Rubalcava-Castillo Fabián Alejandro, Valdivia-Flores Arturo Gerardo, Luna-Ruíz José de Jesús, Íñiguez-Dávalos Luis Ignacio, Martínez-Calderón Víctor Manuel, Meraz Jiménez Antonio de Jesús, Sosa-Ramírez Joaquín
Centro de Ciencias Agropecuarias Universidad Autónoma de Aguascalientes Aguascalientes Mexico.
Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur Universidad de Guadalajara Autlán de Navarro Mexico.
Ecol Evol. 2023 Jul 4;13(7):e10262. doi: 10.1002/ece3.10262. eCollection 2023 Jul.
Carnivorous mammals disperse seeds through endozoochory and diploendozoochory. The former consists of ingestion of the fruit, passage through the digestive tract, and expulsion of the seeds, a process that allows scarification and dispersal of the seeds over long or short distances. The latter is typical of predators that expel seeds that were contained in the prey and the effects of which may differ from those of endozoochory with respect to the retention time of the seeds in the tracts, as well as their scarification and viability. The objective of this study was to conduct an experimental evaluation comparing the capacity of each mammal species in terms of the dispersal of seeds and, at the same time, to compare this capacity through the two dispersal systems: endozoochory and diploendozoochory. We measured dispersal capacity using indices of recovery, viability, changes in testas, and retention time of seeds in the digestive tract. fruits were collected in the Sierra Fría Protected Natural Area in Aguascalientes, Mexico, and were administered in the diet of captive mammals: gray fox (), coati () and domestic rabbits (). These three mammals represented the endozoochoric dispersers. For the diploendozoochoric treatment, seeds excreted by rabbits were incorporated into the diets of captive mammals: bobcat () and cougar (), in a local zoo. Seeds present in the scats were then collected, and recovery rates and retention times were estimated. Viability was estimated by X-ray optical densitometry and testa thicknesses were measured and surfaces checked using scanning electron microscopy. The results showed a recovery of seeds greater than 70% in all the animals. The retention time was <24 h in the endozoochory but longer at 24-96 h in the diploendozoochory ( < .05). Seed viability ( ± SD) was decreased in rabbits (74.0 ± 11.5%), compared to fruits obtained directly from the canopy (89.7 ± 2.0%), while gray fox, coati, bobcat, and cougar did not affect seed viability ( < .05). An increase in the thickness of the testas was also observed in seeds excreted from all mammals ( < .05). Through evaluation, our results suggest that mammalian endozoochory and diploendozoochory contribute to the dispersal of by maintaining viable seeds with adaptive characteristics in the testa to promote forest regeneration and restoration. In particular, feline predators can provide an ecosystem service through scarification and seed dispersal.
肉食性哺乳动物通过内吞传播和双内吞传播来扩散种子。前者包括果实的摄取、通过消化道以及种子的排出，这一过程使得种子能够进行破皮处理并在长距离或短距离内扩散。后者是捕食者的典型特征，它们排出猎物中所含的种子，其效果在种子在消化道中的保留时间、破皮处理以及活力方面可能与内吞传播有所不同。本研究的目的是进行一项实验评估，比较每种哺乳动物在种子扩散方面的能力，同时通过内吞传播和双内吞传播这两种扩散系统来比较这种能力。我们使用恢复指数、活力、种皮变化以及种子在消化道中的保留时间来衡量扩散能力。果实采自墨西哥阿瓜斯卡连特斯的弗里亚山脉自然保护区，并投喂给圈养哺乳动物：灰狐（）、长鼻浣熊（）和家兔（）。这三种哺乳动物代表内吞传播扩散者。对于双内吞传播处理，将家兔排出的种子纳入当地动物园圈养哺乳动物：短尾猫（）和美洲狮（）的饮食中。然后收集粪便中的种子，并估计回收率和保留时间。通过X射线光密度测定法估计活力，测量种皮厚度并使用扫描电子显微镜检查表面。结果表明，所有动物的种子回收率均大于70%。内吞传播中的保留时间小于24小时，但双内吞传播中的保留时间更长，为24 - 96小时（<0.05）。与直接从树冠获取的果实（89.7±2.0%）相比，家兔体内种子的活力（±标准差）有所下降（74.0±11.5%），而灰狐、长鼻浣熊、短尾猫和美洲狮对种子活力没有影响（<0.05）。在所有哺乳动物排出的种子中还观察到种皮厚度增加（<0.05）。通过评估，我们的结果表明，哺乳动物的内吞传播和双内吞传播通过在种皮中保持具有适应性特征的有活力种子来促进森林更新和恢复，从而有助于种子的扩散。特别是，猫科捕食者可以通过破皮处理和种子传播提供生态系统服务。
