Vegetative Fragments Research Articles

Landscape changes over 30 years of intense economic activity in the upper Paraná River basin

In this study, we show the complexity associated with the recent land cover changes by elucidating the paths of 30 years of changes in the Upper Paraná River Basin (UPRB), a region severely impacted by agricultural activity, one of the areas with the highest density in the production of hydroelectricity, biofuels and food in the world. In this sense, a post-classification comparison approach based on Landsat images was used to identify detailed ‘from-to’ paths behind those land cover changes. The most expressive changes were the expansion of Cropland and Forest areas and the reduction in savannas, with a net change of 17.9%, 4.1%, and −16.9% of the UPRB area, respectively. Cropland areas showed an expressive increase between 1985 and 2015, rising from 249,439 km2 (27.7%) to 412,909 km2 (45.9%). Forest areas increased from 149,389 km2 to 185,839 km2 in the period. Notably, for this class, an intense spatial dynamic of losses (7.5%) and gains (11.6%) took place between 1985 and 2015. This behavior is related to the disappearance of native vegetation fragments in some sub-basins, as well as to afforestation, reforestation, and/or forest restoration in others. The Cerrado (a typical tropical savanna in South America), the most impacted natural biome of the Basin, decreased from 21.9% of the UPRB in 1985 (196,746 km2) to only about 5% of the whole UPRB area in 2015. Grassland areas, mostly used for livestock, decreased from 271,827 km2 (30.2%) to 229,007 km2 (25.5%). This net decrease was associated with a reduction of 160,830 km2 (17.8%) and the appearance of 118,010 km2 (13.2%) in new areas, previously occupied by tropical savannas in 1985. In conclusion, economic factors were the main drivers for land cover changes, especially agriculture and livestock activities, besides forestry and hydroelectric energy production. In addition, Grassland areas that predominated on the left banks of the UPRB in 1985 retreated with the advance of Cropland areas, mainly due to the expansion of sugarcane for ethanol production, a biofuel widely used in Brazil. In turn, pasture areas migrated to the right bank and occupied a significant part of the Cerrado. Finally, our results demonstrate that the transition dynamics among land cover classes can involve complex political-economical mechanisms that are not always captured by remote sensing.

Rare diversity of forest vegetation of the steppe zone: current state, threats and directions of changes

Under the action of various forms of human activity, there was a violation of the integrity and unity of the vegetation cover of the steppe zone of Ukraine. The consequence of this is the fragmentation of vegetation. It was established that the decrease in the area of plant communities leads to an increase in their dependence on environmental factors. An important component of the phytocoenotic cover, and first of all the forest cover, which is the biotic basis of the functioning of the biosphere, its evolution and maintenance of an ecologically balanced state, is a rare phytocoenofund. The purpose of the work was to compile information on the current state of rare groups in the steppe zone using data from ecological and coenotic studies, sociological analysis and assessment of the latest threats to rare forest diversity. A critical analysis of the current rare phytocenophyte, the data of modern synphytosozological studies and the latest geobotanical information on the rare phytocenotic diversity made it possible to establish a modern rare phytocenophyte of the forests of the steppe zone of Ukraine. It has 16 associations of three formations. The sociological analysis showed that all phytocoenoses of 16 rare forest associations are characterized by a rare type of association, are located on the border of the range, and 5 associations are formed by an endemic species. According to their sociological status, they are divided into rare (4 associations) and endangered species (12 associations). The potential for natural recovery of populations of dominant species of groups in specific ecological conditions is very weak or weak in all 16 rare forest associations. Currently, rare forest communities are most negatively affected due to the complete loss or fragmentation of habitats, pollution, overexploitation of species and ecosystems, competition from populations of adventive species, global climate change and unbalanced development of forestry, military actions.

