Spatial Variation In Composition Research Articles

Taxonomic and phylogenetic diversity patterns in the Northern Sporades islets complex (West Aegean, Greece)

The Aegean archipelago has long been the main research area of numerous biogeographers, plant ecologists and taxonomists due to its intricate palaeogeography and high environmental and topographical heterogeneity. Nevertheless, some parts of this archipelago are essentially unexplored and the processes driving spatial variation in species composition remain unaddressed. Aiming to fill these gaps, we investigated the flora and plant diversity patterns of the Northern Sporades island group, as well as its biogeographical relationships. The study area lies in the biogeographical region of the West Aegean islands and comprises 23 islands and islets. The total flora of the study area consists of 1202 infrageneric taxa, belonging to 517 genera and 120 families, reflecting its geographical and bioclimatic characteristics. The endemic element consists of 41 taxa (3.4% of the flora), eight of which are restricted to the West Aegean islands and two are single island endemics. Area emerged as the most important variable in shaping plant species richness, while niche-based processes played a lesser role in driving these patterns. Regarding the taxonomic and phylogenetic beta-diversity patterns, environmental filtering and not dispersal limitation seems to shape the plant assemblages of the Northern Sporades islets. Biogeographically, the Northern Sporades island group seems to be closer connected to the Kiklades rather than to Evvia or the adjacent mainland, due to their longer isolation and separate palaeogeographical history during the Quaternary.

Spatial and temporal turnover of soil microbial communities is not linked to function in a primary tropical forest.

The spatial and temporal linkages between turnover of soil microbial communities and their associated functions remain largely unexplored in terrestrial ecosystems. Yet defining these relationships and how they vary across ecosystems and microbial lineages is key to incorporating microbial communities into ecological forecasts and ecosystem models. To define linkages between turnover of soil bacterial and fungal communities and their function we sampled fungal and bacterial composition, abundance, and enzyme activities across a 3-ha area of wet tropical primary forest over 2 yr. We show that fungal and bacterial communities both exhibited temporal turnover, but turnover of both groups was much lower than in temperate ecosystems. Turnover over time was driven by gain and loss of microbial taxa and not changes in abundance of individual species present in multiple samples. Only fungi varied over space with idiosyncratic variation that did not increase linearly with distance among sampling locations. Only phosphorus-acquiring enzyme activities were linked to shifts in septate, decomposer fungal abundance; no enzymes were affected by composition or diversity of fungi or bacteria. Although temporal and spatial variation in composition was appreciable, because turnover of microbial communities did not alter the functional repertoire of decomposing enzymes, functional redundancy among taxa may be high in this ecosystem. Slow temporal turnover of tropical soil microbial communities and large functional redundancy suggests that shifts in abundance of particular functional groups may capture ecosystem function more accurately than composition in these heterogeneous ecosystems.

Analysis of the Spatial Distribution of Stable Oxygen and Hydrogen Isotopes in Precipitation across the Iberian Peninsula

The isotopic composition of precipitation provides insight into the origin of water vapor, and the conditions attained during condensation and precipitation. Thus, the spatial variation of oxygen and hydrogen stable isotope composition (δp) and d-excess of precipitation was explored across the Iberian Peninsula for October 2002–September 2003 with 24 monitoring stations of the Global Network of Isotopes in Precipitation (GNIP), and for October 2004–June 2006, in which 13 GNIP stations were merged with 21 monitoring stations from a regional network in NW Iberia. Spatial autocorrelation structure of monthly and amount weighted seasonal/annual mean δp values was modelled, and two isoscapes were derived for stable oxygen and hydrogen isotopes in precipitation with regression kriging. Only using the GNIP sampling network, no spatial autocorrelation structure of δp could have been determined due to the scarcity of the network. However, in the case of the merged GNIP and NW dataset, for δp a spatial sampling range of ~450 km in planar distance (corresponding to ~340 km in geodetic distance) was determined. The range of δp, which also broadly corresponds to the range of the d-excess, probably refers to the spatially variable moisture contribution of the western, Atlantic-dominated, and eastern, Mediterranean-dominated domain of the Iberian Peninsula. The estimation error of the presented Iberian precipitation isoscapes, both for oxygen and hydrogen, is smaller than the ones that were reported for the regional subset of one of the most widely used global model, suggesting that the current regional model provides a higher predictive power.

