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1.
Proc Biol Sci ; 290(1998): 20222450, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37161334

RESUMEN

Alien species are widely linked to biodiversity change, but the extent to which they are associated with the reshaping of ecological communities is not well understood. One possible mechanism is that assemblages where alien species are found exhibit elevated temporal turnover. To test this, we identified assemblages of vascular plants in the BioTIME database for those assemblages in which alien species are either present or absent and used the Jaccard measure to compute compositional dissimilarity between consecutive censuses. We found that, although alien species are typically rare in invaded assemblages, their presence is associated with an increase in the average rate of compositional change. These differences in compositional change between invaded and uninvaded assemblages are not linked to differences in species richness but rather to species replacement (turnover). Rapid compositional restructuring of assemblages is a major contributor to biodiversity change, and as such, our results suggest a role for alien species in bringing this about.


Asunto(s)
Tracheophyta , Biodiversidad , Bases de Datos Factuales , Especies Introducidas
2.
Biota Neotrop. (Online, Ed. ingl.) ; 22(spe): e20221407, 2022. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1403631

RESUMEN

Abstract: Despite their negative environmental impacts, human-modified environments such as agricultural and urban landscapes can have a relevant role on biodiversity conservation as complements of protected areas. Such anthropized landscapes may have endangered, valuable, and nuisance species, although most of them do not fit in any of these categories. Therefore, in such environments we must deal with the same decision-making process concerning the same possible interventions proposed by Caughley (1994) to wildlife management, which are related to biological conservation, sustainable use, control/coexistence, and monitoring. Such decision-making process should be based on good science and good governance. On such context, the first step should be to implement multifunctional landscapes, which keep their primary mission of human use, but incorporate a second but fundamental mission of biological conservation. In this study we present a summary of the research carried out at the Biota Program of Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) in this field since the late 1990's and propose priorities for biodiversity research and governance in multifunctional landscapes for the near future.


Resumo Apesar de seus impactos ambientais negativos, ambientes modificados pelo homem, como paisagens agrícolas e urbanas, podem ter um papel relevante na conservação da biodiversidade como complementos de áreas protegidas. Tais paisagens antropizadas podem ter espécies ameaçadas, valiosas e incômodas, embora a maioria delas não se enquadre em nenhuma dessas categorias. Portanto, em tais ambientes devemos lidar com o mesmo processo de tomada de decisão sobre as mesmas possíveis intervenções propostas por Caughley (1994) para o manejo da vida selvagem, que estão relacionadas à conservação biológica, uso sustentável, controle/coexistência e monitoramento. Esse processo de tomada de decisão deve ser baseado em boa ciência e boa governança. Neste contexto, o primeiro passo deverá ser a implementação de paisagens multifuncionais, que mantenham a sua missão primordial de uso humano, mas que incorporem uma segunda, mas fundamental missão de conservação biológica. Neste estudo apresentamos um resumo das pesquisas realizadas no Programa Biota da Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) neste campo desde o final da década de 1990 e propomos prioridades para pesquisa e governança da biodiversidade em paisagens multifuncionais para o futuro próximo.

3.
Sci Total Environ ; 704: 135397, 2020 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-31810678

RESUMEN

The Brazilian savanna (Cerrado) has been extensively converted to croplands, pastures and forestry plantations, and the deforestation frontier continues expanding. Land conversion may cause critical changes in soil functioning, yet very little is still known about the impact of Cerrado conversion on nutrient cycling and soil fertility. Here, we addressed this knowledge gap by investigating the effects of the woodland cerrado (cerradão) conversion into pastures and Eucalyptus plantations on nitrogen availability and mineralization potential, considering a wide range of spatial and temporal variability due to soil depth, site conditions, and seasonal variation. For three sites in São Paulo state and each of the target land cover types, we assessed the total N and inorganic N (NH4-N and NO3-N) pools, potentially mineralizable nitrogen (PMN) and soil urease activity in the first 2 m of the soil profile. Cerrado conversion to either pastures or Eucalyptus plantations significantly reduced NH4-N, while NO3-N showed similar values in Cerrado and Eucalyptus and lower values in pastures. We found a consistent pattern of lower N mineralization in the uppermost soil layers associated to Cerrado conversion, with decreases in PMN rate and urease activity. The soil below 30 cm depth showed no relevant changes. Considering the first 30 cm of the soil profile, the reduction in the stocks of inorganic N (NH4-N + NO3-N) ranged from ~14% for the conversion to Eucalyptus to ∽20% for the conversion to pasture. The impact of land conversion on N cycling surpassed the influence of the spatial (between-site) and seasonal variation. Overall, the results indicate a decline in available N and overall soil fertility due to Cerrado conversion, which could further increase N limitation in the Cerrado region, increase fertilization needs for future exploitation, and compromise the recovery of Cerrado in case of land abandonment or restoration.


