Livestock intensification and environmental sustainability: An analysis based on pasture management scenarios in the brazilian savanna.

Brazil's major beef production occurs in the Cerrado, predominantly as extensive pastures that covers ∼50 Mha of the biome, of which approximately 2/3 show signs of degradation. Pasture recovery is now a key environmental policy, as it improves land use efficiency and soil carbon sequestration. However, as intensification leads to higher cattle stocking rates and external inputs (fertilizers, liming, etc.), the impact of improved pastures on greenhouse gas mitigation is still debatable. This study focused on the Cerrado biome and aimed to (i) quantify soil carbon stock changes under different scenarios of management and recovery of degraded pastures. In addition, (ii) the potential for capturing carbon in the soil to mitigate emissions of greenhouse gases (GHG) by the intensification of pastures was evaluated. Soil C stock changes (0-20 cm) were assessed using the Century model version 4.5, which had been previously validated for the region. Model parameters were adjusted for three pastures classes (degraded, intermediately degraded, and not degraded) within a time-series (1985-2020) of land use maps for the Cerrado, serving as baselines. Scenarios of pasture intensification were modeled against these baselines, and an analysis was carried out on the estimated changes in soil C stock and greenhouse gas balance. Before the intensification scenario (year 2020), the total carbon stock was estimated to be ∼1830 Mt for the whole pasture area, whose spatial distribution corresponded to edaphoclimatic contrasts and pasture conditions. The highest soil organic carbon stocks were observed in the non-degraded pastures. With the increase in carrying capacity, beef production is estimated to potentially increase by 1/3 due to the recovery of degraded areas through intensive management. This increase would be sufficient to meet the projected ∼12% increase in Brazil's livestock production by the end of the decade if all pasture areas are restored, which is much possibly an unrealistic scenario as not all degraded areas are suitable for crops or can successfully improve pasture yield. In addition, the increase in soil C stocks was only sufficient to compensate for 27% and 42% of the GHG emissions resulting from intensification in areas with intermediate and severe degradation, respectively. Therefore, to strike a balance between economic considerations and environmental impact, additional strategies are needed to reduce GHG emissions and/or enhance C sinks, such as increasing tree density on farms. From this perspective, implementing livestock intensification at the landscape scale can promote C stocks and the diversity of ecosystem services, opening the possibility of ecosystem restoration.

Co-benefits, trade-offs, barriers and policies for greenhouse gas mitigation in the agriculture, forestry and other land use (AFOLU) sector.

The agriculture, forestry and other land use (AFOLU) sector is responsible for approximately 25% of anthropogenic GHG emissions mainly from deforestation and agricultural emissions from livestock, soil and nutrient management. Mitigation from the sector is thus extremely important in meeting emission reduction targets. The sector offers a variety of cost-competitive mitigation options with most analyses indicating a decline in emissions largely due to decreasing deforestation rates. Sustainability criteria are needed to guide development and implementation of AFOLU mitigation measures with particular focus on multifunctional systems that allow the delivery of multiple services from land. It is striking that almost all of the positive and negative impacts, opportunities and barriers are context specific, precluding generic statements about which AFOLU mitigation measures have the greatest promise at a global scale. This finding underlines the importance of considering each mitigation strategy on a case-by-case basis, systemic effects when implementing mitigation options on the national scale, and suggests that policies need to be flexible enough to allow such assessments. National and international agricultural and forest (climate) policies have the potential to alter the opportunity costs of specific land uses in ways that increase opportunities or barriers for attaining climate change mitigation goals. Policies governing practices in agriculture and in forest conservation and management need to account for both effective mitigation and adaptation and can help to orient practices in agriculture and in forestry towards global sharing of innovative technologies for the efficient use of land resources. Different policy instruments, especially economic incentives and regulatory approaches, are currently being applied however, for its successful implementation it is critical to understand how land-use decisions are made and how new social, political and economic forces in the future will influence this process.