Flexible feeding patterns of copepod Centropages tenuiremis in fluctuating conditions: a possible survival strategy to cope with disturbance

Centropages tenuiremis is a species with a wide distribution range in disturbed coastal waters. However, due to a lack of dietary information, it remains unclear as to how they maintain such dominance in fluctuating conditions. In this study, C. tenuiremis was collected from the Daya Bay Nuclear Power Plant both in inlet and outfall regions at 06:00, 12:00 and 18:00 on April 27, 2011 and their in situ diet was analyzed using a PCR protocol targeting 18S ribosomal genes. Thirty-four species of prey organisms were identified totally, including Dinophyta, Baciliariophyta, Viridiplantae, Rhizaria, Apicomplexa, Chordata, Mollusca, Arthropoda and Fungi, indicating an obvious omnivorous feeding habit of C. tenuiremis. Centropages tenuiremis obviously exhibited spatial and temporal variations in diet composition. More plant prey (land plants and phytoplankton) were consumed in the morning (~50%), while more animal prey (metazoans and protozoans) were ingested at midday and night (60%–70%). Furthermore, a more diverse diet was detected in the outfall region (10–11 taxa), where the temperatures were relatively higher and more fluctuating, than in the control region (5–10 taxa). This finding indicated that C. tenuiremis could potentially expand its food spectrum under stressful condition. Specifically, C. tenuiremis exhibited phytoplankton preference (58.62%–67.64%) in the outfall region with a lower omnivory index (0.27–0.35) than in the control region (0.51–0.95). However, phytoplankton density was lower than that in the control region, suggesting a possible herbivorous tendency of C. tenuiremis under elevated temperatures to balance the energy acquirement and feeding effort. The flexible food choices of C. tenuiremis observed here could effectively buffer environmental fluctuations and might be an important survival strategy in coastal ecosystems.

Patterns of local, intercontinental and interseasonal variation of soil bacterial and eukaryotic microbial communities.

Although ongoing research has revealed some of the main drivers behind global spatial patterns of microbial communities, spatio-temporal dynamics of these communities still remain largely unexplored. Here, we investigate spatio-temporal variability of both bacterial and eukaryotic soil microbial communities at local and intercontinental scales. We compare how temporal variation in community composition scales with spatial variation in community composition, and explore the extent to which bacteria, protists, fungi and metazoa have similar patterns of temporal community dynamics. All soil microbial groups displayed a strong correlation between spatial distance and community dissimilarity, which was related to the ratio of organism to sample size. Temporal changes were variable, ranging from equal to local between-sample variation, to as large as that between communities several thousand kilometers apart. Moreover, significant correlations were found between bacterial and protist communities, as well as between protist and fungal communities, indicating that these microbial groups change in tandem, potentially driven by interactions between them. We conclude that temporal variation can be considerable in soil microbial communities, and that future studies need to consider temporal variation in order to reliably capture all drivers of soil microbiome changes.

The multi‐component Hekla Ö Tephra, Iceland: a complex widespread mid‐Holocene tephra layer

ABSTRACTLarge Plinian eruptions from Hekla volcano, Iceland, produce compositionally zoned tephra used as key markers in tephrochronology. However, spatial variations in chemical composition of a tephra layer may complicate its identification. An example is the 5950–6180 cal a bp Hekla Ö tephra layer, which shows compositional spread from rhyolite, dacite and andesite to basalt. In soil sections north of Hekla, the SiO2 content of the tephra glass reaches 76 wt% in the lowest unit of the Hekla Ö deposit and decreases to 62–63 wt% in the uppermost unit. Intermingled within the whole deposit are basalt tephra grains having 46–47 wt% SiO2. The composition of the basalt glass includes primitive basalt and a more evolved basalt (MgO >6 and <6 wt%, respectively). Together with literature data, the Hekla Ö tephra and the so‐called T‐Tephra/Hekla‐T are most likely from contemporaneous eruptions of different vents on the Hekla volcanic system, forming a single important marker tephra (Hekla ÖT) deposited over 80% of Iceland. Identification is complicated by its spatial compositional heterogeneity, such as systematic decrease in SiO2 content from the east to the west of Hekla volcano. Consequently, an individual tephra layer from a large explosive eruption can have different composition at different locations. © 2020 John Wiley & Sons, Ltd.

