Biology subjects

Lin, T.-Y.

Publications and source records attributed to Lin, T.-Y..

At least 19 recordsLinked to original sources

bioRxiv2026

The Dark Ecology Dataset: Measurements of Aerial Biomass in US Weather Radar from 1995 to 2025

The US NEXRAD radar network has monitored the aerosphere over the US and its territories continuously since the 1990s and archived nearly 300 million radar volume scans. These data contain a wealth of information about the movements of birds, bats, and insects. Historically, this biological information was difficult to access due to the amount of data and challenges in analyzing it. In the last 15 years, fueled by computational and methodological advances, large-scale aeroecology research has blossomed. However, comprehensive analyses of the NEXRAD archive remain very costly. We collected measurements from every volume scan in the NEXRAD archive--nearly 300 million data files total--to assemble a dataset of aerial biological activity over the US from 1995 to 2025. The core data are vertical profiles, which summarize biological activity at different heights above the radar station for each volume scan. We also provide time series data products that aggregate vertical profiles to point measurements at radar stations across time. These data products can support a range of aeroecology analyses at significantly reduced effort.

ecology↗

bioRxiv2025

Phosphatidylinositol Transfer Protein-1 Integrates Insulin/IGF-1 and TOR Signaling to Negatively Regulate Lifespan and Healthspan in Caenorhabditis elegans

BackgroundPhosphatidylinositol transfer protein-1 (pitp-1) is involved in phosphoinositide turnover. The role of pitp-1 in promoting healthy longevity remains unknown. Our previous work showed that the phosphoinositide turnover genes dagl-1 and dgk-5 regulates lifespan, as overexpression of dagl-1 or knockdown of dgk-5 prolongs lifespan and enhances oxidative stress resistance through TOR signaling. As pitp-1 is a key component of this pathway, we investigated its role in lifespan regulation and the underlying mechanisms, aiming to clarify whether it represents a critical regulator of healthy longevity and how it coordinates conserved signaling pathways to regulate aging. MethodsC. elegans mutants, RNAi-mediated knockdown, and transgenic overexpression were applied to assess lifespan, motility, stress resistance. Temporal and tissue-specific RNAi were applied to identify the critical time window and tissue for pitp-1-mediated lifespan regulation. TOR signaling was measured by phosphorylated S6 kinase and puromycin incorporation, and transcriptomic analysis identified affected pathways. Resultspitp-1 negatively regulates lifespan and healthspan in Caenorhabditis elegans. Genetic deletion or RNAi-mediated knockdown of pitp-1 extends lifespan, attenuates age-related motility decline, and increases oxidative stress resistance. Temporal and spatial analyses reveal that suppression of pitp-1 in neurons during early adulthood is sufficient to promote healthy longevity. Mechanistically, these beneficial effects upon pitp-1 reduction are mediated by suppressing TOR signaling. Conversely, pitp-1 overexpression shortens lifespan and impairs healthspan via TOR activation. Moreover, pitp-1 is transcriptionally repressed by DAF-16 downstream of insulin/IGF-1 signaling (IIS), and contributes to IIS-mediated lifespan extension. ConclusionThese findings identify pitp-1 as a novel regulator of healthy aging that integrates IIS and TOR pathways, providing new insights into conserved mechanisms for promoting healthy longevity.

genetics↗

bioRxiv2025

Innovations in spinal cord cell type heterogeneity across vertebrate evolution

Vertebrates display remarkable diversity of sensorimotor behaviors, each adapted to distinct ecological and survival demands. This diversity raises fundamental questions about the evolutionary origin of motor control: do conserved spinal circuits underlie these behaviors, and how have they diverged across species. Recent studies detail spinal cell-type architecture in mammals but comparable, high-resolution atlases of the non-mammalian spinal cord are lacking. Here, we compare spinal cord cell types between fish, frogs, mice and humans, spanning [~]450 million years of evolution. Across species, we define highly conserved programs of cell type specification that segregate spinal neurons into nearly identical cardinal classes during development. This contrasts with adult stages, when spinal cell-type composition selectively diverges for excitatory neuron subpopulations. Using spatial transcriptomics, we localize this species divergence to the superficial, dorsal spinal cord, where variant neuropeptide expression defines mammalian-specific cell types. The most dorsal spinal cord thus emerges as a recently evolved hub for sensory integration in mammals, a neospinal cord analogous to the neocortex.

