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1.
Bioscience ; 73(8): 560-574, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37680688

RESUMO

Biological invasions are a global challenge that has received insufficient attention. Recently available cost syntheses have provided policy- and decision makers with reliable and up-to-date information on the economic impacts of biological invasions, aiming to motivate effective management. The resultant InvaCost database is now publicly and freely accessible and enables rapid extraction of monetary cost information. This has facilitated knowledge sharing, developed a more integrated and multidisciplinary network of researchers, and forged multidisciplinary collaborations among diverse organizations and stakeholders. Over 50 scientific publications so far have used the database and have provided detailed assessments of invasion costs across geographic, taxonomic, and spatiotemporal scales. These studies have provided important information that can guide future policy and legislative decisions on the management of biological invasions while simultaneously attracting public and media attention. We provide an overview of the improved availability, reliability, standardization, and defragmentation of monetary costs; discuss how this has enhanced invasion science as a discipline; and outline directions for future development.

2.
J Environ Manage ; 318: 115588, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35779299

RESUMO

Second-growth forests (SGF) are critical components for limiting biodiversity loss and climate change mitigation. However, these forests were established after anthropic disturbances such as land use for planting, and in highly human-modified landscapes. These interventions can decrease the ability of biological communities to recover naturally, and it is necessary to understand how multiple drivers, from local scale to landscape scale influence the diversity and carbon stock of these forests in natural regeneration. For this, we used data from 37 SGF growing on areas previously used for eucalyptus plantations in the Brazilian Atlantic Forest, after the last cut cycle. For each SGF, the forest tree species diversity was calculated based on the Hills number, and we also calculated the above-ground carbon stock. Then, we evaluated the influence of multiple environmental factors on these indexes: soil properties, past-management intensity, patch configuration, and landscape composition. Little influence of soil properties was found, only soil fertility negatively influenced above-ground carbon stock. However, past-management intensity negatively influenced tree species diversity and carbon stock. The isolation of other forests and tree species propagules source distance (>500 ha) also negatively influenced the diversity of species. This is probably due to the favoring of tree pioneer species in highly human-modified landscapes because they are more tolerant of environmental changes, less dependent on animal dispersal, and have low carbon stock capacity. Thus, areas with higher past-management intensity and more isolated areas are less effective for passive restoration and may require intervention to recover tree diversity and carbon stock in the Atlantic Forest. The approach, which had not yet been applied in the Atlantic Forest, brought similar results to that found in other forests, and serves as a theoretical basis for choosing priority areas for passive restoration in the biome.


Assuntos
Carbono , Árvores , Animais , Biodiversidade , Ecossistema , Florestas , Humanos , Solo , Clima Tropical
3.
Sci Total Environ ; 917: 170336, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38280594

RESUMO

Urbanization is an important driver of global change associated with a set of environmental modifications that affect the introduction and distribution of invasive non-native species (species with populations transported by humans beyond their natural biogeographic range that established and are spreading in their introduced range; hereafter, invasive species). These species are recognized as a cause of large ecological and economic losses. Nevertheless, the economic impacts of these species in urban areas are still poorly understood. Here we present a synthesis of the reported economic costs of invasive species in urban areas using the global InvaCost database, and demonstrate that costs are likely underestimated. Sixty-one invasive species have been reported to cause a cumulative cost of US$ 326.7 billion in urban areas between 1965 and 2021 globally (average annual cost of US$ 5.7 billion). Class Insecta was responsible for >99 % of reported costs (US$ 324.4 billion), followed by Aves (US$ 1.4 billion), and Magnoliopsida (US$ 494 million). The reported costs were highly uneven with the sum of the five costliest species representing 80 % of reported costs. Most reported costs were a result of damage (77.3 %), principally impacting public and social welfare (77.9 %) and authorities-stakeholders (20.7 %), and were almost entirely in terrestrial environments (99.9 %). We found costs reported for 24 countries. Yet, there are 73 additional countries with no reported costs, but with occurrences of invasive species that have reported costs in other countries. Although covering a relatively small area of the Earth's surface, urban areas represent about 15 % of the total reported costs attributed to invasive species. These results highlight the conservative nature of the estimates and impacts, revealing important biases present in the evaluation and publication of reported data on costs. We emphasize the urgent need for more focused assessments of invasive species' economic impacts in urban areas.