Beta diversity patterns of Bromeliaceae growing on rocky cliffs within the Atlantic Forest in southern Brazil

Abstract: In recent years there has been increasing attention in patterns of β-diversity and mechanisms related to variations in species composition. In this study, we evaluated beta diversity patterns of bromeliads growing on cliffs immersed in Atlantic Forest. We hypothesized that the species composition varies according to the spatial scale, inferring that there is a replacement of species influenced mainly by environmental factors. The study was carried out on sandstone cliffs included in contiguous but distinct vegetation formations: Evergreen and Seasonal forests. Twenty-four vertical rocky outcrops were sampled. The spatial variation in species composition was evaluated by two β-diversity components, turnover and nestedness. Multivariate analysis and variation partitioning were performed to distinguish niche and stochastic processes. We recorded 26 bromeliad species and a significantly higher contribution of turnover explaining beta diversity. Environmental factors affect β-diversity patterns of Bromeliaceae. However, individually, the environmental predictors do not explain the data variation. Environmental variations spatially structured, and spatial variables determinate the dissimilarity in the composition of bromeliads on cliffs. Thus, our results revealed that both environmental and spatial effects can act together to define the floristic composition of rock-dwelling bromeliad communities.

Mineralogical and geochemical composition of the subsurface sediments at the mouth of Wadi Al- Hamd, Red Sea coast, Saudi Arabia: implication for provenance and climate

The present work is related to mineralogy and geochemistry of sedimentary successions of the modern Red Sea coastal plain at the mouth of Wadi Al-Hamd, Northern Saudi Arabia. It identifies the provenance, weathering effect, and paleoenvironment of the area. The mineralogical composition is dominated by quartz, plagioclase, and trace of feldspars, clay minerals, mica, and hornblende. Additionally, traces of non-detrital minerals including high and low Mg calcite, dolomite, halite, and anhydrite were locally detected. Four chemo-facies, dominated by three associations of element groups linked with detrital minerals, grain size properties, and biogenic products were recognized. The mineralogical and geochemical indices showed that sediments were derived from the intermediate igneous rocks at active continental margin and continental island arc settings. Weathering indices showed that the sediments were poorly weathered, consistent with the arid-to-semi-arid climate of the area. The spatial and vertical variations of mineralogical and chemical composition reflect variation depositional environments, hydraulic sorting, and the influence of coastal processes.

Seasonal and spatial variations in physico-chemical parameters of water and proximate composition of Macrobrachium macrobrachion from Ologe lagoon and Badagry creek, Lagos, Nigeria

In this study, seasonal and spatial variations in physicochemical parameters of water and proximate composition of Macrobrachium macrobrachion from Badagry Creek and Ologe Lagoon were examined. Samples of water and M. macrobrachion were collected from both stations on a monthly basis for six months. The physicochemical parameters monitored were pH, temperature, total suspended solids, total dissolved solids, total solids, total alkalinity, free carbondioxide, conductivity, salinity, dissolved oxygen, biochemical oxygen demand, ammonia and turbidity, while the proximate composition parameters were moisture content, crude protein, crude fibre, carbohydrate, crude lipids and ash. It was observed that alkalinity, salinity, dissolved oxygen, temperature and ammonia determined for both sample stations were within recommended limit of Food and Agricultural Organization, except pH for Badagry creek. There was no significant difference (p > 0.05) in seasonal variations of most physico-chemical parameters in both stations except for pH in Ologe lagoon, and electrical conductivity (EC), total dissolved solids (TDS) and total solids (TS) in both stations. Also, with the exception of EC, TDS and TS, there was no significant difference for spatial variation of physico-chemical parameters between the two stations. Moisture content, lipid and ash contents showed significant seasonal variation in Ologe lagoon, while crude protein and crude fibre recorded no significant difference. For Badagry creek, with the exception of moisture content, all other proximate composition parameters showed significant difference. However, there was no significant spatial variation in proximate composition between the prawns in Ologe lagoon and Badagry creek. There were gradual effects of season on water quality and proximate composition but these effects still support growth and survival of the prawn. However, regulatory measures should be put in place to protect these water bodies from direct/indirect human activities that can cause adverse damages.

