Identificação do potencial de espécies campestres nativas para uso na recuperação de áreas degradadas via semeadura direta nos Campos Sulinos

Os Campos Sulinos são formações campestres cuja conservação está ameaçada pela crescente conversão de áreas e por invasão de espécies exóticas. Dentre as invasoras, destaca-se a gramínea cespitosa Eragrostis plana, com alta produção e viabilidade de sementes. Entretanto, ainda são poucos os estudos sobre restauração ecológica nestes ecossistemas. Este estudo objetivou avaliar o potencial de espécies campestres nativas quanto à germinação e estabelecimento inicial em competição com E. plana, visando o uso em projetos de restauração. Foram utilizadas seis espécies nativas (Aristida laevis, Aristida jubata, Paspalum plicatulum, Panicum olyroides, Anthaenantia lanata, Chamaecrista repens) para o experimento com semeadura direta. Cada espécie foi colocada isoladamente em vasos contendo 20 sementes, e em vasos acompanhadas da exótica E. plana (10 sementes de cada), com cinco réplicas por tratamento. Os vasos ficaram em casa de vegetação por 3 meses. Taxa de germinação, taxa de sobrevivência, índice da taxa de germinação (GRI) e biomassa foliar e radicular por indivíduo de cada espécie e a biomassa de E. plana isolada (controle) e com cada espécie nativa foram analisados com ANOVA e GLM. As espécies A. laevis e A. jubata tiveram maior taxa de germinação (0,9±0,09 e 0,76±0,06) e alto GRI, porém baixa sobrevivência (0,37±0,08 e 0,52±0,18). As menores taxas de germinação foram para P. olyroides (0,17±0,16) e C. repens (0,24±0,13). A. lanata obteve GRI, taxa de germinação (0,77±0,12) e sobrevivência (0,66±0,114) medianos. P. plicatulum teve alta sobrevivência (0,91±0,09), com GRI e germinação (0,67±0,16) medianos. Esses dados evidenciam a importância de considerar a sobrevivência para avaliar o potencial uso em restauração. Quanto à biomassa, P. plicatulum teve os maiores valores, similares à E. plana, enquanto as demais espécies tiveram valores muito baixos. Nenhuma espécie nativa afetou a biomassa de E. plana, porém P. plicatulum se mostrou a espécie com maior potencial para competir com a invasora

Pesticide Pollution in the Brazilian Pampa: Detrimental Impacts on Ecosystems and Human Health in a Neglected Biome

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

Studies on diversity and evolution of Iridaceae species in southern Brazil

Plants of the family Iridaceae are well represented in the grassland vegetation of southern Brazil, occurring in the Pampa and Atlantic Forest biomes. Nevertheless, little is known about the taxonomy and evolution of Iridaceae species in southern Brazil. The main goal of this review is to compile published information about South American Iridaceae, and to discuss the evolution and genetic diversity of the family presenting our own research data in the light of the published literature. The main focus is on the genera Calydorea, Cypella, Herbertia, and Sisyrinchium. Aspects of reproductive system and of pollinator attraction are also discussed

Distinct extended amygdala circuits for divergent motivational states

The comorbidity of anxiety and dysfunctional reward processing in illnesses such as addiction(1) and depression(2) suggests that common neural circuitry contributes to these disparate neuropsychiatric symptoms. The extended amygdala, including the bed nucleus of the stria terminalis (BNST), modulates fear and anxiety(3,4), but also projects to the ventral tegmental area (VTA) (5,6), a region implicated in reward and aversion(7–13), thus providing a candidate neural substrate for integrating diverse emotional states. However, the precise functional connectivity between distinct BNST projection neurons and their postsynaptic targets in the VTA, as well as the role of this circuit in controlling motivational states have not been described. Here, we recorded and manipulated the activity of genetically and neurochemically identified VTA-projecting BNST neurons in freely behaving mice. Collectively, aversive stimuli exposure produced heterogeneous firing patterns in VTA-projecting BNST neurons. In contrast, in vivo optically-identified glutamatergic projection neurons displayed a net enhancement of activity to aversive stimuli, whereas the firing rate of identified GABAergic projection neurons was suppressed. Channelrhodopsin-2 (ChR2) assisted circuit mapping revealed that both BNST glutamatergic and GABAergic projections preferentially innervate postsynaptic non-dopaminergic VTA neurons, thus providing a mechanistic framework for in vivo circuit perturbations. In vivo photostimulation of BNST glutamatergic projections resulted in aversive and anxiogenic behavioral phenotypes. In contrast, activation of BNST GABAergic projections produced rewarding and anxiolytic phenotypes, which were also recapitulated by direct inhibition of VTA GABAergic neurons. These data demonstrate that functionally opposing BNST to VTA circuits regulate rewarding and aversive motivational states and may serve as a critical circuit node for bidirectionally normalizing maladaptive behaviors