Assuntos
Insetos , Espécies Introduzidas , Humanos , Animais , Urbanização , Ecossistema
4.
Biol Rev Camb Philos Soc ; 99(4): 1357-1390, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38500298

RESUMO

Standardised terminology in science is important for clarity of interpretation and communication. In invasion science - a dynamic and rapidly evolving discipline - the proliferation of technical terminology has lacked a standardised framework for its development. The result is a convoluted and inconsistent usage of terminology, with various discrepancies in descriptions of damage and interventions. A standardised framework is therefore needed for a clear, universally applicable, and consistent terminology to promote more effective communication across researchers, stakeholders, and policymakers. Inconsistencies in terminology stem from the exponential increase in scientific publications on the patterns and processes of biological invasions authored by experts from various disciplines and countries since the 1990s, as well as publications by legislators and policymakers focusing on practical applications, regulations, and management of resources. Aligning and standardising terminology across stakeholders remains a challenge in invasion science. Here, we review and evaluate the multiple terms used in invasion science (e.g. 'non-native', 'alien', 'invasive' or 'invader', 'exotic', 'non-indigenous', 'naturalised', 'pest') to propose a more simplified and standardised terminology. The streamlined framework we propose and translate into 28 other languages is based on the terms (i) 'non-native', denoting species transported beyond their natural biogeographic range, (ii) 'established non-native', i.e. those non-native species that have established self-sustaining populations in their new location(s) in the wild, and (iii) 'invasive non-native' - populations of established non-native species that have recently spread or are spreading rapidly in their invaded range actively or passively with or without human mediation. We also highlight the importance of conceptualising 'spread' for classifying invasiveness and 'impact' for management. Finally, we propose a protocol for classifying populations based on (i) dispersal mechanism, (ii) species origin, (iii) population status, and (iv) impact. Collectively and without introducing new terminology, the framework that we present aims to facilitate effective communication and collaboration in invasion science and management of non-native species.


Assuntos
Espécies Introduzidas , Terminologia como Assunto , Animais
5.
Sci Total Environ ; 876: 162795, 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-36907404

RESUMO

Changes in physical habitat that are associated with anthropogenic disturbances facilitate the establishment and expansion of non-native species in receiving environments. Here, we evaluated the relative importance of ecosystem variables for the presence and abundance of the invasive fish Poecilia reticulata in Brazil. We collected fish species and assessed environmental variables through an established physical habitat protocol in 220 stream sites located in southeastern and midwestern Brazil. A total of 14,816 P. reticulata individuals were collected in 43 stream sites, and 258 variables that describe the physical characteristics of streams were assessed, including measures of channel morphology, substrate size and type, habitat complexity and cover, riparian vegetation cover and structure, and human influence. Dimensionality reduction methods were employed to limit redundancy, resulting in a smaller set of the most relevant environmental variables. Subsequently, we used random forest models to assess the relative importance of these variables in determining the presence and abundance of P. reticulata. The presence of this invasive fish was primarily explained by human disturbance variables related to urbanization (total impact, pavement, artificial structure areal cover, riparian canopy cover, electrical conductivity, mean thalweg depth, and sand), whereas channel morphology (mean bank full height) and fish cover variables (natural fish cover, and aquatic macrophyte areal cover) were important predictors of its abundance. Identifying which ecosystem variables are favorable to the establishment of non-native species is an important step in preventing future biological invasions, as well as managing those that already occur.


Assuntos
Ecossistema , Poecilia , Humanos , Animais , Espécies Introduzidas , Peixes , Rios/química , Brasil
6.
Sci Rep ; 13(1): 8945, 2023 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-37268662

RESUMO

The high ecological impacts of many invasive alien trees have been well documented. However, to date, we lacked synthesis of their economic impacts, hampering management actions. Here, we summarize the cost records of invasive trees to (I) identify invasive trees with cost information and their geographic locations, (II) investigate the types of costs recorded and sectors impacted by invasive trees and (III) analyze the relationships between categories of uses of invasive trees and the invasion costs attributed to these uses. We found reliable cost records only for 72 invasive trees, accumulating a reported total cost of $19.2 billion between 1960 and 2020. Agriculture was the sector with the highest cost records due to invasive trees. Most costs were incurred as resource damages and losses ($3.5 billion). Close attention to the ornamental sector is important for reducing the economic impact of invasive trees, since most invasive trees with cost records were introduced for that use. Despite massive reported costs of invasive trees, there remain large knowledge gaps on most invasive trees, sectors, and geographic scales, indicating that the real cost is severely underestimated. This highlights the need for further concerted and widely-distributed research efforts regarding the economic impact of invasive trees.


