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California contains a broad geography over which climate conditions can be suitable for cultivating multiple varieties of winegrapes. However, climate change is projected to make winegrape cultivation more challenging across many of California's winegrowing regions. In order to understand the potential effects of climate change on winegrapes, this study models variety-specific phenology for six winegrape varieties and quantifies the change in phenology and viticulturally-important agroclimate metrics over 12 of California's American Viticultural Areas (AVAs) by the mid-21st century. Results show more rapid development for winegrapes with earlier budburst, flowering, veraison, and maturation across all varieties and AVAs. Cabernet Sauvignon shows the greatest change in phenology timing, while Chardonnay shows the least change. Likewise, the West Sonoma Coast AVA shows the greatest average change in phenology timing across varieties and development stages and Lodi AVA shows the least. Projected changes in agroclimatic metrics include an additional month of potentially damaging heat days (above 35 °C) in some AVAs, and decreases in frost days. These results have implications for numerous factors related to viticultural production, including water resources management and crop yield and quality, and underscore the need for California winegrape growers to improve their resilience to climate change by adopting strategies such as increasing soil health and water use efficiency and selecting cultivars suited for future climate conditions. By conducting climate effects analyses at the variety-specific and AVA scale, important information is provided to the winegrowing industry at a resolution that can support decision-making towards resilience.

Climate change is affecting the phenology of organisms and ecosystem processes across a wide range of environments. However, the links between organismal and ecosystem process change in complex communities remain uncertain. In snow-dominated watersheds, snowmelt in the spring and early summer, followed by a long low-flow period, characterizes the natural flow regime of streams and rivers. Here, we examined how earlier snowmelt will alter the phenology of mountain stream organisms and ecosystem processes via an outdoor mesocosm experiment in stream channels in the Eastern Sierra Nevada, California. The low-flow treatment, simulating a 3- to 6-wk earlier return to summer baseflow conditions projected under climate change scenarios in the region, increased water temperature and reduced biofilm production to respiration ratios by 32%. Additionally, most of the invertebrate species explaining community change (56% and 67% of the benthic and emergent taxa, respectively), changed in phenology as a consequence of the low-flow treatment. Further, emergent flux pulses of the dominant insect group (Chironomidae) almost doubled in magnitude, benefitting a generalist riparian predator. Changes in both invertebrate community structure (composition) and functioning (production) were mostly fine-scale, and response diversity at the community level stabilized seasonally aggregated responses. Our study illustrates how climate change in vulnerable mountain streams at the rain-to-snow transition is poised to alter the dynamics of stream food webs via fine-scale changes in phenology-leading to novel predator-prey matches or mismatches even when community structure and ecosystem processes appear stable at the annual scale.

Black, brown, and white mustards are important spice and oil crops cultivated worldwide. In this study, the effect of mustard lines in terms of growth and yield under spring sown conditions during 2 years (2020 and 2021) was investigated under semi-arid climatic conditions in Ankara, Turkey. Fifteen lines and one standard were used in this study. The experiment was carried out according to the randomized block trial design with four replications. The results demonstrated statistically significant lines × years interaction for plant height, number of branches, number of capsules, number of seeds, thousand-seed weight, seed yield and crude oil yield of black, brown, and white mustard lines. The days to emergence, 4–6 leaves rosette stages, 50% flowering, 50% encapsulation, and harvest varied according to species and years. The better production year was 2021, when the highest seed yield (3080 kg ha−1) and oil yield (612 kg ha−1) were determined from the Brassica juncea-Bj3 line, while the lower production year was 2020, when the lowest seed yield (572 kg ha−1) and oil yield (133 kg ha−1) were detected for the B. nigra-Bn5 line. The B. juncea-Bj3 line for crude oil yield (612 kg ha−1) and the Sinapis alba-Sa5 line for seed yield (2282 kg ha−1) appeared to be superior in performance compared to the other lines and standards. The lines can be further exploited for breeding programs through selection and hybridization. Considering the yield data of the lines, it was detected that the lines of Brassica juncea, Sinapis alba and Brassica nigra have an important potential as a raw material resource for different industries. HIGHLIGHTS: The experimental results showed the agronomic potential of growing Brassica species under spring conditions. The yield characteristics of 15 Brassica lines were significantly affected by the environmental situation. The Brassica juncea-Bj3 and Sinapis alba-Sa2 lines were the superior lines and had a high potential for breeding new Brassica cultivars. [ABSTRACT FROM AUTHOR]

Climate change has a substantial influence on the end of the growing season (EOS). The time-lag and cumulative effects are non-negligible phenomena when studying the interactions between climate and vegetation. However, quantification of the temporal effects of climatic factors on the EOS in the context of changing hydrothermal patterns remains scarce. Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) fraction of absorbed photosynthetically active radiation (FPAR), this study first inverted the EOS of typical steppe vegetation in a semi-arid region of China and then quantified the time-lag and cumulative effects of monthly total precipitation (PRE) and monthly average temperature (TEM) on the EOS during 2003–2022. The results showed that a turning point occurred in 2011, when the EOS displayed an advancing trend until 2011, followed by a delayed trend. Accordingly, the climatic background has changed from warming and drying conditions during 2003–2011 to warming and wetting conditions during 2011–2022. The time-lag scales of PRE and TEM on the EOS decreased from 2- and 4-month scales during 2003–2011, respectively, to 1- and 2-month scales during 2011–2022, respectively. The time-lag degree of the hydrothermal factors on the EOS weakened with increased precipitation. The cumulative time scales of the EOS response to PRE and TEM were mainly concentrated within 1-month during different time periods, but the EOS was more sensitive to short-term precipitation. The time lag and cumulative partial correlation coefficient of PRE to EOS changed from mainly negative regulation during 2003–2011 (39.2% and 50.0%, respectively) to mainly positive regulation during 2011–2022 (67.8% and 93.7%, respectively). The time-lag and cumulative effects of TEM on the EOS were positive with the precipitation and temperature gradient under a warming and wetting climate, which indicated that increased precipitation was a prerequisite for temperature to induce a delayed EOS in the semi-arid study region. This study emphasizes the important role of precipitation in regulating the EOS response to hydrothermal factors in semi-arid regions. [ABSTRACT FROM AUTHOR]

Changes in phenology are a conspicuous fingerprint of climate change, leading to fears that phenological mismatches among interacting species will be a leading cause of population declines and extinction. We used quantile regression to analyze museum collection data and estimate changes in the phenological overlap of Baltimore checkerspot butterflies and 12 common nectar plant species over several decades in two geographic regions. We combined these museum data with field estimates of each species' flower density and nectar sugar production to estimate changes in resource availability caused by shifts in phenological overlap. Phenological overlap (measured as the proportion of plant flowering during the flight period of an average butterfly) decreased through time, primarily because the flowering period of nectar plants was longer, but the flight period of butterflies was shorter in recent years. Our study was also motivated by the hypothesis that phenological mismatches may be more severe in the southern region due to a midsummer dearth in floral resources, but this hypothesis was not supported by our data. Although phenological overlap was somewhat smaller in the southern region, changes in overlap through time were similar in both regions. When phenological overlap was weighted by nectar sugar production of different species, the overlap increased in the southern region but decreased in the northern region (the opposite of our prediction). Overall, nectar resources were much more abundant at study sites in our northern region than in our southern region, possibly due to differences in land management. Our study demonstrates the complexities of phenological mismatch of interacting species and highlights that phenological changes may have small impacts on population viability. [ABSTRACT FROM AUTHOR]

Climate change is impacting marine ecosystems throughout the circumpolar Arctic, altering seasonal habitats and the food bases for fishes, seabirds, and marine mammals. Arctic and Subarctic regions provide resources for resident species and for species that migrate to the north from more southerly regions. Changes in northerly latitudes thus impact endemic as well as non-endemic animals. Herein, we review what is known about climate-driven changes in the migration patterns of Arctic and Subarctic marine vertebrates, including: 1) Arctic residents with seasonal movements – those fishes, seabirds, and marine mammals that complete their entire life cycle within the Arctic but exhibit seasonal movements; 2) Breeding migrants – many seabirds enter the Arctic to breed and subsequently migrate south in the fall; and 3) Summer visitors for feeding – certain species of boreal fishes, seabirds and marine mammals arrive during the northern summer to feed on abundant prey though they breed elsewhere. Migratory movements are often driven by the timing and extent of sea ice, which defines suitable habitat for some animals and limits access to open water and prey for others. Longer open-water seasons, warmer ocean temperatures, and stronger winds have resulted in earlier production blooms in spring and often, extended open-ocean plankton blooms into late summer, resulting in altered prey types and distributions. A common thread among taxa is that shifts in distribution and timing of migrating animals indicate they are traveling farther north, or shifting longitudinally, and migrations are occurring over longer seasonal time frames. Species performing multiple lifetime migrations or long-distance migrants may need to adjust migration timing or routing iteratively to match changes in marine productivity. Altered animal distributions or phenology, and reduced sea ice, affects access to animals that are critical nutritional, economical, and cultural components of Indigenous people's lives in the Arctic. Ongoing changes challenge the resilience and adaptability of Arctic people and ecosystems, and will require adaptive research and management approaches. [ABSTRACT FROM AUTHOR]

