Changes In Abundance Of Species Research Articles

Metabolomics and gut metagenomics profile of the healthy adults on consumption of whey protein supplemented with enzymes-probiotics blend

In this randomized, crossover, pilot clinical study, we aimed to evaluate the effect of supplementation of enzymes-probiotics blend with whey protein on the amino acid absorption and gut microbiota. Healthy subjects were supplemented with the whey protein and test i.e. Pepzyme Pro (enzymes-probiotics blend) or placebo i.e. maltodextrin for 15 days with the washout period of 30 days. Blood samples were analyzed for plasma free amino acids, insulin, and CRP. Additionally, urine nitrogen, fecal nitrogen, and gut microbiota were evaluated. On day 15, the test arm showed upward trend in rate of amino acid absorption than placebo arm within 30 min of post ingestion of protein. Moreover, rate of absorption of few essential and branched chain amino acids were significantly higher (methionine (p = 0.049), leucine (p = 0.014), isoleucine (p = 0.053)) in the test arm on day 15. Total branched chain amino acids absorption were found to be significantly higher (p ≤ 0.05) in the test arm than the placebo arm within 30 min of post ingestion on day 15. Uptrend in total amino acid absorption and Cmax, and downtrend in Tmax was observed on day 15 in the test arm. The CRP, fecal nitrogen, and urine nitrogen remained unaltered after supplementation. Microbiota profiling showed significant change in abundance of species of genus Bacteroides and phylum Bacteroidetes. Overall, metagenomics and metabolomics based assessments demonstrated that the consumption of Pepzyme Pro with whey protein could potentially improve protein digestion, amino acid absorption, and modulate gut microbiota.Clinical trial registration The clinical trial registry of India CTRI/2021/09/036169 [Registered on: 02/09/2021]

Plant functional traits and abundance jointly shape keystone plant species in a plant–ectomycorrhizal fungus network

AbstractKeystone species are more important than others for community dynamics and stability. Keystone species can be identified and evaluated by their centrality (i.e., a relative ranking of the topological positional importance of a species) in ecological networks. Studies of node centrality of plant–fungus bipartite networks, for example, have identified the keystone species that are important for maintaining network structure and stability. However, the underlying drivers of the importance of species in a network have rarely been examined. We assessed the centrality (degree, closeness, and betweenness) of plant and fungal species in a plant–ectomycorrhizal fungus network in a subtropical forest in southern China. Based on the phylogenies of plants and fungi and plant traits, we explored ecological factors that led to a species taking a central position or not. We found one plant species (Ternstroemia gymnanthera) and four species of ectomycorrhizal fungi (Russula citrina, Scleroderma sp., and two Cenococcum sp.) were characterized by the highest centrality of degree, closeness, and betweenness among the bipartite network nodes and thus played key roles in maintaining network structure. Centrality for fungi (not for plants) was phylogenetically constrained. Plant traits and abundance together explained 46.36%, 46.0%, and 43.7% of variation in the centrality of degree, closeness, and betweenness of plant species in the bipartite network, respectively. When plant or fungal species were sequentially removed on the order of higher to lower centrality, network was less stable than randomly removed. We suggest that abundance and traits determine the positional importance of plant species in a network. This work helps understand how plant–fungus association networks will respond to species extinction and changes in species abundance and functional traits due to habitat fragmentation and human activities.

Fish responses to underwater sounds depend on auditory adaptations: An experimental test of the effect of motorboat sounds on the fish community of a large fluvial lake.

Freshwater fishes exhibit a wide range of auditory adaptations and capabilities, which are assumed to help them navigate their environment, avoid predators, and find potential mates. Yet, we know very little about how freshwater environments sound to fish, or how fish with different auditory adaptations respond to different soundscapes. We first compiled data on fish hearing acuity and adaptations and provided a portrait of how anthropogenic sounds compare to natural sounds in different freshwater soundscapes. We then conducted a sound-enrichment field experiment at Lake Saint Pierre, a large fluvial lake in Canada, to evaluate the effect of motorboat sound exposure on the fish community by looking at the extent to which changes in species abundances were linked to auditory adaptations. Data compilation showed that the hearing acuity of most species overlaps with a wide range of ambient and anthropogenic underwater sounds while the field experiment showed that species with more specialized auditory structures were captured less often in sound-enriched traps, indicating avoidance behavior. Our findings highlight the importance of considering species' sensorial adaptations when evaluating the community-scale effects of anthropogenic sounds on the fish community, especially at low levels of anthropogenic activity.