Assuntos
Meio Ambiente , Árvores , Agricultura , Espécies Introduzidas
7.
Philos Trans R Soc Lond B Biol Sci ; 378(1867): 20210072, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36373928

RESUMO

Under the UN-Decade of Ecosystem Restoration and Bonn Challenge, second-growth forest is promoted as a global solution to climate change, degradation and associated losses of biodiversity and ecosystem services. Second growth is often invaded by alien tree species and understanding how this impacts carbon stock and biodiversity recovery is key for restoration planning. We assessed carbon stock and tree diversity recovery in second growth invaded by two Acacia species and non-invaded second growth, with associated edge effects, in the Brazilian Atlantic Forest. Carbon stock recovery in non-invaded forests was threefold lower than in invaded forests. Increasingly isolated, fragmented and deforested areas had low carbon stocks when non-invaded, whereas the opposite was true when invaded. Non-invaded forests recovered threefold to sixfold higher taxonomic, phylogenetic and functional diversity than invaded forest. Higher species turnover and lower nestedness in non-invaded than invaded forests underpinned higher abundance of threatened and endemic species in non-invaded forest. Non-invaded forests presented positive relationships between carbon and biodiversity, whereas in the invaded forests we did not detect any relationship, indicating that more carbon does not equal more biodiversity in landscapes with high vulnerability to invasive acacias. To deliver on combined climate change and biodiversity goals, restoration planning and management must consider biological invasion risk. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.


Assuntos
Acacia , Ecossistema , Espécies Introduzidas , Carbono , Filogenia , Florestas , Biodiversidade , Conservação dos Recursos Naturais
8.
Environ Sci Pollut Res Int ; 29(52): 79168-79183, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35708810

RESUMO

Currently, more than five years after the Fundão dam failure in Mariana, Minas Gerais, Brazil, Brachiaria decumbens Stapf. is the main grass in pasturelands affected by the mining tailings. The aim of this study was to investigate the reason for this fact as well as to determine the ecophysiological effects of mining tailings on B. decumbens and to test whether mixing the tailings with unaffected local soil enhances the affected soil properties. For the experiment, two different soils were collected, one unaffected soil without mining tailings (Ref) and the mining tailings (Tec), and we also created a mixture with 50 % of each soil type (Ref/Tec). We cultivated B. decumbens in the three soil treatments in a greenhouse for 110 days and evaluated soil physical-chemical properties and plant ecophysiology. Our results show that the tailings (Tec) compromised the normal ecophysiological state of B. decumbens. The species survived these adverse conditions due to its great efficiency in acquiring some elements. The soil management tested by this work mitigated the stress caused by tailings and can represent an alternative for the environmental recovery of the affected soils.


Assuntos
Brachiaria , Brasil , Mineração , Solo/química , Poaceae
9.
Sci Total Environ ; 775: 144441, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-33715862

RESUMO

We contend that the exclusive focus on the English language in scientific research might hinder effective communication between scientists and practitioners or policy makers whose mother tongue is non-English. This barrier in scientific knowledge and data transfer likely leads to significant knowledge gaps and may create biases when providing global patterns in many fields of science. To demonstrate this, we compiled data on the global economic costs of invasive alien species reported in 15 non-English languages. We compared it with equivalent data from English documents (i.e., the InvaCost database, the most up-to-date repository of invasion costs globally). The comparison of both databases (~7500 entries in total) revealed that non-English sources: (i) capture a greater amount of data than English sources alone (2500 vs. 2396 cost entries respectively); (ii) add 249 invasive species and 15 countries to those reported by English literature, and (iii) increase the global cost estimate of invasions by 16.6% (i.e., US$ 214 billion added to 1.288 trillion estimated from the English database). Additionally, 2712 cost entries - not directly comparable to the English database - were directly obtained from practitioners, revealing the value of communication between scientists and practitioners. Moreover, we demonstrated how gaps caused by overlooking non-English data resulted in significant biases in the distribution of costs across space, taxonomic groups, types of cost, and impacted sectors. Specifically, costs from Europe, at the local scale, and particularly pertaining to management, were largely under-represented in the English database. Thus, combining scientific data from English and non-English sources proves fundamental and enhances data completeness. Considering non-English sources helps alleviate biases in understanding invasion costs at a global scale. Finally, it also holds strong potential for improving management performance, coordination among experts (scientists and practitioners), and collaborative actions across countries. Note: non-English versions of the abstract and figures are provided in Appendix S5 in 12 languages.