Marine phytoplankton are fundamental to Earth's ecology and biogeochemistry. Our understanding of the large-scale dynamics of phytoplankton biomass has greatly benefited from, and is largely based on, satellite ocean color observations from which chlorophyll-a (Chla), a commonly used proxy for carbon biomass, can be estimated. However, ocean color satellites only measure a small portion of the surface ocean, meaning that subsurface phytoplankton biomass is not directly monitored. Chla is also an imperfect proxy for carbon biomass because cellular physiology drives large variations in their ratio. The global network of Biogeochemical (BGC)-Argo floats now makes it possible to complement satellite observations by addressing both these issues at once. In our study, we use ~100,000 water-column profiles from BGC-Argo to describe Earth's phytoplankton carbon biomass and its spatiotemporal variability. We estimate the global stock of open ocean phytoplankton biomass at ~314 Tg C, half of which is present at depths not accessible through satellite detection. We also compare the seasonal cycles of carbon biomass stocks and surface Chla visible from space and find that surface Chla does not accurately identify the timing of the peak annual biomass in two-thirds of the ocean. Our study is a demonstration of global-scale, depth-resolved monitoring of Earth's phytoplankton, which will be crucial for understanding future climate-related changes and the effects of geoengineering interventions if implemented. [ABSTRACT FROM AUTHOR]

Background Damage from insect herbivores can elicit a wide range of plant responses, including reduced or compensatory growth, altered volatile profiles, or increased production of defence compounds. Specifically, herbivory can alter floral development as plants reallocate resources towards defence and regrowth functions. For pollinator-dependent species, floral quantity and quality are critical for attracting floral visitors; thus, herbivore-induced developmental effects that alter either floral abundance or attractiveness may have critical implications for plant reproductive success. Based on past work on resource trade-offs, we hypothesize that herbivore damage-induced effects are stronger in structural floral traits that require significant resource investment (e.g. flower quantity), as plants reallocate resources towards defence and regrowth, and weaker in secondary floral traits that require less structural investment (e.g. nectar rewards). Methods In this study, we simulated early-season herbivore mechanical damage in the domesticated jack-o-lantern pumpkin Cucurbita pepo ssp. pepo and measured a diverse suite of floral traits over a 60-d greenhouse experiment. Key Results We found that mechanical damage delayed the onset of male anthesis and reduced the total quantity of flowers produced. Additionally, permutational multivariate analysis of variance (PERMANOVA) indicated that mechanical damage significantly impacts overall floral volatile profile, though not output of sesquiterpenoids, a class of compounds known to recruit specialized cucumber beetle herbivores and squash bee pollinators. Conclusions We show that C. pepo spp. pepo reduces investment in male flower production following mechanical damage, and that floral volatiles do exhibit shifts in production, indicative of damage-induced trait plasticity. Such reductions in male flower production could reduce the relative attractiveness of damaged plants to foraging pollinators in this globally relevant cultivated species. [ABSTRACT FROM AUTHOR]

With global climate change, linking vegetation phenology with net ecosystem productivity (NEP) is crucial for assessing vegetation carbon storage capacity and predicting terrestrial ecosystem changes. However, there have been few studies investigating the relationship between vegetation phenology and NEP in the middle and high latitudes of the Northern Hemisphere. This study comprehensively analyzed vegetation phenological changes and their climate drivers using satellite data. It also investigated the spatial distribution and climate drivers of NEP and further analyzed the sensitivity of NEP to vegetation phenology. The results indicated that the average land surface phenology (LSP) was dominated by a monotonic trend in the study area. LSP derived from different satellite products and retrieval methods exhibited relatively consistent responses to climate. The average SOS and POS for different retrieval methods showed a higher negative correlation with nighttime temperatures compared to daytime temperatures. The average EOS exhibited a higher negative correlation with daytime temperatures than a positive correlation. The correlations between VPD and the average SOS, POS, and EOS showed that the proportion of negative correlations was higher than that of positive correlations. The average annual NEP ranged from 0 to 1000 gC·m−2. The cumulative trends of NEP were mainly monotonically increasing, accounting for 61.04%, followed by monotonically decreasing trends, which accounted for 17.95%. In high-latitude regions, the proportion of positive correlation between VPD and NEP was predominant, while the proportion of negative correlation was predominant in middle-latitude regions. The positive and negative correlations between soil moisture and NEP (48.08% vs. 51.92%) were basically consistent in the study area. The correlation between SOS and POS with NEP was predominantly negative. The correlation between EOS and NEP was overall characterized by a greater proportion of negative correlations than positive correlations. The correlation between LOS and NEP exhibited a positive relationship in most areas. The sensitivity of NEP to vegetation phenological parameters (SOS, POS, and EOS) was negative, while the sensitivity of NEP to LOS was positive (0.75 gC·m−2/d for EVI vs. 0.63 gC·m−2/d for LAI vs. 0.30 gC·m−2/d for SIF). This study provides new insights and a theoretical basis for exploring the relationship between vegetation phenology and NEP under global climate change. [ABSTRACT FROM AUTHOR]

The article discusses the overlooked habitat of macroalgae in sand grains, specifically focusing on the life cycle of Monostroma angicava in northern Japan. The study reveals that microscopic codiolum sporophytes of M. angicava bore into calcareous sand grains during the summer, showcasing a unique endolithic lifestyle. The research highlights the ecological significance of sand grains as a seasonal habitat for macroalgal life cycle stages, shedding light on the adaptive strategies and dispersal modes of these organisms in coastal ecosystems. [Extracted from the article]

Why nonnative invasive plant species commonly co‐occur, despite their competitive superiority and propensity to displace native species, remains a paradox in invasion biology. Negative interactions among competitively dominant invaders are potentially alleviated by two understudied mechanisms: seasonal priority effects, where phenological separation weakens the effect of competition on species with early phenology; and indirect facilitation, where competition between two species is mitigated by a third species. Although phenological separation has been speculated as a mechanism for explaining co‐occurrence patterns of invasive plants, it has never been directly tested. In a greenhouse experiment, we tested the effect of phenological separation on direct and indirect interactions between three co‐occurring invasive plant species found in the riparian forests of North America. These species have distinct natural phenological separation with reproduction in early spring (Ficaria verna), mid‐spring (Alliaria petiolata), and late summer (Microstegium vimineum). When phenology was experimentally synchronized, direct pairwise interactions among invasive species were overwhelmingly negative, asymmetric, and unlikely to promote co‐occurrence. However, increasing phenological separation generated seasonal priority effects, which weakened the effect of competition on species with early phenology. Furthermore, the addition of a third species generated indirect facilitative effects, which balanced competitive outcomes among the two weakest competitors. Based on these findings, we conclude that phenological separation modulates the strength of both seasonal priority effects and indirect facilitation within species interaction networks and may promote the co‐occurrence of three common invasive species within this study system. We articulate how future studies can test the external validity of these findings in more complex environmental conditions and with a larger range of invasive plants. [ABSTRACT FROM AUTHOR]

Ecotones are the transition zones between ecosystems and can exhibit steep gradients in ecosystem properties controlling flows of energy and organisms between them. Ecotones are understood to be sensitive to climate and environmental changes, but the potential for spatiotemporal dynamics of ecotones to act as indicators of such changes is limited by methodological and logistical constraints. Here, we use a novel combination of satellite remote sensing and analyses of spatial synchrony to identify the tropical dry forest–rainforest ecotone in Area de Conservación Guanacaste, Costa Rica. We further examine how climate and topography influence the spatiotemporal dynamics of the ecotone, showing that ecotone is most prevalent at mid‐elevations where the topography leads to moisture accumulation and that climatic moisture availability influences up and downslope interannual variation in ecotone location. We found some evidence for long‐term (22 year) trends toward upslope or downslope ecotone shifts, but stronger evidence that regional climate mediates topographic controls on ecotone properties. Our findings suggest the ecotone boundary on the dry forest side may be less resilient to future precipitation reductions and that if drought frequency increases, ecotone reductions are more likely to occur along the dry forest boundary. [ABSTRACT FROM AUTHOR]

The article explores the role of ephemeral river islands in the Meta River in eastern Colombia as habitats for migratory songbirds from the northern and southern hemispheres during migration and the nonbreeding period. The islands emerge during the dry season, providing roosting and foraging sites for thousands of migratory birds. The study highlights the importance of understanding the habitat use and quality of nonbreeding areas for long-distance migrants and raises questions about the ecological associations, spatial-temporal dynamics, and conservation priorities of these ephemeral islands. [Extracted from the article]

