Simpson Evenness Research Articles

Effects of the main media of wind and water on the biodiversity pattern of grassland and its driving mechanism in Poyang Lake

AbstractAs important media for species diffusion, water and wind are two important factors for grassland biodiversity conservation in lake areas. Exploring their driving mechanism on grassland biodiversity is crucial for maintaining the lake ecosystem's equilibrium. Our study utilizes the data of wind velocity and water level, which are significant performance factors for wind and water respectively in Poyang Lake from 2000 to 2020 to reveal their interannual time‐series fluctuation characteristics and their influence mechanism on the grassland biodiversity pattern. Landscape pattern indices and biodiversity indicators, such as the number of patches (NP), patch density (PD), landscape spreading index (CI), landscape fragmentation index (LSD), landscape aggregation index (AI), Simpson diversity index (MSIDI) and Simpson evenness index (MSIEI) were analysed, trend analysis, redundancy analysis and structural equation modelling were applied in this study. The main results were: (1) From 2000 to 2020, Poyang Lake's wind velocity decreased gradually, and the water level first decreased and then rose. NP in Poyang Lake fluctuated substantially, LSD fluctuated frequently and obvious temporal heterogeneity existed. (2) CI and AI increased from low to high value, facilitating species dispersal and migration. The dominant species with high aggregation gradually established stronger connectivity. Moderate spreading degree and aggregation degree maintained high biodiversity and evenness, whereas excessive spreading degree and aggregation degree led to homogenization of species, decrease in biodiversity, reduction in species evenness, and increase in dominance. (3) As the landscape transformed from having no obvious dominant species to being dominated by several dominant species, MSIEI and landscape dominance changed from high to low and low to high respectively. Moreover, the biodiversity shifted from high to low, and species distribution in the landscape shifted from balanced to unbalanced. (4) The effect of water level on PD, AI, LSD, MSIDI and MSIET was significantly higher than that of wind velocity. LSD was mainly regulated by the minimum wind velocity affecting the maximum and average water levels. MSIDI and MSIET were primarily governed by the minimum wind velocity affecting the minimum water level. The minimum water level decreased as the minimum wind velocity increased, and MSIDI and MSIET weakened as the minimum water level decreased.

Specialization: A multidimensional and integrative perspective

AbstractSpecialization remains as a controversial and ambiguous term in ecology. Although it has been usually measured using a dichotomic and simplified classification of specialists and generalists, its nature is by far more complex. In the context of biotic interactions, assigning these two labels is usually based on the number of interacting partners (one or few vs. many). Here, we provide a more precise, quantitative, and objective interpretation of the specialization phenomenon combining three different dimensions (specificity, preference, and selectivity) that offer complementary information to quantify specialization. Hence, partner richness is a metric associated with the specificity, Simpson's evenness is related to the preference and d′ index to the selectivity of the biotic interactions. Consequently, we propose a 3D specialization space combining these three metrics which allows to identify the degree of biotic specialization fleeing from its simplified historical interpretation. The proposed space was subsequently evaluated in five natural interacting systems (host–parasite, plant–ant, plant–pollinator, plant–seed disperser, and mycobiont–cyanobacteria) using available data comprising 116 networks with quantitative observations. The results indicate the prevalence of a lax specialization, where most organisms tended to show low values in at least one of the metrics. Predominantly, observations showed high values of specificity and low values of preference and selectivity. This relaxed specialization provides advantages of being specialized, without sentencing it when being too tight. The implementation of this framework provides a useful tool that allows to identify specialization in a more objective, integrative, and universal way for future specialization studies.

A zooarchaeological perspective on late pleistocene/early holocene human behaviour in the Maloti-Drakensberg region, southern Africa: The view from Ha Makotoko and Ntloana Tšoana rock-shelters, Lesotho

