Could bovine livestock intensification in Pantanal be neutral regarding enteric methane emissions?

Bovine livestock is a major anthropogenic greenhouse gas source via enteric methane. Brazilian bovine livestock is also responsible for emissions from land-use changes. In contrast, enteric emissions from extensive cattle systems in wetlands might have been overestimated. We provide scientific evidences that the human footprint of bovine products delivered by the Pantanal can be much lower. To assess this, a historical cloud-free imagery of the Landsat-5, spanning 26 years, were processed for mapping spatiotemporal landscapes in a Pantanal farm under cattle intensification studies. Eight landscape categories were identified according to spatiotemporal dynamics of interannual floods. The spatiotemporal map allowed in the field the adoption of stratified random samplings of chamber gas fluxes. The combination of stratified sampled landscapes with Monte Carlo simulations of measured methane emissions in wet and dry soils permitted to integrate landscapes emissions at annual basis with biased uncertainties. Assuming enteric emissions obtained for the Pantanal region, our results suggest that the landscapes methane emissions are 10- to 23-fold superior than the enteric emissions of traditional bovine systems. While enteric emissions seem negligible with respect to net farmland emissions, cattle livestock provide important environmental services like carbon recycling through non-competing herbivory. Moreover, cattle might be making use of a biomass that would undergo decomposition during the flooding phase. Our analysis thus indicate that enteric emissions from traditional bovine systems in flooding farmlands could be considered neutral. By contrast, intensification to improve the stocking rate should be accounted as net anthropogenic emissions. A case study of intensification allowed an increase of 48% in the stocking rate, which is associated with net anthropogenic emissions from 534 bovine animals or about 27 to 63 Mg of enteric CH4 per year. In short, the competition between traditional and distinct levels of cattle intensification will result from a trade-off between public policies and strategic market niches (organic, sustainable) for the optimal landscape management of the Pantanal.

Chave de identificação de espécies lenhosas de um trecho de Floresta Ombrófila Densa Atlântica, no Sudeste do Brasil, baseada em caracteres vegetativos / Identification key for woody species of an Atlantic Rain Forest remnant, in the Southeast of Brazil, based on vegetative characters

O presente trabalho objetivou a elaboração de uma chave de identificação para 185 espécies ocorrentes em um trecho de Floresta Ombrófila Densa no município de Cananéia, Sul do Estado de São Paulo (24° 54' S e 47° 56' O). A chave é baseada em caracteres morfológicos tais como filotaxia, composição e formato do limbo, estípulas, indumento, exsudados, estruturas secretoras internas e externas e pontuações. Foram feitas imagens de ramos, estruturas reprodutivas e de algumas estruturas vegetativas de 123 espécies de modo a auxiliar na identificação das mesmas. A maioria das espécies (84 por cento) foi facilmente separada na chave e somente algumas apresentaram dificuldades para serem distinguidas, sendo necessária, nesses casos, a utilização de caracteres reprodutivos.

Our main objective was to elaborate an identification key for 185 woody species from an Atlantic Rain Forest fragment in Cananéia, in the South of São Paulo State (24° 54' S and 47° 56' W). The key is based on morphological characters such as phyllotaxis, leaf type and shape, stipules, indument, exsudates, and glands. Images of branches, details of the reproductive and vegetative structures of 123 species were acquired to support the species identification. Most of the species (84 percent) can be easily separated in the key based on vegetative characters. For the other species, reproductive characters must be also considered.