Highbush blueberries (Vaccinium spp.) are cultivated crop plants worldwide and they are still gaining importance. However, a common uniform description of the phenological development was missing so far. In this work, a specific code is presented, based on the decimal BBCH scale. The BBCH scale comprises the macrostages 0–9, with macrostage 4 being omitted here, because it has no relevance for blueberry crops grown in the field. Each macrostage is subdivided in several microstages, each describing a notable developmental stage. The BBCH code takes special reference to the fruit development, fruit ripening, and several fruit pickings, which are typical for blueberries. For each macrostage the main development as well as cultivation characteristics are explained in more detail. The new BBCH code is compared with other descriptions of phenotypical development of highbush blueberries and transformations are suggested. The BBCH code is developed for cultivated highbush blueberries and is therefore applicable to northern, southern, and rabbiteye blueberries as well. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: The iconic Yoshino cherry tree in Japan is experiencing shifts in its blossom timing due to climate warming. To develop a genetically informed predictive model for bud dormancy release, we examined seasonal gene expression in Yoshino cherry trees at three different locations. Our experiments, coupled with the analysis of DORMANCY‐ASSOCIATED MADS‐box (DAM) genes, highlighted DAM4 as the most reliable indicator for the rate of bud dormancy release. Our study demonstrated that seasonal gene expression profiles serve as a valuable indicator for forecasting the timing of dormancy release, benefiting Japanese traditions and providing insights into the biological impacts of climate change. Summary: The Yoshino cherry tree Cerasus × yedoensis 'Somei‐yoshino' stands out as an iconic springtime symbol in Japan. For the Yoshino cherry trees to bloom in the spring, dormant buds must undergo a period of exposure to low temperatures, allowing them to break dormancy. Key genes related to dormancy release, known as DORMANCY‐ASSOCIATED MADS‐box (DAM), have been extensively studied. However, it remains unclear how these genes function in natural environments to regulate the timing of bud dormancy release.To develop a genetically informed predictive model for bud dormancy release, we explored seasonal changes in genome‐wide gene expression profiles in the Yoshino cherry trees at three distinct sites in Japan. Five distinct genome‐wide transcription profiles, subjectively named as modes—early summer, summer, autumn, winter, and spring—were identified, with the winter and spring modes observed when the daily mean temperature was below approximately 10°C.Our experiments of bud dormancy release, along with the assessment of expression profiles of DAM genes, have revealed that among the six DAM genes, DAM4 expression profile is the most indicative of the rate of bud dormancy break. Our estimates suggest that, on average, the tree needs to be exposed to temperatures below 10.1°C for 61.1 days to suppress DAM4 expression to the threshold required for bud dormancy release.Our projections for the timing of bud dormancy release indicated a delay of approximately 2.3 days per decade from 1990 to 2020. Our study demonstrated that gene expression serves as a valuable indicator for forecasting the timing of dormancy release. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Long‐term phenology data is crucial to elucidate the effects of climate change on plants, but such efforts are lacking in the tropics. Historical records at the Singapore Botanic Gardens and ongoing phenological monitoring have allowed us to study leafing behaviour and its association with changing rainfall patterns over nine decades in equatorial Singapore. We found that the leafing behaviour of trees in our tropical site changed between 1927 and 2022. This study was made possible by assiduous past and present record‐keeping, and demonstrates the potential of botanical gardens as sentinels of environmental change, which is especially important in the tropics. Summary: Understanding tropical phenology and the potential impacts of a changing climate requires long‐term monitoring but such efforts are rare in the tropics. We took advantage of the availability of historical phenological and weather records at the Singapore Botanic Gardens and ongoing phenological monitoring to ask whether leafing behaviour has changed over an exceptionally long period of about nine decades, and whether these changes are associated with changing rainfall patterns in supposedly aseasonal Singapore.Records of leaf flush intervals from 1927 to 1939 in the Singapore Botanic Gardens were compared against leaf flush intervals calculated from present‐day phenological monitoring conducted since 2016. Daily rainfall was modelled as a predictor of present‐day leaf flushing events using moving‐window analyses.Leaf flush intervals have shortened considerably for most of the species that were monitored in the two periods. Mean daily rainfall over a window of 1 to 4 months before was negatively associated with probability of leaf flushing for five species and positively associated with four out of a total of 23 species analysed. Long‐term rainfall records from 1929 to 2022 show that February has become drier and May has become wetter since the 1960s.The results consistently support that more distinctive dry and wet periods today compared to nine decades ago have resulted in more frequent leaf flushing, which may have implications for plant‐herbivore interactions, nutrient cycling and consequently plant health and ecosystem resilience. We also demonstrate the potential and importance of supporting long‐term research in botanical gardens in the tropics. [ABSTRACT FROM AUTHOR]

Foxtail millet hybrid development encounters challenges due to its self-pollinating nature, small florets, and tool availability for confirming true hybrid. Our research aimed to assess flowering phenology and explore artificial hybridization employing SiDREB2 based-SNAP marker. The research consisted of three experiments. The first experiment focused on the panicle phenology of foxtail millet, while the second experiment focused on floret phenology and reproductive organs. The artificial hybridization successfulness was validated with SNAP markers based on the SiDREB2 gene in the third experiment. Observations on two genotypes (ICERI-5 and ICERI-6) revealed panicle initiation at 49-69 days after planting (DAP), with anthesis occurring 6 days after panicle emergence (DAPE). Florets exhibited the formation of reproductive organs at 3 DAPE, delineating distinct stages of pollen development leading up to anthesis. Our findings emphasized the significance of implementing male-sterile induction treatment at 4 DAPE to regulate pollen development for successful hybridization by 6 DAPE. The hybrid evaluation revealed varied germination rates and confirmed hybrid percentages across different crossing series, validated by SiDREB2-based SNAP marker. ICERI-5xBotok-4 exhibited high germination but a low confirmed hybrid percentage, while Botok-4xICERI-5 and Botok-10xICERI-6 showed the opposite trend. Reciprocal crossings showed unilateral incompatibility in confirmed hybrid percentage. [ABSTRACT FROM AUTHOR]

Crop phenological information must be reliably acquired earlier in the growing season to benefit agricultural management. Although the popular shape model fitting (SMF) method and its various improved versions (e.g., SMF by the Separate phenological stage, SMF-S) have been successfully applied to after-season crop phenology detection, these existing methods cannot be applied to within-season crop phenology detection. This discrepancy arises due to the fact that, in the within-season scenario, phenological stages can beyond the defined cut-off time. Consequently, enhancing the alignment of the vegetation index (VI) curve segments prior to the cut-off time does not necessarily guarantee accurate within-season phenological detection. To resolve this issue, a new method named s patio t emporal s hape m odel f itting (STSMF) was developed. STSMF does not seek to optimize the local curve matching between the target pixel and the shape model; instead, it determines similar local VI trajectories in the neighboring pixels of previous years. The within-season phenology of the target pixel was thus estimated from the corresponding phenological stage of the determined local VI trajectories. When compared with ground phenology observations, STSMF outperformed the existing SMF and SMF-S which were modified for the within-season scenario ( SMF ws and SMFS ws ) with the smallest mean absolute differences (MAE) between observed phenological stages and their corresponding model estimates. The MAE values averaged over all phenological stages for STSMF, SMFS ws , and SMF ws were 9.8, 12.4, and 27.1 days at winter wheat stations; 8.4, 14.9, and 55.3 days at corn stations; and 7.9, 12.4, and 64.6 days at soybean stations, respectively. Intercomparisons between after-season and within-season regional phenology maps also demonstrated the superior performance of STSMF (e.g., correlation coefficients for STSMF and SMFS ws are 0.89 and 0.80 at the maturity stage of winter wheat). Furthermore, the performance of STSMF was less affected by the detection time and the determination of shape models. In conclusion, the straightforward, effective, and stable nature of STSMF makes it suitable for within-season detection of agronomic phenological stages. [ABSTRACT FROM AUTHOR]

We studied the breeding ecology of Whinchats Saxicola rubetra in four tiny (less than 10 breeding pairs) populations in nature reserves in the Dutch province of Drenthe. We focussed on reproductive rates (laying date, clutch size, hatchling number, breeding success), proportion of unpaired males and nestling diet. Breeding pairs appeared to cluster together, thereby leaving other seemingly suitable parts of the area unoccupied. Clutch size, nest and pair success were similar to or higher than those in other studies. Laying of first eggs peaked during 16–20 May and laying dates had not advanced since the 1950s, in contrast to many other songbirds. We found 34% of the males remained unpaired, limiting the population reproduction rate. Whinchats provided their nestlings primarily with beetles and caterpillars and feeding frequency appeared to depend on prey species. Higher feeding frequencies may lead to a higher risk of nest predation. Being single-brooded, Whinchat populations may be more affected by nest predation than populations of multi-brooded species. [ABSTRACT FROM AUTHOR]

