Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Conserv Biol ; 37(6): e14148, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37424356

RESUMO

Civilizations, including ancient ones, have shaped global ecosystems in many ways through coevolution of landscapes and humans. However, the cultural legacies of ancient and lost civilizations are rarely considered in the conservation of the Eurasian steppe biome. We used a data set containing more than 1000 records on localities, land cover, protection status, and cultural values related to ancient steppic burial mounds (kurgans); we evaluated how these iconic and widespread landmarks can contribute to grassland conservation in the Eurasian steppes, which is one of the most endangered biomes on Earth. Using Bayesian logistic generalized regressions and proportional odds logistic regressions, we examined the potential of mounds to preserve grasslands in landscapes with different levels of land-use transformation. We also compared the conservation potential of mounds inside and outside protected areas and assessed whether local cultural values support the maintenance of grasslands on them. Kurgans were of great importance in preserving grasslands in transformed landscapes outside protected areas, where they sometimes acted as habitat islands that contributed to habitat conservation and improved habitat connectivity. In addition to steep slopes hindering ploughing, when mounds had cultural value for local communities, the probability of grassland occurrence on kurgans almost doubled. Because the estimated number of steppic mounds is about 600,000 and similar historical features exist on all continents, our results may be applicable at a global level. Our results also suggested that an integrative socioecological approach in conservation might support the positive synergistic effects of conservation, landscape, and cultural values.


Contribución de los valores culturales para la conservación esteparia en los antiguos montículos funerarios de Eurasia Resumen Las civilizaciones modernas y antiguas han moldeado de muchas maneras los ecosistemas globales mediante la coevolución del paisaje y la humanidad. Sin embargo, pocas veces se considera el legado cultural de las civilizaciones perdidas o antiguas para la conservación del bioma de la estepa euroasiática. Usamos un conjunto de datos que contiene más de 1,000 registros de las localidades, cobertura del suelo, estado de protección y valores culturales relacionados con los antiguos montículos funerarios de esta estepa (kurgans). Después analizamos cómo estos símbolos icónicos y distribuidos extensamente pueden contribuir a la conservación de los pastizales en la estepa euroasiática, uno de los biomas en mayor peligro de extinción. Analizamos el potencial de conservación de los montículos en paisajes con diferentes niveles de transformación en el uso de suelo mediante regresiones logísticas generalizadas bayesianas y regresiones logísticas de probabilidades proporcionales. También comparamos el potencial de conservación de los montículos dentro y fuera de las áreas protegidas y evaluamos si los valores culturales locales conservan los pastizales dentro de estas mismas áreas. Los kurgans fueron de gran importancia para la conservación de los pastizales en los paisajes transformados ubicados fuera de las áreas protegidas, en donde llegaron a fungir como hábitats aislados que contribuyeron a la conservación y conectividad del hábitat. Además de que las pendientes pronunciadas impiden el arado, cuando los montículos contaban con valor cultural para las comunidades locales, la probabilidad de que el pastizal se ubicara sobre un kurgan casi se duplicó. Ya que se estima que el número de montículos esteparios ronda los 6,000 y que rasgos históricos similares existen en todos los continentes, nuestros resultados pueden aplicarse a nivel global. Nuestros resultados también sugieren que una estrategia socio-ecológica integradora para la conservación podría respaldar los efectos sinérgicos positivos de la conservación, el paisaje y los valores culturales.


Assuntos
Biodiversidade , Ecossistema , Humanos , Conservação dos Recursos Naturais/métodos , Teorema de Bayes , Pradaria
2.
Sci Rep ; 12(1): 21239, 2022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36481682

RESUMO

Sowing is widely used for the restoration of species-rich grasslands but still there are knowledge gaps regarding the most suitable application of different seed mixtures. We tested the effect of seed mixtures application timing on the establishment of sown forbs and weed control. 36 experimental plots with nine sowing treatments were established in an abandoned cropland in Hungary. Grass-seeds, diverse forb seed mixture and the combination of the two were applied: diverse forb mixture was sown simultaneously or 1, 2 or 3 years after grass sowing, in plots sown previously with grass or in empty plots (fallows). All sowing treatments supported the rapid establishment of the sown species in large cover and hampered weed encroachment. Forbs performed better when sown into fallows than in grass-matrix and forbs establishment was worse in older fallows than in younger ones. Grasses expressed a strong priority effect, especially when forbs were sown at least two years later than grasses. We also investigated the relation between seed germinability, weather parameters and establishment success. Germination rate in the greenhouse could not predict the establishment success of forbs in the field and showed great differences between years, hence we recommend sowing target forbs in multiple years.


