Physicochemical characterization of quartzitic degraded soils and adjacent areas of rupestrian fields, Serra do Cipó, MG, Brazil

Apesar de obras rodoviárias serem importante fonte de degradação de solos e paisagens, existem poucos estudos de restauração destes ambientes. Processos erosivos causados por estas ações acabam por comprometer a regeneração natural e a capacidade do solo em armazenar carbono e água, bem como sua resiliência frente a precipitações intensas. O impacto sobre a segurança de comunidades urbanas e sobreo ecoturismo é significativo. Além disso, a falta de conhecimento básico sobre solos e a qualidade de sua cobertura acaba por tornar limitante a qualidade de processosde recuperação. Este trabalho teve como objetivo a comparação das características físico-químicas dos solos das áreas degradadas pelas obras de implantação da rodovia MG-010 com os solos da vegetação preservada no entorno. Esta rodovia corta áreas de campo rupestre na Área de Proteção Ambiental Morro da Pedreira, adjacente ao Parque Nacional Serra do Cipó. Foram feitas análises físico-químicas em amostras de solo coletadas em seis áreas degradadas e suas respectivas áreas adjacentes preservadas. Os solos nas áreas degradadas diferiram significativamente das áreas adjacentes em quase todos os atributos químicos e físicos avaliados. Com exceção do pH e do teor de alumínio, as áreas degradadas mostraram-se significativamente menos férteis que as áreas adjacentes de campo rupestre. Não foi observado nenhum tipo de regeneração substancial da vegetação local mesmo após décadas de retirada do solo superficial, sugerindo que a qualidade física e química destes solos tenha sido o principal fator que impediu sua regeneração. Tal fato indica que os campos rupestres sejam ambientes extremamente frágeis e de baixa resiliência, demandando estratégias de restauração ecológica condizentes com suas peculiaridades bióticas e abióticas.Palavras-chave: Cadeia do Espinhaço, conservação, fertilidade do solo, obras rodoviárias.While road works are an important source of soil and landscape degradation, there are few studies on restoration of these environments. Erosive processes caused by these actions end up compromising the natural regeneration, the ability to store carbon and water in soil, decreasing its resilience in the face of intense rainfall. The impact on thes afety of urban communities and ecotourism is significant. Furthermore, the lack of basic knowledge about soils and the quality of the land cover eventually become a limiting factor for land reclamation. This study aimed to compare the physical and chemical properties of degraded soils with the soils of preserved adjacent areas, along the MG-010 highway. This highway cuts through areas of rupestrian fields in the Environmental Prorecuperatection Area Morro da Pedreira, next to Serra do Cipó National Park. Physicochemical analyses were made on soil samples collected in six degraded areas and their adjacent preserved areas. The soils in degraded areas differed significantly from adjacent areas in almost all chemical and physical attributes evaluated. With exception of pH and aluminium content, the degraded areas had lower soil fertility than the adjacent areas of rupestrian fields. We did not observed any substantial regeneration of local vegetationeven after decades of topsoil being removed suggesting that the physical and chemical quality of these soils were the major factors that prevented their regeneration. This fact indicates that the rupestrian fields are extremely fragile environments with low resilience, requiring special strategies for ecological restoration in order to keep its biotic and abiotic peculiarities.Key words: Conservation, Espinhaço Range, highway works, soil fertilit

Acute Exposure to Two Biocides Causes Morphological and Molecular Changes in the Gill Ciliary Epithelium of the Invasive Golden Mussel Limnoperna fortunei (Dunker, 1857)

Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L−1) and NaDCC (1.5 mg L−1) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time