Assuntos
Espécies Introduzidas , Idioma , Europa (Continente)
10.
Int Ophthalmol ; 30(5): 553-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20668914

RESUMO

To describe the intra-ocular manifestations of cat-scratch disease (CSD) found at two uveitis reference centers in Brazil. Retrospective case series study. Review of clinical records of patients diagnosed with CSD in the Uveitis Department of São Geraldo Hospital and the Ophthalmology Department of the Instituto de Pesquisa Clínica Evandro Chagas-FIOCRUZ, from 2001 to 2008. In the 8-year period, 24 patients with the diagnosis of CSD were identified. Twelve patients were male and 12 female. The mean age was 27.04 years (range 7-56). Sixteen patients (66.6%) presented with a history of a cat scratch and all patients reported cat exposure. Visual acuity ranged from counting fingers to 1.0 in the affected eye. Thirteen patients presented with bilateral disease. Sixteen (66.6%) patients complained of systemic symptoms, including fever, lymphadenopathy, liver and spleen enlargement and rash. All patients presented with serum antibodies (IgG) to Bartonella henselae. Thirty-seven eyes were affected. The most common findings were small areas of retinal infiltrates which occurred in 11 eyes (29.7%) and angiomatous lesions which occurred in nine eyes (24.3%). Neuroretinitis occurred in only six eyes (16.2%). The most common findings of CSD in our study were retinal infiltrates and angiomatous lesions. CSD patients may present with significant visual loss. Patients may benefit from systemic treatment with antibiotics.


Assuntos
Bartonella henselae , Doença da Arranhadura de Gato/diagnóstico , Infecções Oculares Bacterianas/diagnóstico , Adolescente , Adulto , Animais , Doença da Arranhadura de Gato/complicações , Gatos , Criança , Infecções Oculares Bacterianas/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Retinite/etiologia , Retinite/microbiologia , Acuidade Visual , Adulto Jovem
11.
Am J Ophthalmol ; 141(2): 400-1, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16458711

RESUMO

PURPOSE: To characterize ocular manifestations of cat-scratch disease in HIV-positive patients. DESIGN: Retrospective case series study. METHODS: Records and photography of patients with the diagnosis of cat-scratch disease and HIV were reviewed. RESULTS: From 2001 and 2004 three patients with cat-scratch disease and HIV were identified. All patients presented with subretinal mass associated with an abnormal vascular network. Fluorescein angiography revealed this abnormal vascular network more clearly. All patients were treated with antibiotics alone with good response. CONCLUSIONS: Subretinal mass associated with abnormal vascular network is characteristic of cat-scratch disease in HIV-positive patients. Fluorescein angiography is important to characterize this vascular pattern, and patients may benefit from systemic treatment.


Assuntos
Doença da Arranhadura de Gato/diagnóstico , Infecções Oculares Bacterianas/diagnóstico , Soropositividade para HIV/diagnóstico , Doenças Retinianas/diagnóstico , Vasos Retinianos/patologia , Adulto , Antibacterianos/uso terapêutico , Anticorpos Antibacterianos/sangue , Bartonella henselae/imunologia , Doença da Arranhadura de Gato/tratamento farmacológico , Doença da Arranhadura de Gato/microbiologia , Ciprofloxacina/uso terapêutico , Doxiciclina/uso terapêutico , Quimioterapia Combinada , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/microbiologia , Angiofluoresceinografia , Soropositividade para HIV/tratamento farmacológico , Soropositividade para HIV/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Retinianas/tratamento farmacológico , Doenças Retinianas/microbiologia , Vasos Retinianos/efeitos dos fármacos , Vasos Retinianos/microbiologia , Estudos Retrospectivos
12.
PhytoKeys ; (50): 61-99, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26140021