Suspected eosinophilic bronchopneumopathy in a six‐banded armadillo (Euphractus sexcinctus)

AbstractThis report documents the clinical presentation, diagnosis and treatment of a suspected eosinophilic bronchopneumopathy (EBP) in a captive 6‐year‐old female six‐banded armadillo (Euphractus sexcinctus). Clinical findings included weight loss, relapsing chronic rhinitis despite antibiotic and antifungal treatments, and abnormal respiratory sounds. EBP was highly suspected using complete blood count, computed tomography and histopathology performed on nasal biopsies. Severe hypereosinophilia (6630 cells/μl), a marked necrotic ulcerative chronic rhinitis with encrusted microscopic vegetable fragments and a diffuse bilateral interstitial pulmonary pattern evidenced on medical imaging were the main findings on further procedures. Corticosteroid therapy along with targeted antibiotics and animal isolation in an environment with reduced allergens resulted in decreased hypereosinophilia and clinical recovery. To the authors’ knowledge, this is the first time that EBP is suspected in another species than dogs.

Karstic Limestone Outcrops Harbor High Bat Diversity in a Deeply Anthropized Landscape in Southeastern Brazil

The availability of shelter in karst areas affects the richness, abundance, and assemblage composition of bat species and may play an important role in movement dynamics, activity patterns, and foraging behavior. Our work in the midwestern region in the state of Minas Gerais, southeastern Brazil, showed a high richness of the bat fauna, given the anthropic impact caused by mineral exploration and agricultural activities, thus leaving vegetation islands over karst areas in a vast anthropized matrix. Sampling at 12 sites resulted in 1,444 captures of bats, representing 30 species. Our beta diversity partitioning analyses indicated a pattern of turnover, i.e. species replacement, suggesting that these vegetation fragments may function as ecological springboards or stopping points.

Gamma diversity: derived from and a determinant of alpha diversity and beta diversity. An analysis of three tropical landscapes

Using three taxonomic groups of beetles we examine how alpha and beta diversity influence the species richness of a landscape (gamma diversity), and vice versa. That is, how the species richness of a landscape – which is a historical and biogeographical phenomenon – contributes to the values of alpha diversity (1) at a given site, (2) in a community, (3) in terms of cumulative species richness by community, and also contributes to (4) the intensity of species exchange between communities. To explore this question, we used two subfamilies of Scarabaeoidea: Scarabaeinae and Geotrupinae, and the family Silphidae. In all analyses these three taxonomic groups are considered as a single indicator group: the copronecrophagous beetles. Information is also included on the subfamily Aphodiinae (Scarabaeoidea), coprophagous beetles not included in the indicator group. Several types of vegetation located in three landscapes (tropical, transition and mountain) were studied, and these are located along an altitudinal gradient in the central part of the state of Veracruz, Mexico. We base this study on the following concepts. The alpha diversity of an indicator group reflects the number of species that use a given environment or resource in a given place or community. Spacial beta diversityis related to the response of organisms to spatial heterogeneity. Gamma diversity depends primarily on the historical and geographic processes that operate on the mesoscale level and is also affected by alpha and beta diversity. It is on this scale of landscape that human actions, such as the modification and fragmentation of vegetation, have their most important effects. These are, however, often beyond the scope of ecological analyses carried out on a local scale. In the three landscapes, sampling was carried out regularly at 67 sites, with complementary sampling at another 69 sites. Twenty-six types of vegetation communities were studied. A total of 16,152 specimens representing 60 species were captured (52 species of Scarabaeinae, 4 Geotrupinae and 4 Silphidae). In the tropical landscape the community richest in species was low deciduous forest. In the transition landscape, cloud forest was the richest. Each of these communities is the most representative of their respective altitudinal bands. In contrast, the greatest species richness in the mountain landscape occurred in the mountain grasslands and pastures; types of community favoured by or even created by human intervention. This is explained by the expansion of heliophilous species from the Mexican High Plateau into these areas. In the tropical landscape the species richness of the pastures is similar to that of its forests, but with a partially different composition which is characterized by the dominance of heliophilous and coprophagous species; the latter, in addition to the more ubiquitous species that are shared with the tropical forest. In the transition landscape the cloud forest and the coffee plantations with polyspecific shade are important in the context of conserving the fauna. This type of community offers arboreal cover and occupies the majority of this landscape, allowing the groups of insects studied to move between remnant fragments of cloud forest. On the landscape scale but not locally, the fragmentation of natural communities does not appear to have reduced the number of species for the beetles of the indicator group. In each landscape disturbance by human activity appears to have been overcome for distinct reasons. In the tropical landscape we find the heliophilous beetle fauna characteristic of pastures, and this has increased by two species of recent invaders. In the transition landscape, the coffee plantations with polyspecific shade create a communication matrix, while in the mountain landscape the expansion of the mountain pastures has made conditions more favourable for heliophilous species. These results are not necessarily expected for other groups of organisms.

