Patterns and controls of aboveground litter inputs to temperate forests
Patterns and controls of aboveground litter inputs to temperate forests
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DOI：
10.1007/s10533-022-00988-8
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发表时间：
2022-11
期刊：
影响因子：
4
通讯作者：
F. Jevon;Alexander Polussa;A. Lang;J. William Munger;S. Wood;W. Wieder;M. Bradford
中科院分区：
文献类型：
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作者：
F. Jevon;Alexander Polussa;A. Lang;J. William Munger;S. Wood;W. Wieder;M. Bradford
地上凋落物生产是森林碳和养分进入土壤碎屑库的重要生物地球化学途径。然而，地上凋落物生产的模式和控制通常基于对秋季叶片投入与地上树木生产的关系的理解。本文利用三个不同的温带森林地上凋落物生产数据来源，探讨在其他因素的影响下，如凋落物生产的气候敏感性、叶状、细木屑和生殖凋落物输入的季节性等，地上木屑生产力如何影响叶状凋落物生产。研究发现，凋落叶产量随地上木本产量的增加而增加，这种关系受到植物功能群和气候的调节。基面积对凋落物产量也有重要的控制作用。针叶林产生的凋落叶大约是阔叶落叶林的一半。凋落物产量对不同地点和年份的气候变化都很敏感，因此在温暖、潮湿的地点和年份产生更多的凋落物。平均72%的地上凋落物是叶面物质，其余部分大致均匀地分布在细木屑和生殖物质之间，尽管约88%的阔叶凋落物在秋季掉落，但同期只有约61%的针叶、37%的细木屑和43%的生殖物质掉落。总之，这些结果说明了针叶林和落叶林凋落物生产控制的关键差异，并强调了经常被忽视的凋落物通量的重要性，包括非秋季和非叶面凋落物。
Aboveground litter production is an important biogeochemical pathway in forests whereby carbon and nutrients enter soil detrital pools. However, patterns and controls of aboveground litter production are often based on an understanding of how autumnal, foliar inputs are related to aboveground tree production. Here we use three separate data sources of aboveground litter production in temperate forests to ask how aboveground woody productivity affects foliar litter production in light of other factors, such as the climate sensitivity of litter production and the seasonality of not only foliar but also fine woody debris and reproductive litter inputs. We find that foliar litter production increases with aboveground woody production, and this relationship is modified both by plant functional group and climate. Basal area also provides a crucial control on litter production. Conifer forests produce approximately half as much foliar litter as broadleaf deciduous forests. Litter production is sensitive to both among-site and among-year variation in climate, such that more litter is produced in warmer, wetter locations and years. On average 72% of aboveground litter is foliar material, with the remaining split about evenly between fine woody debris and reproductive material, and although about 88% of broadleaf litter falls during autumn, only about 61% of needles, 37% of fine woody debris and 43% of reproductive material falls during the same period. Together these results illustrate key differences in the controls of litter production in coniferous and deciduous forests, and highlight the importance of often overlooked litter fluxes, including non-autumn and non-foliar litterfall.