Re-excavation of Ha Makotoko and Ntloana Tšoana rock-shelters in western Lesotho, produced abundant faunal remains (both macro and micro) from people using the Robberg technocomplex during the late Pleistocene (Ha Makotoko and Ntloana Tšoana (15.4–13.4 kcal. BP) and early Holocene (Ntloana Tšoana 11.1–10.2 kcal. BP). This faunal material allows us to identify the subsistence strategies they employed, using the unbiased Simpson's evenness index (1-D′), and Shannon's evenness index to track diet breadth. Detailed analyses of the sites' microfauna indicates that eagle owls and/or small carnivores — not humans — were responsible for introducing them into the deposits. A chi-squared test comparing diet breadth across the sites identifies hunting strategy, focused on size 2 and 3 migratory ungulates (equids, suids, and bovids), supplemented with size 1 and 4 bovids. Comparing the evenness values from Ha Makotoko and Ntloana Tšoana to published data from other Robberg-associated sites in the wider Maloti-Drakensberg region (Sehonghong, Rose Cottage Cave and Tloutle) allows variability in subsistence strategies to be addressed. A chi-squared test comparing ungulate size classes, small mammals and fish with the evenness index reveals two important statistical differences: the warm period occupation (16.5–14.3 kcal. BP) at Rose Cottage Cave presents a narrow diet heavily focused on size 3 ungulates (with a lack of fish). At the other end of the climate spectrum, cold conditions at Sehonghong immediately before the Last Glacial Maximum were associated with a narrow diet focused on intensive fishing, with lower-than-expected numbers of size 3 ungulates. The deposits at Ntloana Tšoana, Ha Makotoko, and Tloutle, along with the Younger Dryas-associated assemblage from Sehonghong, on the other hand, present broad diets. Fish and small mammals make more of a contribution to the expanding diet in the highlands. Our approach demonstrates the flexibility that makers of Robberg tools displayed in adapting to the changing climatic and ecological conditions of this high-elevation region in the interior of southern Africa during Marine Isotope Stage 2 and across the Pleistocene/Holocene transition.

Quantitative Assessment of Macrophytes Diversity and their Status in Wetlands of Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh (India)

The most significant and taxonomically varied biotic element in every aquatic environment is aquatic macrophytes. They play a vital role in maintaining the ecosystem's structure and functionality. Additionally serving as bioindicators of the general health of a water body are macrophyte kinds, variety, density, and depth. In present study, the quantitative diversity of aquatic macrophytes was assessed from different wetlands of Guru Ghasidas Vishwavidyalaya which is a central university and holds four important water bodies in Bilaspur district of Chhattisgarh state, India. A total of 33 aquatic macrophytes species were identified belonging to 21 families from wetlands of Guru Ghasidas Vishwavidyalaya. These macrophytes were grouped as floating, submerged and emergent mainly dominated by emergent macrophyte species followed by floating and submerged i.e., 23, 8 and 2 species respectively. The highest species diversity was observed in Pond 1 and 4 with 26 species each and highest species richness was observed in Pond 4 with 158 individual counts, the highest IVI was achieved by emergent Ipomoea carnea (16.492) and the highest occurring family was found to be Cyperaceae (12.12% of total species). Other diversity indices were calculated as 3.451, 0.042, 33 and 0.946 for Shannon-Wiener Index (H’), Simpson's Index (D), Species Richness (R), and Evenness (E) respectively. However, for the conservation and sustainable utilization of aquatic ecosystems, it is necessary to understand the status and importance of macrophytes to the ecosystem and its functioning.

Taxonomic and functional diversity of aquatic macroinvertebrate from natural forest as reference for streams health indicators in Lasolo Watershed, Southeast Sulawesi, Indonesia

Abstract. Nasaruddin N, Sabaruddin L, Analuddin K, Sudia LB. 2023. Taxonomic and functional diversity of aquatic macroinvertebrate from natural forest as reference for streams health indicators in Lasolo Watershed, Southeast Sulawesi, Indonesia. Biodiversitas 24: 5523-5538. Macroinvertebrates are known to play a crucial role in nutrient recycling and serve as valuable stream degradation indicators. Therefore, this study aimed to examine the structural and functional diversity of macroinvertebrate communities as a reference for stream health indicators in tropical Sulawesi, Indonesia. Spatial sampling using a multi-habitat method was conducted between September 2021 and March 2022 in five streams connected to natural forest and three from drainage areas in dryland farming. Data on forest cover, physical-chemical variables, and macroinvertebrate samples were collected, while the species richness and diversity trends across streams were analyzed using individual rarefaction curves. In addition, the composition of macroinvertebrate functional group was also evaluated. The results showed that 2474 individuals belonging to 77 genera were recorded throughout the area. We found a reduction in taxa composition by comparing the reference and impacted stream at the genus, family, and order levels with approximate values of 83.1%, 74.07%, and 55.6%, respectively. At least seven significantly different potential metrics that differentiated between reference and the impacted ecosystem were found, including the number of family taxa (#family), the number of insect taxa (#insect), the number of Ephemeroptera-Plecoptera-Trichoptera taxa (#EPT), the number of scraper taxa (#scraper), as well as Shannon-Wiener diversity, Simpson Evenness, and Margalef Richness index. These metrics offer a strong method for assessing land use change and their impact on freshwater biodiversity, emphasizing the importance of conservation efforts in the ecosystem.