Culture of Gracilaria gracilis and Chondracanthus teedei from Vegetative Fragments in the Field and Carpospores in Laboratory

Gracilarioids and Gigartinales are of great economic importance due to the phycocolloids they contain in their cell wall and are used in different industries worldwide. Field and laboratory cultures of two species of red seaweeds (Gracilaria gracilis and Chondracanthus teedei), confirmed after DNA analysis, were carried out to foster the increasing use of this species in Spain as a food source. Vegetative cultures carried out in an open-lock gate within a traditional salina in the ay of Cadiz (Southern Spain) rendered maximum growth rates in April (3.64% day−1) for G. gracilis and in November (4.68% day−1) for C. teedei, the latter showing significant differences between the months of the year. For laboratory cultures, samples of the two species used for sporulation were obtained from tidal creeks in several nearby locations of the Bay. In order to grow fertile carposporophytes from spores, Provasoli enriched seawater medium (ES medium), Miquel A + B and f/2 were used as culture medium at a temperature of 18 °C and irradiance of 30 µmol m−2 s−1 in 12:12 h photoperiod. Both species developed a basal disc after 12–15 days in ES medium and Miquel A + B, and new microscopic seedlings were observed at 20–25 days in ES medium. With f/2 medium, no growth was observed after sporulation. The life cycle of G. gracilis was completed in ES medium over a period of 11 months with a mean growth rate of 3.28% day−1. The present study is an important step towards the development of seaweed cultivation in the Bay of Cadiz, especially in integrated multi-trophic cultivation in salinas as part of the more sustainable use of the marine resources in coastal communities.

Relationship between forest integrity, drainage headboards and patch-level metrics as subsidy for planning and conservation in fragmented Atlantic Forest areas

Forests worldwide are essential goods for humanity as they provide support, provision, regulation, and cultural ecosystem services. In Brazil, the Atlantic Forest has lost much of its original cover, is currently represented by relatively small fragments in an anthropized matrix. Therefore, it is very relevant to analyze if forest fragments change in related the fragmentation of the original native vegetation and how they maintain their quality. This study aimed to analyze whether patch-level metrics are related to forest quality (biotic integrity) and whether relief features such as headboards are related to forest fragmentation patterns to provide subsidies for public planning and environmental conservation policies. The methodology involved mapping forest fragments (F) and drainage headboards (DH), calculating patch-level metrics (AREA, SHAPE, PROX), and the biotic integrity (BII) of the forest. Spearman's Correlation Coefficient was used to test the relationship between variables. The results showed a significative robust relationship between AREA and BII and significative medium relationship between SHAPE and DH, confirming partially the initial assumptions of the research. We concluded that the integrity of the forest fragment and the presence of drainage headboards must be considered in public planning and environmental conservation policies.

ANALYSIS OF LANDSCAPE TRANSFORMATIONS IN THE URBAN-RURAL GRADIENT OF THE METROPOLITAN DISTRICT OF QUITO

In contexts of globalization, economic restructuring and information and communication revolution, the relocation of services in peripheries and new urban expansion patterns have drastically altered periurban landscapes. However, due to its transformation speed, there is limited knowledge regarding the spatiotemporal changes of these interstitial territories. Calculating landscape metrics in high resolution satellite images, this research analyses spatiotemporal transformations in the Metropolitan District of Quito urban-rural gradient, testing a novel and accurate method to identify urbanization tendencies. The results evidence the main role that new road-infrastructures have had in the urban expansion. Also, the analyses identify significant changes in agricultural coverages (related to rural lots subdivision) and the processes of vegetation fragmentation, evidencing the environmental fragility of these territories in transformation. Finally, the Markov chains modelling technique was applied, exploring the landscape change probabilities in the following years. This methodology can be particularly useful in land-use planning policies since it provides precise knowledge about the main tendencies of urbanization.