Evaluating top-down, bottom-up, and environmental drivers of pelagic food web dynamics along an estuarine gradient.

Identification of the key biotic and abiotic drivers within food webs is important for understanding species abundance changes in ecosystems, particularly across ecotones where there may be strong variation in interaction strengths. Using structural equation models (SEMs) and four decades of integrated data from the San Francisco Estuary, we investigated the relative effects of top-down, bottom-up, and environmental drivers on multiple trophic levels of the pelagic food web along an estuarine salinity gradient and at both annual and monthly temporal resolutions. We found that interactions varied across the estuarine gradient and that the detectability of different interactions depended on timescale. For example, for zooplankton and estuarine fishes, bottom-up effects appeared to be stronger in the freshwater upstream regions, while top-down effects were stronger in the brackish downstream regions. Some relationships (e.g., bottom-up effects of phytoplankton on zooplankton) were seen primarily at annual timescales, whereas others (e.g., temperature effects) were only observed at monthly timescales. We also found that the net effect of environmental drivers was similar to or greater than bottom-up and top-down effects for all food web components. These findings can help identify which trophic levels or environmental factors could be targeted by management actions to have the greatest impact on estuarine forage fishes and the spatial and temporal scale at which responses might be observed. More broadly, this study highlights how environmental gradients can structure community interactions and how long-term data sets can be leveraged to generate insights across multiple scales.

A new approach for assessing winning and losing plant species facing climate change on the GLORIA alpine summits

Climate change in alpine habitats has a direct impact on vascular plant species, and is leading to changes in species abundance and distribution. Alpine plant communities are expected to experience a turnover of species over time, due to the loss of cold-adapted specialists and the upslope migration of more thermophilic taxa. Therefore, assessments of single species changes are important for research and conservation. Here, we propose a new analysis protocol for the GLORIA (GLobal Observation Research Initiative in Alpine environments) network, and potentially, for other monitoring programmes capable of defining winning and losing plant species. The proposed approach involves the non-parametric Cliff's ‘Delta’ measure of ‘effect size’, which provides a measure of the intensity of species abundance changes over time and is applicable for vegetation data collected using both re-visitation and long-term monitoring approaches. Compared to other methods, Cliff's ‘Delta’ was more conservative and efficient in detecting winning/losing taxa, as well as being suitable to analyse data of rare species with few records. To test the effectivity of the Cliff ‘Delta’ method, we analysed the vegetation data from three Italian GLORIA sites. We investigated 413 vascular plant species and found a total of 41 winning and 24 losing species. Moreover, we used Cliff ‘Delta’ to assess whether plant assemblages are responding differently among sites and plant growth forms. Our findings showed that alpine plant communities are changing faster on Apennines sites and that growth form types respond differently across the study sites.

Effects of storms on fisheries and aquaculture: An Icelandic case study on climate change adaptation

ABSTRACT Climate change research on fisheries is often focused on changes in species abundance and distribution, yet the impacts of severe weather events are also important. Climate models indicate that storm frequency and intensity may increase in the North Atlantic; however, uncertainties remain and consequences in Iceland are not well studied. This research represents a first attempt to understand local to regional implications of storminess on Icelandic fisheries industries. Using an interdisciplinary approach, the analysis (1) provides regional future wind speed projections in Iceland and surroundings under the Shared Socioeconomic Pathway (SSP) 3–7.0 scenario, (2) documents current local experiences using exploratory interviews with various stakeholders in fisheries and aquaculture, and (3) explores research priorities for understanding climate-change adaptations in coastal communities. Projections show that whereas areas of the west, south, and east of Iceland may experience fewer storm days, the region north/northeast of Iceland features an increase in storm days. Potential adaptations include a flexible management system that does not punish fishers for lost time due to bad weather, cooperative market arrangements among sectors, and job security considerations for fishers and fish processing workers. Future projections are needed for other variables such as precipitation, and future socioeconomic studies should address the predictions and impacts of storminess.

