Considering the need to produce effective bioherbicides to control weeds and thus reduce the contamination of environments through the use of agrochemicals in control of these plants, the scientific community has been studying the allelopathic activity of several species of Caatinga, once studies indicate that some species of this biome presentind to have activity allelopathic about other plants. On this, the present study aimed to evaluate the allelopathic potential and phenolic composition of extracts of Libidibia ferrea Mart. ex Tul. on seed germination and seedling development of Calotropis procera (Aiton) WT Aiton. and Cenchrus echinatus L. For the allelopathy test, leaf, bark and root extracts, both hot (100 °C) and cold (25 °C), were used, followed by a control group (distilled H2O). Phytochemical prospecting was performed by High Performance Liquid Chromatography (HPLC). The results showed that the hot L. ferrea bark extract has allelopathic activity on C. procera and C. echinatus, which was observed in all parameters analyzed. The phytochemical results showed that L. ferrea extracts present several phenolic compounds which are possibly responsible for the results observed against the two weed species studied, with standing out Gallic acid, Catechin, Caffeic acid, Ellagic acid, and Quercetin. It is therefore necessary to isolate these compounds in view of a potential future use for L. ferrea extracts in the production of a bioherbicide.

No abstract

Cereus jamacaru DC subsp. jamacaru, has been suffering from severe anthropic pressure, in addition, when their seeds are dispersed, some end up not germinating due to the action of allelochemicals. Therefore, the present study was to evaluate the allelopathic effect of the essential oil (EO) from four species over C. jamacaru germination, as well as to identify their constituents. Four plants were selected for EO extraction (Mesospherum suaveolens (L.) Kuntze, Lantana montevidensis (Spreng.) Briq., Lantana camara L., and Tarenaya spinosa (Jacq.) Raf.) and the chemical analysis was performed by GC-MS. In order to evaluate the allelopathic activity of the EO's, the C. jamacaru seeds were treated with the EO's. The results showed that the EO's presented heterogeneity in their composition, with M. suaveolens presenting the highest number of constituents (44), followed by L. camara (26), T. spinosa (23) and L. montevidensis (22). All the oils negatively affected the C. jamacaru germination percentage in a concentration-dependent manner. Regarding the GVI, the M. suaveolens, L. montevidensis and L. camara OEs significantly decreased this index at all analyzed concentrations. Based on the results obtained, it is suggested that C. jamacaru should not be sown close to the aforementioned aromatic species in reforestation programs.

Through this study, the objective was to contribute to the knowledge regarding floristic composition, classification and conservation status of the studied plant species as well as the dispersion syndromes of flora found in a disjoint Cerrado area ​in the Chapada do Araripe, Crato-CE. For the research development Rapid Survey method, applied in three walking lines (Line 1, Line 2 and Line 3) was adopted. Floriferous branches, fruits and seeds from species in the study area were collected in order to identify them and to characterize their diaspores, in view of fitting them into the corresponding dispersion syndromes. A total of 103 species were identified, the richest species taxa were: Fabaceae, Apocynaceae, Euphorbiaceae, Malpighiaceae and Myrtaceae. The most abundant species in the studied area were: Cordiera myrciifolia (“bola”) Miconia albicans (“Candeiro-de-pelo”), Caryocar coriaceum (pequi) and Copaifera langsdorffii (“pau d'oleo”). Three new occurrences were also recorded for the state of Ceará: Eriope tumidicaulis, Myrciaria cf. tenella and Stachytapheta cf. crassifolia. The most frequent dispersion syndrome was zoochoria, followed by anemocoria. Considering that most of the species occurring in the study area have their dispersion diaspores transported by a fauna element, the importance of these species for the maintenance of the observed floristic richness is evident.

Em 1996 foi revelado à ciência o soldadinho-do-araripe (Antilophia bokermanni), pássaro endêmico da vegetação das encostas da Chapada do Araripe, no Ceará. Por sua distribuição restrita em remanescentes florestais sob pressão antrópica foi considerada Criticamente em Perigo de extinção global em 2000. Para modificar esta perspectiva, em 2003, foi iniciado um esforço contínuo de pesquisas, desenvolvimento de políticas públicas, educação ambiental e restauração florestal, visando promover a sua conservação. O foco principal deste empenho tem sido buscar a manutenção dos serviços ambientais provenientes de seu hábitat, sobretudo relacionados às águas, pois principalmente ao longo dos cursos d'água são construídos seus ninhos e concentram-se os frutos que lhe servem de alimento. Durante a execução destas ações, o Projeto Soldadinho-doararipe, estimula a participação da sociedade, beneficiária direta da conservação hídrica e florestal. Neste artigo estão os principais resultados obtidos em dez anos de atividades, tendo como objetivo inspirar outras iniciativas de conservação. Palavras-chave: Serviços ambientais. Mata Úmida. Projeto Soldadinho-do-araripe. Conservação.