Spatial variation in the benthic community composition of coral reefs in the Wakatobi Marine National Park, Indonesia: updated baselines and limited benthic community shifts

AbstractCoral reefs have experienced extensive degradation across the world over the last 50 years as a result of a variety of stressors operating at a range of spatial and temporal scales. In order to assess whether declines are continuing, or if reefs are recovering, detailed baseline information is required from across wide spatial scales. Unfortunately, for some regions this information is not readily available, making future reef trajectories difficult to determine. Here we characterized the current benthic community state for coral reefs in the Wakatobi region of Indonesia, one of the most biodiverse marine regions in the world. We surveyed 10 reef sites (5, 10 and 15 m depth) to explore spatial variation in coral reef benthic communities and provide a detailed baseline. Previous data (2002–2011) were available for coral, sponges, algae and soft coral at six of our study sites. Using this information, we determined if any changes had occurred in dominance of these benthic groups. We found that benthic assemblage composition differed significantly over relatively small spatial scales (2–10 km) and hard coral cover was highly variable, ranging from 7–48% (average 19.5% ± 1.5 SE). While coral cover appears to have declined at all sites where data were available since 2002, we found little evidence for widespread increases in other benthic groups or regime shifts. Our study provides a comprehensive baseline dataset for the region that can be used in the future to determine rates of change in benthic communities.

Monitoring Post-Fire Recovery of Chaparral and Conifer Species Using Field Surveys and Landsat Time Series

Recovery trajectories derived from remote sensing data are widely used to monitor ecosystem recovery after disturbance events, but these trajectories are often retrieved without a precise understanding of the land cover within a scene. As a result, the sources of variability in post-disturbance recovery trajectories are poorly understood. In this study, we monitored the recovery of chaparral and conifer species following the 2007 Zaca Fire, which burned 97,270 ha in Santa Barbara County, California. We combined field survey data with two time series remote sensing products: the relative delta normalized burn ratio (RdNBR) and green vegetation (GV) fractions derived from spectral mixture analysis. Recovery trajectories were retrieved for stands dominated by six different chaparral species. We also retrieved recovery trajectories for stands of mixed conifer forest. We found that the two remote sensing products were equally effective at mapping vegetation cover across the burn scar. The GV fractions (r(78) = 0.552, p < 0.001) and normalized burn ratio (r(78) = 0.555, p < 0.001) had nearly identical correlations with ground reference data of green vegetation cover. Recovery of the chaparral species was substantially affected by the 2011–2017 California drought. GV fractions for the chaparral species generally declined between 2011 and 2016. Physiological responses to fire and drought were important sources of variability between the species. The conifer stands did not exhibit a drought signal that was directly correlated with annual precipitation, but the drought likely delayed the return to pre-fire conditions. As of 2018, 545 of the 756 conifer stands had not recovered to their pre-fire GV fractions. Spatial and temporal variation in species composition were important sources of spectral variability in the chaparral and conifer stands. The chaparral stands in particular had highly heterogeneous species composition. Dominant species accounted for between 30% and 53% of the land cover in the surveyed chaparral patches, so non-dominant land cover types strongly influenced remote sensing signals. Our study reveals that prolonged drought can delay or alter the post-fire recovery of Mediterranean ecosystems. It is also the first study to critically examine how fine-scale variability in land cover affects time series remote sensing analyses.

Marker gene analysis reveals the spatial and seasonal variations in the eukaryotic phytoplankton community composition in the Yangtze River, Three Gorges Reservoir, China

ABSTRACTThe eukaryotic phytoplankton community in the Three Gorges Reservoir (TGR) of the Yangtze River in China was investigated, based on marker gene analysis of the 18S rRNA V4 region. Community composition was investigated in four seasons (to assess seasonal variation) and in the mainstream and tributary of the river (to assess spatial variation). Chlorophyll a concentration was used to estimate eukaryotic phytoplankton biomass. A significant negative correlation of biomass and evenness was found in the TGR; this relationship may be due to a few highly competitive species dominating the eukaryotic phytoplankton community, suggesting that eukaryotic phytoplankton bloom events tend to occur in such communities. Our results showed that eukaryotic phytoplankton is more likely to bloom in the tributary when compared with mainstream, and we identified two unreported algal blooms, Tetraselmis and Mychonastes. Phylogenetic analysis revealed a novel lineage in Cryptophyta and substantially more diverse species in Bacillariophyta, two high relative abundance operational taxonomic units in Bacillariophyta classified to Peridiniopsis diatom endosymbionts; their high relative abundance may result from a high relative abundance of the genus Peridiniopsis. We found that Cryptomonas was the most widely distributed genus and had the highest relative abundance, and species in TGR that have higher relative abundance tend to be distributed more widely.