Assuntos
Poaceae , Controle de Plantas Daninhas , Hungria
3.
Transplant Proc ; 54(9): 2589-2592, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36396469

RESUMO

BACKGROUND: Among renal transplant recipients, renal cell carcinoma in the native kidneys represents the most common solid tumor. At the Department of Surgery, Transplantation and Gastroenterology of Semmelweis University annual control abdominal ultrasound examination is recommended for transplant patients. Our goal was to evaluate the effectiveness of the ultrasound screening program at our institute and to learn about the characteristics of shrunken kidney tumors. METHODS: Retrospectively, we processed the results of abdominal and pelvic ultrasound examinations of 1687 kidney transplant patients, which were performed at our institute between January 1, 2012 and December 31, 2016. RESULTS: A total of 26 tumors were detected during the abovementioned period of time, of which 18 were renal cancers. Renal cancer was significantly (P = 0.029) more common in men. Seventeen renal cancers were classified as stage I and one as stage IV disease. The mean time of dialysis was 37.73 ± 24.37 months. The mean time between kidney transplantation and tumor recognition was 7.9 ± 6.29 years. The 5-year survival was 66%; however, it should be noted that only 1 patient lost his life due to his tumor disease. The mean time between the last 2 ultrasound examinations was 27.8 ± 23.89 months. Only 57% of tumors were detected by screening. No significant differences in tumor size, stage, and survival could be detected between screened and nonscreened renal cancer patients. CONCLUSIONS: Ultrasound examination at least every 2 years is an effective tool for the early detection of renal cell carcinoma of the shrunken kidneys.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Transplante de Rim , Masculino , Humanos , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/etiologia , Transplante de Rim/efeitos adversos , Transplante de Rim/métodos , Estudos Retrospectivos , Diálise Renal , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/etiologia , Rim
4.
PeerJ ; 10: e13226, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35402097

RESUMO

Background: Soil seed banks play a central role in vegetation dynamics and may be an important source of ecological restoration. However, the vast majority of seed bank studies examined only the uppermost soil layers (0-10 cm); hence, our knowledge on the depth distribution of seed bank and the ecological significance of deeply buried seeds is limited. The aim of our study was to examine the fine-scale vertical distribution of soil seed bank to a depth of 80 cm, which is one of the largest studied depth gradients so far. Our model systems were alkaline grasslands in East-Hungary, characterised by harsh environmental conditions, due to Solonetz soil reference group with Vertic horizon. We asked the following questions: (1) How do the seedling density and species richness of soil seed bank change along a vertical gradient and to what depth can germinable seeds be detected? (2) What is the relationship between the depth distribution of the germinable seeds and the species traits? Methods: In each of the five study sites, four soil cores (4 cm diameter) of 80 cm depth were collected with an auger for soil seed bank analysis. Each sample was divided into sixteen 5-cm segments by depth (320 segments in total). Samples were concentrated by washing over sieves and then germinated in an unheated greenhouse. Soil penetration resistance was measured in situ next to each core location (0-80 cm depth, 1-cm resolution). We tested the number and species richness of seedlings observed in the soil segments (N = 320), using negative binomial generalized linear regression models, in which sampling layer and penetration resistance were the predictor variables. We ran the models for morphological groups (graminoids/forbs), ecological groups (grassland species/weeds) and life-form categories (short-lived/perennial). We also tested whether seed shape index, seed mass, water requirement or salt tolerance of the species influence the vertical distribution of their seed bank. Results: Germinable seed density and species richness in the seed bank decreased with increasing soil depth and penetration resistance. However, we detected nine germinable seeds of six species even in the deepest soil layer. Forbs, grassland species and short-lived species occurred in large abundance in deep layers, from where graminoids, weeds and perennial species were missing. Round-shaped seeds were more abundant in deeper soil layers compared to elongated ones, but seed mass and ecological indicator values did not influence the vertical seed bank distribution. Our research draws attention to the potential ecological importance of the deeply buried seeds that may be a source of recovery after severe disturbance. As Vertisols cover 335 million hectares worldwide, these findings can be relevant for many regions and ecosystems globally. We highlight the need for similar studies in other soil and habitat types to test whether the presence of deep buried seeds is specific to soils with Vertic characteristics.