Impact of spawn concentrations on Atlantic herring (Clupea harengus) egg survival in Baltic Sea inshore spawning areas

Fish species classified as demersal substrate spawners attach their eggs on macrophytes or hard substratum. As a result of consecutive events of egg deposition and successive waves of spawning adults, the formation of multiple egg layers on spawning substrate was already observed for demersal spawning fish species, such as the Atlantic herring (Clupea harengus, Linnaeus 1758). However, empirical information on the effects of egg concentration on herring egg survival are scarce. Hypothesizing that high egg concentration has a negative effect on herring egg survival, we experimentally investigated egg mortalities in artificially spawned egg clusters of 1–10 vertical layers. Moreover, potential effects of egg packing density (loose and dense) in one single layer set-up were investigated. We found decreasing herring egg survival in clusters of increasing egg layers. Although egg mortality was lowest in surface layers, a layerwise analysis did not reveal a stepwise increase of egg mortality from outermost to innermost eggs. Furthermore, egg mortality in surface layers significantly increased with increasing egg layer number underneath, indicating that the extent of layering is affecting egg mortality also in surface layers. This implies a reproductive disadvantage not only for eggs being spawned in the beginning of consecutive spawning events but also for latest spawned eggs. However, different egg packing densities in single layer spawn did neither influence the fertilization success nor mortality of herring eggs. Increased thickness of egg layers may result from the ongoing reduction and fragmentation of coastal vegetation due to eutrophication and coastal modifications. Our results indicate that such multiple egg layer deposition has the potential to negatively impact hatching success in demersal spawning fish species, such as the herring.

Geoprocessing and Landscape Ecology for Assessment Fragmentation and Connectivity of the Habitats of the Microregion of Ceres, Goiás (Brazil)

This study aimed to map and evaluate the evolution of habitat fragmentation between 2009 and 2018, using the Microregion of Ceres (Goiás) as a sample reference, using principles of Landscape Ecology. The methodology comprised the mapping of the fragments in the two years analyzed, using the OLI/Landsat 8 sensor, using scenes 222/70 and 222/71. The SPRING 5.2 software was used, where the supervised classification was performed, applying the semi-automatic process. The computational algorithm applied to classify the scenes was Maxver, which classifies pixel by pixel and groups the information of each one into homogeneous regions. After extracting the fragments of native vegetation, the methodology proposed by Juvanhol et al. (2011), in which the fragments were grouped into classes: Very Small (MP) ≤5 hectares; Small (P) ≥5.01 and ≤10 hectares; Medium (M) ≥10.01 and ≤100 hectares and Large (G) ≥100.01 hectares. For the analysis based on metrics in Landscape Ecology, the ArcGis 9.2 Patch Analyst extension was used. The results showed the expansion of vegetation cover areas in the study area, concentrated on tops of hills, APP and legal reserves. However, they pointed out intense fragmentation of native vegetation, which hinders the performance of fragments as habitats. It is considered that, from the contemporary problem of degradation of natural environments to the detriment of economic development, studies like this are necessary in order to identify existing environmental problems and propose strategies to minimize and mitigate ecological imbalances.

Posidonia oceanica wrack beds as a fish habitat in the surf zone

Drifting macrophyte detritus cast along the shore, often called wrack, can wash around, accumulate in the surf zone and constitute a habitat where fishes forage and/or hide. We compared fish assemblages associated with Posidonia oceanica wrack beds with those associated with bare sand in the surf zone of Sardinia Island (Italy), NW Mediterranean Sea. In July–August 2020, in situ non-destructive visual censuses were performed to count fishes and record their behaviour at 3 locations, each including 3 shores characterized by both P. oceanica wrack beds and bare sand. The assemblages were mainly composed of small and juvenile/sub-adult individuals and significantly differed between the two habitats. Nine taxa were shared by both habitat types, seven were exclusively associated with P. oceanica wrack and only one species was found exclusively on sand. Higher species richness and fish density (without considering the contribution of gregarious fish in the water column) were observed on P. oceanica wrack than on sand. Assemblages were numerically dominated by Diplodus sargus, D. vulgaris and Mullus surmuletus. These species and other fishes, mostly represented by invertivorous (e.g., labrids) and omnivorous species, were often observed feeding on P. oceanica wrack and using the resuspended dark-brown vegetal fragments to hide. These findings clearly suggest that P. oceanica wrack beds attract fishes from surrounding habitats, some of them of commercial importance, providing food and habitat for juvenile and sub-adult stages.