Phytoplankton composition of the urban man-made lakes of Yamoussoukro (Côte d’Ivoire)

Objective: Spatial and seasonal variations of phytoplankton composition in the urban man-made lake of Yamoussoukro city has been analysed to identify the most representative species of these polluted urban lake. Methodology and results: The composition of phytoplankton assemblage in urban man-made lakes of Yamoussoukro City were investigated from December 2015 to October 2017 on a bi-monthly basis, at 28 stations on 8 lakes. One hundred and Ninety six (196) phytoplankton taxa were identified representatives of 63 genera, 33 families, 17 orders, 8 classes and 5 phyla. Most of these genera belong to Chlorophyta (34.8%) followed by Euglenophyta (30.39 %) next Cyanobacteria (19.11 %), Bacillariophyta (14.16%) and Dinophyta (0.9 %). The Genera T rachelomonas (23 taxa), Scenedesmus (20 taxa), Phacus (16 taxa), Lepocinclis (9 taxa) were found to be dominant (>10%) in phytoplankton taxonomic richness. The greatest species richness was found in the lake 5 (99 taxa) and the smallest was recorded in the lake 7 (9 taxa). Conclusion and application of results: This study revealed a first inventory of phytoplankton taxa of the Yamoussoukro’s urban man-made lakes and proposes a pattern of the spatio-temporal variability of the phytoplankton community. The lakes were rich in the number of taxa (196), because the waters of the lake are stagnant. Chlorophyta and Euglenophyta dominated the phytoplankton communities. The highest number of taxa (99) was recorded in the lake 5, while the lowest number of taxa (10) was found in the lake 7. The best represented genus are by order of importance, Trachelomonas (23 taxa) scenedesmus (20 taxa), Phacus (16 taxa) and Lepocinclis (9 taxa). The results of the study of phytoplankton in Yamoussoukro urban lakes could serve as references to evaluate the ecological health of water bodies. Keywords: phytoplankton, urban man-made lake, taxonomic richness, Yamoussoukro

Controls of Land Use and the River Continuum Concept on Dissolved Organic Matter Composition in an Anthropogenically Disturbed Subtropical Watershed.

About 250 Tg of dissolved organic carbon are annually transported from inland waters to coastal systems making rivers a critical link between terrestrial and ocean carbon pools. During transport through fluvial systems, various biogeochemical processes selectively remove or transform labile material, effectively altering the composition of dissolved organic matter (DOM) exported to the ocean. The river continuum concept (RCC) has been historically used as a model to predict the fate and quality of organic matter along a river continuum. However, the conversion of natural landscapes for urban and agricultural practices can also alter the sources and quality of DOM exported from fluvial systems, and the RCC may be significantly limited in predicting DOM quality in anthropogenically impacted watersheds. Here, we studied DOM dynamics in the Altamaha River watershed in Georgia, USA, a fluvial system where headwater streams are highly impacted by anthropogenic activities. The primary goal of this study was to quantitatively assess the importance of both the RCC and land use as environmental drivers controlling DOM composition. Land use was a stronger predictor of spatial variation (∼50%) in DOM composition defined by both excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) and ultrahigh-resolution mass spectrometry. This is compared to an 8% explained variability that can be attributed to the RCC. This study highlights the importance of incorporating land use among other controls into the RCC to better predict the fate and quality of DOM exported from terrestrial to coastal systems.

