Universidade Estadual de Feira de Santana - UEFS, Programa de Pós-graduação em Ecologia e Evolução, Feira de Santana, BA, Brasil.
Universidade Federal do Vale do São Francisco - UNIVASF, Colegiado de Ecologia, Laboratório de Ecologia Básica e Aplicada, Senhor do Bonfim, BA, Brasil.
Braz J Biol. 2022 Sep 5;82:e264348. doi: 10.1590/1519-6984.264348. eCollection 2022.
Habitat loss reduces biodiversity and threatens ecological services. The use of techniques for vegetation restoration such as direct seeding seems promising, mainly because it reduces costs and labor. The aim of this study was to investigate which are the main ecological filters that can inhibit the success of direct seeding, using Syagrus coronata (Mart.) Beccari (Arecaceae), a species that has great ecological and extractive importance for the Brazilian semi-arid region, and is found in habitats with different management intensities. The following hypotheses were tested: (1) managed habitat (pasture) and natural habitat (caatinga vegetation) show differences in seed fate; and (2) defleshed fruits will have greater seed germination success compared to not defleshed. Seed fate was evaluated for two consecutive years, year I (2016-2017) and year II (2017-2018). Within these years, 800 mature fruits were buried along 300 m transects, half with defleshing treatment, and monitored during 240 days. The highest seed survival occurred in year II, this result may be associated with higher rainfall recorded during the experiment, considering that there was no difference in seed germination between habitats. Defleshing facilitated germination and reduced insect predation, likely by removing invertebrate larvae before they have reached the seed. Desiccation was the major cause of mortality in the entire study and was higher in the managed habitat. Water insufficiency may have caused the deactivation of antioxidant mechanisms and affected the embryo. Although defleshing may favor germination, this procedure would not be indicated for pastures as it favors desiccation. The study showed how habitat management and fruit defleshing can affect seed fate. More studies on ecological relationships need to be carried out to increase understanding of how habitat modification affects the functioning of arid ecosystems.
生境丧失会降低生物多样性并威胁生态系统服务功能。利用植被恢复技术，如直播，似乎很有前景，主要是因为它降低了成本和劳动力。本研究旨在调查哪些是主要的生态过滤器可以抑制直接播种的成功，使用 Syagrus coronata (Mart.) Beccari（棕榈科），该物种在巴西半干旱地区具有重要的生态和提取意义，并存在于不同管理强度的栖息地中。提出了以下假设：（1）管理生境（牧场）和自然生境（疏林植被）在种子命运方面存在差异；（2）去果皮的果实将比不去果皮的果实具有更高的种子发芽成功率。种子命运在连续两年进行了评估，第一年（2016-2017 年）和第二年（2017-2018 年）。在这两年中，沿着 300 米的样带共埋藏了 800 个成熟的果实，一半进行了去果皮处理，并在 240 天内进行了监测。第二年的种子存活率最高，这一结果可能与实验期间记录的更高降雨量有关，因为栖息地之间的种子发芽没有差异。去果皮促进了发芽并减少了昆虫捕食，可能是因为在昆虫幼虫到达种子之前就将其去除。干燥是整个研究中死亡的主要原因，在管理生境中更高。水分不足可能导致抗氧化机制失活并影响胚胎。尽管去果皮可能有利于发芽，但该程序不适用于牧场，因为它会导致干燥。该研究表明生境管理和果实去果皮如何影响种子命运。需要进行更多的生态关系研究，以增加对生境变化如何影响干旱生态系统功能的理解。