Monitoring spatiotemporal dynamics of large herbivores across an African rangeland using hierarchical multi‐species distance sampling

AbstractA relative lack of standardised long‐term monitoring data often limits the ability of African conservancies to quantify their efficacy to protect wildlife. In this study, we combined eight 2‐km long transects surveyed monthly between October 2017 and March 2020 (total 240 transects sampled) with a hierarchical multi‐species and multi‐season distance sampling modelling framework to: (1) estimate monthly density of an ensemble of 10 different large herbivores and (2) understand how species respond to changes in vegetation productivity and time across the Naboisho Conservancy in the Greater Mara Ecosystem, Kenya. We documented a total of 55,298 individuals from 6830 animal groups. The median coefficient of variation for all density estimates was 27.67%. On average, number of groups was higher at intermediate levels of vegetation productivity. We found that in general, populations of large herbivores remained stable in the conservancy during the study period, except for wildebeest which decreased in density. We showed that multi‐species monitoring frameworks can be used to understand how species abundance changes across space and time, providing indications as to how they are responding to environmental dynamics or management prescriptions—both of which are valuable tools for under‐resourced wildlife conservancies.

Effects of climate change and variability on large pelagic fish in the Northwest Atlantic Ocean: implications for improving climate resilient management for pelagic longline fisheries

Climate change influences marine environmental conditions and is projected to increase future environmental variability. In the North Atlantic, such changes will affect the behavior and spatiotemporal distributions of large pelagic fish species (i.e., tunas, billfishes, and sharks). Generally, studies on these species have focused on specific climate-induced changes in abiotic factors separately (e.g., water temperature) and on the projection of shifts in species abundance and distribution based on these changes. In this review, we consider the latest research on spatiotemporal effects of climate-induced environmental changes to HMS’ life history, ecology, physiology, distribution, and habitat selection, and describe how the complex interplay between climate-induced changes in biotic and abiotic factors, including fishing, drives changes in species productivity and distribution in the Northwest Atlantic. This information is used to provide a baseline for investigating implications for management of pelagic longline fisheries and to identify knowledge gaps in this region. Warmer, less oxygenated waters may result in higher post-release mortality in bycatch species. Changes in climate variability will likely continue to alter the dynamics of oceanographic processes regulating species behavior and distribution, as well as fishery dynamics, creating challenges for fishery management. Stock assessments need to account for climate-induced changes in species abundance through the integration of species-specific responses to climate variability. Climate-induced changes will likely result in misalignment between current spatial and temporal management measures and the spatiotemporal distribution of these species. Finally, changes in species interactions with fisheries will require focused research to develop best practices for adaptive fisheries management and species recovery.

Mechanistic partitioning of species richness in diverse tropical forest tree communities with immigration and temporal environmental stochasticity

Abstract Hyperdiverse tropical forest tree communities illustrate a fundamental problem in ecology: How can many species coexist given relatively few limiting resources? Neutral theory provides a solution by positing that species have equal fitness and hence drift to extinction slowly. However, neutral theory seriously under‐predicts temporal changes in species abundances. This can be remedied by breaking neutrality and adding temporal environmental stochasticity (TES), but the mechanisms mediating the effects of TES on species richness remain unclear. Here, we make progress by analysing a local community model with species competing for a common resource under TES, to derive formulae partitioning species richness according to different mechanisms. By applying our formulae to generic parameter sets for tropical forest tree communities, we found that when the autocorrelation time of TES was short, the dominant mechanism driving species richness was non‐linear averaging of the interspecific competition term over time, which reduced the typical strength of interspecific competition and boosted richness relative to the neutral case. However, greater immigration to the community resulted in more species and hence weaker non‐linear averaging due to the law of large numbers. In contrast, when the autocorrelation time of TES was long, the dominant mechanism driving species richness was strong selection between changes in environmental conditions, which increased the typical strength of interspecific competition and reduced richness relative to the neutral case. By applying our formulae to a specific parameter set for a tropical forest tree community in Panama, we found that TES had minor effects on species richness because (i) the immigration rate was sufficiently large for non‐linear averaging of the interspecific competition term to be weak and (ii) the autocorrelation time was sufficiently short to suppress the effects of selection. Synthesis. We provide a novel mechanistic explanation of how TES affects tree species richness in tropical forests, in particular how TES often has minor effects on richness despite having substantial effects on temporal changes in species abundances. This provides a deeper insight into why a neutral model with added TES can accurately capture static and dynamic aspects of tree community diversity in the tropics.

