Macedo-Santana Franceli, Horn Christa, Ticktin Tamara, Pulido Silva María Teresa, Endress Bryan A, Lopez-Toledo Leonel
Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacan, Mexico.
San Diego Zoo Wildlife Alliance, Escondido, CA, United States of America.
PeerJ. 2025 Jun 5;13:e19266. doi: 10.7717/peerj.19266. eCollection 2025.
The leaves of many palm species represent important non-timber forest products (NTFPs), which may be intensively harvested by local people in many tropical areas. Additionally, in some regions livestock graze in natural forests, and they may browse on palm leaves, especially during the dry season. Thus, harvesting and browsing can result in the loss of leaf area of individual palms, which may alter functional traits of individuals and change demographic patterns of populations. Currently, there are few studies that analyze the effects of multiple disturbances on these traits. The goals of this study were to evaluate the effects of browsing, leaf harvesting and the interaction between these two factors on individual traits and demographic patterns of the palm in northwestern Mexico.
A browsing and leaf harvesting experiment was conducted on natural populations of the species. Individuals were subjected to different harvesting intensities and the presence or absence of cattle. Annual censuses were conducted from 2011 to 2014, and individual traits (leaf length, petiole length, and leaf production) and vital rates were monitored.
At the individual level, the analyzed traits mostly increased as function of leaf harvest and browing, especially during the first two years. Palms experiencing leaf harvesting and browsing had 1.5 to 6.0 times higher levels of leaf production than control palms, especially juveniles and small adults. At the demographic level, the effects of browsing and leaf harvest were low or null, since survival was not affected by them. Browsing positively affected the growth of individuals in the first 2 years, while leaf harvesting had a negative effect in year three. There was a positive relationship between the probability of reproduction and leaf harvest; however, high leaf harvest resulted in two to three times fewer fruits produced. After 3 years of experimental management, multiple of the analyzed attributes decreased, suggesting that changed patterns of resource allocation. Based on our results, can be considered a species that tolerates high levels of defoliation and browsing for 2 years, but not likely longer. This study contributes basic ecological information useful for the conservation and management of , but overall it also highlights that different anthropogenic activities may act as drivers affecting the functional response and demography of NTFP species and they should be considered for the long-term integral management of these species.
许多棕榈树种的叶子是重要的非木材林产品（NTFPs），在许多热带地区，当地居民可能会大量采摘这些叶子。此外，在一些地区，牲畜会在天然森林中放牧，它们可能会啃食棕榈叶，尤其是在旱季。因此，采摘和啃食会导致单株棕榈叶面积的损失，这可能会改变个体的功能性状并改变种群的人口统计学模式。目前，很少有研究分析多种干扰对这些性状的影响。本研究的目的是评估啃食、叶片采摘以及这两个因素之间的相互作用对墨西哥西北部棕榈个体性状和人口统计学模式的影响。
对该物种的自然种群进行了啃食和叶片采摘实验。个体被施加不同的采摘强度以及有无牛的存在。在2011年至2014年期间进行年度普查，并监测个体性状（叶长、叶柄长度和叶片产量）和生命率。
在个体水平上，所分析的性状大多随着叶片采摘和啃食而增加，尤其是在最初两年。经历叶片采摘和啃食的棕榈比对照棕榈的叶片产量高出1.5至6.0倍，尤其是幼树和小成年树。在种群统计学水平上，啃食和叶片采摘的影响较低或没有影响，因为存活率不受它们的影响。啃食在最初两年对个体生长有积极影响，而叶片采摘在第三年有负面影响。繁殖概率与叶片采摘之间存在正相关关系；然而，高叶片采摘导致果实产量减少两到三倍。经过3年的实验管理，多个分析属性下降，表明资源分配模式发生了变化。根据我们的结果，可被认为是一种能够忍受高水平落叶和啃食两年，但不太可能更长时间的物种。本研究为该物种的保护和管理提供了有用的基础生态信息，但总体而言，它也强调不同的人为活动可能作为驱动因素影响非木材林产品物种的功能反应和种群统计学，在对这些物种进行长期综合管理时应予以考虑。
