Rubalcava-Castillo Fabián Alejandro, Sosa-Ramírez Joaquín, Luna-Ruíz José de Jesús, Valdivia-Flores Arturo Gerardo, Íñiguez-Dávalos Luis Ignacio
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. 2021 Feb 9;11(9):3794-3807. doi: 10.1002/ece3.7201. eCollection 2021 May.
The seed dispersal mechanisms and regeneration of various forest ecosystems can benefit from the actions of carnivores via endozoochory. This study was aimed to evaluate the role of carnivores in endozoochory and diploendozoochory, as well as their effect on seed viability, scarification, and germination in two forest ecosystems: temperate and tropical dry forest. We collected carnivore scat in the Protected Natural Area of Sierra Fría in Aguascalientes, Mexico, for 2 years to determine the abundance and richness of seeds dispersed by each carnivore species, through scat analysis. We assessed seed viability through optical densitometry using X-rays, analyzed seed scarification by measuring seed coat thickness using a scanning electron microscope, and evaluated seed germination in an experiment as the percentage of seeds germinated per carnivore disperser, plant species, and forest type. In the temperate forest, four plant species (but mainly ) were dispersed by four mammal species. The gray fox dispersed the highest average number of seeds per scat (66.8 seeds). Bobcat dispersed seeds through diploendozoochory, which was inferred from rabbit () hair detected in their scats. The tropical dry forest presented higher abundance of seeds and richness of dispersed plant species (four species) than in the temperate forest, and the coati dispersed the highest number of seeds (8,639 seeds). Endozoochory and diploendozoochory did not affect viability in thick-testa seeds (1,480 µm) in temperate forest and thin-testa seeds (281 µm) in tropical dry forest. Endozoochory improved the selective germination of seeds. Nine plant species were dispersed by endozoochory, but only one species ( sp.) by diploendozoochory. These results suggest that carnivores can perform an important ecological function by dispersing a great abundance of seeds, scarifying these seeds causing the formation of holes and cracks in the testas without affecting viability, and promoting the selective germination of seeds.
各种森林生态系统的种子传播机制和更新可通过内吞传播从食肉动物的行为中受益。本研究旨在评估食肉动物在内吞传播和双内吞传播中的作用，以及它们对两个森林生态系统（温带和热带干燥森林）中种子活力、种皮划痕和发芽的影响。我们在墨西哥阿瓜斯卡连特斯的弗里亚山脉自然保护区收集了两年的食肉动物粪便，通过粪便分析来确定每种食肉动物物种传播的种子的丰度和丰富度。我们使用X射线通过光学密度测定法评估种子活力，使用扫描电子显微镜测量种皮厚度来分析种子种皮划痕，并在实验中评估种子发芽情况，以计算每种食肉动物传播者、植物物种和森林类型的种子发芽百分比。在温带森林中，四种植物物种（但主要是 ）由四种哺乳动物物种传播。灰狐每堆粪便传播的种子平均数量最多（66.8颗种子）。短尾猫通过双内吞传播种子，这是从它们粪便中检测到的兔子（ ）毛发推断出来的。热带干燥森林中种子的丰度和传播植物物种的丰富度（四种）高于温带森林，浣熊传播的种子数量最多（8639颗种子）。内吞传播和双内吞传播对温带森林中厚种皮种子（1480微米）和热带干燥森林中薄种皮种子（281微米）的活力没有影响。内吞传播提高了种子的选择性发芽。九种植物物种通过内吞传播，而只有一种物种（ 属）通过双内吞传播。这些结果表明，食肉动物可以通过传播大量种子、划破这些种子（导致种皮上形成孔洞和裂缝）而不影响活力以及促进种子的选择性发芽来发挥重要的生态功能。
