Search Results (36)

Accurate taxonomy is fundamental for assessing extinction risks and implementing conservation strategies. We evaluated the extinction risk of Grindelia atlantica (Asteraceae), endemic to southern Brazil, using the IUCN criteria, and comparing three scenarios of taxonomic accuracy and data availability. Herbaria records and field surveys confirmed the historical existence of five records and currently only two remaining, isolated populations, totaling 633 individuals (513 in Pelotas and Rio Grande; 120 in Jaguarão). Habitat loss and invasive species are the primary threats. Analyses resulted in an Extent of Occurrence of 475.832 km² and an Area of Occupancy of 36 km². These findings, coupled with significant population decline, justify the classification as Critically Endangered. The results emphasize the critical role of reliable taxonomy in conservation biology. They demonstrate the impact of a few errors on extinction risk assessments, which can unfold in the misallocation of resources or insufficient protection. This is critical, particularly for endemic species like G. atlantica in the threatened Pampas, one of Brazil’s most degraded biomes and the least represented in preserves. The creation of a conservation unit is proposed as an urgent measure to ensure the survival of this species and its habitat, benefiting other endemic and rare threatened animal and plant species. Full article

Old vineyards in production in the Pampa biome have high levels of metals, such as copper (Cu), zinc (Zn), and manganese (Mn). The high metal contents in the soil can damage the growth and development of the cover plant species that cohabit the vineyards. However, it is possible to define the critical toxicity level (CTL) of metals in soil and tissue in order to monitor and define possible strategies for reducing metal inputs and selecting more tolerant species. This study aimed to define the CTL of Cu, Zn, and Mn in the soil and plant tissue of plants present between the rows of vineyards with different cultivation histories in the Pampa biome in South America. For this purpose, soil and plant tissue samples were collected in a native field area (NF), without agricultural cultivation and in two vineyards, vineyard 1 (V1) and vineyard 2 (V2), both with a history of fungicide application. To define the CTL, the foliar concentrations and soil contents of Cu, Zn, and Mn were correlated with the dry mass production of the shoot. The CTLs for Cu, Zn, and Mn in the soil were set at 15, 3.0, and 35 mg kg⁻¹, respectively. In the tissue, CTLs for Cu, Zn, and Mn were estimated at 75, 77, and 380 mg kg⁻¹, respectively. The contents of Cu, Mn, and Zn in the soil of the vineyards are above the CTL. The concentrations of the metals in the tissue varied, with samples above the CTL for Cu and Zn in the vineyards. The values of Cu, Zn, and Mn in NF are below the CTL in soil and tissue. The high contents of Cu, Zn, and Mn in the soil and tissue limited the dry mass production of the plants between the rows of vineyards. Full article

Integrated approaches such as the WEF nexus (water–energy–food) have been key to measuring the efficiency of production systems. In southern Brazil, where extensive livestock farming and integrated agricultural systems coexist in anthropized natural grasslands, such an assessment is crucial for balancing production and conservation. This research aimed to assess the sustainability of different livestock systems in Brazil’s Pampa biome from the perspective of the WEF nexus. One hundred and twenty-one systems were analyzed and divided into extensive livestock systems (ELSs) and integrated livestock systems (ILSs). The MESMIS methodology was used to construct and measure 37 WEF nexus indicators. The data were analyzed using a raincloud diagram and compared using Student’s t-test. In terms of water, the results showed that the ELS was more sustainable in terms of the scope of production. In terms of energy, the ELS stood out in the scope of the sustainability of mechanical energy use. The ILS was superior in terms of social and associative participation in the food nexus, while the ELS stood out in terms of sustainable production management. In general, in both systems, the sustainability indices for the water nexus were optimal, but the situation was alarming for the energy and food nexus. This research contributes by applying the WEF nexus to the analysis of the sustainability of livestock systems, offering a replicable model for other natural grassland regions. Full article