neuroscience↗

bioRxiv2025

Human induced pluripotent stem cell-derived microglia with a CX3CR1-V249I genetic variant exhibit dysfunctional phenotypes and modulate neuronal growth and function

The involvement of microglia in neurodegenerative diseases has drawn increasing attention, as many genetic risk factors are preferentially expressed in microglia. Microglial fractalkine receptor (CX3CR1) signaling regulates many key microglial functions, and the CX3CR1-V249I single nucleotide polymorphism (SNP) has been associated with increased risk for multiple neurodegenerative conditions, including Alzheimers disease, yet its functional consequences in human microglia remain unexplored. In this study, we generated iPSC-derived human microglia-like cells (hMGLs) and found that the CX3CR1-V249I variant increased susceptibility to starvation-induced cell death, reduced amyloid-beta uptake, altered microglial morphology, and impaired migration, with more pronounced effects in homozygous cells. Co-culture with neurons demonstrated that hMGLs with the CX3CR1-V249I variant misregulated neuronal properties, including abnormal neuronal growth as well as an induction of neuronal hyperexcitability. These findings highlight the critical role of CX3CR1 in regulating microglial function and implicate the V249I variant in driving pathogenic microglial states relevant to neurodegeneration.

neuroscience↗

bioRxiv2025

Storage stability of non-encapsulated pneumococci in saliva is dependent on null-capsule clade, with strains carrying aliC and aliD showing a competitive disadvantage during culture enrichment

BackgroundNon-encapsulated Streptococcus pneumoniae (NESp) represent up to 19% of circulating pneumococci and exhibit high rates of antimicrobial resistance. Saliva is increasingly used as a pneumococcal carriage study specimen, and we recently developed a qPCR assay to enhance carriage surveillance and characterization of NESpn in saliva. Previous work has established that pneumococci remain viable in unsupplemented saliva for extended periods under various conditions, however these findings may not be applicable to NESp. Therefore, to ensure the robustness of NESp detection in saliva-based carriage studies we evaluated the impact of transport and storage conditions of saliva samples on NESp detection. MethodsSix NESp strains from two clinically relevant NESp null capsule clades (NCC), NCC1 (carrying pspK) and NCC2 (carrying aliC and aliD), were spiked into lytA-negative saliva and incubated through various temperatures and freeze-thaw conditions. Endpoints were processed using either culture-enrichment and DNA extraction (CE-DNA), or an extraction-free method without CE, before testing for lytA using qPCR. Detection stability was assessed using regression modelling over temperature, time and freeze-thaws. ResultsFollowing CE-DNA, detection of NESp remained stable for [≤]24 or [≤]72 hours when stored at room temperature or 4{degrees}C, respectively, and over 2 freeze-thaw cycles (-80{degrees}C), with glycerol-supplementation providing slight benefits. Stability of detection when using CE-DNA depended on NCC; detection of NCC2 strains was lower, and less stable than NCC1. Compared to CE-DNA, extraction-free detection was more stable, with no significant loss over 72 hours at room temperature and over 3 freeze-thaw cycles. With extraction-free detection, there were also negligible diderences in detection between NCC1 and NCC2. Additionally, extraction-free detection of NCC1, and less so NCC2, increased over the first 24 hours when stored at 20-30{degrees}C, suggesting growth in saliva. Testing of{Delta} aliCaliD and{Delta} pspK mutants revealed these genes increased in vitro viability of NCC2 and NCC1, respectively, but did not significantly alter competitive fitness during CE. ConclusionNCC1 NESp strains exhibit similar stability patterns in unsupplemented saliva as encapsulated pneumococci. NCC2 strains, however, are less resilient during CE, likely due to competition with other oral microbes. Therefore, recovery of NCC2 NESp may be impacted by transport and storage conditions, leading to an underestimation of carriage prevalence when tested using CE-based methods. For the reliable carriage surveillance of NESp, samples should be stored at 4{degrees}C soon after collection and at -80{degrees}C within 72 hours. Methods which directly detect DNA without CE may provide a less biased accounting of NCC2 strains.

microbiology↗

bioRxiv2024

An abundance of aliC and aliD genes were identified in saliva using a novel multiplex qPCR to characterize group II non-encapsulated pneumococci with improved specificity

