Applying a participatory methodology to evaluate ecosystem services in the Pampa biome: lessons learned from the Tessa methodology in Uruguay

Identifying and measuring ecosystem services involving local stakeholders has been characterised as a novel approach in the literature. This article describes the methodology used in the participatory workshops, the lessons learned, and the specific results of applying the Tessa method. The methodology was piloted with 56 researchers and technicians, more than 22 institutions, and 54 livestock producers involved with the grassland conservation initiative, Alianza del Pastizal. Identified change agents with the most significant impact include the absence of a rural workforce, the lack of family succession, and weeding and overgrazing of grasslands. The primary ecosystem services identified included the production of fodder, meat/wool, wildlife forage, way of life/culture, and medicinal plants. The methodology presented here is replicable, capable of expansion to more groups, contributes to a better understanding, by the producers, of their problems and points to the need for the development of public incentive policies.

Patterns and Controls of the Latent and Sensible Heat Fluxes in the Brazilian Pampa Biome

Energy and water exchange between the surface and the atmosphere are important drivers to Earth’s climate from local to global scale. In this study, the energy dynamic and the biophysical mechanisms that control the energy partitioning over a natural grassland pasture over the Brazilian Pampa biome are investigated using two micrometeorological sites located 300 km apart, in Southern Brazil. The latent heat flux, LE, was the main component of the energy balance in both autumn-winter (AW) and spring-summer (SS) periods. Annually, approximately 60% of the available energy is used for evapotranspiration (ET). However, the Bowen ratio presents seasonal variability greater in AW than SS. Global radiation, Rg, is the atmospheric variable controlling LE and sensible heat flux, H. Hysteresis curves in the daily cycle were observed for ET and surface conductance, Cs, regarding the environmental variables, net radiation, vapor pressure deficit, and air temperature. Among the variables analyzed in the Pampa biome, surface conductance and evapotranspiration respond more strongly to the vapor pressure deficit. The hysteresis cycles formed by ET and conductance show a substantial biophysical control in the ET process. The results obtained here allowed a comprehension of the biophysical mechanisms involved in the energy partition process in natural grassland. Therefore, this study can be used as a base for research on land-use changes in this unique ecosystem of the Pampa biome.

Sustainability of Livestock Systems in the Pampa Biome of Brazil: An Analysis Highlighting the Rangeland Dilemma

The objective of this study was to analyse the sustainability of different livestock systems in the Brazilian Pampa biome, from the perspective of the rangeland dilemma. We used the indicator-based framework for evaluating the sustainability of natural resource management systems (MESMIS). These were constructed for social, economic and environmental dimensions, and they were measured across a study suite of 115 establishments, representing the rangeland livestock system (RLS), intensive livestock system, and livestock–agricultural system (ALS). Indicator averages were compared between three systems via ANOVA and Tukey test. The results allocated a higher level of sustainability to RLS. When the three land-use systems were analysed across the dimensions, significant differences were found in their environmental sustainability, with the ALS presenting poorer results. Within each dimension, there were significant differences in the indicators for production systems, social participation and capital flow. We discussed two main points: the results found through the concept of the rangeland dilemma, by exploring its conditions, in addition to exposing the concept of functional integrity. In conclusion, an approach to develop policies for the Pampa is to recognize the rangeland as a “common good”, to generate income and stimulate the local economy.

Semiaquatic bugs (Hemiptera, Heteroptera, Gerromorpha) from Rio Grande do Sul, southern Brazil

Rio Grande do Sul (RS) is the southernmost state in Brazil and includes areas within the Pampa and Atlantic Forest biomes. The semiaquatic bugs (Hemiptera, Heteroptera, Gerromorpha) from RS are poorly known, with only 14 previously recorded species. We carried out two expeditions in this state, in 2002 and 2019, across 19 municipalities. Here, we provide new records for 19 species, of which 13 are recorded for the first time from the state, five have their distributions expanded, and one is recorded again from a same locality previously reported in the literature. Furthermore, 13 species were collected for the first time in the Pampa biome and one in the Atlantic Forest.

Potential Phytoremediation of Pampa Biome Native And Invasive Grass Species Cohabiting Vineyards Contaminated With Cu In Southern Brazil

The aims of the present study are to evaluate whether the growth of Pampa biome native grass species Axonopus affinis, Paspalum notatum and Paspalum plicatulum, as well as of invasive grass species Cynodon dactylon, is compromised by excessive Cu availability in the soil (0, 35 and 70 mg of Cu kg-1), to determine the impact of excessive Cu on the physiological responses of the investigated species and to assess whether these species have the potential to enable the phytoremediation of soils contaminated with Cu. C. dactylon presented the best performance in soil contaminated with 35 mg of Cu kg-1. In C. dactylon, the concentrations of chlorophyll b and carotenoids increased, as did the photosynthetic rate and plant growth. Phytotoxic effects of Cu in soil contaminated with 70 mg of Cu kg-1 were more severe on A. affinis and led to plant death. The other species presented reduced photosynthetic and growth rates, as well as increased activity of antioxidant enzymes such as SOD and POD. This very same Cu level has decreased photosynthetic pigment concentrations in P. notatum and P. plicatulum. On the other hand, it did not change chlorophyll a and b concentrations in C. dactylon and increased carotenoid concentrations in it. High values recorded for Cu bioaccumulation-in-grass-root factor, mainly in P. plicatulum, have indicated that the investigated plants are potential phytostabilizers. High C. dactylon biomass production - in comparison to other species - compensates for the relatively low metal concentration in its tissues by increasing metal extraction from the soil. This makes C. dactylon more efficient in the phytoremediation process than other species.

Adequacy of methodologies for determining SCS / CN in a watershed with characteristics of the Pampa biome

The Soil Conservation Service Curve Number Model is a conceptual model intended for estimating effective rainfall (ER). This model is grounded in a parameter – referred to as Curve Number (CN), which is determined from information on the characteristics of the watershed. The Standard Method (M1) for determining the CN is based on soil and land-use tables; however, some authors have proposed alternative methodologies for defining the CN value from monitored rainfall-runoff events, such as those described by Hawkins (1993) (M2), Soulis and Valiantzas (2012) (M3), and Soulis and Valiantzas (2013) (M4). The objective of this study was to evaluate the impact of using these methods for determination of the CN parameter on the estimation of ER, taking as reference forty rainfall-runoff events monitored between 2015 and 2018 in the Cadeia River Watershed, which has characteristics of the Pampa biome. The different methods assessed for definition of the CN parameter resulted in contrasting performances with respect to the estimation of ER for CRW, as the following findings: i) M1 gave ER values with little reliability, mainly due to the classification of antecedent moisture content classes; ii) M3 provided the best results in determining ER, followed by M2; and iii) the ER values estimated according to M4 differed from those observed, mainly for events with lower rainfall depths.