Pioneers of post‐agricultural forest successions are adapted for herbivory avoidance but not biotic seed dispersal

AbstractQuestionNatural reforestation is an important component of climate mitigation and adaptation, but the ecological processes promoting or constraining it are poorly understood. In this study we employ a stand reconstruction approach (which uses ages of extant trees to estimate year of establishment for each individual tree) to test for general trait‐based effects on tree species arrival order in post‐agricultural forest successions.LocationNaturally reforesting post‐agricultural landscapes throughout New Zealand.MethodsAges were obtained for 2434 individuals spanning 30 tree species across a nationwide network of 128 plots in 14 naturally reforesting post‐agricultural sites. These ages were used to calculate individual‐level arrival times (relative to the oldest individual in each plot). We estimated species‐level arrival times by fitting linear mixed‐effects (LME) regressions (with species identity as the fixed effect, and plots nested within sites as the random effects) to individual arrival time data. We used back‐casting (where arrival time data are used to document individual‐level presence in plots through time) to track annual changes in species abundance and community‐weighted mean (CWM) trait values.We used standardised major axis (SMA) regressions to examine the effect of traits related to resource use strategy, herbivory avoidance, seed dispersal and disturbance response on species‐level arrival times. We used LME regressions to test for changes in CWM trait values with stand age.ResultsThe earliest‐arriving species had traits associated with herbivory avoidance, were abiotically dispersed and had short predicted dispersal distances. There was no evidence that traits linked to resource use strategy or disturbance response affected species arrival times. Every significant species‐level relationship was recovered in community‐level LME analyses.ConclusionsOur findings suggest that mammalian herbivore control and enhancement of biotic (bird) seed dispersal may be key management interventions in realising the full climate mitigation and adaptation potential of natural reforestation in post‐agricultural landscapes.

A meta-analysis of tissue microbial biomarkers for recurrence and metastasis in multiple cancer types.

Background. Local recurrence and distant metastasis are the main causes of death in patients with cancer. Only considering species abundance changes when identifying markers of recurrence and metastasis in patients hinders finding solutions.Hypothesis. Consideration of microbial abundance changes and microbial interactions facilitates the identification of microbial markers of tumour recurrence and metastasis.Aim. This study aims to simultaneously consider microbial abundance changes and microbial interactions to identify microbial markers of recurrence and metastasis in multiple cancer types.Method. One thousand one hundred and six non-RM (patients without recurrence and metastasis within 3 years after initial surgery) tissue samples and 912 RM (patients with recurrence or metastasis within 3 years after initial surgery) tissue samples representing 11 cancer types were collected from The Cancer Genome Atlas (TCGA).Results. Tumour tissue bacterial composition differed significantly among 11 cancers. Among them, the tissue microbiome of four cancers, head and neck squamous cell carcinoma (HNSC), lung squamous cell carcinoma (LUSC), stomach adenocarcinoma (STAD) and uterine corpus endometrial carcinoma (UCEC), showed relatively good performance in predicting recurrence and metastasis in patients, with areas under the receiver operating characteristic curve (AUCs) of 0.78, 0.74, 0.91 and 0.93, respectively. Considering both species abundance changes and microbial interactions for the four cancers, a combination of nine genera (Niastella, Schlesneria, Thioalkalivibrio, Phaeobacter, Sphaerotilus, Thiomonas, Lawsonia, Actinobacillus and Spiroplasma) performed best in predicting patient survival.Conclusion. Taken together, our results imply that comprehensive consideration of microbial abundance changes and microbial interactions is helpful for mining bacterial markers that carry prognostic information.