RESUMO

We describe seven new species of Selaginellasubg.Stachygynandrum (Selaginellaalstonii, Selaginellablepharodella, Selaginellacrinita, Selaginellamucronata, Selaginellamucugensis, Selaginellasaltuicola, and Selaginellasematophylla) from Brazil and discuss their possible affinities and conservation status. Scanning electron micrographs of stem sections, leaves, and spores are provided to illustrate the new taxa. In Selaginellaalstonii and Selaginellasaltuicola vegetative growth from strobilus tips is reported and discussed. Four of the new species are from the Espinhaço Mountain Range associated with Campos Rupestres (montane savannah/rocky fields) vegetation. Three of these (i.e., Selaginellablepharodella, Selaginellacrinita, and Selaginellamucugensis) were collected in the northern part of the range in Chapada Diamantina, state of Bahia, while Selaginellaalstonii is from the southern part of the range in the state of Minas Gerais. Selaginellamucronata is found in Atlantic Rainforest vegetation in the state of Espírito Santo, whereas Selaginellasaltuicola inhabits Cerrado (tropical savannah) vegetation in the state of Mato Grosso. Selaginellasematophylla is the most widely distributed of the new species and was collected in Espírito Santo, Minas Gerais, and Rio de Janeiro states in Campos Rupestres and Atlantic Rainforest vegetation. Selaginellaalstonii occurs in rocky caves, Selaginellablepharodella, Selaginellacrinita, Selaginellamucugensis, and Selaginellasematophylla seem adapted to seasonally dry places, living on sandy or humid soils, Selaginellamucronata occupies humid, forest understory, and Selaginellasaltuicola is adapted to wet places associated with rocks or logs in waterfalls. Of the seven new species, six are considered local endemics (except for Selaginellasematophylla) because of their restricted currently known distributions to one or two localities within a single state in Brazil. Additionally, we propose new synonymy for Selaginellapalmiformis (syn. = Selaginellabahiensissubsp.manausensis, ≡ Selaginellamanausensis) and Selaginellavestiens (syn. = Selaginellafragillima); the last species is endemic to Brazil, recorded in the states of Goiás and Minas Gerais. Finally, based on literature discussed and this study, we conclude that the number of well-documented Brazilian Selaginella species is 61, of which 58 are native and three introduced and naturalized. These statistics are likely to change with further work on Selaginella from Brazil.


ResumenDescribimos siete nuevas especies de Selaginellasubg.Stachygynandrum (Selaginellaalstonii, Selaginellablepharodella, Selaginellacrinita, Selaginellamucronata, Selaginellamucugensis, Selaginellasaltuicola y Selaginellasematophylla) de Brasil y discutimos sus posibles afinidades y estado de conservación. Micrografias electrónicas de barrido de secciones de los tallos, hojas y esporas se proveen para ilustrar los nuevos taxa. Igualmente, se describe y discute el crecimiento vegetativo a partir del ápice de los estróbilos en Selaginellaalstonii y Selaginellasaltuicola. Cuatro de las especies nuevas proceden de la Cadena del Espinhaço asociadas a vegetación de Campos Rupestres (sabana montana). Tres de éstas (i.e., Selaginellablepharodella, Selaginellacrinita y Selaginellamucugensis) fueron recolectadas en la parte norteña de la Cadena del Espinhaço en la Chapada Diamantina, estado de Bahia, mientras que Selaginellaalstonii se registra para la parte sureña en el estado de Minas Gerais. Selaginellamucronata se encuentra en vegetación de Bosques Lluviosos del Atlántico en el estado de Espírito Santo, mientras que Selaginellasaltuicola habita vegetación de Cerrado (sabana tropical) en el estado de Mato Grosso. De las nuevas especies, Selaginellasematophylla es la más ampliamente distribuida y se ha recolectada en los estados de Espírito Santo, Minas Gerais y Río de Janeiro en vegetación de Campos Rupestres y Bosques Lluviosos del Atlántico. Selaginellaalstonii crece sobre rocas en cuevas, mientras que Selaginellablepharodella, Selaginellacrinita, Selaginellamucugensis y Selaginellasematophylla parecen estar adaptadas a lugares estacionalmente secos, creciendo sobre suelos arenosos o húmedos; a su vez, Selaginellamucronata crece en el sotobosque de bosques húmedos y Selaginellasaltuicola está adaptada a vivir en lugares húmedos asociada a rocas o troncos en cascadas. De las siete nuevas especies, seis son consideradas tentativamente endémicas locales (con la excepción de Selaginellasematophylla) debido a su distribución restringida a una o dos localidades dentro de un sólo estado de Brasil. Adicionalmente, proponemos nuevos sinónimos para Selaginellapalmiformis (syn. = Selaginellabahiensissubsp.manausensis, ≡ Selaginellamanausensis) y Selaginellavestiens (syn. = Selaginellafragillima), la cual se confirma como endémica de Brasil donde se registra para los estados de Goiás y Minas Gerais. Finalmente, de acuerdo con este estudio y la literatura discutida, estimamos que el número de especies brasileñas de Selaginella debidamente documentadas es de 61, de las cuales 58 son nativas y tres introducidas y naturalizadas. Esta estadística muy probablemente cambiará conforme se realicen estudios adicionales sobre Selaginella en Brasil.