Florística e estrutura da vegetação arbustivo-arbórea em uma área de cerrado rupestre no parque estadual da Serra de Caldas Novas, Goiás / Floristic and structure of woody vegetation of a "cerrado rupestre" area in Serra de Caldas Novas state park, Goiás

O cerrado sentido restrito é a fitofisionomia predominante do bioma Cerrado, ocupando grandes extensões do Planalto Central brasileiro. Quando essa vegetação se desenvolve sobre Neossolos Litólicos recebe a denominação de cerrado rupestre. O conhecimento sobre as comunidades arbustivo-arbóreas deste subtipo fitofisionômico do Cerrado é muito limitado. O objetivo deste estudo foi analisar a composição florística e a estrutura da vegetação arbustivo-arbórea em uma área de cerrado rupestre localizada no Parque Estadual da Serra de Caldas Novas (PESCAN), Goiás, Brasil e comparar suas características florísticas e estruturais com aquelas de outras áreas de cerrado sentido restrito localizadas no Brasil Central. Foram amostrados todos os indivíduos com diâmetro a 30 cm do solo > 5 cm, presentes em 10 parcelas aleatórias de 20 × 50 m. A riqueza florística registrada foi de 66 espécies, distribuídas em 53 gêneros e 31 famílias botânicas. A vegetação estudada tem características florísticas e estruturais semelhantes àquelas registradas em outras áreas de cerrado sentido restrito sobre solos profundos, porém, com a presença de algumas espécies típicas de cerrado rupestre, como Schwartzia adamantium (Cambess.) Gir.-Cañas e Wunderlichia mirabilis Riedel ex Baker e algumas raras para o bioma, por exemplo, Peltogyne confertiflora (Mart. ex Hayne) Benth., Myrcia canescens O. Berg e Myrcia variabilis DC. A área basal encontrada foi relativamente elevada (12,39 m².ha-1) devido à alta densidade de indivíduos (1.357 ind.ha-1), bem como a abundância de indivíduos de grande porte, de espécies como Sclerolobium paniculatum Vogel, Pterodon pubescens (Benth.) Benth., S. adamantium e P. confertiflora. Dessa forma, o substrato raso sob o cerrado rupestre do PESCAN, não limitou o desenvolvimento da vegetação arbustivo-arbórea, nem condicionou o estabelecimento de uma flora diferenciada. No entanto, a elevada importância estrutural de poucas espécies lenhosas típicas e adaptadas aos ambientes rupestres garante certa peculiaridade florística à comunidade estudada.

The cerrado stricto sensu is the predominant phytophisiognomy of the Cerrado biome, covering large areas of the Brazilian Central Plateau. When the vegetation grows on rocky soils, it is known locally as "cerrado rupestre". Our knowledge of the tree-shrub communities of this Cerrado vegetation subtype is very limited. The aim of this study was to analyze the floristic composition and structure of tree-shrub vegetation in an area of cerrado rupestre located in the Serra de Caldas Novas State Park (PESCAN), Goiás, Brazil, and to compare the floristic and structural characteristics with those from other areas of cerrado stricto sensu located in Central Brazil. We sampled all individuals with a diameter > 5 cm at 30 cm above ground level, presented in 10 randomly plots of 20 × 50 m. The floristic richness survey revealed 66 species, distributed in 53 genera and 31 botanical families. The studied vegetation had floristic and structural characteristics similar to those recorded in other areas of cerrado stricto sensu growing on deep soils, however, there were some species typically of cerrado rupestre, such as Schwartzia adamantium (Cambess.) Gir.-Cañas and Wunderlichia mirabilis Riedel ex Baker and other less abundant characteristic species for this biome, for instance, Peltogyne confertiflora (Mart. ex Hayne) Benth., Myrcia canescens O. Berg and Myrcia variabilis DC. The total basal area was relatively high (12.39 m².ha-1) due to the high density of individuals (1.357 ind.ha-1) as well as the abundance of large individuals of species such as Sclerolobium paniculatum Vogel, Pterodon pubescens (Benth.) Benth., S. adamantium and P. confertiflora. Hence, the flat soil surface of cerrado rupestre of PESCAN did not limit the growth of wood vegetation, nor conditioned the establishment of a distinguished flora. Nevertheless, the elevated structural importance of few wood species typical and adapted of rock environments guarantee some floristic peculiarity of the community survey.