Impact of Stem Branches Evolution on the Subsequent Development of Positive Leaders

The evolution of stem branches is critical in the complex morphological development of positive leader channels, yet it remains poorly understood. In this study, we demonstrate that when the number of stem branches is limited to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2-3$</tex>, branches aligned with the main channel are more likely to transition into the leader channel, resulting in straight, single-channel leader development. As the number of branches increases to 4-5, branches located on the secondary outer side of the main channel have a higher probability of evolving into the leader channel, leading to either single-channel or dualchannel propagation. Leaders that develop along the main channel tend to exhibit a straight morphology. In contrast, those evolving from outer branches appear zigzagged in singlechannel formation and bifurcated in dual-channel cases. Notably, increasing the number of stem branches reduces the likelihood of straight leader propagation. These findings reveal the influence of stem branch evolution on leader morphology and offer new insights into the complexity and stochasticity of leader development pathways.