Bravo-Monzón Ángel E, Montiel-González Cristina, Benítez-Malvido Julieta, Arena-Ortíz María Leticia, Flores-Puerto José Israel, Chiappa-Carrara Xavier, Avila-Cabadilla Luis Daniel, Alvarez-Añorve Mariana Yolotl
Laboratorio de Ecología Funcional de Ecosistemas Terrestres, Escuela Nacional de Estudios Superiores Unidad Mérida, Universidad Nacional Autónoma de México, Mérida 97357, Yucatán, Mexico.
Laboratorio de Ecología de Hábitats Alterados, Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, Mexico.
Plants (Basel). 2022 Feb 14;11(4):516. doi: 10.3390/plants11040516.
The effect of anthropogenic disturbance on plant community traits and tradeoffs remains poorly explored in tropical forests. In this study, we aimed to identify tradeoffs between defense and other plant functions related to growth processes in order to detect potential aboveground and edaphic environmental conditions modulating traits variation on plant communities, and to find potential assembly rules underlying species coexistence in secondary (SEF) and old-growth forests (OGF). We measured the foliar content of defense phytochemicals and leaf traits related to fundamental functions on 77 species found in SEF and OGF sites in the Jalisco dry forest ecoregion, Mexico, and we explored (1) the trait-trait and trait-habitat associations, (2) the intra and interspecies trait variation, and (3) the traits-environment associations. We found that phytochemical content was associated with high leaf density and leaf fresh mass, resulting in leaves resistant to drought and high radiation, with chemical and physical defenses against herbivore/pathogen attack. The phytochemicals and chlorophyll concentrations were negatively related, matching the predictions of the Protein Competition Model. The phylogenetic signal in functional traits, suggests that abundant clades share the ability to resist the harsh biotic and abiotic conditions and face similar tradeoffs between productive and defensive functions. Environmental filters could modulate the enhanced expression of defensive phytochemicals in SEF, while, in OGFs, we found a stronger filtering effect driving community assembly. This could allow for the coexistence of different defensive strategies in OGFs, where a greater species richness could dilute the prevalence of pathogens/herbivores. Consequently, anthropogenic disturbance could alter TDF ecosystem properties/services and functioning.
在热带森林中，人为干扰对植物群落特征及其权衡关系的影响仍未得到充分研究。在本研究中，我们旨在确定防御与其他与生长过程相关的植物功能之间的权衡关系，以便检测调节植物群落特征变异的潜在地上和土壤环境条件，并找出次生林（SEF）和原始林（OGF）中物种共存的潜在组装规则。我们测量了墨西哥哈利斯科干旱森林生态区SEF和OGF站点中发现的77个物种的防御性植物化学物质的叶片含量以及与基本功能相关的叶片特征，并探讨了（1）特征-特征和特征-栖息地关联，（2）种内和种间特征变异，以及（3）特征-环境关联。我们发现，植物化学物质含量与高叶片密度和叶片鲜质量相关，从而使叶片具有抗旱和抗高辐射能力，并具备针对食草动物/病原体攻击的化学和物理防御能力。植物化学物质和叶绿素浓度呈负相关，符合蛋白质竞争模型的预测。功能性状中的系统发育信号表明，丰富的进化枝具有抵抗恶劣生物和非生物条件的能力，并且在生产和防御功能之间面临相似的权衡。环境过滤可能会调节SEF中防御性植物化学物质的增强表达，而在OGF中，我们发现了更强的过滤效应驱动群落组装。这可能使不同的防御策略在OGF中共存，其中更高的物种丰富度可以稀释病原体/食草动物的流行率。因此，人为干扰可能会改变热带干旱森林生态系统的属性/服务和功能。