Four new species of Pleroma (Melastomataceae) from campos rupestres and vegetation on granitic inselbergs in Eastern Minas Gerais, Brazil

Eastern Minas Gerais has been historically neglected regarding biodiversity sampling effort. However, recent botanical explorations have revealed several new taxa for its flora, especially from disjunct fragments of campos rupestres vegetation, which form a mosaic with granitic inselbergs in the region. In this article, we add four new species of Pleroma (Melastomataceae) to the growing list of new taxa: P. brevicomosum, P. caetanoi, P. miconiifolium and P. petrophylax. We provide descriptions, detailed photographs, taxonomic comparisons, a distribution map and conservation status assessments for these new taxa. All four species are assessed under a category of threat, highlighting the need for conservation actions in these biodiverse albeit still poorly known areas.

Agroecology niche for New Zealand's native earthworms

Exotic lumbricid earthworms have had some limited success colonising productive agricultural pastures in New Zealand, in place of native megascolecid species that did not adapt to the conversion from native vegetation cover. Native earthworms in lowland intensively-farmed landscapes are now almost entirely restricted to small fragments of native vegetation on marginal land where they coexist with adventive lumbricids. In recent years, regular pasture replacement using cultivation has been largely replaced by herbicide spray-out followed by direct drilling; much less soil disturbance potentially creates a new opportunity for native earthworms to colonise pastures. Reclaiming native earthworm habitat is critical not only to protecting diversity, but also to sustaining New Zealand's unique soil ecosystem services strongly associated to role of native species; however, there have been no studies related to this. Using a mesocosm experiment, we investigated how native and exotic earthworms modify physicochemical properties of a sheep-grazed pasture soil. The pasture soil was found to be equally suitable for the growth and survival of native and exotic species. Most burrowing earthworms increased the more soluble forms of macronutrients (N, P, S, K and Mg), but differences between native and exotic species were found to be larger than between functional groups. Two species of native earthworms, Octochaetus multiporus and Maoridrilus transalpinus, modified some soil properties in similar way to exotic species, but had significantly different impacts on pH, mineralisation of nutrients, and plant availability of trace elements. Compared to control, plant available N (PAN) and S concentrations were higher by more than 100% and 40%, respectively, in soils with presence of burrowing activity of the two native earthworms. Future co-existence of communities of native and exotic earthworms in agricultural pastures appears realistic, and this would benefit conservation of native species as well as dairy production. Further research may also reveal additional and unique benefits to soil quality that could be attributable to this formerly unavailable niche for native earthworms.

Foreign body aspiration in an adult: An endobronchial "Melon-oma".

Background: Foreign body (FB) aspirations in adults are relatively uncommon. The most commonly aspirated FBs in adults are organic, especially vegetable matter, peanuts, and fragments of bones. We report a rare case of a FB discovered in the left main bronchus of an adult male admitted to the intensive care unit. Case report: A 52-year-old male smoker with COPD presented to the emergency department with a two-day history of increasing dyspnea and cough. He was hypoxic and febrile with a temperature of 38°C. Auscultation revealed decreased breath sounds over the left lung and a few rhonchi on the right side. Chest x-ray showed left lung collapse. His condition rapidly worsened, and he was immediately intubated for acute respiratory failure. CT chest identified a large endobronchial mass obstructing the left main bronchus. Flexible bronchoscopy confirmed a soft and mobile brownish lesion in the left main bronchus. The histological appearance of the specimen retrieved was consistent with an organic foreign body. This was later identified as a melon chunk. It was removed successfully via flexible bronchoscopy by cutting it into smaller pieces to aid retrieval. Conclusion: FB aspiration can occur in all age groups but is less common in adults accounting for only 0.16%–0.33% of adult bronchoscopic procedures. Early detection of an aspirated FB is essential to avoid significant complications, morbidity, and mortality.