A new framework for analysis of the spatial patterns of 15-minute neighbourhood green space to enhance carbon sequestration performance: A case study in Nanjing, China

As the most fundamental unit of urban development, the performance of green space carbon sequestration in neighborhoods is, therefore, a crucial factor in the pursuit of carbon neutrality. Consequently, studying the performance of carbon sequestration from the spatial structure of green spaces in conjunction with the recreational features of the neighborhood is urgent and necessary. Herein, for the first time, we combined four types of indicators, namely carbon sequestration, green space spatial structure, natural environment, and human activities, using three types of 15-minute neighborhoods in the Nanjing metropolitan area as an example. As observed, the area indicator percentage of landscape (PLAND) contributed directly to the carbon sequestration of green areas and also influenced the carbon sequestration by affecting the average normalized vegetation index (NDVI) level; the shape indicator Simpson's evenness index (SIEI) not only helped to reduce the average temperature in the neighborhood but also improved the average NDVI level, both of which can contribute to carbon sequestration; the aggregation indicators aggregation index (AI) had no direct effect on the carbon sequestration performance but contributed to it by lowering the temperature. Thus, the current study revealed the mechanism by which the spatial characteristics of residential green spaces influenced carbon sequestration and proposed a new direction for future sustainable urban development.

Microbial community diversity and potential functionality in response to dam construction along the Three Gorge Reservoir, China.

River and reservoir bacterial communities are the most basic part of river biomes and ecosystem structure, and play an important role in river biological processes. Yet, it remains unclear how highly regulated dam reservoirs affect both soil and sediment bacterial communities. A temporal distribution pattern of bacterial communities was investigated using Illumina MiSeq sequencing in a transition section of the Three Gorges Reservoir (TGR). In total, 106,682 features belong to the bacteria kingdom, encompassing 95 phyla, 228 classes, 514 orders, 871 families, 1959 genera, and 3,053 species. With water level regulation, Shannon diversity index, and observed species differed significantly, with no significant difference in Simpson evenness. Both in the high water level period (October) and the low water level period (June), Proteobacteria, Acidobacteri, and Chloroflexi were the most abundant phyla. Whereas, based on PCA plots and Circos plot, the microbial community structure has changed significantly. LEfSe method was used to identify the classified bacterial taxa with significant abundance differences between the low water level and high water level periods. KOs (KEGG Orthology) pathway enrichment analysis were conducted to investigate functional and related metabolic pathways in groups. To some extent, it can be inferred that water level regulation affects community growth by affecting the metabolism of the microbial community.

The Diversity of Gut Microbiota at Weaning Is Altered in Prolactin Receptor-Null Mice.

Maternal milk supports offspring development by providing microbiota, macronutrients, micronutrients, immune factors, and hormones. The hormone prolactin (PRL) is an important milk component with protective effects against metabolic diseases. Because maternal milk regulates microbiota composition and adequate microbiota protect against the development of metabolic diseases, we aimed to investigate whether PRL/PRL receptor signaling regulates gut microbiota composition in newborn mice at weaning. 16SrRNA sequencing of feces and bioinformatics analysis was performed to evaluate gut microbiota in PRL receptor-null mice (Prlr-KO) at weaning (postnatal day 21). The normalized colon and cecal weights were higher and lower, respectively, in the Prlr-KO mice relative to the wild-type mice (Prlr-WT). Relative abundances (Simpson Evenness Index), phylogenetic diversity, and bacterial concentrations were lower in the Prlr-KO mice. Eleven bacteria species out of 470 differed between the Prlr-KO and Prlr-WT mice, with two genera (Anaerotruncus and Lachnospiraceae) related to metabolic disease development being the most common in the Prlr-KO mice. A higher metabolism of terpenoids and polyketides was predicted in the Prlr-KO mice compared to the Prlr-WT mice, and these metabolites had antimicrobial properties and were present in microbe-associated pathogenicity. We concluded that the absence of the PRL receptor altered gut microbiota, resulting in lower abundance and richness, which could contribute to metabolic disease development.

Diversity of diversity indices: Which diversity measure is better?

