Résumé
Objective:To systematically evaluate the safety of heavy metals in Dendrobii Officinalis Caulis and its rhizosphere soil and bedrock in epiphytic culture imitated wild rock fissure. The distribution characteristics of heavy metals in carbonate-black limestone-Dendrobii Officinalis Caulis system in the study area were analyzed. Method:Samples of biennial Dendrobii Officinalis Caulis， black calcareous soil and carbonate rocks were collected from fracture-epiphytic culture in karst area of Guizhou province. The contents of Cu， Pb， As， Cd in Dendrobii Officinalis Caulis， and Cu， Pb， As， Cd， Cr in soil and bedrock were determined by inductively coupled plasma-mass spectrometry （ICP-MS）. The detection conditions were as follows：plasma power of 1 550 W， feedback power of 2 W， sampling depth of 9 mm， atomization chamber temperature at 2 ℃， analysis mode of full quantitative， and double charge of <1.5%. Hg content in Dendrobii Officinalis Caulis was determined by atomic fluorescence spectrometry， and Hg content in soil and bedrock was determined by mercury analyzer. SPSS 26.0 software was used to analyze the test data. Result:The contents of Cu， Pb， As， Cd and Hg in Dendrobii Officinalis Caulis were all within the safety threshold. The contents of Pb， As， Cd， Hg and Cr in black calcareous soil were higher than the corresponding background values of Chinese soil （<italic>P</italic><0.05， <italic>P</italic><0.01）， Cd in black calcareous soil was slightly polluted， while Cr， Cu， As， Pb and Hg were clean. The contents of Cu， As， Pb， Cd， Hg and Cr in carbonate rocks were significantly lower than those in black calcareous soil （<italic>P</italic><0.01）. The order of heavy metals in black calcareous soil affected by parent rock was Hg>Cd>Cu>As>Cr>Pb. The bioconcentration factor （BCF） of heavy metals in Dendrobii Officinalis Caulis was in the order of Cu>Cd>Pb=Hg>As， but the BCFs of these five heavy metals were all low （all <10%）. The contents of Cu， Pb， Cd and Hg in Dendrobii Officinalis Caulis increased slightly with the increase of heavy metal content in the rhizosphere soil， while the content of As decreased with the increase of As content in the rhizosphere soil. In addition to Cu content in Dendrobii Officinalis Caulis， the migration characteristics of Pb， As， Cd and Hg in the system of carbonate-black limestone-Dendrobii Officinalis Caulis showed consistency. Conclusion:The distribution characteristics of heavy metals in geotechnical plant system in the study area show obvious inheritance. The characteristics of high content， low activity and low pollution risk of heavy metals in black limestone soil and low BCF are the main factors affecting the safety threshold of five heavy metals in Dendrobii Officinalis Caulis.
Résumé
We present herein a synthesis of faunistic data from caves in the Serra da Bodoquena karst area, middle Paraguay River basin, Mato Grosso do Sul State. Those include phreatic, submerged and dry caves. Emphasis is given to troglobites (exclusively subterranean species), potentially threatened due to their morphological, physiological and behavioral specializations, associated to generally small distributions. The Bodoquena karst area distinguishes as a spot of high diversity of troglobites, such as trichomycterid and heptapterid catfishes, aquatic planarians and gastropods, arachnids (Eusarcus opilionids, ctenid spiders), Polydesmida diplopods, several collembolans, some insects, and Peracarida crustaceans, which include interesting phylogenetic relicts as spelaeogriphaceans. Four geographic compartments corresponding to microbasins, seemingly with biogeographic importance for the subterranean fauna, are recognized. Phreatobic troglobites (Trichomycterus catfishes, aquatic peracarids, planarians) distribute widely across these compartments and some well beyond (the spelaeogriphacean Potiicoara brasiliensis reaches Mato Grosso state), while those living in base-level streams (Rhamdia and Ancistrus catfishes) and the terrestrial ones, that live in the vadose (aerated zone) are generally restricted to one compartment. Many subterranean ecosystems in Mato Grosso do Sul are endangered by several threats described here and urgent actions for effective protection are required to guarantee a sustainable use of the land and the karst aquifers.
Neste trabalho, são reunidos dados faunísticos sobre os táxons registrados em cavernas, freáticas, submersas e secas, da área cárstica da Serra da Bodoquena, na bacia do médio Rio Paraguai, Estado do Mato Grosso do Sul. É dada maior ênfase ès espécies exclusivamente subterrâneas (troglóbias), potencialmente ameaçadas de extinção devido ès especializações morfológicas, fisiológicas e comportamentais, e a distribuição geralmente restrita. A Serra da Bodoquena destaca-se por sua alta diversidade de troglóbios, entre peixes siluriformes, planárias aquáticas e gastrópodes, aracnídeos (opiliões Eusarcus, aranhas Ctenidae), diplópodes Polydesmida, diversos colêmbolos e alguns insetos, e crustáceos Peracarida, que incluem destacados relictos filogenéticos, como os crustáceos Speleogriphacea e anfípodes Megagidiella. São reconhecidos quatro compartimentos de aparente relevância biogeográfica para cavernícolas, correspondendo a microbacias na área. Troglóbios freáticos (bagres Trichomycterus, crustáceos Peracarida aquáticos, planárias) apresentam distribuições amplas através desses compartimentos, atingindo áreas distantes, como o Mato Grosso no caso dos Spelaeogriphacea Potiicoara brasiliensis, enquanto as espécies aquáticas que vivem em riachos (siluriformes como Rhamdia e Ancistrus) e os terrestres em geral, que vivem na zona vadosa, descontínua, tendem a apresentar distribuições restritas aos respectivos compartimentos. Muitos ecossistemas subterrâneos do Mato Grosso do Sul estão vulneráveis ès várias ameaças descritas aqui e ações urgentes de proteção efetiva são necessárias para garantir uma utilização sustentável da terra e dos aquíferos cársticos.