Espinosa Juncal, Rodríguez de Rivera Óscar, Madrigal Javier, Carrillo Cristina, de La Cruz Ana Carmen, Fernandes Paulo, Martín-Pinto Pablo, Guijarro Mercedes
Sustainable Forest Management Research Institute, University of Valladolid, Spain; Center for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, Portugal.
Department of Mathematics and Statistics. Faculty of Environment, Science and Economy, University of Exeter, UK.
J Environ Manage. 2025 Aug;389:125939. doi: 10.1016/j.jenvman.2025.125939. Epub 2025 Jun 9.
This study analyzes the effects of prescribed summer fires on the quantity, fractions and temporal patterns of litterfall biomass in Pinus nigra stands in the long-term. Although a number of studies have demonstrated the effects of low intensity (spring and autumn) burning on P. nigra litterfall production, composition and fall patterns, information about the effects of summer prescribed fires on these biomass input characteristics is scarce. We conducted summer experimental fires in June 2019 within an experimental design framework whereby spring and autumn prescribed burning had been carried out in 2016. Litterfall was collected monthly for 43 months. An immediate strong effect was recorded ensuing the shedding of scorched foliage, and the mean annual litterfall biomass was slightly higher in experimental summer fire plots than in unburned plots, with differences tending to decrease across the study period. The experimental summer fire did not alter the typical seasonal distribution of litterfall patterns, with a peak in summer and a minimum in winter. The proportion of different fractions of litterfall and monthly and annual trends of needles, branches and bark did not appear to be altered by the experimental summer fires. Besides, a Bayesian analysis conducted to assess the influence in the short-term of variables related to fire treatments, including spring, autumn and summer burns, showed basal area of the plots to be the most important variable determining the amount of litterfall, whereas meteorological variables were not influent. As summer experimental fires increase litterfall at the onset of the wildfire season, increasing fire hazard, forest managers should take this one-time event into account when deciding when to burn.
本研究长期分析了规定夏季火烧对黑松林凋落物生物量的数量、组分及时间格局的影响。尽管已有多项研究证实了低强度（春季和秋季）火烧对黑松凋落物产量、组成及掉落模式的影响，但关于夏季规定火烧对这些生物量输入特征影响的信息却很匮乏。我们于2019年6月在一个实验设计框架内进行了夏季实验火烧，该框架下2016年已进行过春季和秋季规定火烧。连续43个月每月收集凋落物。火烧后焦叶脱落产生了立竿见影的强烈影响，实验夏季火烧地块的年均凋落物生物量略高于未火烧地块，且这种差异在整个研究期间有减小趋势。实验夏季火烧并未改变凋落物模式的典型季节分布，夏季达到峰值，冬季降至最低。实验夏季火烧似乎并未改变凋落物不同组分的比例以及针叶、树枝和树皮的月度及年度变化趋势。此外，为评估与火烧处理相关变量（包括春季、秋季和夏季火烧）在短期内的影响而进行的贝叶斯分析表明，地块的基部面积是决定凋落物量的最重要变量，而气象变量并无影响。由于夏季实验火烧会在野火季节开始时增加凋落物量，从而增加火灾隐患，森林管理者在决定何时进行火烧时应考虑到这一一次性事件。