Effects of Multiple Drivers of Environmental Change on Native and Invasive Macroalgae in Nearshore Groundwater Dependent Ecosystems

AbstractGroundwater dependent ecosystems (GDE) are increasingly recognized as critical components of sustainable groundwater management, but are threatened by multiple drivers of environmental change. Despite this importance, data that link drivers of hydrologic change to GDEs are scarce. This study adapts a land‐sea modeling framework by calibrating marine models with macroalgal experiments to quantitatively assess impacts of climate and land use change on submarine groundwater discharge (SGD) and subsequent habitat suitability for a native (Ulva lactuca) and an invasive (Hypnea musciformis) macroalgae in nearshore GDEs in Kona, Hawai'i. Lab analyses demonstrate that while U. lactuca grows optimally in low‐salinity, high‐nutrient waters, H. musciformis appears constrained to a salinity threshold and exhibits low growth in low salinity despite high nutrient concentrations. Land‐sea model results predict that while a dry future climate (Representative Concentration Pathway 8.5 mid‐century) coupled with increased urban development will likely reduce SGD, protecting native forests may prevent further loss of SGD quantity. This prevention thus partially mitigates the decline in habitat suitability of U. lactuca due to the combined effects of climate and land use change. Findings also suggest that, in contrast to the native U. lactuca, reductions in SGD may favor H. musciformis growth if introduced to Kona. Collectively, this study demonstrates the importance of considering multiple drivers of environmental change on GDEs. This study bridges experiments with models to spatially map changes in species abundance beyond their current habitat conditions, and thus informs management actions that can explicitly incorporate future human and climate‐related impacts.

Оценка воздействия лесозаготовительной деятельности на сохранение биоразнообразия северного региона

In the context of sustainable forestry, biodiversity conservation assessment is a necessary element in asset and service accounting. Logging is an important driver of economic growth in the northern regions of Russia. The past twenty years have seen changes in timber harvesting technologies and forest management principles, which has led to an increase in research interest in identifying ecosystem responses in terms of biodiversity conservation. This study aims to assess changes in biodiversity within the active forest management territory of the Komi Republic, encompassing ten municipal districts and 24 forestry areas. The objectives of the study include evaluating the impact of factors such as population density, road network, and intact area on biodiversity preservation. Statistical analysis methods were utilized to assess the biodiversity status, focusing on the number of rare species threatened by logging. The analysis studied changes in species abundance, territorial distribution across forestry areas, and changes in their conservation status. Using statistical and factor analysis methods, the study identified the impact of forestry and anthropogenic factors on the conservation of species. The novelty of the research consists in identifying the stability degree of ecosystems by analyzing the state of large areas that have experienced long-term anthropogenic impacts on the Komi Republic territory. Most forests within the active forest management zone demonstrated favorable ecosystem conditions, with logging activities causing lichen disappearance and reduced fish numbers only in individual small areas. The anthropogenic impact had minimal influence on the number of rare species due to low population and road network density. Large areas of undisturbed forests contribute to the natural preservation of biodiversity, but their significant reduction in the southern area causes a threat to the existence of rare species. The greatest impact on the change in biodiversity on the territories affected by active forest management is caused by factors such as the level of territorial exploration, the preservation of undisturbed forests, and selective logging. The practical significance of this study lies in the potential application of the proposed algorithm by large Russian forest businesses when conducting their operations.