This study analyzed the impact of land use and cover changes, along with climate variability, on water consumption by quantifying actual evapotranspiration (${\mathrm{ET}}_{\mathrm{a}}$) in the Tres Cruces River basin (TCR) in Uruguay. Using Landsat 8 and 9 images from 2014 to 2024, the SAFER method (Simple Algorithm for Evapotranspiration Retrieving), applied for the first time in Uruguay, estimated ${\mathrm{ET}}_{\mathrm{a}}$ for natural vegetation (grasslands and riparian forests) and commercial afforestation areas. Quality metrics, including determination coefficient (r² = 0.87), Pearson correlation (r = 0.94), root mean square error (RMSE = 1.46 mm/day), and Nash–Sutcliffe efficiency (NSE = 0.34), were utilized for SAFER’s optimal parameterization based on the literature. Results revealed monthly ${\mathrm{ET}}_{\mathrm{a}}$ variability and highlighted higher ${\mathrm{ET}}_{\mathrm{a}}$ values for afforestation areas, exceeding grasslands by 26.5% and riparian forests by 4.79%, reflecting increased water demand due to greater biomass and photosynthetic activity. Additionally, prolonged drought periods correlated with increased water consumption by forest vegetation, despite the Standardized Precipitation-Evapotranspiration Index (SPEI) remaining within normal bounds during the 2020–2023 drought. These findings underscore the significant hydrological implications of converting grasslands to afforestation and the need for integrated water resource management amid expanding commercial forestry in the region. Full article

Angelonia Bonpl. (Plantaginaceae) is a neotropical genus of ornamental interest, with some Mexican species already commercialized in the horticultural trade. Angelonia integerrima Spreng. is the only species of the genus native to Southern Brazil, and, despite its high ornamental potential, its reproductive requirements are unknown. Flower features and natural pollination were studied in the field in three localities within Southern Brazil. Pollination was recorded through pictures and videos. The breeding system was studied through controlled pollinations applied to plants excluded from pollinators. Germination was studied under controlled temperatures (20°, 25°, and 30 °C). According to our results, flowers are protandrous and keep their fresh appearance for up to nine days. The flowers produce oils in a pair of trichromes located inside the corolla. The plants are pollinator-dependent and self-compatible. The sole pollinators are oil-gathering solitary bees, Centris trigonoides Lepeletier, 1841 and Centris sp. (Apidae), that pollinate the flowers while collecting the floral oils. Germination proceeds better at 25 °C, reaching success of 50%. The domestication of this plant for horticultural purposes in Southern Brazil would be desirable not only for its ornamental characters but also for ecosystemic reasons since the species is already adapted to environmental conditions and its flowers offer resources for native, solitary bees. Full article

The Amazon rainforest plays a fundamental role in regulating the global climate and therefore receives special attention when Brazilian environmental issues gain prominence on the global stage. However, other Brazilian biomes, such as the Pampa and the Atlantic Forest in southern Brazil, have been facing significant environmental challenges, either independently or under the influence of ecological changes observed in the Amazon region. The state of Rio Grande do Sul is located in the extreme south of Brazil and in 2024 was hit by major rainfalls that caused devastating floods. The Pampa is a non-forest biome found in Brazil only in Rio Grande do Sul. This biome is seriously threatened by loss of vegetation cover and many classes of pollutants, including pesticides and plastics. Mining ventures are also important sources of soil, water and air pollution by potentially toxic elements in Rio Grande do Sul, threatening both the Pampa and the Atlantic Forest. Furthermore, southern Brazil is often affected by pollution caused by smoke coming from fires observed in distant biomes such as the Pantanal and the Amazon. Considering the significant environmental challenges observed in southern Brazil, this article revisits the historical participation of Rio Grande do Sul in Brazilian environmentalism and highlights the main environmental challenges currently observed in the state, followed by an in-depth analysis of the effects of pollution and extreme weather events on biodiversity and human health in the region. This review encompassed specifically the following categories of pollutants: potentially toxic elements (e.g., arsenic, cadmium, chromium, cobalt, copper, lead, mercury, titanium), air pollutants, plastics, and pesticides. Pathogen-related pollution in the context of extreme weather events is also addressed. This article emphasizes the critical importance of often-overlooked biomes in Brazilian conservation efforts, such as the Pampa biome, while also underscoring the interconnectedness of climate change, pollution, their shared influence on human well-being and ecological balance, using Rio Grande do Sul as a case study. Full article