The article evaluates the dependence of the most common indices of species diversity on sample size and determines their ability to differentiate between different types of ecosystems, with a special emphasis on discriminating between natural and anthropogenic ecosystems. An approach to adjusting the indices to reduce their dependence on sample size was also proposed. The study was conducted in seven types of ecosystems: four were natural and three were anthropogenically transformed. Samples of soil animals were selected in 2011–2013 and 2021 using the same methods. A total of 20,518 soil animal specimens belonging to 202 species were collected in all study locations. The null alternative was generated by randomly selecting samples containing 2, 3, ..., 110 soil animals from the combined soil animal sample. For each gradation of sample size, 200 sample variants were formed. The density of soil macrofauna in natural ecosystems ranged from 3.6 ± 1.5 to 15.2 ± 6.9 specimens per sample, and in artificial ecosystems – from 13.2 ± 7.6 to 21.0 ± 11.9 specimens per sample. The number of species ranged from 22–80 species, and in artificial ecosystems it was 38–99 species. Indicators of species diversity correlated with each other. A high level of correlation was observed between indicators within groups of indices: indices of species richness and indices of heterogeneity and evenness. Fisher’s log-series alpha and the fundamental parameter of biodiversity were highly correlated with each other, as well as with the Margalef, species richness, and Chao’s species abundance indices. The log-normal distribution best describes the dominance patterns in terms of abundance in the natural ecosystems, and the Zipf-Mandelbrot distribution best describes the dominance patterns in terms of abundance in the artificial ecosystems. Diversity indices were ordered in the space of two dimensions, one explaining the variation between ecosystems and the other depending on sample size. The ordering of the traditional indices showed that there is a vacancy for the best index in the sense that such an index should best explain differences between ecosystems and differences between natural and artificial ecosystems. It should also be independent of sample size. The Simpson heterogeneity index and the Simpson evenness index were the best of the traditional indices, but they did not explain differences between ecosystems very well, especially when it came to distinguishing between natural and artificial ecosystems. The Margalef index, which is supposed to be independent of sample size, on the other hand, showed a very high level of dependence. Such a dependence was also found for the Menhinick index, though to a lesser extent. Obviously, size dependence negatively affects the differential ability of the indices. The corrected indices of species richness and the Shannon index are practically independent of sample size and have a greater ability to differentiate ecosystems by the level of diversity, with natural ecosystems characterized by consistently higher values of the corrected indices than artificial ecosystems. The dependence on the sample size makes indices from different ecosystems practically incomparable, which makes their use meaningless. Even minor differences in sample size can lead to significant deviations in the values of diversity indices. The application of the Michaelis-Menten model allowed us to suggest a method of correction of species richness indices and the Shannon index. After the correction, the indices are practically independent of the sample size, and their differential ability to characterize individual ecosystems and the level of anthropogenic transformation increases significantly.

Fishery livelihoods and an adaptation to climate change-induced threats at the Bhomra Wetland: a case study through a stakeholder-driven approach

Abstract The main aim of the present study is to assess the present ecological status of Bhomra wetland with respect to the fisheries and associated ecosystem services and to prescribe some climate-smart adaptation technologies in changing climate. The analysis showed increasing temperature (Kendall's tau = 0.60, p<0.05) and decreasing rainfall (Kendall's tau = −0.33, p<0.05) in the studied region over the last two decades. The wetland is dominated by Cypriniformes species followed by Perciformes species. The overall production of the fish (i.e., 32155 kg) from the wetland in 2020 is below the average production of the last 10 year (i.e., 54704 kg). Canonical correspondence analysis reviled a strong correlation (p<0.05) between the fish assemblage and ecological parameters (mainly total alkalinity and available nitrate) of the wetland. Though the species diversity was moderate along with the moderate species richness (i.e., Shannon-Weiner diversity index = 1.581±0.007), the evenness (Simpson evenness index = 0.995±0.001) was high throughout the wetland. The wetland was found suitable for carp culture, but the ecosystem's health has degraded over time. The communication further suggests several climate-resilient strategies for sustainable utilization of wetland ecosystem services and increasing adaptive capacity of the fishers.

The Middle Ear Microbiota in Healthy Dogs Is Similar to That of the External Ear Canal.