13.
Br J Ophthalmol ; 98(9): 1218-20, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24820044

RESUMO

BACKGROUND/AIMS: Toxoplasmic retinochoroiditis is the commonest known cause of posterior uveitis worldwide and reactivation is unpredictable. Based on results from one study, the authors proposed that antitoxoplasmic therapy should be initiated as prophylaxis for intraocular surgery in patients with toxoplasmic scars. The aim of this study is to analyse the risk of toxoplasmic retinochoroiditis reactivation following intraocular procedures. METHODS: Retrospective analysis of the medical records of a total of 69 patients who underwent intraocular surgery and presented with toxoplasmic retinochoroiditis scars. RESULTS: No patient received prophylactic antitoxoplasmic therapy. Reactivation following the surgical procedure occurred in four cases, with one at 3 months and the others respectively at 13, 14 and 17 months. CONCLUSIONS: Our study shows that intraocular surgery did not result in a significant reactivation rate of toxoplasmic retinochoroiditis in the absence of preoperative prophylactic antitoxoplasmic therapy.


Assuntos
Coriorretinite/etiologia , Infecção da Ferida Cirúrgica/etiologia , Toxoplasmose Ocular/etiologia , Vitrectomia , Adolescente , Adulto , Idoso , Coriorretinite/prevenção & controle , Coccidiostáticos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Facoemulsificação , Recidiva , Estudos Retrospectivos , Medição de Risco/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Toxoplasmose Ocular/prevenção & controle , Adulto Jovem
14.
Rev. biol. trop ; Rev. biol. trop;66(2): 937-951, abr.-jun. 2018. tab, graf
Artigo em Espanhol | LILACS, SaludCR | ID: biblio-977356

RESUMO

Resumen Aunque los inselbergs son afloramientos rocosos icónicos con un alto valor biogeográfico, poco se conoce sobre los mecanismos responsables de la estructuración de comunidades vegetales. El objetivo de esta investigación fue evaluar cómo el tamaño de los parches de vegetación influye en la relación especie-área y distribución de la abundancia de especies de una comunidad en un inselberg del Monumento Natural "Piedra La Tortuga", región Guayana, Venezuela. Por este motivo, se establecieron tres preguntas de investigación: ¿Cuál es el efecto del tamaño de los parches sobre la riqueza de especies? ¿Qué tipo de modelo especie-área (SAR) presenta mejor ajuste en esos parches de vegetación? ¿Cómo es la distribución de las abundancias de las especies (SADs) es inducida por el tamaño de los parches? Se realizó un muestreo aleatorio estratificado en parches que oscilaron entre 0.34 y 14.8 m2, totalizando 40 unidades muestrales (226 m2). Todos los individuos encontrados en los 40 parches fueron identificados a nivel de especie. La composición florística en las diferentes muestras estuvo representada por 19 familias, 22 géneros y 24 especies, de las cuales 50 % son endémicas de inselbergs y dos están amenazadas de extinción. Se identificaron dos grupos de tamaños de parches (grandes 8-15 m2 y pequeños ≤ 7.9 m2) en relación a la abundancia y composición de especies, con diferencias significativas entre los grupos. Las curvas de acumulación de especies para cada grupo de tamaño de parche muestran una tendencia contrastante con marcadas diferencias en la riqueza observada entre los grupos de tamaños de parches. Las curvas de los modelos SADs tuvieron un ajuste significativo de la serie geométrica en las dos categorías de parches. El modelo SAR de la función potencia presentó los mejores ajustes especie-área, donde el aumento del área de los parches explicó un 82 % de la variación en el aumento del número de especies. Los resultados de este estudio demuestran por primera vez como el tamaño de los parches de vegetación de un inselberg tropical tiene una fuerte influencia sobre la riqueza, distribución de la abundancia y composición de especies. Así mismo, se determinó que el modelo geométrico SAD presentó el mejor ajuste en la comunidad en función del tamaño de los parches como un indicador de recursos, donde la abundancia de una especie puede ser equivalente a una proporción del espacio ocupado. También se presume que los cambios de tamaño de los parches, podría estar asociado con la disponibilidad de nutrientes y agua, como ha sido demostrado en otros ambientes de tierras secas. En algunos estudios se ha argumentado que la variación en la composición de especies entre los perfiles de vegetación de inselbergs tropicales está condicionada principalmente por la estructura del hábitat y el déficit hídrico. Sin embargo, no se había discutido cómo el tamaño de los parches de vegetación tiene un efecto en la riqueza. Los análisis SADs y SAR pueden proporcionar explicaciones complementarias sobre la estructuración de comunidades vegetales en inselbergs.