BackgroundSurveillance of pneumococcus is reporting increasing prevalence of non-encapsulated pneumococci (NESp). NESp are an important reservoir for genetic exchange among streptococci, including for antimicrobial resistance (AMR), and are increasingly implicated in disease. Disease-associated NESp commonly carry the virulence genes pspK, or aliC and aliD in their cps locus instead of capsule genes. While molecular methods targeting the cps region are widely used for serotyping encapsulated strains, there are few assays available for classification of NESp, meaning it is not widely undertaken. Therefore, we exploited these genes as targets for a novel qPCR assay for detecting and classifying NESp strains with improved efficiency and specificity. MethodsWe conducted bioinformatic analysis on sequences from 30 NESp and 23 other mitis-group streptococcal sequences and developed a multiplex-qPCR, targeting pspK, aliD and two regions of aliC. The assay was validated using 11 previously characterised, and 5 uncharacterised NESp isolates. We then applied the assay to DNA extracted from culture-enriched saliva, and isolated and characterised suspected NESp colonies, with confirmation by whole genome sequencing. ResultsBioinformatic analyses demonstrated that previously published primers for aliC and aliD had low pneumococcal-specificity but indicated that targeting two regions of aliC would improve species-specificity, without compromising sensitivity. Our novel multiplex assay accurately typed all isolates. When screening saliva, we found a high prevalence of aliC and aliD, even in samples negative for pneumococcal genes lytA and piaB. Isolated colonies which were aliC and aliD positive could be differentiated as non-pneumococcal streptococci using our assay. ConclusionOur multiplex-qPCR assay can be used to efficiently screen even highly polymicrobial samples, such as saliva, for NESp genes, to detect and differentiate potentially pathogenic NESp clades from closely related mitis-group streptococci. This will allow for a better understanding of the true prevalence of NESp, and their impact upon pneumococcal carriage, disease, and AMR.

microbiology↗

bioRxiv2024

Modeling integration site data for safety assessment with MELISSA

Gene and cell therapies pose safety concerns due to potential insertional mutagenesis by viral vectors. We introduce MELISSA, a statistical framework for analyzing Integration Site (IS) data to assess insertional mutagenesis risk. MELISSA employs regression models to estimate and compare gene-specific integration rates and their impact on clone fitness. We tested MELISSA under three settings. First, we conducted simulation studies to verify its performance under controlled conditions. Second, we characterized the IS profile of a lentiviral vector on Mesenchymal Stem Cells (MSCs) and compared it with that of Hematopoietic Stem and Progenitor Cells (HSPCs), in addition to comparing the in vitro clonal dynamics of MSCs isolated from alternative tissues. Finally, we applied MELISSA to published IS data from patients enrolled in gene therapy clinical trials, successfully identifying both known and novel genes that drive changes in clone growth through vector integration. MELISSA identifies over- and under-targeted genes, estimates IS impact and explores biological relevance through pathway analysis. This offers a quantitative tool for researchers, clinicians, and regulators to bridge the gap between IS data and safety and efficacy evaluation, facilitating the generation of comprehensive data packages supporting Investigational New Drug (IND) and Biologics License (BLA) applications and the development of safe and effective gene and cell therapies.

bioinformatics↗

bioRxiv2024

Characterization, enrichment, and computational modeling of cross-linked actin networks in trabecular meshwork cells

PurposeCross-linked actin networks (CLANs) are prevalent in the glaucomatous trabecular meshwork (TM), yet their role in ocular hypertension remains unclear. We used a human TM cell line that spontaneously forms fluorescently-labeled CLANs (GTM3L) to explore the origin of CLANs, developed techniques to increase CLAN incidence in GMT3L cells, and computationally studied the biomechanical properties of CLAN-containing cells. MethodsGTM3L cells were fluorescently sorted for viral copy number analysis. CLAN incidence was increased by (i) differential sorting of cells by adhesion, (ii) cell deswelling, and (iii) cell selection based on cell stiffness. GTM3L cells were also cultured on glass or soft hydrogel to determine substrate stiffness effects on CLAN incidence. Computational models were constructed to mimic and study the biomechanical properties of CLANs. ResultsAll GTM3L cells had an average of 1 viral copy per cell. LifeAct-GFP expression level did not affect CLAN incidence rate, but CLAN rate was increased from [~]0.28% to [~]50% by a combination of adhesion selection, cell deswelling, and cell stiffness-based sorting. Further, GTM3L cells formed more CLANs on a stiff vs. a soft substrate. Computational modeling predicted that CLANs contribute to higher cell stiffness, including increased resistance of the nucleus to tensile stress when CLANs are physically linked to the nucleus. ConclusionsIt is possible to greatly enhance CLAN incidence in GTM3L cells. CLANs are mechanosensitive structures that affect cell biomechanical properties. Further research is needed to determine the effect of CLANs on TM biomechanics and mechanobiology as well as the etiology of CLAN formation in the TM.