The influence of the landscape pattern on the urban land surface temperature varies with the ratio of land components: Insights from 2D/3D building/vegetation metrics

Recently, the impact of multidimensional building/vegetation landscape patterns on urban land surface temperature (LST) has received extensive attention. However, investigations on how two-dimensional (2D)/three-dimensional (3D) building and vegetation landscape patterns affect the urban thermal environment under different cover types are still limited. Thus, we use the boosted regression tree model to explore the separate and combined relative contributions and marginal effects of 2D/3D building and vegetation landscape patterns on the LST and to examine the impacts of differences in building and vegetation coverage. The results indicate that the mean architecture height, building coverage ratio, high building ratio, vegetation coverage ratio, and architecture height standard deviation are the main metrics affecting the LST, with relative contributions of 24.8%, 14.9%, 14.7%, 8.2%, and 7.6%, respectively. The building landscape roughness and fragmentation have the greatest influence on the LST, with contributions of 1.2 °C and 0.8 °C, respectively. Furthermore, changes in the building and vegetation coverage can significantly affect the LST. When building coverage dominates, building-based metrics largely affect the LST. When vegetation coverage dominates, the impact of vegetation landscape diversity, roughness, and fragmentation on the LST gradually increases. This study provides insights for improving urban thermal environment.

The influence of landscape structure on the dispersal pattern of yellow fever virus in the state of São Paulo

Man-made changes to the landscape play a crucial role in altering the epidemiologic patterns of infectious diseases, mainly as a result of pathogen spillover. Sylvatic yellow fever is ideally suited to modeling of this phenomenon as the risk of transmission of the disease as well as its circulation and dispersal are associated with forest fragmentation. In this study we investigated the temporal dispersal pattern of yellow fever virus (YFV) by means of confirmed cases of epizootics in non-human primates in municipalities in the state of São Paulo where there was no recommendation for vaccination in 2017. We analyzed the resistance to dispersal associated with different classes of land use and the geographic distances between the different locations where epizootics were recorded. The model that best explained the temporal dispersal pattern of YFV in the study area indicated that this was influenced by the geographic distance between collection locations and by the permeability of the forest edges (150 m) at the interface with the following core areas: Water, Agricultural, Non-Forest Formation and Forestry. Water, Agricultural, Urban and Forest core areas and the interfaces between the latter two formed important barriers to circulation of the virus. These findings indicate that fragmentation of vegetation tends to decrease the time taken for pathogens to spread, while conservation of forest areas has the opposite effect.

Landscape Dynamics (landDX) an open-access spatial-temporal database for the Kenya-Tanzania borderlands

The savannas of the Kenya-Tanzania borderland cover >100,000 km2 and is one of the most important regions globally for biodiversity conservation, particularly large mammals. The region also supports >1 million pastoralists and their livestock. In these systems, resources for both large mammals and pastoralists are highly variable in space and time and thus require connected landscapes. However, ongoing fragmentation of (semi-)natural vegetation by smallholder fencing and expansion of agriculture threatens this social-ecological system. Spatial data on fences and agricultural expansion are localized and dispersed among data owners and databases. Here, we synthesized data from several research groups and conservation NGOs and present the first release of the Landscape Dynamics (landDX) spatial-temporal database, covering ~30,000 km2 of southern Kenya. The data includes 31,000 livestock enclosures, nearly 40,000 kilometres of fencing, and 1,500 km2 of agricultural land. We provide caveats and interpretation of the different methodologies used. These data are useful to answer fundamental ecological questions, to quantify the rate of change of ecosystem function and wildlife populations, for conservation and livestock management, and for local and governmental spatial planning.

The importance of overbank deposits and paleosol analyses for comprehensive volcanic hazard evaluation: the case of Holocene volcanism at Miravalles Volcano, Costa Rica

