Search

Current estimates predict a world population growth of 9.6 billion by the year 2050, many of whom will live in countries already facing food insecurity. To feed this population, agricultural production will have to increase by approximately 50%, a difficult situation due to the effects of climate change. In order to achieve food production goals without putting the environment at risk, FAO, since 2009, has supported member countries in their initiatives to implement Climate-Smart Agriculture (CSA) that takes into account local and national specificities and priorities, to sustainably increase productivity and resilience, strengthen food security and mitigate damage from greenhouse gases (GHG). This literature review seeks to contribute to discussions on the recognition of the CSA concept, its applicability in agricultural systems and review advantages or disadvantages to face global climate change. In Brazil, there is growing concern, due to the country's high vulnerability and low development capacity to face environmental impacts. However, despite the attractiveness of the concept, specific criteria to guide the approaches and technologies to be used have not yet been defined.

O milho é uma cultura altamente sensível às deficiências hídricas sofridas por as mudanças climáticas súbitas e inesperadas dos últimos anos. É por isso que se avaliou o efeito do potencial osmótico (PO) na germinação e crescimento de plântulas de dois híbridos de milho (BM709 e Milho Doce 159-cat S2). Um DIC foi usado com um arranjo bifatorial com 2 níveis de variedades e 6 níveis de potencial osmótico com 2 repetições. O PO: 0; -0,2; -0,4; -0,6; -0,8 e -1,0 Mpa foram usados. A tendência de ambos os híbridos foi diminuir seu potencial de crescimento tanto na raiz quanto no nível da parte aérea em -0,4 MPa. Apesar de observar graficamente uma menor capacidade de resposta da variedade 1 v.s. da variedade 2, não foram encontradas diferenças significativas quando elas foram comparadas as duas variedades versus os potenciais osmóticos, porém, apresentam-se diferenças significativas na capacidade germinativa de cada uma.

Many recent amphibian declines have been associated with chytridiomycosis, a cutaneous disease caused by the chytrid fungus Batrachochytrium dendrobatidis , but increasing evidence suggests that this pathogen may coexist with some species without causing declines. In the Venezuelan Andes, the disappearance of three anuran species during the late eighties was attributed to B. dendrobatidis. Recently, this pathogen was found to be prevalent in this region on the introduced American bullfrog, Lithobates catesbeianus. As a first step toward assessing the risk of amphibian communities to B. dendrobatidis in this region, we conducted a broad survey across multiple habitat types and an altitudinal gradient spanning over 2000 m. We diagnosed 649 frogs from 17 species using real time and conventional PCR assays, and recorded relevant abiotic characteristics of host habitats. Infection was detected in 10 native species of pond, stream and terrestrial habitats from 80–2600 m, representing nine new host records. L. catesbeianus was the most important reservoir with 79.9% of individuals infected and an average of 2299 zoospores. Among native frogs, Dendropsophus meridensis, an endangered species sympatric with L. catesbeianus, showed the highest infection prevalence and mean zoospore load (26.7%; 2749 zoospores). We did not detect clinical signs of disease in infected hosts; however, species such as D. meridensis may be at risk if environmental stress exacerbates vulnerability or pathogen loads. While surveillance is an effective strategy to identify highly exposed species and habitats, we need to understand species-specific responses to B. dendrobatidis to stratify risk in amphibian communities.