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Gene Flow and Vertical Stratification of Pollination in the Bat‐Pollinated Liana Marcgravia longifolia
No full textABSTRACT Pollen dispersal is a key driver of gene flow in plant populations, shaping their spatial genetic structure (SGS). In tropical forests, plant‐pollinator interactions vary across vertical strata due to differences in microclimate, resource availability, and foraging behavior. Bats are an important tropical pollinator group and have been observed to exhibit vertical stratification in their foraging activity, with interaction frequencies differing across forest layers. They are highly mobile and expected to transport pollen over long distances; however, their actual contribution to gene flow has rarely been investigated. Marcgravia longifolia , a bat‐pollinated Neotropical liana, offers a unique system for studying gene flow across forest strata. Unlike most other plant species, M. longifolia produces flowers from the forest floor to the canopy, allowing us to study how bat pollination differs across strata. This study examines pollen dispersal distances, the vertical stratification of gene flow, and SGS in M. longifolia at a 100 ha study site in western Amazonia. Pollen dispersal distances were up to 1350 m, with longer distances observed in the understory and midstory, where bat foraging activity is more frequent. We detected no SGS, suggesting extensive gene flow facilitated by bat pollination across forest strata. These findings underscore the critical role of bats in shaping plant genetic structure and demonstrate how vertical forest stratification influences gene flow in tropical ecosystems.RESUMEN La dispersión del polen es un factor clave del flujo génico en las poblaciones de plantas, dando forma a su estructura genética espacial (SGS). En los bosques tropicales, las interacciones planta‐polinizador varían a lo largo de los estratos verticales debido a diferencias en el microclima, la disponibilidad de recursos y el comportamiento de forrajeo. Los murciélagos son un grupo de polinizadores importante en los trópicos y se ha observado que presentan una estratificación vertical en su actividad de forrajeo, con frecuencias de interacción que difieren entre los distintos estratos del bosque. Son altamente móviles y se espera que transporten polen a largas distancias; aunque su contribución real al flujo génico ha sido raramente investigada. Marcgravia longifolia , una liana neotropical polinizada por murciélagos, ofrece un sistema único para estudiar el flujo génico a través de los estratos del bosque. A diferencia de la mayoría de las especies de plantas, M. longifolia produce flores desde el suelo del bosque hasta el dosel, lo que permite estudiar cómo varía la polinización por murciélagos en los distintos niveles. Este estudio examina las distancias de dispersión del polen, la estratificación vertical del flujo génico y la SGS en M. longifolia en un sitio de estudio de 100 hectáreas en la Amazonía occidental. Las distancias de dispersión del polen alcanzaron hasta 1350 metros, observándose distancias mayores en el sotobosque y el estrato medio, donde la actividad de forrajeo de los murciélagos es más frecuente. No se detectó SGS, lo que sugiere un flujo génico extenso facilitado por la polinización por murciélagos a través de los estratos del bosque. Estos resultados destacan el papel crucial de los murciélagos en la formación de la estructura genética de las plantas y demuestran cómo la estratificación vertical de los bosques influye en el flujo génico en los ecosistemas tropicales.ABSTRACT Pollen dispersal is a key driver of gene flow in plant populations, shaping their spatial genetic structure (SGS). In tropical forests, plant‐pollinator interactions vary across vertical strata due to differences in microclimate, resource availability, and foraging behavior. Bats are an important tropical pollinator group and have been observed to exhibit vertical stratification in their foraging activity, with interaction frequencies differing across forest layers. They are highly mobile and expected to transport pollen over long distances; however, their actual contribution to gene flow has rarely been investigated. Marcgravia longifolia , a bat‐pollinated Neotropical liana, offers a unique system for studying gene flow across forest strata. Unlike most other plant species, M. longifolia produces flowers from the forest floor to the canopy, allowing us to study how bat pollination differs across strata. This study examines pollen dispersal distances, the vertical stratification of gene flow, and SGS in M. longifolia at a 100 ha study site in western Amazonia. Pollen dispersal distances were up to 1350 m, with longer distances observed in the understory and midstory, where bat foraging activity is more frequent. We detected no SGS, suggesting extensive gene flow facilitated by bat pollination across forest strata. These findings underscore the critical role of bats in shaping plant genetic structure and demonstrate how vertical forest stratification influences gene flow in tropical ecosystems.RESUMEN La dispersión del polen es un factor clave del flujo génico en las poblaciones de plantas, dando forma a su estructura genética espacial (SGS). En los bosques tropicales, las interacciones planta‐polinizador varían a lo largo de los