Assuntos
Ecossistema , Solo , Pradaria , Banco de Sementes , Sementes , Plântula , Plantas Daninhas
6.
Nat Ecol Evol ; 5(9): 1283-1290, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34294898

RESUMO

Restoration of degraded drylands is urgently needed to mitigate climate change, reverse desertification and secure livelihoods for the two billion people who live in these areas. Bold global targets have been set for dryland restoration to restore millions of hectares of degraded land. These targets have been questioned as overly ambitious, but without a global evaluation of successes and failures it is impossible to gauge feasibility. Here we examine restoration seeding outcomes across 174 sites on six continents, encompassing 594,065 observations of 671 plant species. Our findings suggest reasons for optimism. Seeding had a positive impact on species presence: in almost a third of all treatments, 100% of species seeded were growing at first monitoring. However, dryland restoration is risky: 17% of projects failed, with no establishment of any seeded species, and consistent declines were found in seeded species as projects matured. Across projects, higher seeding rates and larger seed sizes resulted in a greater probability of recruitment, with further influences on species success including site aridity, taxonomic identity and species life form. Our findings suggest that investigations examining these predictive factors will yield more effective and informed restoration decision-making.


Assuntos
Ecossistema , Plântula , Mudança Climática , Humanos , Plantas , Sementes
7.
Sci Total Environ ; 763: 144199, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33383506

RESUMO

Small natural features (SNFs), such as road verges, midfield islets, rocky outcrops and ancient burial mounds, provide safe havens for species of natural habitats in human-modified landscapes; therefore, their great ecological importance is in contrast to their small size. SNFs often have a high topographical heterogeneity and abiotic conditions, which differ from their surroundings; therefore, they provide a unique opportunity for establishing links between environmental heterogeneity (EH) and biodiversity. However, no study has so far investigated the EH components of topographically heterogeneous SNFs in a comprehensive framework, by linking environmental and biotic parameters. To fill this knowledge gap, we evaluated the EH components and their effect on biodiversity on ancient mounds covered by semi-natural grasslands in the Pannonian (Hungary) and Continental (Bulgaria) biogeographical regions. We designated 16 study sites, each containing a few-metre-high mounds with five microsites (top, north-, east-, south- and west-facing slopes) and a nearby plain grassland. At each microsite, we measured soil moisture, soil chemical properties, solar radiation and microclimate; and recorded the cover of vascular plants in a total of 480 plots. On the mounds, topographical heterogeneity was associated with sharp differences in microclimate and soil properties. Besides the contrast between mild north-facing and harsh south-facing slopes, east- and west-facing slopes also sustained unique microsites characterised by dynamic diurnal changes in air temperature and vapour pressure deficit. Various combinations of the EH components resulted in unique plant species compositions within the microsites, and supported the co-occurrence of species typical of contrasting habitat types, even within a couple of metres. By combining high-resolution measurements of abiotic factors with fine-scale vegetation sampling, our study provides evidence that widespread SNFs with complex topography harbour several grassland-specialist plant species and introduce a high level of EH to otherwise homogeneous plain landscapes, which cover one third of the global land area.