The Aquatic Warbler Acrocephalus paludicola is a globally threatened, long-distance migratory passerine that continues to decline in abundance and range. Studies throughout its annual cycle are needed, including during migration, when information on habitat availability and usage are important for conservation. Here, the autumn occurrence (distribution, abundance, phenology) of Aquatic Warblers in Portugal is described taking advantage of an increase in capture effort with diurnal song playback. The species was captured at six new sites and seen at a further three, increasing the total number of sites to 16. Salreu marshlands appeared to be the most important with 93% of all captures since 2009, although ringing effort was highly variable between sites. We show that song playback did not influence age nor sex ratios, but tended to attract individuals with lower body mass, presumably those that arrived recently at stopover sites. Adult males migrated earlier than all other sex and age categories, in accordance with their limited role in parental care. Furthermore, we show that at least some individuals fuel up at Portuguese stopovers, which increases their importance for conservation. In addition, at Salreu marshlands, the abundance of Aquatic Warblers was significantly greater at an active than at a dry, abandoned (extensive) rice field, suggesting this land-use change may affect the quality of stopover sites. Recommendations regarding habitat management and conservation measures are proposed. [ABSTRACT FROM AUTHOR]

Drought dramatically impacts the autumn phenology of vegetation. However, the underlying mechanisms of vegetation autumn phenology responses to drought in tropical and subtropical forests remain unclear. Here, we employed three fitting methods to extract the end‐of‐photosynthetic‐growing‐season (EOPS) dates and quantified their responses to drought intensity using ridge regression and correlation analysis. Our analysis revealed a general delay in the trend of EOPS at an average rate of 3.6 days per decade from 2001 to 2020 in southern China. The standardized precipitation evapotranspiration index (SPEI) emerged as the primary influencing predictor of EOPS processes, surpassing the impacts of temperature, precipitation, and radiation. Notably, our analysis highlighted a shift in the response of EOPS to drought from delay to advancement when drought intensity exceeded 0.38. Incorporating this reversal phenomenon into EOPS models is crucial for accurately predicting autumn phenology under future escalating drought conditions. Plain Language Summary: Ongoing climate change is substantially altering autumn phenology, and subsequently impacting terrestrial carbon and water balance. Tropical and subtropical forests, being major reservoirs of global carbon, are experiencing notable effects due to escalating drought conditions. However, the underlying mechanisms of its autumn phenology responses to drought remain unclear. We employed three fitting methods to extract the end‐of‐photosynthetic‐growing‐season (EOPS) dates of subtropical and tropical forests and quantified their response to drought intensity through ridge regression and correlation analysis. Our analysis revealed a delay in EOPS across over 70% of the studied forests during the period 2001–2020, and we found that the standardized precipitation evapotranspiration index (SPEI) primarily determined the EOPS processes. Interestingly, our analysis demonstrated a shift in the response of EOPS to drought from delay to advancement when drought intensity exceeded 0.38. These findings underscore the existence of a critical threshold in drought severity, beyond which a reversal in the response of EOPS to drought is anticipated. This reversal effect may stem from vegetation's adaptive strategies and environmental constraints. Incorporating this reversal phenomenon into EOPS modeling is imperative for enhancing predictions of autumn phenology and advancing our comprehension of carbon and water balances in forest ecosystems. Key Points: The standardized precipitation evapotranspiration index (SPEI) emerged as the primary influencing predictor factor on EOPS processesIncreasing drought induces contrasting shifts in the autumnal photosynthetic phenology of tropical and subtropical forestsThe effect of drought on autumn photosynthetic vegetation phenology shifts from delay to advancement as drought intensity exceeds 0.38 [ABSTRACT FROM AUTHOR]

Early maturity and simultaneous increase in yield of cotton are pivotal for increasing the productivity of cropping systems involving cotton. Current two-year study was performed to simultaneously enhance the earliness and yield of cotton by modulating plant population (PP) (5.3 and 8.8 plants m−2), foliar boron (B) (0, 0.6 and 1.2 g/L B) and 0.07 g/L mepiquat chloride (MC) solution (at squaring and flowering stages) application. Internodes length was exalted at high PP (8.8 plants m-2) and B (1.2 g/L B), while declined by MC. Nevertheless, nodes above the white flower and cracked boll were decreased at high PP, and the application of B and MC indicated earlier cutout. Similarly, high PP, and application of 1.2 g/L B and MC at squaring reduced calendar and thermal time needed for flowering and boll opening. The boll maturation period was not affected by the application of B and MC but declined at high PP. Earliness index, production rate index (PRI) and seed cotton yield were increased at high PP, application of 1.2 g/L B and MC at squaring. In crux, increasing PP and B concentration, and MC application at squaring resulted in early maturity and enhanced seed cotton yield by modulating plant structure and time required for various phenophases. [ABSTRACT FROM AUTHOR]

The extended distributional record of a threatened species of Ceropegia namely Ceropegia gardneri from Kerala is provided. This species exhibits a narrow range of distribution along the Western Ghats and in Sri Lanka. Details of four other rare species of Ceropegia are also given. Notes on taxonomy, phenology, distribution and conservation status are also provided for the better understanding of the species. [ABSTRACT FROM AUTHOR]

Summary Societal impact statement The European spruce bark‐beetle, Ips typographus, is a major pest of Norway spruce across mainland Europe; however, until 2018, it was considered absent from the United Kingdom (UK). The finding of a breeding population of I. typographus in Kent, England, in 2018 and subsequent findings in pheromone traps across the southeast of England, has led to an urgent need to improve understanding of environmental suitability across the UK. Two distinct published phenological models for I. typographus, developed in Sweden and Austria, were adapted for use in the UK and validated against pheromone trap data collected at the original site of infestation and in the surrounding area from 2019 to 2022. Both models captured some, but not all, of the within‐season variation in trap catches. One, the PHENIPS model, more accurately captured early season flight patterns. The climate in the southeast of England is mild enough to facilitate two generations of the beetle, while further north the pest is expected to be univoltine. At high altitude in Scotland, there is insufficient thermal warming within a season for the completion of one annual generation. Phenological modelling does not explain why the pest failed to establish in England prior to 2018 including when a large amount of infested material was imported to sawmills in the 1940s. Under 2 and 3°C global warming scenarios, we might expect to see an increase in potential voltinism across the UK in the next few decades, increasing the risk of large outbreaks of I. typographus were it allowed to establish. In 2018, a breeding population of the European spruce bark‐beetle, Ips typographus, was discovered in woodland in southeast England. Ips typographus is a major forest pest in continental Europe; however, despite previous findings at ports and sawmills, this was the first recorded infestation in the UK. The number of generations per year (voltinism) varies with latitude and altitude. Applying a phenological model, we find that the current climate in southern UK could support two generations, while temperature accumulation in parts of Scotland may be insufficient to support one generation. Global warming will increase voltinism and hence the risk of establishment. [ABSTRACT FROM AUTHOR]

Phenological mismatch has been highlighted as a reason why climate change is causing declines of migratory populations. The likelihood of declines due to phenological mismatch might depend on what cues trigger migration. Migrants that use environmental cues (e.g. temperature, resource availability) to trigger migration are often considered to be less vulnerable than migrants that use temporal information (e.g. photoperiod). We developed a proof‐of‐concept model that demonstrates that which cue type performs better in the context of phenological change can depend on differences in seasonal amplitude between the habitats used by a migrant. Environmental cues perform better than temporal cues when the habitat that undergoes a phenological change has a larger seasonal amplitude. This result aligns with observations that populations of short‐distance migrants that use environmental cues are less likely to decline as a consequence of phenological mismatch than long‐distance avian migrants that use temporal cues. Temporal cues perform better than environmental cues when the habitat that undergoes a phenological change has a smaller seasonal amplitude. This result may correspond to empirical scenarios where the more seasonal habitat is associated with variation in precipitation patterns or human actions that are not changing in phenology. In addition to these results, we offer distinctions that will help clarify future work on phenological mismatch. First, we highlight the difference between the cue accuracy (difference between the timing of migration using the cue and optimal migration timing) and the cue efficacy (the difference between the fitness using the cue and the fitness using optimal migration). Second, we recommend considering both how the benefits available from migrating and the benefits that are captured by migrants change with phenological change. [ABSTRACT FROM AUTHOR]

