Direct seeding is a promising and low-cost restoration technique. To avoid wasting seeds, the selection of species with high field performance in their establishment can increase efficiency. We aimed to identify groups of forest species with the ability for direct seeding in a seasonal forest, investigate taxonomic similarity effects on species behavior regarding seeds’ and seedlings’ early functional traits, and classify species based on their probability of success by direct seeding. A planting system of 38 seasonal forest species was implemented at a density of 250,000 seeds ha−1. The emergence was monitored over 720 days, and all individuals were identified, tagged, counted, and measured for height (H) and diameter at collar height (DCH). We evaluated early traits of seed vigor (field seed emergence), seedling performance, probability of success, and species autoecology. Species’ ability for direct seeding was more related to the level of species phylogeny than to their family. Pioneer and non-pioneer species demonstrated similar abilities for direct seeding associated with field emergence, seedling abundance, and persistence. Field seed emergence traits influenced species’ ability for direct seeding more than seedling survival or growth. Species’ ability for direct seeding was related to early seed vigor traits expressed by field seed emergence and was independent of their density.
In Brazil, most degraded areas are occupied by exotic and invasive species, which require alternatives for their management. We evaluated the allelopathic effects of Waltheria indica in the laboratory from aqueous extracts of leaves and roots on the germination of the species Lactuca sativa L. (lettuce), Urochloa brizantha (Hochst. ex A.Rich.) RDWebster (brachiaria) and Handroanthus chrysotrichus (Mart. ex DC.) Mattos (yellow Ipe). We collected adult one-year-old Waltheria indica shrubs in ecological restoration areas by direct seeding. We used two treatments with aqueous extracts of leaves and roots and a control without extract, with ten repetitions of 10 seeds per treatment, totaling 600 seeds per test species. Germination and use of tetrazolium assays to evaluate the potential respiratory activity of the roots were used. The aqueous extract of W.indica leaves affected the number of germinated seeds of all test species, while the aqueous extract of roots affected only L. sativa and H. chrysotrichus. There were no significant differences between treatments (leaf and root extracts) in species germination. The aqueous extracts of Waltheria indica leaves and roots affected germination and cellular respiration of the studied species, mainly in Lactuca sativa. The identification of W. indica allelopathic compounds may be an initial step so that in the future new bioherbicides are produced from extracts of this species, or even that its seeds can be sown together with non-sensitive native species, aiming for control of exotic species in ecological restoration projects.
Nas comunidades vegetais, as plantas podem interagir de maneira positiva, negativa ou neutra. Essa á uma característica muito importante para garantir a sobrevivência, além de fornecer informações para construção de conhecimento e produtos a serem utilizados no controle específico de algumas plantas daninhas. O objetivo do trabalho foi realizar revisão bibliográfica sobre os efeitos da alelopatia em comunidades vegetais, podendo ser observado tanto nas competições intraespecífica quanto na interespecífica. Com base nos resultados da literatura é provável que os compostos alelopáticos possam alterar componentes do ecossistema que, por sua vez, conduzem processos e interações, as quais modificam a composição e dinâmica das comunidades vegetais. No entanto, uma grande lacuna na pesquisa da alelopatia recai sobre a inexistência de metodologias a serem aplicadas em campo que demonstrem o papel desses compostos no desenvolvimento interespecífico e ao longo da comunidade. Desse modo, faz-se necessário que os estudos levem em consideração quais as fontes de variação entre as espécies, os tipos de impactos causados nas espécies associadas e, principalmente, os seus efeitos em nível de comunidade.
A pandemia SARS-Cov-2 estabeleceu a necessidade de adoção de medidas restritivas para conter a disseminação do vírus. Em 2021, devido ao elevado número de casos de COVID-19 no município de Araraquara, Brasil, e após o esgotamento das vagas hospitalares em 2021, foi anunciado um bloqueio. Analisamos o efeito do distanciamento social dessa cidade, utilizando dados fornecidos pela prefeitura municipal ao longo de um período total de 90 dias. Usamos esses dados em uma tabela de vida, uma importante ferramenta que avalia o impacto de doenças na dinâmica populacional de uma espécie. Os resultados indicaram uma taxa básica de mortalidade de 0,0138 no período analisado e uma redução considerável no número de casos infectados e óbitos por COVID-19 após 24 dias de isolamento. Nossos resultados mostraram a eficácia do distanciamento social em conter a propagação da doença, com redução de 80% no número de óbitos, bem como a utilidade da tábua de vida como ferramenta útil para análise de dados.
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