cell biology↗

bioRxiv2024

Somite-independent regeneration of the axolotl primary body axis

Primary body-axis development is a highly conserved process that proceeds through somitogenesis and subsequent subdivision into dermatome, myotome, and sclerotome. Defects in somitic-clock genes such as Hes7 lead to vertebral-segmentation defects in mice and fish. Here we show that in the axolotl, although Hes7 is necessary for proper embryonic vertebral segmentation, it is-- surprisingly--dispensable during tail regeneration. We investigated the mechanism of vertebral segmentation during regeneration which initially occurs through extension of a cartilage rod ventral to the spinal cord. We find that the regenerating cartilage rod undergoes a periodic wrinkling that provides a template for vertebral segmentation. Via direct mechanical measurements and biophysical perturbations, we show that a model of compression-induced buckling instability can predict vertebral segmentation. The cartilage rod and other somitic derivatives (muscle, cartilage, tendon, fibroblasts) arise from tendon-like, Lfng+ multi-potent mesenchymal progenitors, which display a gene regulatory state distinct from somitic progenitors. In summary, we uncover a mechanism of vertebral segmentation during axolotl tail regeneration that is distinct from the somite-based developmental mechanism.

developmental biology↗

bioRxiv2023

Giant genes are rare but implicated in cell wall degradation by predatory bacteria

Across the tree of life, gene lengths vary, but most are no more than a few thousand base pairs in length. The largest protein often reported is the [~]40,000 aa eukaryotic Titin. Even larger proteins may occur in the rapidly expanding set of metagenome-derived sequences, but their existence may be obscured by assembly fragmentation. Here, we leverage genome curation to complete metagenome-derived sequences that encode predicted proteins of up to 85,804 aa. Overall, the findings illuminate a huge knowledge gap related to giant proteins. Although predicted proteins of >30,000 aa occur in bacterial phyla such as Firmicutes and Actinobacteria, they are most common in ca. Omnitrophota, ultra small bacteria that adopt predatory lifestyles. All full length giant genes encode numerous transmembrane regions and most encode divergent secA DEAD helicase domains. In silico structural prediction of protein subregions was required to identify domains in unannotated protein segments, and revealed putative domains implicated in attachment and carbohydrate degradation. Many giant genes in new complete and near-complete Omnitrophota genomes occur in close proximity to genes homologous to type II secretion systems as well as carbohydrate import systems. This, in combination with the domain content, suggests that many bacterial giant proteins enable prey adhesion and cell wall digestion during bacterial predation.

microbiology↗

bioRxiv2023

Selective activation of intracellular β1AR using a spatially restricted antagonist

G-protein-coupled receptors (GPCRs) regulate several physiological and pathological processes and represent the target of approximately 30% of FDA-approved drugs. GPCR-mediated signaling was thought to occur exclusively at the plasma membrane. However, recent studies have unveiled their presence and function at subcellular membrane compartments. There is a growing interest in studying compartmentalized signaling of GPCRs. This requires development of novel tools to separate GPCRs signaling at the plasma membrane from the ones initiated at intracellular compartments. We took advantage of the structural and pharmacological information available for {beta}1-adrenergic receptor ({beta}1AR), an exemplary GPCR that functions at subcellular compartments, and rationally designed spatially restricted antagonists. We generated a cell impermeable {beta}1AR antagonist by conjugating a suitable pharmacophore to a sulfonate-containing fluorophore. This cell-impermeable antagonist only inhibited {beta}1AR on the plasma membrane. In contrast, a cell permeable {beta}1AR agonist containing a non-sulfonated fluorophore, efficiently inhibited both the plasma membrane and Golgi pools of {beta}1ARs. Furthermore, the cell impermeable antagonist selectively inhibited the phosphorylation of downstream effectors of PKA proximal to the plasma membrane in adult cardiomyocytes while {beta}1AR intracellular pool remained active. Our tools offer promising avenues for investigating compartmentalized {beta}1AR signaling in various context, potentially advancing our understanding of {beta}1AR-mediated cellular responses in health and disease. They also offer a general strategy to study compartmentalized signaling for other GPCRs in various biological systems.