Our study investigated how different levels of antioxidants and contrasting proportions of native legumes in the diet affect lamb meat quality. Twenty-four male Texel lambs were randomly assigned to three groups: two groups on a natural pasture in southern Brazil (Pampa Biome), each at a different proportion of legumes: Low-legume (LL, 4.37%) and High-legume (HL, 14.01%); the other group was stall-fed (Control) to achieve the same growth rates as the grazing groups. Cold carcass yield from the Control lambs was higher than HL. The meat from pasture-fed animals had a higher deposition of muscle α-tocopherol and lower lipid oxidation (TBARS values) after 9 days of storage. LL lambs had higher subcutaneous fat thickness, which promoted better sensory quality of the meat, as assessed by a trained panel. Pasture-based diets enhanced odd- and branched-chain fatty acids (OBCFAs), trans vaccenic acid, and total conjugated linoleic acids (CLAs), while decreasing elaidic acid. Despite the lower ∆9-desaturase activity, the higher proportion of Desmodium incanum (condensed tannin-rich native legume) in the HL diet did not impact meat nutritional quality. Finishing lambs on the Pampa Biome grasslands is an option for improving the oxidative stability and beneficial fatty acid content of lamb meat, which improves product quality and human consumer health. Full article

The Dwarf Palm, Butia lallemantii Deble & Marchiori, is an endangered species endemic to the Pampa biome and typically grows in sandy and rocky soils. Given its economic, ecological, and cultural relevance, it is crucial to understand the ecology and biology of this species to encourage its preservation and highlight its significance for the Pampa. This study aims to investigate whether this palm relies on animal vectors for pollination, analyze its breeding system, and propose strategies for its conservation and sustainable use. We conducted field observations on pollination ecology, identified floral visitors, and designed six breeding system experiments to test cross-compatibility, self-compatibility, and apomixis. Additionally, we conducted a literature review to propose conservation strategies. Butia lallemantii is pollinator-dependent and self-compatible. The flowers are mostly melittophilous and offer pollen and nectar for floral visitors. The main pollinators are native Meliponinae and Halictinae bees and the introduced Apis mellifera. This study represents the first comprehensive and complete examination of the breeding system and pollination process on Butia palms. This palm can provide materials for industries, but urgent actions are needed to preserve the remaining populations through effective policies and strategies. Furthermore, this palm should be integrated into diversified agroecosystems to evaluate its adaptability to cultivation. Full article

The Brazilian Pampa biome has natural pastures that have been used for centuries for cattle grazing. This is considered a sustainable system because it combines the conservation of natural vegetation and high-quality meat production, protecting the biome from commercial agriculture’s advances. However, whether it is a source or a sink of carbon dioxide (CO₂) has yet to be evaluated. Hence, this study aimed to quantify the net ecosystem exchange (NEE) of the CO₂ of a natural pasture of the Pampa biome used for livestock production. The experimental area is located in a subtropical region of southern Brazil, where eddy covariance (EC) measurements were conducted from 2015 to 2021 in a rotational cattle grazing system. The seven months of the warm season (September to March) were characterized as CO₂ absorbers, while the five months of the cold season (April to August) were CO₂ emitters. Throughout the six years and with complete data, the ecosystem was an absorber of atmospheric CO₂, with an average value of −207.6 g C m⁻² year⁻¹. However, the significant interannual variability in NEE was observed, with cumulative values ranging from −82.0 to −385.3 g C m⁻² year⁻¹. The results suggest the coupling of climatic conditions to pasture management can be the factor that modulated the NEE interannual variability. The cattle raising system on the natural pastures of the Pampa absorbs CO₂, which is further evidence of its sustainability and need for conservation. Full article

