Tree diversity and above-ground biomass in the South America Cerrado biome and their conservation implications

Less than half of the original two million square kilometers of the Cerrado vegetation remains standing, and there are still many uncertainties as to how to conserve and prioritize remaining areas effectively. A key limitation is the continuing lack of geographically-extensive evaluation of ecosystem-level properties across the biome. Here we sought to address this gap by comparing the woody vegetation of the typical cerrado of the Cerrado–Amazonia Transition with that of the core area of the Cerrado in terms of both tree diversity and vegetation biomass. We used 21 one-hectare plots in the transition and 18 in the core to compare key structural parameters (tree height, basal area, and above-ground biomass), and diversity metrics between the regions. We also evaluated the effects of temperature and precipitation on biomass, as well as explored the species diversity versus biomass relationship. We found, for the first time, both that the typical cerrado at the transition holds substantially more biomass than at the core, and that higher temperature and greater precipitation can explain this difference. By contrast, plot-level alpha diversity was almost identical in the two regions. Finally, contrary to some theoretical expectations, we found no positive relationship between species diversity and biomass for the Cerrado woody vegetation. This has implications for the development of effective conservation measures, given that areas with high biomass and importance for the compensation of greenhouse gas emissions are often not those with the greatest diversity

Evaluation of phenolics and cysteine sulfoxides in local onion and shallot germplasm from Italy and Ukraine

Onions (Allium cepa L.) are the most important Allium vegetables whose increasing popu- larity is related to their pungent taste and richness in non-nutrient bioactive compounds. Many diverse local types are present and valued in several areas, although still poorly characterized. In the present study, fresh edible parts from Italian and Ukrainian bulb onion, potato onion, and shallot populations were analyzed for their phenolic and cysteine sulfoxide content and antioxidant capacity. Fifteen phenolic compounds, belonging to flavonols and anthocyanins, and two cysteine sulfoxides, methiin and isoalliin, were quan- tified. Total phenolics and cysteine sulfoxides were in the range 2595\u20139840 and 6777\u201318,916 mg kg-1 d.m., respectively. On average, potato onion phenolic con- tent was 55 and 59 % higher than in bulb onion and shallot accessions, respectively. Bulb and potato onions showed a similar cysteine sulfoxide content, whereas in shallots sulfoxide level was about 17 % lower. Flavonols were related to antioxidant capacity in both low and high anthocyanin types; however anthocyanins gave a prominent contribution to total antioxidant capacity in red onions. Quantitative vari- ations of some components allowed a clear discrimi- nation among the three groups of onions, highlighting the possibility of selection for both low or high content of specific components