Insights into the Relationships between Morphological Traits of Larrea divaricata and Climate Variables in Southern South America

Abstract

Premise of research. How vegetation adapts to environmental changes is one of the most important questions in plant science. Temperature and precipitation are considered the main climatic drivers of morphological variations in vegetation. Several studies have demonstrated that leaf morphology varies reliably with increasing latitude, and this is mostly attributed to changes in temperature and precipitation patterns. The morphological responses of plants to temperature and rainfall regimes in arid lands are still scarcely known and understood. We analyze the morphological variation in leaf traits (size and shape) as well as the internode distance in the species Larrea divaricata and their relationship with bioclimatic variables along a latitudinal gradient in central western Argentina. Methodology. We combined a set of morphological features and bioclimatic indexes using multivariate statistics and detected six relevant regions with clear differences in both plant morphology and climatic variables. Pivotal results. The largest foliar areas were located in sites with higher seasonal precipitation. Leaf shape was influenced by temperature, and the internode distances were larger under semihumid conditions. Conclusions. The plant traits of L. divaricata were influenced by the latitudinal gradient and the predominant climate conditions of each recognized region. The study of foliar morphology allowed us to identify environmental factors that potentially influenced morphological responses in the studied species. As a preliminary stage in our research, our contribution attempts to recognize woody plant adaptations to climate influence. Other environmental variables must be included in future work for a more complete analysis.