Otitis media can be a consequence of chronic otitis externa and could represent a perpetuating factor. While the microbiota of the EEC in healthy dogs and in the presence of otitis externa has been described, only sparse information is available concerning the normal microbiota of the middle ear. The objective was to compare the tympanic bulla (TB) with the external ear canal (EEC) microbiota in healthy dogs. Six healthy experimental Beagle dogs were selected based on the absence of otitis externa, negative cytology and bacterial culture from the TB. Samples from the EEC and TB were collected directly after death using a total ear canal ablation and lateral bulla osteotomy. The hypervariable segment V1-V3 of the 16S rDNA was amplified and sequenced with a MiSeq Illumina. The sequences were analyzed by the Mothur software using the SILVA database. No significant differences between the EEC and TB microbiota for the Chao1 richness index (p = 0.6544), the Simpson evenness index (p = 0.4328) and the reciprocal Simpson alpha diversity (p = 0.4313) were noted (Kruskal-Wallis test). A significant difference (p = 0.009) for the Chao1 richness index between the right and left EEC was observed. The microbiota profile was similar in the EEC and the TB of the Beagles.

Growth of water hyacinth biomass and its impact on the floristic composition of aquatic plants in a wetland ecosystem of the Brahmaputra floodplain of Assam, India.

Inland water plants, particularly those that thrive in shallow environments, are vital to the health of aquatic ecosystems. Water hyacinth is a typical example of inland species, an invasive aquatic plant that can drastically alter the natural plant community's floral diversity. The present study aims to assess the impact of water hyacinth biomass on the floristic characteristics of aquatic plants in the Merbil wetland of the Brahmaputra floodplain, NE, India. Using a systematic sampling technique, data were collected from the field at regular intervals for one year (2021) to estimate monthly water hyacinth biomass. The total estimate of the wetland's biomass was made using the Kriging interpolation technique. The Shannon-Wiener diversity index (H'), Simpson's diversity index (D), dominance and evenness or equitability index (E), density, and frequency were used to estimate the floristic characteristics of aquatic plants in the wetland. The result shows that the highest biomass was recorded in September (408.1 tons/ha), while the lowest was recorded in March (38 tons/ha). The floristic composition of aquatic plants was significantly influenced by water hyacinth biomass. A total of forty-one plant species from 23 different families were found in this tiny freshwater marsh during the floristic survey. Out of the total, 25 species were emergent, 11 were floating leaves, and the remaining five were free-floating habitats. Eichhornia crassipes was the wetland's most dominant plant. A negative correlation was observed between water hyacinth biomass and the Shannon (H) index, Simpson diversity index, and evenness. We observed that water hyacinths had changed the plant community structure of freshwater habitats in the study area. Water hyacinth's rapid expansion blocked out sunlight, reducing the ecosystem's productivity and ultimately leading to species loss. The study will help devise plans for the sustainable management of natural resources and provide helpful guidance for maintaining the short- to the medium-term ecological balance in similar wetlands.

Burdur İli farklı anason (Pimpinella anisum L.) ve rezene (Foeniculum vulgare Mill.) agro- ekosistemlerinde epigean Hexapoda türlerinin biyolojik çeşitlilik parametrelerinin hesaplanması

This study was carried out to compare the biodiversity parameters of epigean insect species in 3 different regions with different geographical conditions. Tefenni Plain, Beyköy (Abdülmelik) Plain and Çaylı Mountain Village, which are located at 3 different altitudes, were chosen as the study area. Pitfall traps were placed in agro-ecosystems of anise and fennel in each region and epigean insect species caught with pitfall traps were checked weekly. A total of 2086 individuals belonging to 117 epigean insect species, mostly from the carabid family, were sampled. The highest number of individuals were sampled in Tf and Ta with 841 and 440, respectively. The results of Shannon-Wiener diversity were found to be the highest in Ta with 2.7893 while the lowest was found in Ca with 2.1775. Similar to Shannon-Wiener diversity results, Simpson diversity results were calculated as highest in Ta with 0.9196 and lowest in Ca with 0.7813. Simpson's dominance results determined that Ca was the highest dominant agro-ecosystem with 0.2187. The second and third most dominant agro-ecosystems were found to be Tf and Cf with 0.1847, 0.1635, respectively. According to both Shannon and Simpson Evenness; the population densities of epigean species living in Bf and Ba were found to be more balanced than in other agro-ecosystems. The percentage similarity analysis shows that the regions selected in different altitudes were more similar to each other than the plants of the same species. Contrary to expectations, it was observed that epigean insect species did not show distribution according to plant pattern and were not directly related to plants. It is thought that the epigean insect species sampled are affected by the altitude difference

IMPACTS OF CLIMATE CHANGE ON PHYTOPLANKTON COMPOSITION AND VARIABILITY IN IKO RIVER, COASTAL WATER OF EASTERN OBOLO, NIGERIA