estratos verticales debido a diferencias en el microclima, la disponibilidad de recursos y el comportamiento de forrajeo. Los murciélagos son un grupo de polinizadores importante en los trópicos y se ha observado que presentan una estratificación vertical en su actividad de forrajeo, con frecuencias de interacción que difieren entre los distintos estratos del bosque. Son altamente móviles y se espera que transporten polen a largas distancias; aunque su contribución real al flujo génico ha sido raramente investigada. Marcgravia longifolia , una liana neotropical polinizada por murciélagos, ofrece un sistema único para estudiar el flujo génico a través de los estratos del bosque. A diferencia de la mayoría de las especies de plantas, M. longifolia produce flores desde el suelo del bosque hasta el dosel, lo que permite estudiar cómo varía la polinización por murciélagos en los distintos niveles. Este estudio examina las distancias de dispersión del polen, la estratificación vertical del flujo génico y la SGS en M. longifolia en un sitio de estudio de 100 hectáreas en la Amazonía occidental. Las distancias de dispersión del polen alcanzaron hasta 1350 metros, observándose distancias mayores en el sotobosque y el estrato medio, donde la actividad de forrajeo de los murciélagos es más frecuente. No se detectó SGS, lo que sugiere un flujo génico extenso facilitado por la polinización por murciélagos a través de los estratos del bosque. Estos resultados destacan el papel crucial de los murciélagos en la formación de la estructura genética de las plantas y demuestran cómo la estratificación vertical de los bosques influye en el flujo génico en los ecosistemas tropicales.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659Eva Mayr-Stihl Stiftung https://doi.org/10.13039/50110002280
Hybridization Resulted in Shifts from Dioecy to Monoecy in Weeping Willows (Salix L.)
No full textBackground/Objectives: In flowering plants, hybridization is an important evolutionary force that might change sex distributions and sex determination systems (SDSs). However, little is known about processes in the first hybrid generations. Here, we study a cultivated putative hybrid cross of weeping willows (genus Salix, S.), S. alba × babylonica to gain insights into the effects of hybridization into SDSs. Methods: We analyzed the genetic structure of pure S. alba, pure S. babylonica, and the putative hybrid crosses in Central Europe using RADSeq data and five independent methods (NeighborNet, genetic structure analysis, Principal Component Analysis, hybrid index and heterozygosity analysis, and hybrid class analysis). The genetic SDS was analyzed on male, female, and mixed (monoecious) phenotypes by detecting sex-specific genomic markers using RADSex. Results: Genetic analyses indicate that most of the weeping willows represent F1 hybrids (S. alba × babylonica), and only two putative S. alba backcrosses. Hybrid index, heterozygosity, and hybrid class analyses provided more interpretable results than the other methods. The parental species were consistently dioecious, whereas hybrids had male, female, and monoecious phenotypes. RADSex revealed a male heterogametic XY system for S. alba, and this was combined in the hybrids with the previously known ZW system of S. babylonica. Conclusions: We confirmed the historical records stating that S. alba × babylonica are mostly F1 hybrids. We report for the first time that the combination of XY and ZW systems in primary hybrids results in regular shifts to monoecy
The Effect of Stellar Magnetic Activity on Measurements of Morning and Evening Asymmetry of Planetary Terminator
No full textAbstract Differences in the ingress and egress shapes of transit light curves can indicate morning–evening temperature contrasts on transiting planets. Here, we pinpoint an alternative mechanism that can introduce asymmetries in transit light curves, potentially affecting the accurate determination of morning–evening differences. Small-scale magnetic field concentrations on the surfaces of the host star affect the visibility of stellar limb regions, making them brighter relative to the nonmagnetic case. A difference in magnetization between the star’s western and eastern limbs can thus create an asymmetry in limb brightness and, consequently, an asymmetry between transit ingress and egress. We model the limb darkening and stellar limb asymmetry in solar-like stars using the 3D radiative magnetohydrodynamics (MHD) code Max-Planck-Institute für Sonnensystemforshung (MPS)/University of Chicago Radiative MHD (MURaM) to simulate magnetized stellar atmospheres and the MPS-ATLAS code to synthesize spectra using a ray-by-ray approach. Our results show that ingress–egress depth differences can reach up to 600 ppm for a 10,000 ppm transit at 0.6 μ m, depending on the magnetization of the stellar limbs, significantly interfering with planetary signals. Observations of the Sun show that such concentrations are often not accompanied by spots and do not manifest in photometric variability, indicating that even photometrically quiet stars can produce such asymmetries. However, planetary and stellar asymmetries exhibit distinct wavelength dependencies, which we propose to leverage for disentangling them
Improved confidence intervals for finite mixture regression based on resampling techniques