Acca sellowiana is a subtropical tree in the myrtle family (Myrtaceae) native to southern Brazil and northeastern Uruguay. It is recognized for its value as a fruit-bearing, ornamental, and medicinal species. Based on distinctive characteristics of fruits, seeds, and leaves, as well as its geographical distribution pattern, two variants of the species are distinguished: the “Brazilian type” and the “Uruguayan type”. The objective of this study was to characterize, for the first time, the diversity of 202 individuals from four wild populations in Uruguay, representative of the species’ most southern natural distribution. Twenty-three morphological descriptors (leaf, flower, and fruit) and 204 RAPD (Random Amplified Polymorphic DNA) markers were used. The morphological data collected validated the main criteria that distinguish “Uruguayan type” populations from “Brazilian type” populations, such as lower seed weight and fruit size, thin and slightly rough skin, high pulp percentage, and hairy white abaxial leaf surfaces. Analyses of both morphological and molecular data indicated wide diversity and strong population structuring, which is relevant information for designing conservation plans, sustainable utilization, and genetic improvement of the plant genetic resources of this species. Full article

Determining the period of weed coexistence with eucalyptus stands assists in the integrated management of weed competition, which reduces the application of herbicides, economic costs, and environmental damage. Therefore, the objectives of the present study were to evaluate the impact of a hybrid stand of Eucalyptus grandis × Eucalyptus urophylla trees on biomass production, the concentration and stock of macro and micronutrients, and the efficiency of nutrient utilization under different periods of coexistence with weeds. Our study is the first to report the impacts of weed management on the biomass and nutrients present in the leaves, branches, stembark, and stemwood at the time of mid-rotation (4.5 years old). The experiment was carried out in southern Brazil in the Pampa biome and followed a randomized block design, with three replications. The treatments consisted of increasing periods of coexistence with or control of weeds. The total biomass in the coexistence up to 378 days treatment was 53.7 Mg ha⁻¹, and in the control treatment up to 168 days, it was 81.4 Mg ha⁻¹, differing statistically. This reduction was in the order of 34%. The continuous presence of weeds led to a significant reduction in the production of wood and total biomass. The highest nutrient utilization efficiency (NUE) was observed for wood. The control of weeds for up to 168 days promoted greater productivity than controlling weeds for 378 days. This recommendation can be adopted by plantation managers for this region, reducing the amount of herbicide applied on the stand. Full article

The Brazilian Pampa biome covers half of Rio Grande do Sul state, in the extreme south of Brazil, creating an ecotone zone with the Atlantic Forest and bordering Pampa’s territory belonging to Uruguay and Argentina. Pampa is a non-forest biome mainly composed of grasslands and mosaics of grassland-forest vegetation. This biome shows significant animal and plant diversity, contributing to the maintenance of important ecosystem services, including CO₂ capture, pollination, and water cycle regulation. However, forestry plantations, inappropriate cattle ranching, mining activities, unplanned urbanization, and the cultivation of monocultures (soy, rice, tobacco, and other cash crops) significantly threaten the conservation of the Pampa biome. A major problem observed in the Pampa, due to the great connection of this biome with agricultural areas, is pesticide pollution, which significantly affects the health of humans and animals that occupy the region. A robust body of evidence indicates that aquatic and terrestrial ecosystems in the Brazilian Pampa are extensively contaminated with pesticides, as indicated by studies involving animal biomarkers and pesticide analyses performed on water and soil samples. Human studies also suggest that pesticides affect different body systems, facilitating the onset of various chronic diseases. Brazil’s conservation actions and policies have a special focus on forest ecosystems, neglecting non-forest biomes and thus aggravating the problems related to Pampa’s conservation. In this article, we discuss some problems caused by pesticide pollution in the Brazilian Pampa, drawing attention to the need for intensification of policies focused on the promotion of human and environmental health. Finally, we suggest the bioecological bioeconomy as an alternative for Rio Grande do Sul to progress its economic development but with less dependency on detrimental activities to the Pampa biome. Full article