Asunto(s)
Agricultura , Conservación de los Recursos Naturales , Ecosistema , Monitoreo del Ambiente , Eucalyptus , Nitrógeno/análisis , Brasil , Agricultura Forestal , Bosques , Pradera , Suelo
4.
Environ Manage ; 55(6): 1377-89, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25860593

RESUMEN

Strictly Protected Areas and riparian forests in Brazil are rarely large enough or connected enough to maintain viable populations of carnivores and animal movement over time, but these characteristics are fundamental for species conservation as they prevent the extinction of isolated animal populations. Therefore, the need to maintain connectivity for these species in human-dominated Atlantic landscapes is critical. In this study, we evaluated the landscape connectivity for large carnivores (cougar and jaguar) among the Strictly Protected Areas in the Atlantic Forest, evaluated the efficiency of the Mosaics of Protected Areas linked to land uses in promoting landscape connectivity, identified the critical habitat connections, and predicted the landscape connectivity status under the implementation of legislation for protecting riparian forests. The method was based on expert opinion translated into land use and land cover maps. The results show that the Protected Areas are still connected by a narrow band of landscape that is permeable to both species and that the Mosaics of Protected Areas increase the amount of protected area but fail to increase the connectivity between the forested mountain ranges (Serra do Mar and Serra da Mantiqueira). Riparian forests greatly increase connectivity, more than tripling the cougars' priority areas. We note that the selection of Brazilian protected areas still fails to create connectivity among the legally protected forest remnants. We recommend the immediate protection of the priority areas identified that would increase the structural landscape connectivity for these large carnivores, especially paths in the SE/NW direction between the two mountain ranges.


Asunto(s)
Migración Animal , Conservación de los Recursos Naturales/métodos , Ecosistema , Bosques , Panthera/crecimiento & desarrollo , Puma/crecimiento & desarrollo , Animales , Brasil , Humanos
5.
Appl Plant Sci ; 3(2)2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25699216

RESUMEN

UNLABELLED: • PREMISE OF THE STUDY: We developed and validated microsatellite primers for Vellozia squamata (Velloziaceae), an endemic species of the cerrado (Brazilian savannas), to investigate the influence of different fire regimes on its genetic diversity and population structure. • METHODS AND RESULTS: Using a selective hybridization method, we tested 51 SSR loci using a natural population of V. squamata and obtained 47 amplifiable loci. Among these, 26 loci were polymorphic and the average values of genetic diversity were: average number of alleles per locus ([Formula: see text]) = 6.54, average number of alleles per polymorphic locus ([Formula: see text]) = 7.13, average observed heterozygosity [Formula: see text] = 0.22, average expected heterozygosity [Formula: see text] = 0.49, and average fixation index [Formula: see text] = 0.55. • CONCLUSIONS: These 26 loci allowed us to assess the effects of distinct fire regimes on the genetic structure of V. squamata populations with the aim of establishing strategies for the conservation of this endemic species. The markers can also be useful for future pharmaceutical studies, as the species has great potential for medicinal and cosmetic applications.

7.
Comp Biochem Physiol A Mol Integr Physiol ; 147(3): 586-593, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17321770

RESUMEN

Brazil stood out as the country with the highest number of submissions to the editorial project dedicated to Latin America by the journal Comparative Biochemistry and Physiology. Therefore, we felt that it was important to critically discuss the state of comparative biochemistry and physiology in this country. Our study is based on data collected from the ISI Web-of-Science. We analyzed publication trends through time, availability of novel approaches and techniques, patterns of collaboration among different geographical regions, patterns of collaboration with researchers abroad, and relative efforts dedicated to the study of biochemical and physiological adaptation of native fauna representing different terrestrial Brazilian biomes. Overall, our data shows that comparative biochemistry and physiology is a lively and productive discipline, but that some biases limit the scope of the field in Brazil. Some important limitations are the very heterogeneous distribution of research nuclei throughout the country and the absence of some important approaches, such as remote sensing and the use of molecular biology techniques in a comparative or evolutionary context. We also noticed that international collaboration far surpasses interregional collaboration, and discuss the possible causes and consequences of this situation. Finally, we found that Brazilian comparative biochemistry and physiology is biome-biased, as the Amazonian fauna has received far more attention than the whole pool of fauna representing other terrestrial biomes. We discuss the possible causes of these biases, and propose some directions that may contribute to invigorate the field in the country.


Asunto(s)
Bioquímica , Fisiología Comparada , Animales , Fenómenos Bioquímicos , Brasil , Conducta Cooperativa , Geografía , Cooperación Internacional , Edición
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