No full textDeutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165
Spatial prediction of evapotranspiration in a tropical mosaic landscape using remote sensing and explainable machine learning
No full textAbstract Context Tropical forest regions are being transformed to other land covers at a high rate, often resulting in landscapes with heterogeneous vegetation structures. In combination with environmental factors this may influence ecosystem services, including evapotranspiration (ET). Objectives We aimed to predict the spatial variability of ET using spaceborne observations in a heterogenous tropical landscape, with a particular focus on elucidating the importance of vegetation structural characteristics and their interactions with environmental factors. Methods The study region was located in northeastern Madagascar. Daily ET was retrieved from ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS). Meteorological, topographical, soil and vegetation structure predictor variables were procured from various open sources. We applied forward feature selection and target oriented cross validation to address potential spatial autocorrelation and used SHAP analyses for elucidating interactions. Results Random forest models achieved high accuracies in the spatial prediction of ET, with R 2 values between 0.7 and 0.9 across different days. The explainable machine learning method, SHAP, revealed that highest contribution was by meteorological variables, followed by vegetation structure, topography, and soil. Analysis of key interactions between variables highlighted the role of vegetation structure in driving ET under different rainfall and wind speed conditions. Conclusions We conclude that the spatial variability of ET in this tropical mosaic landscape can be explained by a combination of biophysical variables, with vegetation structure contributing significantly. The underlying relationships can be useful to understand and potentially steer the climate regulation function of human-modified landscapes.Deutscher Akademischer AustauschdienstGeorg-August-Universität Göttingen http://dx.doi.org/10.13039/50110000338
Dynamic release kinetics and biological impact of leachables from 3D-printed oral devices: An integrated in vitro and computational exposure model
No full textForest conversion alters microbial decomposition of soil organic matter
No full texthttp://dx.doi.org/10.13039/501100012166 National Key Research and Development Program of Chinahttp://dx.doi.org/10.13039/100014718 Innovative Research Group Project of the National Natural Science Foundation of Chinahttp://dx.doi.org/10.13039/501100018647 RUDN Universityhttp://dx.doi.org/10.13039/501100001809 National Natural Science Foundation of Chin
Influence of genetic adaption of rainbow trout (Oncorhynchus mykiss) fed with alternative protein sources based on Arthrospira platensis and Hermetia illucens on disease resistance against viral haemorrhagic septicaemia virus (VHSV)
No full texthttp://dx.doi.org/10.13039/100011937 Lower Saxony State Ministry of Science and Culturehttp://dx.doi.org/10.13039/501100010570 Niedersächsisches Ministerium für Wissenschaft und Kulturhttp://dx.doi.org/10.13039/501100014417 Państwowy Instytut Weterynaryjny - Państwowy Instytut Badawczyhttp://dx.doi.org/10.13039/501100005629 Stiftung Tierärztliche Hochschule Hannove
Diversity and Activity Patterns of Medium‐Sized and Large Terrestrial Mammals in Agroforests of a Peruvian Amazon Rainforest Region
No full textABSTRACT Agroforests offer potential for biodiversity conservation through a land‐sharing approach. However, it remains uncertain whether they can support medium‐sized and large forest‐dependent terrestrial mammals. We evaluated the diversity and activity patterns of such mammals in agroforests and natural forests in the northern buffer zone of the Tambopata National Reserve in the Peruvian Amazon. For agroforests specifically, we examined the influence of connectivity to the core zone of the reserve, vegetation structure and human presence on mammal diversity and activity. In total, 21 species were recorded using camera traps. Agroforests supported 15 species, significantly fewer than neighbouring forests. Five of the seven threatened species were found exclusively in forests. Nonetheless, one third of the recorded species exhibited similar or higher trapping rates in agroforests, with Tapirus terrestris showing rates up to 6.3 times higher than in forests. The diurnality index across cathemeral species was significantly higher in agroforests adjacent to the protected area and marginally so in forests. In agroforests, mammal diversity increased with greater tree DBH, canopy cover and taller understorey vegetation. The trapping rate of Dasyprocta variegata also increased with total tree species richness. Agroforests along the Tambopata River can thus support a substantial number of medium‐sized and large terrestrial mammals. However, forests remain critical for conserving mammal species richness, particularly for those of urgent conservation concern. Enhanced vegetation structure in agroforests—particularly larger trees, a denser canopy, and taller understorey vegetation—can increase their value as a habitat for medium‐sized and large forest‐dependent terrestrial mammals.Idea Wild https://doi.org/10.13039/100007142Deutscher Akademischer Austauschdienst https://doi.org/10.13039/50110000165