cell biology↗

bioRxiv2023

Exploring the Conformational Landscape of Cryo-EM Using Energy-Aware Pathfinding Algorithm

Cryo-electron microscopy (cryo-EM) is a powerful technique for studying macromolecules and holds the potential for identifying kinetically preferred transition sequences between conformational states. Typically, these sequences are explored within two-dimensional energy landscapes. However, due to the complexity of biomolecules, representing conformational changes in two dimensions can be challenging. Recent advancements in reconstruction models have successfully extracted structural heterogeneity from cryo-EM images using higher-dimension latent space. Nonetheless, creating high-dimensional conformational landscapes in the latent space and then searching for preferred paths continues to be a formidable task. This study introduces an innovative framework for identifying preferred trajectories within high-dimensional conformational landscapes. Our method encompasses the search for the shortest path in the graph, where edge weights are determined based on the energy estimation at each node using local density. The effectiveness of this approach is demonstrated by identifying accurate transition states in both synthetic and real-world datasets featuring continuous conformational changes.

bioinformatics↗

bioRxiv2022

Epinephrine inhibits PI3K alpha via the Hippo kinases.

The phosphoinositide 3-kinase, p110, is an essential mediator of insulin signaling and glucose homeostasis. We systematically interrogated the human serine, threonine, and tyrosine kinome to search for novel regulators of p110 and found that the Hippo kinases phosphorylate and completely inhibit its activity. This inhibitory state corresponds to a conformational change of a membrane binding domain on p110, which impairs its ability to engage membranes. In human primary hepatocytes, cancer cell lines, and rodent tissues, activation of the Hippo kinases, MST1/2, using forskolin or epinephrine is associated with phosphorylation and inhibition of p110, impairment of downstream insulin signaling, and suppression of glycolysis and glycogen synthesis. These changes are abrogated when MST1/2 are genetically deleted or inhibited with small molecules. Our study reveals a novel inhibitory pathway of PI3K signaling and a previously unappreciated link between epinephrine and insulin signaling.

physiology↗

bioRxiv2022

GPCR-dependent spatiotemporal cAMP generation confers functional specificity in cardiomyocytes and cardiac responses

Cells interpret a variety of signals through G protein-coupled receptors (GPCRs) and stimulate the generation of second messengers such as cyclic adenosine monophosphate (cAMP). A long-standing puzzle is deciphering how GPCRs elicit different physiological responses despite generating similar levels of cAMP. We previously showed that some GPCRs generate cAMP from both the plasma membrane and the Golgi apparatus. Here, we demonstrate that cardiomyocytes distinguish between subcellular cAMP inputs to elicit different physiological outputs. We show that generating cAMP from the Golgi leads to regulation of a specific PKA target that increases the rate of cardiomyocyte relaxation. In contrast, cAMP generation from the plasma membrane activates a different PKA target that increases contractile force. We further validated the physiological consequences of these observations in intact zebrafish and mice. Thus, we demonstrate that the same GPCR acting through the same second messenger regulates cardiac contraction and relaxation dependent on its subcellular location.

cell biology↗

bioRxiv2022

A global atlas of substrate specificities for the human serine/threonine kinome

Protein phosphorylation is one of the most widespread post-translational modifications in biology. With the advent of mass spectrometry-based phosphoproteomics, more than 200,000 sites of serine and threonine phosphorylation have been reported, of which several thousand have been associated with human diseases and biological processes. For the vast majority of phosphorylation events, it is not yet known which of the more than 300 protein Ser/Thr kinases encoded in the human genome is responsible. Here, we utilize synthetic peptide libraries to profile the substrate sequence specificity of nearly every functional human Ser/Thr kinase. Viewed in its entirety, the substrate specificity of the kinome was substantially more diverse than expected and was driven extensively by negative selectivity. Our kinome-wide dataset was used to computationally annotate and identify the most likely protein kinases for every reported phosphorylation site in the human Ser/Thr phosphoproteome. For the small minority of phosphosites where the protein kinases involved have been previously identified, our predictions were in excellent agreement. When this approach was applied to examine the signaling response of tissues and cell lines to hormones, growth factors, targeted inhibitors, and environmental or genetic perturbations, it revealed unexpected insights into pathway complexity and compensation. Overall, these studies reveal the full extent of substrate specificity of the human Ser/Thr kinome, illuminate cellular signaling responses, and provide a rich resource to link unannotated phosphorylation events to biological pathways.

