Abstract Mulching application and salvage logging are often performed in forests after wildfire to avoid soil erosion and recover timber values, respectively. Mulch may increase soil moisture and decrease contrasted temperatures, which thus promotes seedling recruitment, whereas logging operations may destroy seedlings or generate soil compaction, which may enhance soil erosion and to cause plant seedling damage. We investigated whether and to what extent postfire mulching application and logging initially altered some mineral soil properties and pine seedling density and growth in contrasting Mediterranean climate sites (Lietor, in SE. Spain, in semiarid climate and A Gudina in NW Spain, in subhumid climate). Twelve plots were set up among four different experimental conditions (mulching + salvage logging, mulching + no salvage logging, no mulching + salvage logging, and no mulching + no salvage logging) in the two sites (semiarid and. subhumid climates). The subhumid site was affected by fire in autumn and the semiarid site was affected by fire in summer. Mulching was applied one and three months after wildfire in A Gudina and Lietor, respectively, whereas logging was applied three months after mulching in Lietor and immediately after mulching in A Gudina. One year after wildfire in A Gudina (Pinus pinaster Ait. stands) and two years after wildfire in Lietor (Pinus halepensis M. stands), all surviving seedlings in each plot were counted. Our results suggest that soil organic matter content and total nitrogen were significantly affected by treatments at Lietor (semiarid climate), whereas no differences were detected at the A Gudina site (subhumid climate). Results confirmed that regardless of whether tree felling took place, mulch treatment improved seedling density (over 40% higher when mulching was applied) and seedling height in the short term in a semiarid climate. The limited water availability and the light demands of pine species could be decisive for understanding the effect of mulching and logging operations for initial seedling recruitment in Lietor. The mulching + logging combination showed the highest seedling density at A Gudina (subhumid climate), which could be related to increased light availability after tree felling. Seedling height, stem dry weight, root length, leave-covered shoot length and leave-covered shoot dry weight were always higher in mulching + salvage logging plots at A Gudina. Our results generally suggest the compatibility between mulching and logging, which enhance initial seeding recruitment in burned semiarid and subhumid Mediterranean pine forests.

中文翻译：

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野火后秸秆覆盖和打捞伐木影响西班牙两个地中海气候区的初始松树苗密度和生长

摘要 野火发生后的森林经常进行覆盖和抢救性采伐，以避免水土流失和恢复木材价值。覆盖物可能会增加土壤水分并降低对比温度，从而促进幼苗补充，而伐木作业可能会破坏幼苗或产生土壤板结，这可能会加剧土壤侵蚀并导致植物幼苗受损。我们调查了火后覆盖应用和伐木是否以及在多大程度上改变了对比地中海气候地点（位于西班牙东南部的 Lietor，处于半干旱气候和位于西班牙西北部，处于半湿润气候的 A Gudina）的一些矿质土壤特性和松树幼苗密度和生长）。在四种不同的实验条件（覆盖+补救伐木、覆盖+无补救伐木、在两个地点（半干旱和半湿润气候）不进行覆盖 + 补救伐木，以及不进行覆盖 + 不采取补救伐木）。半湿润地区秋季受火灾影响，半干旱地区夏季受火灾影响。A Gudina 和 Lietor 分别在野火后 1 个月和 3 个月进行覆盖，而 Lietor 覆盖后三个月和 A Gudina 覆盖后立即进行伐木。A Gudina 野火发生一年后（Pinus pinaster Ait. 林分）和 Lietor 野火发生两年后（Pinus halepensis M. 林分），计算了每个地块中所有存活的幼苗。我们的结果表明土壤有机质含量和总氮受到 Lietor（半干旱气候）处理的显着影响，而在 A Gudina 站点（半湿润气候）未检测到差异。结果证实，无论是否发生树木砍伐，在半干旱气候下，覆盖物处理都能在短期内提高幼苗密度（使用覆盖物时高出 40% 以上）和幼苗高度。有限的可用水量和松树的光照需求对于了解覆盖和伐木作业对 Lietor 初始幼苗补充的影响可能是决定性的。覆盖 + 伐木组合在 A Gudina（半湿润气候）显示出最高的幼苗密度，这可能与树木砍伐后光照增加有关。在 A Gudina 的覆盖 + 补救伐木地块中，幼苗高度、茎干重、根长、叶覆盖枝条长度和叶覆盖枝条干重总是较高。我们的结果通常表明覆盖和伐木之间的兼容性，