On the flanks of the dormant Miravalles volcano, systematic fieldwork and radiocarbon dating of buried humus-rich soils (paleosols) and wood fragments, augmented by mineralogical and geochemical analysis, reveal extensive and previously undocumented Holocene activity. Phase 1 consisted of a ~ 6300 BCE (8.3 ka) volcanic debris avalanche and thick lapilli blast and fallout deposit that appear coeval. Hiatus 1 marks 2600 years of inactivity followed by Phase 2 lapilli interbedded with two lahars below a basaltic lava flow that dates to 3400 BCE (5.3 ka). Hiatus 2 lasted 1800 years from 3300 to 1500 BCE (5.3 ka to 3.5 ka), after which a very active Phase 3 ensued from 1600 BCE to 1500 CE (3.5 to 0.5 ka) with ≥ four lapilli eruptions, ≥ 4 lahars, ≥ 6 layers of ash and pumice, and small andesitic lava flows. The most recent evidence for eruption is a 1070 CE lapilli overlain by poorly-sorted gravels that may represent distal lahar sediments. Evidence indicates the occurrence of at least two, if not three, destructive lahars on the west flank of Miravalles in the past 500 years. The floodplain sedimentary record indicates much more activity of Miravalles volcano over the past 3500 years (since ~ 1500 BCE) than previously known, with a minimum of 24 events in that span. Overbank floodplain deposits are likely to contain the most compete record of recent activity in active and dormant volcanoes, and in the absence of dateable vegetation fragments, radiocarbon dating of paleosol A-horizons is very useful, with a precision of ~ 5 to 10% for a given age, e.g., 1200 ybp ± 60 to 120 y.

Ischaemic Stroke Complicating Infective Endocarditis: Microbleeds Are the Diagnostic Clue

Introduction: Ischemic strokes represent a classic complication of infective endocarditis (IE) and are most often related to the fragmentation of valvular vegetation. In most cases, they occur in the Sylvian territory and are related to Staphylococcus aureus. MRI can demonstrate, in addition to the AVCI image, cerebral microbleeds (CMBs) that are very suggestive of the diagnosis. We present the case of a patient who presented an ischemic stroke occurring in the context of infective endocarditis. Observation: A 32-year-old woman with no previous medical history initially presented with acute febrile headache, two weeks later she developed right hemiplegia with aphasia in the context of fever. Her general examination revealed lesions on the soles of her feet, in the form of nodules, infected in places, suggestive of Janeway nodules (characteristic of IE). The brain MRI showed an ischemic stroke in the Sylvian territory, with the presence of multiple microbleeds on the magnetic susceptibility sequences. The biological examination showed a severe inflammatory syndrome; the transthoracic echocardiography (TTE) confirmed the presence of vegetation on the aortic valve; and the blood cultures showed a Staphylococcus aureus. Antibiotic therapy was started, and the patient was transferred to the cardiology department. Discussion: Our observation has a double interest. The first is clinical due to the presence of plantar nodules (Janeway’s nodules) that are characteristic of IE which should orientate the diagnosis before the installation of the stroke, and the second is radiological and linked to the discovery of microbleeds. Their presence is increasingly reported in the literature, but their pathophysiology is not yet very clear. Conclusion: Stroke is the most frequent extracardiac complication during IE. The presence of microbleeds contributes to early diagnosis, especially in asymptomatic forms.

Ground-dwelling Spider Communities Respond to Changes in Riparian Vegetation Widths.

Spiders play a key role in the ecological dynamics in riparian habitats. However, most studies on the effects of changes in riparian habitats on spider communities have focused on the conversion of riparian forest to other land uses rather than on a gradient of forest widths. We assessed the community structure of ground-dwelling spiders in riparian vegetation fragments with varying widths in Southern Brazil. We selected four fragments with different riparian vegetation widths (> 40 m; < 30 m; < 15 m; < 5 m). In each fragment, spiders were seasonally collected using pitfall traps. We tested the effects of riparian vegetation widths and environmental variables (litter height, litter cover and canopy openness) on the taxonomic and guild composition of spider communities. The taxonomic and guild composition of ground-dwelling spiders varied among the widest (> 40 and < 30 m) and narrower riparian widths (< 15 m and < 5 m). While hunting spiders were associated with the narrower widths, web-building spiders were associated with the wider widths. Spider composition was influenced by the leaf litter height in the widest widths (> 40 and < 30 m) and by canopy openness in the narrowest width (< 15 m). Reductions in riparian vegetation were associated with significant changes in the community structure of ground-dwelling spiders, likely through top-down mechanisms associated with the higher litter input in wider fragments. In summary, the fragmentation of the riparian forests of Sothern Brazil are negatively associated with web-building spiders.