Variable Crustal Production Originating From Mantle Source Heterogeneity Beneath the South East Indian Ridge and Amsterdam‐St. Paul Plateau

AbstractThe Amsterdam‐St. Paul (ASP) Plateau formed by interaction between the South East Indian Ridge (SEIR) and the ASP mantle plume during the last 10 Myr. The combined bathymetry and gravity‐derived crustal thickness anomalies along the present and paleoaxes of the SEIR atop the plateau indicate: (1) a thicker crust and shallower water depth along the southern part of segment I2 during much of the last 10 Myr; (2) an earlier decrease (~1.4 Ma) in crustal thickness along the southern part of I2 compared to the northern part (~0.9 Ma) during the most recent period of reduced magmatism; (3) a topographic transition at ~0.7 Ma and during the last 0.1 Myr; and (4) an approximately uniform crustal thickness (8 km) along the entire I2 segment today. These observations require spatial and temporal variations in magma production during construction of the ASP Plateau over the last 3 Myr. We propose that during periods of weaker plume magma flux, spatial variations in upper mantle temperature and composition are small, and lead to small variations in crustal thickness along‐axis. In contrast, during periods of stronger plume magma flux, spatial contrasts in upper mantle temperature and composition (fertility) are large, leading to significant variations in crustal thickness. Along‐axis variations of 3He/4He, Δ8/4Pb, K/Ti, and Na8 in “zero‐age” basalts indicate that there is a gradient in the underlying mantle material, from a “common” mantle plume component (Δ8/4Pb~60) stronger in the north to a DUPAL component (Δ8/4Pb~110) dominating in the south.

Early growth of the Indian lithosphere: Implications from the assembly of the Dharwar Craton and adjacent granulite blocks, southern India

This study provides a new perspective into the Archean accretionary tectonic evolution of the Dharwar Craton and the adjacent high-grade granulite blocks of southern India. The necessary constraints for this tectonic assembly were derived using new petrochemical and zircon U-Pb age data from the granulite facies Biligiri Rangan Block (BRB), which occupies a central key position in the Archean collage of southern India. The BRB, composed largely of charnockites and mafic granulites, is a vestige of ca. 3400–3200 Ma cratonic fragment that was amalgamated with the Western Dharwar Craton (WDC) at ca. 2700–2500 Ma. The spatial variations in composition and evolution of the charnockites (i.e. low- and high-Sr/Y variants) are attributed to arc magmatic processes at different crust-mantle depths accompanied by a flat- or shallow-dipping subduction geometry. Different stages in the subduction processes such as exhumation and magma underplating (ca. 2800–2950 Ma), initial arc magmatism (ca. 2700–2650 Ma), and peak magmatism together with metamorphism (ca. 2700–2500 Ma) were identified from zircon age populations of different rock-types. Our new results integrated with all published geological and geophysical data lead to the conclusion that the Kollegal and Mettur Shear Zones on the western and eastern sides of the BRB respectively were sited on an east-dipping Archean suture and a closed back-arc basin. We propose a tectonic model for southern India according to which subduction-accretion of the Coorg Block in the Mesoarchean (ca. 3300–3100 Ma) and of the Nilgiri Block, Biligiri Rangan Block and the Eastern Dharwar Craton in the Neoarchean (ca. 2700–2500 Ma) led to closure of the Paleo-Dharwar Ocean and to terminal collision with the Western Dharwar Craton.

Ungulate turnover in the Koobi Fora Formation: Spatial and temporal variation in the Early Pleistocene

The Koobi Fora Formation, located east of Lake Turkana in northern Kenya, is well-known for its well-sampled vertebrate fossil record. Thousands of identifiable remains have been collected from three Early Pleistocene geologic members of the Koobi Fora Formation: the Upper Burgi (1.98–1.87 Ma), KBS (1.87–1.56 Ma), and Okote (1.56–1.38 Ma). The large sample from these members permits analysis of spatial and temporal variation in species composition, particularly as it relates to broader changes within the basin. To investigate paleoecological trends in the Koobi Fora Formation during this period, we examine spatial and temporal variation in the proportional abundance of a large sample (NISP = 3713) of ecologically diverse ungulate taxa, in addition to variation in enamel isotope δ13C values. We find that the Karari subregion experienced significant turnover within key large mammalian families (Bovidae, Suidae, and Equidae) during this period, while changes in other subregions (Ileret and Koobi Fora Ridge) were relatively minimal. Our analyses indicate drier conditions in the Karari during the regression of Paleolake Lorenyang as the dominant water-dependent taxa (e.g., the bovid tribe Reduncini and the suid genus Kolpochoerus) were largely replaced with taxa adapted to xeric habitats including the bovid tribe Alcelaphini and the suid genus Metridiochoerus. Little change was detected in proportional abundances of broad dietary groups (grazers: mixed-feeders: browsers). These findings provide a more resolved spatiotemporal resolution for the mammalian communities occupying the region during this time. They further highlight the importance of considering localized habitat differentiation in eastern Africa during the Early Pleistocene, acknowledging that fossil records document complex and dynamic systems which varied spatially and temporally on many scales, much like modern African ecosystems.

