Agroforestry systems (AFS) are policultures with at least one tree species. These systems provide various ecosystem services, income increments and food safety. These ecosystem services include biodiversity conservation, carbon sequestration, reduction of crop diseases, increased biological controls, biological nitrogen fixation and nutrient cycling. A review of potential ecosystem services of AFS on Southern Brazil is presented. In addition, the potential of carbon uptake through conversion to AFS is estimated. The predominant AFS are agroforestry with yerba mate (Ilex paraguariensis A. St. Hil.), silvopastures, citrus and banana orchards, and the palm açaí-juçara (Euterpe edulis Mart.). Considering the conversion of conventional systems to AFS, the silvopastures present the greatest carbon sequestration potentiality due to the great area used for cattle ranching. The conversion of citrus and banana cropping also present great carbon uptake potential besides reducing fungal and bacterial diseases. Southern Brazil presents more than 15 million hectares which could be converted into silvopasture and other AFS by taking as a model the already well-established experiences. Moreover, AFS has become a strategy for forest restoration. There are no negative trade-offs related to the silvopasture and citrus agroforestry adoption. The reasons for the low adoption of AFS are discussed.

Mate (Ilex paraguariensis A. St. Hil.) is a raw material used to prepare popular beverages in South America, whose healthy effects have been pointed out. The leaves and stems of mate contain a complex assemblage of saponins, mainly ursolic acid and oleanolic acid glycosides, and their quantification presents difficulties such as weak cromophorous sites and interference of other compounds. On the other hand, the sugar moieties are a chief character that distinguishes them. We developed and validated a high-performance liquid chromatography method using a refractometer detector for quantifying the major saponins in extractive solution of mate leaves. The validation indicates the suitability of the method, presenting linearity in the concentration range between 102.5 to 854.0 microg/mL to matesaponin 1 and between 103.0 to 515.0 microg/mL to matesaponin 3. The repeatability coefficient of variation was 4.70% and 6.61% for matesaponin 1 and matesaponin 3, respectively. The inter-day coefficient of variation was 6.77% and 7.79% for matesaponin 1 and matesaponin 3, respectively. The analysis of plants from Brazilian States Mato Grosso do Sul and Rio Grande do Sul showed the predominance of matesaponins 1, 2, and 3 in the corresponding extractive solution. The sum of these three saponins ranged between 3 and 10 mg/g for mature leaves in the majority of sampled plants.

Maté (Ilex paraguariensis A. St.-Hil.) is a native plant from southern Brazil and a raw material for beverages. To research on population variability of the species, we compared leaf morphology of three populations from Mato Grosso do Sul (MS), Paraná (PR) and Santa Catarina (SC) States. Lamina measurements included area (A), perimeter (P), length (l), maximum width (w), distance between maximum width and lamina base (dw), base angle (BÂ), biomass (m), and the indexes: relative distance of maximum width (dw/l), ratio length/width (l/w), relative perimeter (RP= P / (l + w), rectangular area index (RAI = A / (l x w)) and leaf mass/area (m/A). We verified differences among populations on A (MS<PR=SC), l (MSPR, MS=SC, PR=SC). The lowest RAI of SC could be explained, at least partially, by a positive correlation between RAI and BÂ (r= 0.6043, p<0.01).