The ecological role of dew in assisting seed germination of the annual desert plant species in a desert environment, northwestern China

O objetivo deste artigo foi realizar uma pesquisa de caráter bibliográfico acerca dos estudos desenvolvidos com representantes da família Fabaceae e destacar quais efeitos alelopáticos tais espécies desempenharam sobre outras plantas. Foram listadas 24 espécies de Fabaceae, sendo o gênero Anadenanthera o mais representativo neste artigo, com três espécies estudadas. A partir da análise dos arquivos, foi evidenciado que os representantes da família Fabaceae investigados apresentam em sua composição química substâncias responsáveis por gerar um efeito alelopático sobre outras espécies, caracterizando, dessa forma, uma função ecológica desses vegetais para a constituição dos ecossistemas em que se incluem. Além disso, tal característica pode despontar uma provável utilização desses seres no controle de plantas daninhas, que representam um grande problema para os agricultores. Também foram percebidos com maior frequência estudos voltados ao uso de bioensaios laboratoriais com o uso da espécie Lactuca sativa, noticiando a carência de estudos mais complexos sobre a ação dos aleloquímicos, quando lançados em condições naturais no ambiente. Palavras-chave: Aleloquímicos. Germinação de Sementes. Leguminosae. Abstract The objective of this paper was to perform a bibliographic research about the studies carried out with representatives of the Fabaceae family and stress out what allelopathic effects such species develop on other plants. Twenty-four Fabaceae species were listed, being the Anadenanthera genus the most representative in this article, with three species studied. It was noticed in the studies analysis that certain Fabaceae species contain in their chemical composition, substances responsible for an allelopathic effect on other species, characterizing an ecological role of these plants for the ecosystems establishment. This feature can suggest the use of these species in weed control, which represent a problem to farmers. It was seen more often studies focused on the use of laboratory bioassays with Lactuca sativa, reporting the lack of more complex studies on the action of allelochemicals when launched in natural conditions in the environment. Keywords: Allelochemicals. Seed Germination. Leguminosae.

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Removal and predation of aril-covered seeds: the case of Afzelia bipindensis (Fabaceae – Detarioidae)

Plant Ecology and Evolution ◽

10.5091/plecevo.2019.1552 ◽

2019 ◽

Vol 152 (3) ◽

pp. 460-469 ◽

Cited By ~ 1

Author(s):

Quentin Evrard ◽

Olivier J. Hardy ◽

Nikki Tagg ◽

Jean-Louis Doucet

Keyword(s):

Seed Germination ◽

Plant Species ◽

Tree Species ◽

Feeding Behaviour ◽

Camera Traps ◽

Regeneration Process ◽

Timber Species ◽

Direct Observations

Background and aims – Most tree species with aril-covered seeds are assumed to be dispersed by frugivores. However, the number of studied African rainforest plant species remains low. This study focused on Afzelia bipindensis, an important timber species, which produces seeds partly covered by an aril. Specifically, this study aimed to: (1) identify the dispersers and the predators of A. bipindensis seeds, (2) characterize the role of those dispersers and predators in the regeneration process, and (3) understand the role of the aril in seed germination in relation to the feeding behaviour of the identified dispersers. Methods – The study took place in a Gabonese evergreen rainforest in 2015 and in a Cameroonian semi-deciduous rainforest in 2016 and 2017. We conducted more than 100 hours of direct observations, and used camera traps to monitor animal activities for 3000 hours within the canopy and 10 000 hours on the ground under fruiting trees. Key results – Three rodent taxa (Cricetomys emini, Funisciurus isabella and an undetermined species of Muridae) were mainly observed interacting with the seeds but neither birds nor monkeys were observed. Rodents removed more than 90% of the seeds, after detaching the aril, to probably cache them in burrows or superficial caches. Seeds from which we manually removed the aril (mimicking rodent behaviour) had a higher germination rate.Conclusions – Rodents may play a more important role than expected in the dynamics of tree species producing aril-covered seeds.

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