This study investigated the effects of climate change on phytoplankton composition and diversity in Iko River, coastal water of Eastern Obolo, Akwa Ibom State, South Eastern Nigeria. The study area was greatly influenced by tidal flush from the Atlantic Ocean. Phytoplankton samples were collected monthly from October 2021 to March 2022 at high tide and low tide from 3 stations. Phytoplankton was identified and diversity was calculated using standard indices. Dissolved oxygen (3.3–6.0 mg/L) was above WHO guidelines of <5.0mg/L and BOD (2.40-5.30 mg/L) in this study was above the (4.0 mg/L) limit recommended as suitable for aquatic life by the National Environmental Standards and Regulation Enforcement Agency (NESREA), which could pose a threat to aquatic life. A total number of 65 species of phytoplankton were identified in the study area. Bacillariophyta was the dominant group (69%) throughout the study in species number, occurrence and abundance. The increasing order of dominance values was; Bacillariophyta > Cyanophyta > Chlorophyta > Dinophyta > Euglenophyta . Diversity indices (Margalef, Shanon, Dominance, Simpson Evenness and Equitability) showed spatial variations significant at (P>0.05). Pollution-indicator species such as; Tabellaria fenestrata, Nitzschia. paradoxa, N. filiformis, N. longissima, Cymbella cuspidata, Melosira distans and Anabaena constrica were recorded at either high tide, low tide or at both tides. Concerted efforts have been recommended to Government agencies and individuals to help reduce natural and anthropogenic pollution of the coastal water bodies.

Ocean kinetic energy and photosynthetic biomass are important drivers of planktonic foraminifera diversity in the Atlantic Ocean

To assess the anthropogenic effect on biodiversity, it is essential to understand the global diversity distribution of the major groups at the base of the food chain, ideally before global warming initiation (1850 Common Era CE). Since organisms in the plankton are highly interconnected and carbonate synthesizing species have a good preservation state in the Atlantic Ocean, the diversity distribution pattern of planktonic foraminifera from 1741 core-top surface sediment samples (expanded ForCenS database) provides a case study to comprehend centennial to decadal time-averaged diversity patterns at pre-1970 CE times, the tempo of the substantial increase in tropospheric warming. In this work, it is hypothesized and tested for the first time, that the large-scale diversity patterns of foraminifera communities are determined by sea surface temperature (SST, representing energy), Chl-a (a surrogate for photosynthetic biomass), and ocean kinetic energy (as EKE). Alpha diversity was estimated using species richness (S), Shannon Wiener index (H), and Simpson evenness (E), and mapped using geostatistical approaches. The three indices are significantly related to SST, Chl-a, and EKE (71-88% of the deviance in the generalized additive mixed model, including a spatial component). Beta diversity was studied through species turnover using gradient forest analysis (59% of the variation). The primary community thresholds of foraminifera species turnover were associated with 5-10 °C and 22-28 °C SST, 0.05-0.15 mg m-3 Chl-a, and 1.2-2.0 cm2 s-2 log10 EKE energy, respectively. Six of the most important foraminifera species identified for the environmental thresholds of beta diversity are also fundamental in transfer functions, further reinforcing the approaches used. The geographic location of the transition between the four main biogeographic zones was redefined based on the results of beta diversity analysis and incorporating the new datasets, identifying the major marine latitudinal gradients, the most important upwelling areas (Benguela Current, Canary Current), the Equatorial divergence, and the subtropical fronts (Gulf Stream-North Atlantic Drift path in the north, and the South Atlantic current in the south). In conclusion, we provide statistical proof that energy (SST), food supply (Chl-a), and currents (EKE) are the main environmental drivers shaping planktonic foraminifera diversity in the Atlantic ocean and define the associated thresholds for species change on those variables.

Experimental warming increases fungal alpha diversity in an oligotrophic maritime Antarctic soil.