Spatio-temporal variations of fish assemblages in seagrass ecosystem of Karang Congkak Island, Kepulauan Seribu

Seagrass are globally known as an essential habitat for marine fishes. The study of fish assemblages in seagrass ecosystem is needed as the first base to select the most suitable coastal fisheries management. The study aims to reveal the composition of fish assemblages both seasonally and spatially in Karang Congkak Island, Kepulauan Seribu. Sampling was performed six times in NW monsoon (March), first transitional monsoon (April-May) and SE monsoon (Juni, August, September) 2018. Fish were sampled at four sites at seagrass ecosystem of Karang Congkak Island, namely eastern, southern, western, and northern by using beach seine net. The differences of juvenile fish assemblages were analyzed using One-Way ANOSIM. A total of 6,326 fish were collected belonging to 78 species, 31 families and 10 orders in which Labridae was the most diverse family. The result indicates strong spatial and temporal variation in fish composition. Fish compositions were dominated by juvenile both spatially and temporally. The most common species that inhabits seagrass beds of the Karang Congkak Island as temporary resident such as Gerres oyena and Siganus canaliculatus, and regular visitor namely Halichoeres argus. Cannonical correspondence analysis indicated strong correlation between several fish species and environmental variables.

Wilderness areas halve the extinction risk of terrestrial biodiversity.

Reducing the rate of global biodiversity loss is a major challenge facing humanity1, as the consequences of biological annihilation would be irreversible for humankind2-4. Although the ongoing degradation of ecosystems5,6 and the extinction of species that comprise them7,8 are now well-documented, little is known about the role that remaining wilderness areas have in mitigating the global biodiversity crisis. Here we model the persistence probabilityof biodiversity, combininghabitat condition with spatial variation in species composition, to show that retaining these remaining wilderness areas is essential for the international conservation agenda. Wilderness areas act as a buffer against species loss, as the extinction risk for species within wilderness communities is-on average-less than half that of species in non-wilderness communities. Although all wilderness areas have an intrinsic conservation value9,10, we identify the areas on every continent that make the highest relative contribution to the persistence of biodiversity. Alarmingly, these areas-in which habitat loss would have a more-marked effect on biodiversity-are poorly protected. Given globally high rates of wilderness loss10, these areas urgently require targeted protection to ensure the long-term persistence of biodiversity, alongside efforts to protect and restore more-degraded environments.

Side-View Operando microscopy of Graphite Anodes to Understand Kinetic Hysteresis

Operando imaging analysis has emerged as a promising characterization tool for the observation of nanoscale processes; chemical synthesis, electrochemical reaction, and physical interaction of various materials. For past a decade, operando microscopy tools have contributed to understanding the lithiation or sodiation behaviors in battery materials for discovering new electrode materials with high performance and identifying the fundamental failure mechanisms that prevent a prolonged cycle life. Among the candidates, graphite anodes have the most promise to apply for lithium-ion batteries, but also have scientific challenges to retain their kinetics upon repeated charge and discharge cycles. To develop a better design of the electrodes, understanding graphite anodes with direct observation has created a high interest. Although such demands lead to extensive studies about operando imaging techniques, the observation is mostly limited for a single particle or a particular position of the electrodes. In this regard, we have demonstrated side-view operando optical microscopy on graphite anodes by a change of color during electrochemical lithiation. Since the color of graphite changes owing to the different bandgap during lithiation and delithiation processes, operando optical microscopy enables to analyze the kinetics of charge and discharge behaviors. In addition, our cell configuration has the manifold advantages of applying and adjusting liquid electrolytes which is similar to commercial cells as a practical application and offering the investigation of the electrode side view. The side-view observation of an electrode level is found that microscale spatial variations in rate and composition control the insertion and desertion to understand the kinetics through the whole electrode. Our results allow for a better fundamental understanding of kinetics in battery materials.