Habitat development and species arrival drive succession of the benthic invertebrate community in restored urban streams

BackgroundUrban streams are characterised by species-poor and frequently disturbed communities. The recovery of heavily polluted urban streams is challenging but the simple community structure makes recolonisation patterns more transparent. Therefore, they are generally applicable model systems for recolonisation of restored streams. Principal questions of stream restoration concern the drivers and patterns of recolonisation processes. Rarely, recolonisation of restored streams is recorded for a sufficient time to observe patterns of habitat and community development in detail. Over 10 years, we monitored benthic habitat changes and macroinvertebrate communities of eight restored sites in an urban stream network that was formerly used as an open sewer and thus, almost uninhabitable for macroinvertebrates prior to restoration. We analysed changes in environmental variables and communities with a selection of multi-variate analyses and identified indicator species in successional stages.ResultsProportions of stony substrate and conductivity decreased over time since restoration, while the riparian vegetation cover increased along with the amount of sandy substrate. The communities fluctuated strongly after restoration but began to stabilise after around eight years. TITAN analysis identified 9 species, (e.g. the mayfly Cloeon dipterum and the beetle Agabus didymus), whose abundances decreased with time since restoration, and 19 species with an increasing abundance trend (e.g. several Trichopteran species, which colonised once specific habitats developed). Woody riparian vegetation cover and related variables were identified as major driver for changes in species abundance. In the last phase of the observation period, a dry episode resulted in complete dewatering of some sites. These temporarily dried sections were recolonised much more rapidly compared to the recolonisation following restoration.ConclusionsOur results underline that community changes following urban stream restoration are closely linked to the evolving environmental conditions of restored streams, in particular habitat availability initialised by riparian vegetation. It takes about a decade for the development of a rich and stable community. Even in streams that were almost completely lacking benthic invertebrates before restoration, the establishment of a diverse macroinvertebrate community is possible, underlining the potential for habitat restoration in formerly heavily polluted urban areas.

Nitrate and a nitrate-reducing Rothia aeria strain as potential prebiotic or synbiotic treatments for periodontitis

A few studies indicate that nitrate can reduce dysbiosis from a periodontitis point of view. However, these experiments were performed on samples from healthy individuals, and it is unknown if nitrate will be effective in periodontal patients, where the presence of nitrate-reducing bacteria is clearly reduced. The aim of this study was to test the effect of nitrate and a nitrate-reducing R. aeria (Ra9) on subgingival biofilms of patients with periodontitis. For this, subgingival plaque was incubated with 5 mM nitrate for 7 h (n = 20) or 50 mM nitrate for 12 h (n = 10), achieving a ~50% of nitrate reduction in each case. Additionally, Ra9 was combined with 5 mM nitrate (n = 11), increasing the nitrate reduced and nitrite produced (both p < 0.05). The addition of nitrate to periodontitis communities decreased biofilm mass (50 mM > 5 mM, both p < 0.05). Five millimolar nitrate, 50 mM nitrate and 5 mM nitrate + Ra9 led to 3, 28 and 20 significant changes in species abundance, respectively, which were mostly decreases in periodontitis-associated species. These changes led to a respective 15%, 63% (both p < 0.05) and 6% (not significant) decrease in the dysbiosis index. Using a 10-species biofilm model, decreases in periodontitis-associated species in the presence of nitrate were confirmed by qPCR (all p < 0.05). In conclusion, nitrate metabolism can reduce dysbiosis and biofilm growth of periodontitis communities. Five millimolar nitrate (which can be found in saliva after vegetable intake) was sufficient, while increasing this concentration to 50 mM (which could be achieved by topical applications such as a periodontal gel) increased the positive effects. Ra9 increased the nitrate metabolism of periodontitis communities and should be tested in vivo.

Synchronized multidecadal trends and regime shifts in North Atlantic plankton populations

Abstract Recent changes in oceanic plankton are being reported at unprecedented rates. Most changes are related to environmental factors, and many were identified as driven by climate, either through natural cycles or by anthropogenic effects. However, the separation of both effects is difficult because of the short length of most observational series. Moreover, some changes are related to trends and cycles, while others were perceived as system shifts, often synchronized over large spatial scales. Here, studies on observational series of plankton, with the focus in the North Atlantic, are reviewed. Two main periods of shifts in plankton assemblages were identified: one in the late 1980s and a more recent one at the beginning of the new millennium. While the origin and extent of most shifts varied locally, their synchronization seems to confirm the response of plankton to changes in warming and in large-scale climatic factors. Changes in species abundance and distribution patterns were generally related to hydrographic factors, but also to non-linear effects of warming, the latter particularly affecting species in regions near the limits of their thermal niches. Indeed, most of the changes were attributed to trade-offs between different biological strategies. Taken together, the reviewed case studies indicate a lagged biological response to variations in the local environment driven by large-scale climate forcing. The challenges for interpreting future shifts include considering local changes within a larger geographical area, variations in species life traits, and potential top-down effects of plankton predators.