The climate of maritime Antarctica has altered since the 1950s. However, the effects of increased temperature, precipitation and organic carbon and nitrogen availability on the fungal communities inhabiting the barren and oligotrophic fellfield soils that are widespread across the region are poorly understood. Here, we test how warming with open top chambers (OTCs), irrigation and the organic substrates glucose, glycine and tryptone soy broth (TSB) influence a fungal community inhabiting an oligotrophic maritime Antarctic fellfield soil. In contrast with studies in vegetated soils at lower latitudes, OTCs increased fungal community alpha diversity (Simpson's index and evenness) by 102-142% in unamended soil after 5 years. Conversely, OTCs had few effects on diversity in substrate-amended soils, with their only main effects, in glycine-amended soils, being attributable to an abundance of Pseudogymnoascus. The substrates reduced alpha and beta diversity metrics by 18-63%, altered community composition and elevated soil fungal DNA concentrations by 1-2 orders of magnitude after 5 years. In glycine-amended soil, OTCs decreased DNA concentrations by 57% and increased the relative abundance of the yeast Vishniacozyma by 45-fold. The relative abundance of the yeast Gelidatrema declined by 78% in chambered soil and increased by 1.9-fold in irrigated soil. Fungal DNA concentrations were also halved by irrigation in TSB-amended soils. In support of regional- and continental-scale studies across climatic gradients, the observations indicate that soil fungal alpha diversity in maritime Antarctica will increase as the region warms, but suggest that the accumulation of organic carbon and nitrogen compounds in fellfield soils arising from expanding plant populations are likely, in time, to attenuate the positive effects of warming on diversity.

Comparison of Basal Area and Trees Abundance for Estimating Tree Diversity in Beech Forests (Case Study: Guilan, Masal, Northern Iran)

Measuring tree species diversity is necessary to manage forest resources sustainably and to better understand the economic consequences to changes in species diversity due to management. This research aimed at comparing the basal area and trees abundance for evaluating tree species diversity in oriental beech (Fagus orientalis Lipsky) forests (Guilan, Masal, Northern Iran). For this study, compartment 515 was selected, and then data were collected through the random-systematic method with a grid dimension of 150×150 m in an area of 50 ha, and lozenge shape with the sizes of 400; 800; 1,000; 1,200; 1,600; 2,000; 2,500; and 5,000 m2 was established. In total, 160 sampling plots were taken. In each plot, the diameter at breast height (DBH≥7.5 cm) of all trees was measured. Diversity and evenness indices were estimated applying different variables (the basal area and the trees abundance) separately. The results elucidated that the error percentage of Mac Arthur’s N1, Hill’s N2 indices, and Simpson's evenness, was lower using basal area compare to the trees abundance. The result of Camargo, Nee, and Smith-Wilson evenness indices revealed that the error percentage by using the trees abundance was lower than the amount of basal area. We recommend using the basal area for estimating tree species diversity.

Multiple-region, N-mixture community model to assess associations of riparian area, fragmentation, and species richness.

The associations of habitat area and fragmentation with species richness long have been major topics within community ecology. Recent discussion has focused on properly assessing fragmentation independent of habitat area (fragmentation per se), and on whether fragmentation has significant negative or positive associations with species richness. We created a novel, multiple-region, N-mixture community model (MNCM) to examine the relations of riparian area and fragmentation with species richness of breeding birds in mountain ranges within the Great Basin, Nevada, USA. Our MNCM accounts for imperfect detection in count data at the survey-point level while allowing comparisons of species richness among regions in which those points are embedded. We used individual canyons within mountain ranges as regions in our model and measured riparian area and the Normalized Landscape Shape Index, a metric of fragmentation that is independent of total riparian area. We found that riparian area, but not its fragmentation, was a primary predictor of canyon-level species richness of both riparian obligates and all species. The relationship between riparian area and riparian obligate species richness was nonlinear: canyons with ≥25 ha woody riparian vegetation had relatively high species richness, whereas species richness was considerably lower in canyons with <25 ha. Our MNCM can be used to calculate other metrics of diversity that require abundance estimates. For example, Simpson's evenness of riparian obligate species had a weak negative association with riparian area and was not associated with fragmentation. Projections of future riparian contraction suggested that decreases in species richness are likely to be greatest in canyons that currently have moderate (~10-25 ha) amounts of riparian vegetation. Our results suggest that if a goal of management is to maximize the species richness of breeding birds in montane riparian areas in the Great Basin, it may be more effective to focus on total habitat area than on fragmentation of patches within canyons, and that canyons with at least moderate amounts of riparian vegetation should be prioritized.