Temperate winters are getting warmer, the length of the growing season is increasing and mid‐winter fluctuations of warm and freezing temperatures are more frequent. Although typically winter dormant, some herbaceous perennials can maintain or grow green leaves during the winter and more species may do so as winters become warmer. For wintergreen leaves to provide an advantage, they must be able to photosynthesize during the warm spells but also withstand freezing temperatures and fluctuations between the two conditions. To understand the leaf traits of wintergreen herbs, we studied three widely distributed perennial species: Bellis perennis, Plantago lanceolata and Trifolium repens. For contrast between winter and growing season leaves, we measured three common leaf economic traits (LDMC, SLA and leaf N content). To assess freezing tolerance, we measured the ice nucleation temperature and LT50 after frost exposure in winter leaves. To confirm photosynthetic ability, we measured photosynthetic efficiency (Fv/Fm value) in winter and late spring. Additionally, we surveyed the green and dead leaf coverage for herbaceous species in a lawn community from winter to early summer (four surveys in total). We used our observations to determine phenological categories and compared them to historical observations of wintergreenness. All three species had denser leaves with lower nitrogen content in winter than in the growing season and relatively high tolerance of freezing temperatures (average of −8°C ice nucleation temperature and −15°C LT50). Both winter and growing season leaves were capable of photosynthesis, but the efficiency was greater for growing season leaves. In the community survey, a majority of the plant species had green leaves in winter, and many were without dead winter leaves. Many wintergreen herbs had previously been labelled ‘summer green’. With these initial investigations into the traits and phenology of wintergreen herbs, we confirm that wintergreen leaves have different traits from typical growing season leaves and are capable of both photosynthesis and freezing tolerance. Wintergreen herbs have a broad range of phenological strategies and differ from observations 20 years ago. In many temperate regions, winter is becoming a new growing season and thus should be included in phenological studies. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Cold ecosystems are experiencing a warming rate that is twice as fast as the global average and are particularly vulnerable to the consequences of climate change. In mountain ecosystems, it is particularly important to monitor vegetation to understand ecosystem dynamics, biodiversity conservation, and the resilience of these fragile ecosystems to global change. Hence, we used satellite data acquired by Sentinel-2 to perform a comparative assessment of the Normalized Difference Vegetation Index (NDVI) and the Plant Phenology Index (PPI) in mountainous regions (canton of Valais-Switzerland in the European Alps) for monitoring vegetation dynamics of four types: deciduous trees, coniferous trees, grasslands, and shrublands. Results indicate that the NDVI is particularly noisy in the seasonal cycle at the beginning/end of the snow season and for coniferous trees, which is consistent with its known snow sensitivity issue and difficulties in retrieving signal variation in dense and evergreen vegetation. The PPI seems to deal with these problems but tends to overestimate peak values, which could be attributed to its logarithmic formula and derived high sensitivity to variations in near-infrared (NIR) and red reflectance during the peak growing season. Concerning seasonal parameters retrieval, we find close concordance in the results for the start of season (SOS) and end of season (EOS) between indices, except for coniferous trees. Peak of season (POS) results exhibit important differences between the indices. Our findings suggest that PPI is a robust remote sensed index for vegetation monitoring in seasonal snow-covered and complex mountain environments. [ABSTRACT FROM AUTHOR]

Gardens can benefit pollinators living in surrounding farmland landscapes, but the reason for their value is not clear. Gardens are no different from many semi-natural farmland habitats in terms of the quantity of floral resources (pollen and nectar) they produce, but the timing of their resource supply is very different, which may explain their value. We show that gardens provide 15% of overall annual nectar in farmland landscapes in Southwest UK, but between 50% and 95% during early spring and late summer when farmland supplies are low. Gardens can therefore reduce seasonal nectar gaps experienced by farmland bumblebees. Consistent with this pattern, bumblebee activity increased in gardens relative to farmland during early spring and late summer. An agent-based model reinforces this point, showing that timing, not quantity, of garden nectar supply enhances bumblebee colony growth and survival in farmland. We show that over 90% of farmland in Great Britain is within 1 km of a garden and therefore positive actions by gardeners could have widespread spillover benefits for pollinators across the country. Given the widespread distribution of gardens around the world, we highlight their important interplay with surrounding landscapes for pollinator ecology and conservation. [ABSTRACT FROM AUTHOR]

Summary: Integrating traits across above‐ and belowground organs offers comprehensive insights into plant ecology, but their various functions also increase model complexity. This study aimed to illuminate the interspecific pattern of whole‐plant trait correlations through a network lens, including a detailed analysis of the root system.Using a network algorithm that allows individual traits to belong to multiple modules, we characterize interrelations among 19 traits, spanning both shoot and root phenology, architecture, morphology, and tissue properties of 44 species, mostly herbaceous monocots from Northern Ontario wetlands, grown in a common garden.The resulting trait network shows three distinct yet partially overlapping modules. Two major trait modules indicate constraints of plant size and form, and resource economics, respectively. These modules highlight the interdependence between shoot size, root architecture and porosity, and a shoot–root coordination in phenology and dry‐matter content. A third module depicts leaf biomechanical adaptations specific to wetland graminoids. All three modules overlap on shoot height, suggesting multifaceted constraints of plant stature. In the network, individual‐level traits showed significantly higher centrality than tissue‐level traits do, demonstrating a hierarchical trait integration.The presented whole‐plant, integrated network suggests that trait covariation is essentially function‐driven rather than organ‐specific. See also the Commentary on this article by Li & He, 244: 337–340. [ABSTRACT FROM AUTHOR]

Winter dormancy is a key process in the phenology of temperate perennials. Climate change is severely impacting its course leading to economic losses in agriculture. A better understanding of the underlying mechanisms, as well as the genetic basis of the different responses, is necessary for the development of climate-resilient cultivars. This study aims to provide an insight into winter dormancy in red raspberry (Rubus idaeus L). We report the transcriptomic profiles during dormancy in two raspberry cultivars with contrasting responses. The cultivar 'Glen Ample' showed a typical perennial phenology, whereas 'Glen Dee' registered consistent dormancy dysregulation, exhibiting active growth and flowering out of season. RNA-seq combined with weighted gene co-expression network analysis identified gene clusters in both genotypes that exhibited time-dependent expression profiles. Functional analysis of 'Glen Ample' gene clusters highlighted the significance of the cell and structural development prior to dormancy entry as well the role of genetic and epigenetic processes such as RNAi and DNA methylation in regulating gene expression. Dormancy release in 'Glen Ample' was associated with up-regulation of transcripts associated with the resumption of metabolism, nucleic acid biogenesis, and processing signal response pathways. Many of the processes occurring in 'Glen Ample' were dysregulated in 'Glen Dee' and 28 transcripts exhibiting time-dependent expression in 'Glen Ample' that also had an Arabidopsis homologue were not found in 'Glen Dee'. These included a gene with homology to Arabidopsis VRN1 (RiVRN1.1) that exhibited a sharp decline in expression following dormancy induction in 'Glen Ample'. Characterization of the gene region in the 'Glen Dee' genome revealed two large insertions upstream of the ATG start codon. We propose that expression below detection level of a specific VRN1 homologue in 'Glen Dee' causes dormancy misregulation as a result of inappropriate expression of a subset of genes that are directly or indirectly regulated by RiVRN1.1. [ABSTRACT FROM AUTHOR]

The phenology of temperate perennials, including the timing of vegetative growth and flowering, is well known to be controlled by seasonal dormancy cycles. Dormant structures are known as buds and have specialized covering structures, symplastic isolation from the plant, and often autonomous stores of carbon and nitrogen reserves. In contrast, in annual plants, our current understanding of the control of the timing of flowering focuses on the mechanisms affecting floral initiation, the transition from a vegetative apical meristem to a inflorescence meristem producing flower primordia in place of leaves. Recently we revealed that annual crops in Brassicaceae exhibit chilling-responsive growth control in a manner closely resembling bud dormancy breakage in perennial species. Here I discuss evidence that vernalization in autumn is widespread and further discuss its role in inducing flower bud set prior to winter. I also review evidence that flower bud dormancy has a more widespread role in annual plant flowering time control than previously appreciated. [ABSTRACT FROM AUTHOR]

To predict ecosystem change in the Arctic Ocean, understanding Arctic phytoplankton phenology is essential. We develop a marine ecosystem model focusing on phytoplankton dynamics and the competition for multiple resources based on knowledge from in situ data obtained in the Chukchi Sea. The model is designed to include the unique ecological characteristics of the Arctic Ocean. To the best of our knowledge, this is the first model successfully simulating the current paradigm for Arctic phytoplankton phenology, including both under‐ice blooms and succession of phytoplankton groups. Sensitivity experiments show that the dominance of diatoms can be sustained by lateral transport of a high‐silicate water mass (Pacific Winter Water). Experiments for future scenarios show that sea ice retreat drives a decrease in large diatoms and an increase in the other relatively small non‐diatom groups. These results suggest that dominant phytoplankton groups can be shifted from diatoms to non‐diatoms under ongoing Arctic Ocean sea ice retreat. Plain Language Summary: Understanding the phytoplankton ecology of the Arctic Ocean is important for predicting ecosystem change as sea ice retreats. We have developed a phytoplankton ecosystem model that describes three different phytoplankton groups, each of which competes for three different nutrients. The model successfully simulates the observed characteristics of the Arctic phytoplankton ecology, such as under‐ice blooms and the growth and decline of the various phytoplankton groups, which was not successfully simulated by previous models. Our results show that horizontal transport of waters with high silicate concentrations play a key role in sustaining silicate‐dependent phytoplankton (diatom) groups. Simulations that explore future sea ice retreat scenarios suggest that the dominant phytoplankton group can be significantly altered by the changing conditions of the Arctic Ocean. Key Points: We develop new ecosystem model for phytoplankton phenology during ice‐covered to open‐water periods using observations from the Chukchi SeaThe model successfully captures the succession of phytoplankton groups reported by previous studies, not resolved by previous modelsThe model predicts that dominant phytoplankton groups can be significantly altered by future sea ice scenarios [ABSTRACT FROM AUTHOR]