Traits help explain species' performance away from their climate niche centre

AbstractAimClimate change impacts on biota are variable across sites, among species and throughout individual species' ranges. Niche theory predicts that population performance should decline as site climate becomes increasingly different from the species' climate niche centre, though studies find significant variation from these predictions. Here, we propose that predictions about climate responses can be improved by incorporating species' trait information.LocationEurope.MethodsWe used observations of plant species abundance change over time to assess variation in climate difference sensitivity (CDS), defined as how species performance (colonization, extinction and abundance change) relates to the difference of site climate from the mean temperature and precipitation of each species' range. We then investigated if leaf economics, plant size and seed mass traits were associated with the species' CDS.ResultsSpecies that performed better (e.g. increased in abundance) towards sites progressively cooler than their niche centre were shorter and had more resource‐acquisitive leaves (i.e. lower leaf dry matter content or LDMC) relative to species with zero or the opposite pattern of temperature difference sensitivity. This result supports the hypothesis that if sites cooler than niche centres are more stressful for a species, then shorter stature is advantageous compared with taller species. The LDMC result suggests the environment selects for more resource‐acquisitive leaf strategies towards relatively cooler climates with shorter growing seasons, counter to expectations that conservative strategies would be favoured in such environments. We found few consistent relationships between precipitation difference sensitivities and traits.Main ConclusionsThe results supported key a priori foundations on how trait‐based plant strategies dictate species responses to climate variation away from their niche centre. Furthermore, plant height emerged as the most consistent trait that varied with species CDS, suggesting height will be key for theory development around species response to climate change.

(095) Contribution of Testicular Microbiome to the Seminal Microbiota: Are There Repercussions After Vasectomy?

Abstract Introduction The human microbiome has been implicated in a variety of clinical conditions. The semen harvests a compendium of microorganisms that potentially originate in different anatomic structures, such as the testis, prostate, and seminal vesicles. However, there is a paucity of data delineating the significance of the human microbiome in male reproductive health, specifically the testicular microbiome and its role over the seminal microbiota. Objective To analyze the changes in seminal microbiome after impeding the paracrine migration of testicular microbiome caused by undergoing a vasectomy. Methods Seminal samples were collected from 40 normozoospermic patients (normal concentration and motility according to the WHO parameters) and 36 post-vasectomy patients (samples were collected &amp;gt;3 months after vasectomy, the timeframe in which the microbiome is expected to have stabilized after the procedure). Sixteen patients gave a pre- and post-vasectomy semen sample. Richness (α-diversity) of the seminal microbiome, calculated by the number of operational taxonomic units, and clusterization (β-diversity), obtained by Bray Curtis distances, were compared between the normozoospermic and post-vasectomy SS, and then only among the paired SS. The relative abundance of species, genera, and phylum was compared among groups using analysis of compositions of microbiomes with bias correction (ANCOM-BC). Secondarily, the association between age, BMI, ethnicity, and recent antibiotic use (&amp;lt;3 months before obtaining SS) with seminal microbiome profiling was analyzed. Statistical significance was assessed at p&amp;lt;0.05. Results Operational taxonomic units (OTUs) were found to be higher in the normozoospermic group (median=35 OTUs) than in the post-vasectomy group (median=29 OTUs) (p=0.018). Similarly, in men who had paired semen samples, the pre-vasectomy samples (median=43 OTUs) had a higher α-diversity than the post-vasectomy samples (median=29 OUTs) (p&amp;lt;0.001), suggesting a higher community heterogenicity in the normozoospermic and pre-vasectomy groups. β-diversity was similar between normozoospermic and post-vasectomy groups (p=0.584), and also between paired semen samples (p=0.080) suggesting a similar community composition among groups. The relative abundance of species, genera, and phylum remained, in its majority, similar between groups. Nonetheless, when relative abundances with a prevalence of less than 10% were analyzed, we found that 12 species and 8 genera differed between normozoospermic and post-vasectomy samples. Age, BMI, ethnicity, and recent antibiotic use were not associated with seminal microbiome composition. Conclusions Our study highlights that the seminal microbiome without the paracrine contribution of testicular microbiome due to vasectomy, would exhibit fewer OTUs and a change in the relative abundance of species and genera. This causes a modification in α-diversity of the semen, implying that testicular microbiome contributes to the configuration and composition of the seminal microbiota. Further investigations are needed to determine the impact of these findings in male’s reproductive health. Disclosure Yes, this is sponsored by industry/sponsor: MicroGenDX Clarification Industry funding only - investigator initiated and executed study Any of the authors act as a consultant, employee or shareholder of an industry for: Acerus, Boston Scientific, Endo Pharmaceuticals and Coloplast.