Voronin Grotto (Middle Urals, Russia): Analysis of vertebrate assemblage with taphonomic remarks and reconstruction of the Late Bronze Age and Early Iron Age human environment in the east end of Europe based on small mammals

We present the Voronin Grotto as a new site where numerous remains of vertebrates (total NISP = 12574) and artefacts (N = 46) were found. The grotto is located in Serga River valley at the foot of the western slope of the Middle Urals, i.e., in the east end of continental Europe. The deposits have been accumulating during the last 3310 years. The AMS dates and artefacts indicate that the grotto was periodically visited by human population in the period between 3310 cal BP (the Late Bronze Age) and 1899 cal BP (the Early Iron Age). Recovered vertebrate assemblage included 49 species belonging to 5 classes (Actinopterygii, Amphibia, Reptilia, Aves, and Mammalia). The bones of fish and amphibians were collected by either otters or minks. Prevailing fish sizes between 10 and 15 cm reconstructed by means of bones confirm this. The bones of small mammals accumulated due to the predation of the owls and mustelids. Most identified vertebrate species currently inhabit the vicinity of the grotto, except for the steppe pika. Steppe pika is now disjointed from the Voronin Grotto by approximately 200–300 km to the south. Perhaps between 3310 and 1899 cal BP, steppe pika inhabited the vicinity of the grotto as the Late Pleistocene and Early Holocene relic. Palaeoenvironmental analysis of small mammal assemblage showed the predominance of woodlands with a significant proportion of open mesophytic meadows around the grotto during the last 3310 years. The landscape did not change significantly during this time. This is consistent with high values of the Simpson evenness index (1–D). Between 3310 and 1899 cal BP, the ratio of forests decreased, while the ratio of open meadows increased. Perhaps this was due to anthropic activity. After 1899 cal BP, the relative abundances of taiga small mammal species increased among forest dwellers, which is consistent with palynological data for the Middle Urals. At approximately 3310 cal BP, the climate of area around the grotto was slightly milder, and the winters were warmer than in the present day. At approximately 1899 cal BP, the climate was similar to the modern climate of the region and was cold, without a dry season, and with warm summers (Dfb type according to the Köppen–Geiger classification) as well as that of the previous period. Towards the recent time, the climate became colder and was possibly cold, without a dry season, but with a cold summer (type Dfc).

Abstract P2-12-04: Characterization of gut microbiome composition in triple negative breast cancer patients treated with neoadjuvant chemotherapy

Abstract Background: Recent evidences showed intestinal microbiota to be implicated in carcinogenesis and response to chemotherapy and immune checkpoint inhibitors in solid tumors. Furthermore, antibiotics are known to deeply influence microbiome composition in healthy people and cancer patients. The role of gut microbiome in triple negative breast cancer (TNBC) is underexplored. Methods: In this pilot prospective study, we characterized the gut microbiome of 30 TNBC patients undergoing neoadjuvant chemotherapy at two Italian Institutions. Fecal samples were collected at 2 timepoints: at the baseline (t0) and at 1 week (t1) from CT. Microbiome was analyzed by 16S rRNA sequencing. Measures of α-diversity expressed by Richness and Simpson evenness were evaluated at the species level. β-diversity was calculated using PERMANOVA test according to UniFrac measures of dissimilarity at the species level.Tumor infiltrating lymphocytes (TILs) were assessed from diagnostic core biopsy and surgical specimen. Results: From September 2017 to March 2020, 30 TNBC patients were enrolled. Median age was 53 years, 43% were premenopausal, 43% were overweight or obese (BMI&amp;gt;25); 97% had a histologic G3 carcinoma, clinical nodal involvements was present in 57%; median TILs at diagnosis was 30%. All patients received anthracycline and taxane-based chemotherapy, including carboplatin in 23 patients (77%). A pCR was achieved in 15 (50%) patients. The overall rate of stool samples collection was 93%. With regards to t0, no differences in terms of α- and β-diversity were found.At t1, α-diversity was significantly higher in pCR group (Simpson evenness index, p=0.016). Considering clinical-pathological features, a BMI &amp;lt;24.9 was associated with higher microbiome richness (p=0.012). Measurements of β-diversity did not differ between groups.As 73% of patients during the treatment phase received antibiotics, with consequent potential microbiome impairment, we repeated analyses at t1 considering fecal samples collected &amp;gt;90 days after the end of antibiotic therapy (N=17). At this analysis, β-diversity evaluated with Unifrac measure was significantly correlated with pCR (p=0.035), with Haemophilus Influentiae being significantly enriched in non-pCR group. Conclusions: Fecal microbiome collection and analysis in this population is feasible and deserves further investigation with regards its association with response to chemotherapy. Citation Format: Grazia Maria Vernaci, Davide Massa, Ilaria Patuzzi, Alice Menichetti, Tommaso Giarratano, Gaia Griguolo, Federica Miglietta, Matteo Fassan, Edoardo Savarino, PierFranco Conte, Valentina Guarneri, Maria Vittoria Dieci. Characterization of gut microbiome composition in triple negative breast cancer patients treated with neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-12-04.