Assuntos
Biodiversidade , Ecossistema , Bulgária , Pradaria , Humanos , Hungria , Plantas
8.
Sci Rep ; 9(1): 1848, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30755623

RESUMO

The maintenance of biodiversity is crucial for ecosystem processes such as plant biomass production, as higher species richness is associated with increased biomass production in plant communities. However, the effects of evenness and functional diversity on biomass production are understudied. We manipulated the composition of an experimental grassland by sowing various seed mixtures and examined the effects of diversity and evenness on biomass production after three years. We found that biomass production increased with greater species and functional richness but decreased with greater species and functional evenness. Standing biomass increased but species number and functional richness decreased with increasing proportion of perennial grasses. Our findings emphasise the importance of productive dominant species, as the proportion of perennial grasses had a positive effect on standing biomass, while species and functional evenness had a negative effect on it. Thus, our findings support the theory that, besides diversity, dominance effects and the so-called mass ratio hypothesis may also play a key role in explaining primary biomass production.


Assuntos
Biodiversidade , Biomassa , Pradaria , Sementes/fisiologia , Agricultura/métodos , Algoritmos , Clima , Herbivoria , Hungria , Modelos Lineares , Poaceae/fisiologia , Especificidade da Espécie
9.
Ecol Evol ; 8(14): 7044-7054, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30073066

RESUMO

In intensively used landscapes, remnant grassland fragments are often restricted to places unsuitable for agricultural cultivation. Such refuges are the ancient burial mounds called "kurgans," which are typical landscape elements of the Eurasian steppe and forest steppe zone. Due to their hill-like shape, loose soil structure and undisturbed status kurgans provide proper habitats for burrowing mammals. Accordingly, grassland vegetation on kurgans is often exposed to bioturbation, which can influence the habitat structure and plant species pool. In our study, we explored the effect of fox burrows and landscape context on the habitat properties and vegetation composition of small landscape elements, using kurgans as model habitats. We surveyed the vegetation of fox burrows and that of the surrounding grassland on five kurgans situated in cleared landscapes surrounded by arable lands and five kurgans in complex landscapes surrounded by grazed grasslands. We recorded the percentage cover of vascular plants, the amount of litter, and soil moisture content in twelve 0.5 m × 0.5 m plots per kurgan, in a total of 120 plots. We found that foxes considerably transformed habitat conditions and created microhabitats by changing the soil nutrient availability and reducing total vegetation cover and litter. Several grassland specialist species, mostly grasses (Agropyron cristatum, Elymus hispidus, and Stipa capillata) established in the newly created microhabitats, although the cover of noxious species was also considerable. We found that landscape context influenced the sort of species which could establish on kurgans by affecting the available species pool and soil moisture. Our results revealed that foxes act as ecosystem engineers on kurgans by transforming abiotic and biotic conditions by burrowing. Their engineering activity maintains disturbance-dependent components of dry grasslands and increases local environmental heterogeneity.

10.
Int J Food Microbiol ; 112(1): 71-4, 2006 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-16934896

RESUMO

Food samples were monitored for contamination with Listeria monocytogenes, and the incidence of human listeriosis was evaluated according to the data obtained in Hungary in the year 2004. Of the food samples tested, the bacterium was most often detectable in milk and dairy products, as 72.1% of all L. monocytogenes strains were isolated from these samples. The food samples most commonly yielded strains of serotype 1/2a (45.1%) and 4b (27.0%). In 2004, 3 perinatal and 14 nonperinatal human listeriosis cases were diagnosed in Hungary. These disease cases were most often caused by strains belonging to serotype 4b (52.8%) and serotype 1/2a (23.5%). On the basis of the antibiotic sensitivity test results of strains isolated from the disease cases, penicillin and aminoglycoside antibiotics or a combination thereof were found to be effective.


Assuntos
Antibacterianos/farmacologia , Contaminação de Alimentos/análise , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Farmacorresistência Bacteriana , Feminino , Humanos , Hungria/epidemiologia , Incidência , Listeria monocytogenes/classificação , Listeriose/tratamento farmacológico , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Vigilância de Evento Sentinela , Sorotipagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...