, leaving seed production as a major demographic process lacking a framework for how it will be affected by global change. Understanding plant reproductive responses to changing climate is complicated by masting, the annually variable seed production synchronized within populations. Predicting trends in masting is crucial, because masting impacts seed predation and pollination enough to override simple trends in mean seed production. Proximate mechanisms of seed production patterns in perennial plants are gathered to identify processes through which masting may be affected by a changing environment. Predicting trends in masting will require understanding the mechanisms that cause predictable seed failure after high‐seed years, and the stochastic mechanisms that synchronize individuals in high‐seed years. [ABSTRACT FROM AUTHOR]

Seedling dynamics are critical for determining community composition and future forest structure. Two mechanisms are crucial drivers of seedling vital rates: biotic interactions and environmental filtering. Biotic interactions at the neighbourhood scale, such as the Janzen–Connell effect, are considered among the main mechanisms maintaining species coexistence. These effects can show considerable temporal variation because of changes in neighbourhood density (i.e. seedling recruitment following masting years) and weather conditions. However, there is limited evidence of whether interannual variation in these conditions modulates biotic interactions and its potential cascading effects on seedling vital rates.We used seedling data collected over 17 years in a subtropical rainforest in northern Taiwan. We modelled interannual variation in first‐year survival and growth of 12,830 seedlings of 36 species and 47 cohorts using (generalized) linear mixed‐effects models with several crowding indices and abiotic conditions (edaphic and topographic factors) as predictors.The first‐year seedling survival and growth depended on both weather conditions and neighbourhood density. Seedling survival was greater when recruitment was more abundant and in years with greater rainfall, and this was mostly mediated by the interaction with conspecific and heterospecific seedlings. Seedling growth decreased with the increasing abundance of new recruits and increased with annual rainfall. Growth was negatively affected by the basal area of conspecific and heterospecific trees and by the density of conspecific seedlings when the number of new recruits was greater. The abiotic factors had a limited effect on seedling survival and growth compared to biotic factors.Synthesis. Our results show that variation in recruitment abundance due to masting and annual rainfall significantly affects seedling vital rates by changing biotic interactions. These findings are in accordance with the economy of scale hypothesis, which predicts higher per‐capita reproductive success in years of higher seed production. Furthermore, the results support the hypothesis that fluctuations in rainfall can alter biotic interactions in forests. Efforts to predict forest community responses to climate changes should consider the temporal variations in biotic interactions. [ABSTRACT FROM AUTHOR]

The southern beech (genus Fuscospora and Lophozonia) forest in New Zealand periodically has "mast" years, during which very large volumes of seeds are produced. This excessive seed production results in a population explosion of rodents and mustelids, which then puts pressure on native birds. To protect the birds, extra pest controls, costing in the order of NZD 20 million, are required in masting areas. To plan pest control and keep it cost-effective, it would be helpful to have a map of the masting areas. In this study, we developed a remote sensing method for the creation of a national beech flowering map. It used a temporal sequence of Sentinel-2 satellite imagery to determine areas in which a yellow index, which was based on red and green reflectance (red-green)/(red + green), was higher than normal in spring. The method was used to produce national maps of heavy beech flowering for the years 2017 to 2021. In 2018, which was a major beech masting year, of the 4.1 million ha of beech forest in New Zealand, 27.6% was observed to flower heavily. The overall classification accuracy of the map was 90.8%. The method is fully automated and could be used to help to identify areas of potentially excessive seed fall across the whole of New Zealand, several months in advance of when pest control would be required. [ABSTRACT FROM AUTHOR]