Understanding the exchange of energy between the surface and the atmosphere is important in view of the climate scenario. However, it becomes a challenging task due to a sparse network of observations. This study aims to improve the energy balance estimates for the Amazon, Cerrado, and Pampa biomes located in South America using the radiation and precipitation forcing obtained from the Clouds and the Earth’s Radiant Energy System (CERES) and the precipitation CPTEC/MERGE datasets. We employed three surface models—Noah-MP, Community Land Model (CLSM), and Integrated Biosphere Simulator (IBIS)—and conducted modeling experiments, termed South America Land Data Assimilation System (SALDAS-2). The results showed that SALDAS-2 radiation estimates had the smallest errors. Moreover, SALDAS-2 precipitation estimates were better than the Global Land Data Assimilation System (GLDAS) in the Cerrado (MBE = −0.16) and Pampa (MBE = −0.19). Noah-MP presented improvements compared with CLSM and IBIS in 100% of towers located in the Amazon. CLSM tends to overestimate the latent heat flux and underestimate the sensible heat flux in the Amazon. Noah-MP and Ensemble outperformed GLDAS in terms latent and sensible heat fluxes. The potential of SALDAS-2 should be emphasized to provide more accurate estimates of surface energy balance. Full article

Phenolic compounds are natural substances that are produced through the secondary metabolism of plants, fungi, and bacteria, in addition to being produced by chemical synthesis. These compounds have anti-inflammatory, antioxidant, and antimicrobial properties, among others. In this way, Brazil represents one of the most promising countries regarding phenolic compounds since it has a heterogeneous flora, with the presence of six distinct biomes (Cerrado, Amazon, Atlantic Forest, Caatinga, Pantanal, and Pampa). Recently, several studies have pointed to an era of antimicrobial resistance due to the unrestricted and large-scale use of antibiotics, which led to the emergence of some survival mechanisms of bacteria to these compounds. Therefore, the use of natural substances with antimicrobial action can help combat these resistant pathogens and represent a natural alternative that may be useful in animal nutrition for direct application in food and can be used in human nutrition to promote health. Therefore, this study aimed to (i) evaluate the phenolic compounds with antimicrobial properties isolated from plants present in Brazil, (ii) discuss the compounds across different classes (flavonoids, xanthones, coumarins, phenolic acids, and others), and (iii) address the structure–activity relationship of phenolic compounds that lead to antimicrobial action. Full article

Spotted fever illness caused by the tick-borne pathogen Rickettsia parkeri has emerged in the Pampa biome in southern Brazil, where the tick Amblyomma tigrinum is implicated as the main vector. Because domestic dogs are commonly parasitized by A. tigrinum, this canid is also a suitable sentinel for R. parkeri-associated spotted fever. Herein, we investigate rickettsial infection in ticks, domestic dogs and small mammals in a natural reserve of the Pampa biome in southern Brazil. The ticks A. tigrinum, Amblyomma aureolatum and Rhipicephalus sanguineus were collected from dogs. Molecular analyses of ticks did not detect R. parkeri; however, at least 34% (21/61) of the A. tigrinum ticks were infected by the non-pathogenic agent ‘Candidatus Rickettsia andeanae’. Serological analyses revealed that only 14% and 3% of 36 dogs and 34 small mammals, respectively, were exposed to rickettsial antigens. These results indicate that the study area is not endemic for R. parkeri rickettsiosis. We tabulated 10 studies that reported rickettsial infection in A. tigrinum populations from South America. There was a strong negative correlation between the infection rates by R. parkeri and ‘Candidatus R. andeanae’ in A. tigrinum populations. We propose that high infection rates by ‘Candidatus R. andeanae’ might promote the exclusion of R. parkeri from A. tigrinum populations. The mechanisms for such exclusion are yet to be elucidated. Full article