systems biology↗

bioRxiv2022

Anti-spike antibody response to natural infection with SARS-CoV-2 and its activity against emerging variants

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has substantially impacted human health globally. Spike-specific antibody response plays a major role in protection against SARS-CoV-2. Here, we demonstrated that acute SARS-CoV-2 infection elicits rapid and robust spike-binding and ACE2-blocking antibody responses, which wane approximately 11 months after infection. Serological responses were found to be correlated with the frequency of spike-specific memory B cell responses to natural infections. Further, significantly higher spike-binding, ACE2-blocking, and memory B cell responses were detected in patients with fever and pneumonia. Spike-specific antibody responses were found to be greatly affected by spike mutations in emerging variants, especially the Beta and Omicron variants. These results warrant continued surveillance of spike-specific antibody responses to natural infections and highlight the importance of maintaining functional anti-spike antibodies through immunization. ImportanceAs spike protein-specific antibody responses play a major role in protection against SARS-CoV-2, we examined the spike-binding and ACE2-blocking antibody responses in SARS-CoV-2 infection at different time points. We found robust responses following acute infection, which waned approximately 11 months after infection. Further, the serological responses were correlated with the frequency of spike-specific memory B cell responses to natural infections. Patients with fever and pneumonia showed significantly stronger spike-binding, ACE2-blocking antibody, and memory B cell responses. Moreover, the spike-specific antibody responses were substantially affected by the emerging variants, especially the Beta and Omicron variants. These results warrant continued surveillance of spike-specific antibody responses to natural infections and highlight the importance of maintaining functional anti-spike antibodies through immunization.

immunology↗

bioRxiv2021

A molecular network of conserved factors keeps ribosomes dormant in the egg

Ribosomes are produced in large quantities during oogenesis and stored in the egg. However, the egg and early embryo are translationally repressed. Using mass-spectrometry and cryo-EM analyses of ribosomes isolated from zebrafish and Xenopus eggs and embryos, we provide molecular evidence that ribosomes transition from a dormant to an active state during the first hours of embryogenesis. Dormant ribosomes are associated with four conserved factors that form two modules and occupy functionally important sites of the ribosome: a Habp4-eEF2 module that stabilizes ribosome levels and a Dap1b/Dapl1-eIF5a module that represses translation. Dap1b/Dapl1 is a newly discovered translational inhibitor that stably inserts into the polypeptide exit tunnel. Thus, a developmentally programmed, conserved ribosome state plays a key role in ribosome storage and translational repression in the egg.

biochemistry↗

bioRxiv2021

Do forest over- and understory respond to the same environmental variables when viewed at the taxonomic and trait level?

While the relative importance of climate filtering is known to be higher for woody species assemblages than herbaceous assemblage, it remains largely unexplored whether this pattern is also reflected between the woody overstory and herbaceous understory of forests. While climatic variation will be more buffered by the tree layer, the understory might also respond more to small-scale soil variation, next to experiencing additional environmental filtering due to the overstorys effects on light and litter quality. For (sub)tropical forests, the understory often contains a high proportion of fern and lycophyte species, for which environmental filtering is even less well understood. We explored the proportional importance of climate proxies and soil variation on the species, functional trait and (functional) diversity patterns of both the forest overstory and fern and lycophyte understory along an elevational gradient from 850 to 2100 m a.s.l. in northern Taiwan. We selected nine functional traits expected to respond to soil nutrient or climatic stress for this study and furthermore verified whether they were positively related across vegetation layers, as expected when driven by similar environmental drivers. We found that climate was a proportionally more important predictor than soil for the species composition of both vegetation layers and trait composition of the understory. The stronger than expected proportional effect of climate for the understory was likely due to fern and lycophytes higher vulnerability to drought, while the high importance of soil for the overstory seemed driven by deciduous species. The environmental drivers affected different response traits in both vegetation layers, however, which together with additional overstory effects on understory traits, resulted in a strong disconnection of community-level trait values across layers. Interestingly, species and functional diversity patterns could be almost exclusively explained by climate effects for both vegetational layers, with the exception of understory species richness. This study illustrates that environmental filtering can differentially affect species, trait and diversity patterns and can be highly divergent for forest overstory and understory vegetation, and should consequently not be extrapolated across vegetation layers or between composition and diversity patterns.

ecology↗