Recruitment of the catadromous and critically endangered European eel Anguilla anguilla in Europe has declined substantially since the 1980s, with considerable knowledge gaps remaining in many aspects of their life cycle. The aim was to assess eel migration phenology in three regulated rivers in England between 2009 and 2019 through analyses of eel numbers using passes at their tidal limits, with calculation of the annual timings of migration initiation (10% of all eels passed, T10), peak (50%, T50) and conclusion (90%, T90). Across the three rivers, T10 varied between Julian Day ('Day') 94 and 173. Years of earlier T10 had significantly earlier T50, where T50 varied between Day 105 and 200. The considerable inter-annual variability in migration timings was associated with environmental variables; earlier T10 and T50 occurred in years of warmer river temperatures (RTs) and cooler sea surface temperatures (SST), and in years where RTs were higher than SSTs. No environmental variables were significant predictors of T90. These results indicate that whilst there is annual variability in the timing of eel migration initiation and peak into freshwaters, this variability is predictable according to differences in environmental conditions. As many of these conditions associated with annual variability in temperature and precipitation then climate change has the potential to shift these migration timings. [ABSTRACT FROM AUTHOR]

The papers presented in this special issue cover a wide range of topics including the impact of climate change on Indian biodiversity through modelling approaches, the resilience of ecosystems to climate-induced shifts, and the role of remote sensing in monitoring forest dynamics. This body of research focuses on various ecological systems, highlighting the consequences of climate change and providing actionable insights for conservation policy and practice. By addressing data gaps, enhancing model precision, and integrating technological advancements like GIS and Earth Observation systems, this research supports the ongoing efforts to conserve biodiversity in fragile ecosystems, such as the Himalaya. Furthermore, studies synthesising and collecting data on India's biodiversity help in understanding patterns of biodiversity and their biotic and abiotic drivers in the country's varied landscapes, which offer valuable perspectives on conservation and sustainable development strategies. By highlighting these diverse research efforts, this special issue seeks to advance our understanding of climate change impacts on biodiversity and foster the development of resilient ecosystems in alignment with the UN Sustainable Development Goals, particularly Goal 13 (Climate Action) and Goal 15 (Life on Land). [ABSTRACT FROM AUTHOR]

Unpredictably fluctuating environments create complex selective landscapes that shape the distribution of key life history traits. Identifying the mechanisms behind dynamic patterns of selection is difficult, yet essential for predicting responses to climate change. We combine long-term measures with field manipulation of natural selection on breeding date in a wild bird to investigate whether highly variable spring cold snaps drive fluctuating selection. We show that variation in cold snap intensity leads to fluctuating selection on breeding date—in weak cold snap years, selection was consistently negative; however, in strong cold snap years, its direction reversed. These patterns were mirrored in a field experiment; nests that were food supplemented during cold snaps avoided cold snap mortality leading earlier breeders to have higher fitness. In contrast, in the non-supplemented group earlier breeders had higher cold snap nest mortality and selection was positive. Using nearly a century of climate data, we show that cold snaps are becoming less frequent and paradoxically occurring later which should allow earlier breeders to avoid them, potentially releasing conflicting selection pressures and facilitating a rapid phenological shift. Thus, rather than constraining a species' ability to adapt, climate change can enable a rapid shift to a new phenotypic optimum. [ABSTRACT FROM AUTHOR]

The bogong moth, Agrotis infusa, an endemic noctuid moth of Australia, is known for its extensive long‐distance movement and summer aestivation in the Australian Alps. Recent studies have focused on moth activity in the Alps, but there are limited data for other regions. This study aims to build on the current understanding of bogong moth movement and breeding patterns using unpublished historical data across eastern Australia. We analysed historical data from moth traps in Victoria, New South Wales (NSW) and South Australia (SA) from the 1960s to early 1990s. The study employed the HYSPLIT model for trajectory analysis of moth flight paths and DARABUG2 for phenological modelling. We examined moth catches across different seasons to infer movement patterns, breeding sources and over‐summering activity. Our findings question several long‐standing assumptions about the spatial ecology of the bogong moth. The trajectory analysis suggests that many aspects of A. infusa movement can be explained via dynamic migration, without fully relying on inherent navigation abilities. Important breeding areas may be beyond the self‐mulching clays of NSW and southern Queensland and include far western NSW, south and central SA and southern Victoria. Substantial moth activity during summer in many traps suggests alternative over‐summering strategies including local breeding or even aestivation in areas other than the Alps. Furthermore, the autumn and winter data imply return migrations from diverse source areas and potential local breeding, expanding the understanding of the moth's life cycle beyond a univoltine pattern. In conclusion, the bogong moth appears to exhibit a more complex and adaptable migration and breeding strategy than previously understood, utilising a range of habitats across eastern Australia for breeding and possibly aestivation. This underscores the need for a revised understanding of bogong moth ecology, which is crucial for its conservation and management, especially considering its recent classification as ‘Endangered’ on the IUCN Red List. [ABSTRACT FROM AUTHOR]

Recently, population declines have been reported for many migratory birds. Because of complex life cycles, determining the causes for such declines is often difficult. Thus, migratory birds are of special conservation interest. We studied the migratory behavior of Hirundo rustica (Barn Swallow) tagged with solar geolocators and determined carryover effects during the entire annual cycle from one breeding season to the next. We used a partial least squares path model (PLS-PM) to disentangle migratory and breeding events that occur in chronological order. In addition, we controlled for broad environmental conditions in the wintering grounds (NDVI and latitude) and the specific molting habitat (δ13C). We did not find a carryover effect from reproduction investment in the attachment year to breeding success in the subsequent year. Individuals that invested more in reproduction departed earlier from the breeding colonies, but this in turn did not affect the onset of autumn migration. Thus, the premigratory period should be acting as a buffer stage counteracting any previous carryover effects from reproduction investment. On the other hand, we found a long-lasting domino effect from the onset of autumn migration to subsequent breeding success, consistent with the notion of a migratory race. Specifically, individuals which started earlier in the autumn migration arrived earlier to the wintering grounds, started earlier in the spring migration arrived earlier to the breeding colonies, and had a higher breeding success. We highlight that the premigratory period (i.e. the time elapsed between departure from breeding areas and the onset of autumn migration) should be important for the life cycle of migratory species, but it has been frequently overlooked. [ABSTRACT FROM AUTHOR]

Background and Aims Pit pairs and their filter-like partition, i.e. pit membranes, play important roles as water pathways, barriers and regulators in the water-conducting system of angiosperms. In Fraxinus species, the intervessel and vessel–parenchyma pit membranes in sapwood are normally encrusted during winter. Although these encrustations inevitably influence the performance of pits, their properties and functions remain unclear. This study aimed to reveal the morphological and chemical characteristics of encrustations in F. mandshurica in order to deepen understanding of the seasonal encrustation of pit membranes. Methods Seasonal and positional variations in the presence and morphology of encrustations were examined by field-emission scanning electron microscopy (FE-SEM). Cryo-FE-SEM for freeze-fixed greenwood samples was conducted to clarify whether encrustations were present in living trees. Chemical components were examined by histochemical staining using light and electron microscopy, immunofluorescence labelling and ultraviolet microspectroscopy. Key Results Encrustations began to deposit in autumn before leaf senescence and disappeared in spring before bud flushing. They infiltrated within the pit membranes, which suggested that they severely limit the permeation of pits. The encrustations differed in morphology among positions: they entirely filled the pit chambers in latewood, while they covered the pit membranes in earlywood. The encrustations were similarly observed in the samples that were freeze-fixed immediately after collection, indicating that they are present in living trees. The encrustations contained polysaccharides, including xyloglucan and homogalacturonan, and phenolic compounds, possibly including flavonoids and coumarins. These chemical components were also detected in droplets found in the latewood vessels with the encrustations, suggesting that the materials constituting encrustations were supplied through the vessel lumens. Conclusions Encrustations undoubtedly cover the pit membranes in living F. mandshurica trees in winter and their morphology and chemical composition indicate that they are impermeable, have positional differences in function and are characterized by elaborate deposition/removal processes. [ABSTRACT FROM AUTHOR]