No evidence of a northward biome shift of treeline in the Mackay Lake region, north-central Canada

ABSTRACT Major changes in boreal and subarctic climates have occurred in recent decades, but uncertainty exists as to how biota are responding, e.g., whether the subarctic forest-tundra (‘treeline’) will advance northward. Ground-based vegetation data from the Mackay Lake region of the Northwest Territories were used to determine if there is evidence of a northward biome shift. Near the treeline, current plant communities are similar to those documented 40–67 years ago. There was little or no evidence of recent tree regeneration by seed, expansion of tree stands, or colonization by trees of adjacent tundra. Black spruce stems require ~75 years to reach 2.5 m in height and be discernible as trees on photography and satellite imagery. Branches 20–30 years old are the preferred age for initiation of an upright stem from layering. Upright stems of clonal spruce within the forest-tundra may be far younger than their near-ground or belowground stems. Whether northward biome migration will occur will depend on the interplay between climatic, landscape, and soil factors, species migration capacities, wildfires, and whether afforestation outpaces deforestation. In the forest-tundra, climatic change may not result in significant biome shifts, but rather in changes in the relative abundance of species already present.

Resident species, not immigrants, drive reorganization of estuarine fish assemblages in response to warming.

Climate change is reshaping biological communities, as species track environmental temperature. Assemblage reorganization is underpinned by shifts in species abundance and distribution, but studies often focus on documenting compositional turnover. As a consequence, phenomena such as the tropicalization of temperate communities have been widely associated with increased occupancy of warm-affinity species. Abundance-weighted change in thermal affinity can be tracked with the Community Temperature Index (CTI), and decomposed into four processes: tropicalization (increasing warm-affinity), borealization (increasing cold-affinity), deborealization (decreasing cold-affinity), and detropicalization (decreasing warm-affinity). Further evaluation of these processes according to species persistence (i.e., immigrant, emigrant, and resident) may provide insights on whether novel communities emerge primarily from local shifts in species abundance or distribution. Using long-term data on fish assemblages undergoing climate change's effects across 19 temperate estuaries surveyed for at least 20 years, we hypothesized (1) deborealization is the main process reshaping communities under climate change, and (2) the contribution of resident species to processes reshaping communities surpass the ones from immigrants and emigrants. Community dissimilarity was calculated through the Temporal Beta Index (TBI), which was further decomposed into species and individual losses and gains. These values were then used as effect sizes in the meta-analyses performed to detect systematic trends in assemblage reorganization in response to climate change. We also calculated CTI and the strength of temperature-related processes for resident, immigrant and emigrant species. Species and individual gains outweighed losses in estuaries. Temperature was correlated with changes in species abundance, but not occurrence. Fish abundance decreased with warming, and initially cooler estuaries gained more fish than warmer ones. Novel communities were shaped by a variety of processes, but mainly tropicalization. Assemblage reorganization was primarily driven by shifts in abundance of resident species with distinct thermal affinities, while contributions of arriving and exiting species played a secondary role. These findings reveal that novel communities are drawn primarily from the local species pool, due to changes in climate-related drivers that favor distinct resident species.