Abstract Although inselbergs are iconic rock outcrops with a high biogeographic value, little is known about drivers responsible for the plant community assembly. The aim of this research was to evaluate how the patch size distribution of vegetation influences the species-area relationship and species abundance distribution of a community in an inselberg of the "Piedra La Tortuga" Natural Monument of the Guayana region, Venezuela. In this context, three research questions were established: What is the effect of patch size on species richness? What species-area model (SAR) has the best fit in those vegetation patches? How is the distribution of species abundances (SADs) induced by the patch size distribution? A stratified random sampling was performed in patches ranging from 0.34 to 14.8 m2, totaling 40 sampling units (226 m2). All individuals found in the 40 patches were identified at species level. The floristic composition in the different samples was represented by 19 families, 22 genera and 24 species, of which 50 % are endemic to inselbergs and two, are threatened of extinction. Two groups of patch sizes were identified (large 8-15 m2 and small ≤ 7.9 m2) in relation to the abundance and composition of species. The species accumulation curves for each patch size group show a contrasting tendency with marked differences in the observed richness among patch size groups. The curves of the SADs models had a significant adjustment of the geometric series in the two categories of patches. The SAR model of the power function presented the best species-area adjustments, where the increase in patch area accounted for 82 % of the variation in the increase in the number of species. The results of this study demonstrate for the first time how vegetation patches of a tropical inselberg have a strong influence on richness, abundance distribution and species composition. Likewise, it was determined that the SAD geometric model presented the best fit in the community as a function of patch size as a resource indicator, where the abundance of a species can be equivalent to a proportion of the space occupied. It is also presumed that changes in patch sizes could be associated with nutrient and water availability, as has been demonstrated in other dryland environments. In some studies it has been argued that variation in species composition among vegetation profiles of tropical inselbergs is mainly conditioned by habitat structure and water deficit. However, it had not been discussed how the size of patches of vegetation has an effect on richness. SADs and SAR analyzes can provide complementary explanations on community assembly in inselbergs. Rev. Biol. Trop. 66(2): 937-951. Epub 2018 June 01.


Assuntos
Florestas , Sedimentos Geológicos , Tabebuia , Dispersão Vegetal , Venezuela
15.
Acta amaz ; Acta amaz;48(3): 248-256, July-Sept. 2018. map, ilus, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1455360

RESUMO

Although inselbergs from around the world are iconic ecosystems, little is known on the underlying mechanisms of community assembly, especially in their characteristic patchy outcrop vegetation. Environmental constraints are expected to cause phylogenetic clustering when ecological niches are conserved within evolutionary lineages. We tested whether vegetation patches from rock outcrops of the Piedra La Tortuga Natural Monument, in the northern Amazon region, are phylogenetically clustered, indicating that environmental filtering is the dominant driver of community assemblage therein. We classified all patches according to their size as very small (< 1 m2), small (1-4 m2), medium-sized (4-8 m2), and large patches (8-15 m2). From each class, we randomly selected 10 patches, totalizing 40 patches covering 226 m2. All individuals found in the 40 isolated patches were identified to the species level. We also correlated measurements of phylogenetic community structure with patch size. We found that species from patches are restricted to the clades monocots, fabids, malvids, and lamiids. We conclude that vegetation in this rock outcrop is phylogenetically clustered. Furthermore, we found that phylogenetic turnover between pairs of patches increases with patch size, which is consistent with a scenario of higher environmental stress in smaller patches. Further research is necessary to identify nurse species in inselberg vegetation, which is pivotal for conservation and restoration of this particular ecosystem.