Background and Aims Spring phenological change of plants in response to global warming may affect many ecological processes and functions. Chilling temperature regulates budburst date by releasing dormancy. However, whether freezing temperatures (<0 °C) contribute to dormancy release remains of debate. Our poor understanding of the role of chilling makes estimating shifts in budburst date difficult. Methods A 2-year chilling–forcing experiment was explicitly designed to test the effects of chilling temperatures on dormancy release of nine temperate woody species in Beijing, China. A total of 1620 twigs were first exposed to a wide range of temperatures (−10 to 10 °C) with different durations and then moved to growth chambers. Based on budburst data in experimental conditions, we examined whether freezing temperatures are effective on dormancy release. We also developed a new framework for constructing chilling functions based on the curve between chilling duration and forcing requirement (FR) of budburst. The chilling function derived from this framework was not affected by experimental forcing conditions. Key Results We demonstrated that freezing temperatures down to −10 °C were effective in dormancy release. The rate of dormancy release, indicated by the rate of decay in the chilling duration–FR curve, did not differ significantly between chilling temperatures in most cases, although it exhibited a maximum value at 0 or 5 °C. The chilling function-associated phenological models could simulate budburst date from independent experimental and observational data with a mean RMSE of 7.07 d. Conclusions The effective freezing temperatures found here are contrary to the well-known assumption of <0 °C temperature generally not contributing to accumulated chilling in many previous chilling functions. A chilling function assuming that temperature below an upper temperature threshold has the same effects on dormancy release could be adopted to calculate chilling accumulation when using experiments to develop spring phenological models based on the chilling–forcing relationship. [ABSTRACT FROM AUTHOR]

Introduction Water deficit is one of the most important factors limiting crop production under rainfed condition. Several methods have been proposed to increase the resistance of crops against water deficit. In this regard, foliar application of methanol and nano zinc oxide can improve the performance of crop plants under water limitation conditions. Zinc deficiency is recognized as a critical problem in plants, especially when grown on soils with high pH values. But, recent researches have shown that application of micronutrients, including Zn, in the form of nano-fertilizers is a viable criterion for growing plants under water deficit condition, as it increases resource use efficiency and reduces environmental pollution. Also, foliar-applied methanol can increase the concentration of CO2 inside the plant tissue and promote photosynthesis rate and growth under water deficit conditions. On the other hand, water deficit is mitigated by stress modulators such as methanol and nano zinc oxide through a variety of mechanisms, including increased photosynthetic efficiency and nutrient acquisition in plants, and enhancement of the antioxidant system towards preventing damage from reactive oxygen species. Considering the above fact, the present study was undertaken to evaluate the effects of nano zinc oxide and methanol foliar application on grain yield and some physiological traits (i.e, relative water content, electrical conductivity of flag leaf, dry matter remobilization from plant’s above-ground parts and hence contribution of photoassimilates remobilization in grain yield) of wheat under rainfed conditions. Materials and Methods A factorial experiment was conducted based on a randomized complete block design with three replications in Sarab in north-west of Iran, in 2018-2019. Experimental factors included nano zinc oxide foliar application at four levels (foliar application with water as control, 0.3, 0.6, and 0.9 g L-1) and methanol application at four levels (foliar application with water as control, 10, 20, and 30% v/v). Methanol was prepared from Mojallal Co. and nano zinc oxide from Pishgaman Nanomaterials Co. Nano zinc oxide consisted of particles of less than 30 nm. Foliar application of nano zinc oxide and methanol were done in stages of tillering and boot stage. Relative water content (RWC) and electrical conductance (EC) of flag leaves was calculated based on the given formula Kheirizadeh Arough et al (2015): RWC (%) = [(FW-DW)/(TW-DW)] × 100 (1) where FW is the fresh weight; DW is the dry weight; and TW is the turgid weight. From each plot, the samples of developed flag leaf were randomly selected and after placing them in aluminum foils, they were transferred to the laboratory very quickly, then the flag leaf samples were kept in flasks containing 25 ml of distilled water. It was then placed at room temperature for 24 hours and then the electrical conductivity was measured by an EC meter (Mi 180 Bench Meter). Dry matter and remobilization of stem reserves to grain yield were evaluated as follows: Dry matter remobilization from shoot (g plant-1) = maximum of dry matter of shoot after anthesis (g plant-1) - shoot dry matter (grains excluded) in maturity (g plant-1). Contribution of dry matter remobilization to grain (%) = [dry matter remobilization from shoot (g plant-1) /grain yield (g plant-1)] × 100. Contribution of dry matter remobilization from stem to grain yield (g plant-1) = [maximum of stem dry matter after anthesis (g plant-1) - stem dry matter in maturity (g plant-1) ] × 100. Analysis of variance was done by SASv9.12. The main effects and interactions were compared by LSD test at the 0.05 probability level. Results and Discussion: Mean comparison showed that the least of dry matter remobilization from above-ground parts (0.21 g plant-1) and contribution of remobilization to grain yield (23.6%), dry matter remobilization from stem (0.17 g plant-1) and contribution of stem reserves to grain yield (10.3%) were obtained at the highest level of nano zinc oxide application. Similar results were obtained in these traits at the highest level of methanol application. Foliar spraying of high rates of nano zinc oxide and methanol increased the relative water content of flag leaf in ear emergence (17%) and grain filling stages (11%), zinc content (62%), protein content (14%) and grain yield (33%) in comparison to control. Conclusions Results of this study taken together, it seems that application of 0.9 g L-1 nano zinc oxide with 30% v/v of methanol can be suggested for improvement of physiological traits and thereby increase in grain yield of wheat under rainfed conditions. [ABSTRACT FROM AUTHOR]

Climate change is shifting the phenology of migratory animals earlier; yet an understanding of how climate change leads to variable shifts across populations, species and communities remains hampered by limited spatial and taxonomic sampling. In this study, we used a hierarchical Bayesian model to analyse 88,965 site‐specific arrival dates from 222 bird species over 21 years to investigate the role of temperature, snowpack, precipitation, the El‐Niño/Southern Oscillation and the North Atlantic Oscillation on the spring arrival timing of Nearctic birds. Interannual variation in bird arrival on breeding grounds was most strongly explained by temperature and snowpack, and less strongly by precipitation and climate oscillations. Sensitivity of arrival timing to climatic variation exhibited spatial nonstationarity, being highly variable within and across species. A high degree of heterogeneity in phenological sensitivity suggests diverging responses to ongoing climatic changes at the population, species and community scale, with potentially negative demographic and ecological consequences. [ABSTRACT FROM AUTHOR]

Migratory fish species have been particularly impacted by changes to the hydrologic and climatic cues to which migration and spawning behaviours have been adapted across generations. While conservation and recovery programs increasingly implement flow management actions to promote successful migration and spawning, uncertainty regarding how spawning migration phenology responds to changing environmental conditions can limit the ability to effectively target such recovery actions. Here, we use a Bayesian hierarchical modelling framework to analyse spawning migration phenology of individually tagged June suckers (Chasmistes liorus) – a federally threatened, long‐lived, iteroparous, adfluvial species endemic to Utah Lake (Utah, USA) and its tributaries. We then examine how annual hydrologic and thermal conditions relate to different components of annual migration phenology, including peak migration date, in‐stream residence time, and among‐individual variation in migration timing. Peak migration date occurred earlier in years with warmer spring air temperatures (a proxy for water temperatures), though this effect interacted with peak runoff timing. Both residence time and among‐individual variation in migration timing were greater in years with larger spring discharge and later peak flows. Residence time was also longer in warmer years. These results highlight how natural and anthropogenic changes to river flow and thermal regimes are likely to impact June sucker migration timing and duration, and our approach can be applied to other migratory species to identify the external drivers of the different components of migration phenology. [ABSTRACT FROM AUTHOR]

Tropical mountain ecosystems harbor diverse biological communities, making them valuable models for exploring the factors that shape ecological interactions along environmental gradients. We investigated the spatial and temporal drivers of plant–hummingbird interaction networks across three forest types (pine‐oak, fir, and subalpine) along a tropical high mountain gradient in western Mexico (2400 to 3700 m.a.s.l.). We measured species abundance, diversity, morphology, and interaction frequencies. Plant diversity metrics significantly declined in the highest elevation subalpine forest, whereas hummingbird diversity remained consistent across elevations. Interaction networks were similarly nested across elevations, but they were more specialized in the subalpine forest, where lower plant species richness and higher floral abundance led to greater resource partitioning among hummingbirds. Plant–hummingbird networks were larger and less specialized during the dry season, driven by greater species diversity and abundance. Species turnover explained network variation along the elevational gradient, while interaction rewiring and the arrival of migratory hummingbirds explained changes between seasons. Phenological overlap was the most important driver of the observed variation in interaction frequencies across elevations and seasons. Flower abundance had a minor influence on interaction frequencies at low‐ and mid‐elevation networks, and hummingbird abundance was significant for dry‐ and rainy‐season networks. Morphological matching was significant in the low‐elevation forest and in the dry season. Plant phylogenetic relatedness had negligible effects on interaction patterns, but hummingbird phylogeny influenced feeding preferences in high‐elevation and rainy‐season networks. Our findings highlight the role of species turnover, interaction rewiring, and phenological overlap in structuring plant–hummingbird networks, with specific effects of abundance, morphology, and phylogeny varying with elevation and season. High‐elevation ecosystems play a crucial role as reservoirs of floral resources for both resident and migratory hummingbirds during resource‐scarce periods, emphasizing their importance in maintaining biodiversity in tropical mountain gradients. [ABSTRACT FROM AUTHOR]

For organisms in temperate environments, seasonal variation in resource availability and weather conditions exert fluctuating selection pressures on survival and fitness, resulting in diverse adaptive responses. By manipulating resource availability on a local spatial scale, we studied seasonal patterns of resource use within natural populations of burying beetles Nicrophorus vespilloides in a Norfolk woodland. Burying beetles are necrophagous insects that breed on vertebrate carcasses. They are active in Europe between April and October, after which they burrow into the soil and overwinter. Using breeding and chemical analyses, we compared the fecundity and physiological state of beetles that differed in their seasonal resource use. We found seasonal variation in carrion use by wild burying beetles and correlated differences in their reproductive success and cuticular hydrocarbon profiles. Our results provide novel insight into the seasonal correlates of behaviour, physiology and life history in burying beetles. [ABSTRACT FROM AUTHOR]

Research into freshwater communities often aims to link patterns of species distribution in ponds with underlying biotic factors. However, errors with species detection (e.g. false negatives) may underestimate distribution and bias assessments of community structure. Occupancy models that account for imperfect detection offer a solution to this problem. Here, we used three methods (call/visual encounter surveys, dip‐netting and newt trapping) to survey amphibians and fish (potential amphibian predators) at 100 ponds in an urbanised landscape in Hungary over one breeding season. We estimated species detection probabilities for amphibians (all life stages combined) and fish using occupancy models to gain insight into amphibian‐fish relationships and other survey‐specific variables. We detected nine amphibian and 20 fish species. There were relatively low but variable estimated probabilities of detection for amphibians (mean: 0.320, 95% Bayesian credible interval: 0.142–0.598), with three species having detection rates < 0.1. Probabilities of detection peaked in the middle of the breeding season and increased with survey effort. Detection probabilities of five species were negatively associated with the detection of fish at a pond, while there were positive relationships between detection and emergent vegetation cover. We found no substantial differences in detection rates among the three survey methods. The probability of detecting fish was much higher than for amphibians (0.588, 0.503–0.717) but was lower at ponds with high emergent vegetation where amphibian detection was higher. Our results underscore the importance of accounting for the imperfect detection of both response organisms and potentially interacting species in aquatic community studies. We recommend applying multi‐species occupancy models to enable inference for both common and rare species at ponds in landscapes subjected to human disturbances. [ABSTRACT FROM AUTHOR]

The temporal separation of male and female flowering—known as dichogamy—is a widespread adaptation across the plant kingdom that increases reproductive success and enhances plant fitness. Differences in timing between male and female flowering can be highly sensitive to environmental variation—and with widespread evidence of shifts in seasonal timing of flowering (i.e., phenology) due to anthropogenic warming—climate change may alter the sequences of male and female flowering for a diversity of taxa around the globe. However, we currently lack a broad understanding of both the extent to which climate change may alter patterns of dichogamy and the potential implications of these shifts for plant reproduction. Here I present evidence that links variation in dichogamy to variation in temperature for a variety of plant taxa. I synthesize the limited number of studies that have investigated shifts in dichogamy specifically in the context of climate change, and detail the physiological, genetic, and developmental factors that control the relative timing of male and female flowering. The literature indicates that dichogamy is highly plastic and sensitive to temperature variation. Plasticity in dichogamy is observed across species with different sexual systems and growth habits, and in both female‐first and male‐first flowering taxa, but at present, no clear patterns of dichogamy shifts related to these associated traits are discernible. Together, these lines of evidence suggest that sequences of male and female flowering are likely to shift with climate change. However, more research is needed to better understand and predict the ecological consequences of shifting patterns of dichogamy in the context of global change. [ABSTRACT FROM AUTHOR]

In long‐distance dispersal events, colonising species typically begin with a small number of founding individuals. A growing body of research suggests that establishment success of small founding populations can be determined by the context of the colonisation event and the new environment. Here, we illuminate the importance of these sources of context dependence. Using a spatially explicit, temporally dynamic, mechanistic, individual‐based simulator of a model amphibian species, the cane toad (Rhinella marina), we simulated colonisation scenarios to investigate how (1) the number of founding individuals, (2) the number of dispersal events, (3) landscape's spatial composition and configuration of habitats ('spatially heterogeneous landscapes') and (4) the timing of arrival with regards to dynamic environmental conditions ('dynamic environmental conditions') influence the establishment success of small founding populations. We analysed the dynamic effects of these predictors on establishment success using running‐window logistic regression models. We showed establishment success increases with the number of founding individuals, whereas the number of dispersal events had a weak effect. At ≥ 20 founding individuals, propagule size swamps the effects of other factors, to whereby establishment success is near‐certain (≥ 90%). But below this level, confidence in establishment success dramatically decreases as number of founding individuals decreases. At low numbers of founding individuals, the prominent predictors are landscape spatial heterogeneity and dynamic environmental conditions. For instance, compared to the annual mean, founding populations with ≤ 5 individuals have up to 18% higher establishment success when they arrive in 'packed' landscapes with relatively limited and clustered essential habitats and right before the breeding season. Accounting for landscape spatial heterogeneity and dynamic environmental conditions is integral in understanding and predicting population establishment and species colonisation. This additional complexity is necessary for advancing biogeographical theory and its application, such as in guiding species reintroduction efforts and invasive alien species management. [ABSTRACT FROM AUTHOR]

Premise: Agriculture expansion, livestock, and global change have transformed biological communities and altered, through aerosols and direct deposition, N:P balance in soils of inter‐Andean valleys, potentially affecting flowering phenology of many species and thereby flowering synchrony and plant reproduction. Methods: We evaluated the influence of variation in temperature and moisture along the local elevational gradient and treatments with the addition of N and P and grazing on flowering synchrony and reproduction of Croton, a dominant shrub of the inter‐Andean dry scrub. Along the elevational gradient (300 m difference between the lowest and highest site), we set up plots with and without grazing nested with four nutrient treatments: control and addition of N or P alone or combined N + P. We recorded the number of female and male flowers in bloom monthly from September 2017 to August 2019 to calculate flowering synchrony. We assessed fruiting, seed mass, and pre‐dispersal seed predation. Results: Higher growing‐season soil temperatures, which were negatively associated with local elevation and higher nitrogen availability promoted flowering synchrony of Croton, particularly among larger plants. Greater flowering synchrony, high soil temperatures, and addition of N + P resulted in production of more fruits of Croton, but also intensified pre‐dispersal seed predation. Conclusions: Temperature, availability of moisture throughout the elevational gradient, and nutrient manipulation affected flowering synchrony, which subsequently affected production of fruits in Croton. These results emphasize the critical role of current anthropogenic changes in climate and nutrient availability on flowering synchrony and reproduction of Croton, a dominant plant of the inter‐Andean scrub. [ABSTRACT FROM AUTHOR]

Plant responses to damage by insectivorous herbivores are well-documented in mature leaves. The resulting herbivore-induced plant volatiles (HIPVs) protect the plant by attracting carnivorous arthropods and even some insectivorous vertebrates, to parasitize or consume the plant invaders. However, very little is known about plant production of HIPVs in developing buds, particularly when herbivorous insects are too small to be considered a prey item. It is additionally unclear whether plants respond differently to generalist and specialist chewing insects that overlap in distribution. Therefore, we compared HIPV production of Downy oak (Quercus pubescens Willd.) buds infested with freshly hatched caterpillars of Tortrix viridana (specialist) and Operophtera brumata (generalist), against uninfested buds. Of the compounds identified in both years of the experiment, we found that (Z)-hex-3-enyl acetate, (E)-β-ocimene, acetophenone, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, α-copaene, α-humulene, (E)-caryophyllene, and (E,E)-α-farnesene appeared to be higher in infested buds compared to controls. We found no difference in HIPV production between the specialist and the generalist herbivores. Production of HIPVs was also associated with leaf damage, with higher HIPV production in more severely attacked buds. Thus, our study shows that oak trees already start responding to insect herbivory before leaves are developed, by producing compounds similar to those found in damaged mature leaves. Future work should focus on how Downy oak may benefit from initiating alarm cues at a time when carnivorous arthropods and insectivorous vertebrates are unable to use herbivorous insects as host or food. [ABSTRACT FROM AUTHOR]