Ainda que os inselbergs ao redor do mundo sejam ecossistemas icônicos, pouco se sabe sobre os mecanismos subjacentes que estruturam suas comunidades vegetais, especialmente nas manchas de vegetação sobre afloramentos rochosos. Espera-se que as restrições ambientais causem agrupamento filogenético quando os nichos ecológicos são conservados dentro das linhagens evolutivas. Nós testamos se as manchas de vegetação dos afloramentos rochosos do Monumento Natural Piedra La Tortuga, no norte da região amazônica, apresentam indicadores filogenéticos de que a filtragem ambiental é o principal direcionador da estruturação da comunidade. Classificamos todas as manchas de acordo com seu tamanho como muito pequenas (<1 m2), pequenas (1-4 m2), médias (4-8 m2) e grandes (8-15 m2). Selecionamos aleatoriamente 10 manchas em cada classe de tamanho, totalizando 40 manchas cobrindo 226 m2. Todos os indivíduos encontrados nas 40 manchas foram identificados ao nível de espécie. Correlacionamos as medidas da estrutura filogenética da comunidade com o tamanho das manchas e encontramos que as espécies das manchas são restritas aos clados das monocotiledôneas, fabídeas, malvídeas e lamiídeas. Concluímos que a vegetação neste afloramento rochoso é agrupada filogeneticamente. Além disso, encontramos que o turnover filogenético entre pares de manchas aumenta com o tamanho da mancha, o que é consistente com um cenário de alto estresse ambiental nas manchas menores. São necessárias mais pesquisas para identificar espécies facilitadoras, que são fundamentais para a conservação e restauração destes ecossistemas.


Assuntos
Filogenia , Plantas/classificação , Plantas/genética , Variação Genética , Ecossistema Amazônico
18.
Rev. bras. oftalmol ; 61(11): 834-836, nov. 2002.
Artigo em Português | LILACS | ID: lil-335171

RESUMO

Objetivo: Relatar um caso de endoftalmite pós-cirúrgica crônica por Aeromonas hydrophila. Local: Centro Oftalmológico de MG e Departamento de Uveítes do Hospital São Geraldo, UFMG. Método: Relato de caso. Resultado: Após tratamento cirúrgico instituído, baseado em biópsia vítrea para cultura bacteriológica, explantação de lente intra-ocular e saco capsular, vitrectomia posterior e injeção intravítrea de antimicrobianos (vancomicina e ceftazidima), obtivemos sucesso anatômico e funcional deste olho, com acuidade visual final de 0,5 com correção óptica. Conclusão: Este nosso relato demonstra o primeiro caso de endoftalmite pós-cirúrgica por Aeromonas hydrophila tratado com sucesso e alcançando boa recuperação anatômica e funcional do bulbo ocular.


Assuntos
Humanos , Feminino , Idoso , Aeromonas hydrophila , Endoftalmite , Infecções por Bactérias Gram-Negativas , Extração de Catarata/efeitos adversos , Avaliação de Processos e Resultados em Cuidados de Saúde , Complicações Pós-Operatórias
19.
Rev. bras. oftalmol ; 61(8): 603-607, ago. 2002. ilus
Artigo em Inglês, Português | LILACS | ID: lil-335152

RESUMO

Objetivo: Relatar uma série de 5 casos de distrofia viteliforme foveomacular de início na vida adulta, uma das distrofias padrão da mácula, em associação com o desenvolvimento de buraco macular. Local: Manhattan Eye, Ear & Throat Hospital, New York, NY, USA. Métodos: Relato de uma série de casos. Resultados: Cinco casos de distrofia viteliforme foveomacular de início na vida adulta, uma das distrofias padrão da mácula, desenvolveram buraco macular. Todos os 5 casos, ou 7 olhos, evoluíram com perda de visão, e em um olho foi realizada cirurgia para buraco macular e obtido sucesso anatômico (fechamento do buraco). Conclusão: Distrofia viteliforme foveomacular de início na vida adulta pode associar?se ao desenvolvimento de buraco macular e esta associação pode resultar em perda de visão.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Distrofias Hereditárias da Córnea/fisiopatologia , Perfurações Retinianas/fisiopatologia , Macula Lutea , Doenças Retinianas
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