Litterfall production plays a fundamental role in the dynamics and function of tropical forest ecosystems, as it supplies 70–80% of nutrients entering the soil. This process varies annually and seasonally, depending on multiple environmental factors. However, few studies spanning several years have addressed the combined effect of climate variables, successional age, topography, and vegetation structure in tropical dry forests. In this study, we evaluated monthly, seasonal, and annual litterfall production over a five-year period in semideciduous dry forests of different successional ages growing on contrasting topographic conditions (sloping or flat terrain) in Yucatan, Mexico. Its relationship with climate and vegetation structural variables were also analyzed using multiple linear regression and generalized linear models. Litterfall was measured monthly in 12 litterfall traps of 0.5 m² in three sampling clusters (sets of four 400 m² sampling plots) established in forests of five successional age classes, 3–5, 10–17, 18–25, 60–79, and >80 years (in the latter two classes either on slopping or on flat terrain), for a total of 15 sampling clusters and 180 litterfall traps. Litterfall production varied between years (negatively correlated with precipitation), seasons (positively correlated with wind speed and maximum temperature), and months (negatively correlated with relative humidity) and was higher in flat than in sloping sites. Litterfall production also increased with successional age until 18–25 years after abandonment, when it attained values similar to those of mature forests. It was positively correlated with the aboveground biomass of deciduous species but negatively correlated with the basal area of evergreen species. Our results show a rapid recovery of litterfall production with successional age of these forests, which may increase with climate changes such as less precipitation, higher temperatures, and higher incidence of hurricanes.

中文翻译：

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多种因素影响墨西哥热带干旱森林的季节性和年度凋落物产量

凋落物的产生在热带森林生态系统的动态和功能中起着根本性的作用，因为它提供了70-80％的养分进入土壤。此过程每年和每个季节都会变化，具体取决于多种环境因素。然而，很少有研究跨越几年来研究热带干旱森林中气候变量，演替年龄，地形和植被结构的综合影响。在这项研究中，我们评估了在墨西哥尤卡坦州不同地形条件（倾斜或平坦的地形）下生长的不同演替年龄的半落叶干旱森林中五年内的月度，季节和年度凋落物产量。还使用多元线性回归和广义线性模型分析了其与气候和植被结构变量的关系。三个采样组中的²个（每组四个400 m ²在三个连续年龄等级（3-5、10-17、18-25、60-79和> 80年）的森林中建立了采样区（在后两个等级中，无论是坡度还是平坦地形），总共15个采样集群和180个凋落物陷阱。凋落物的产生在年份（与降水成负相关），季节（与风速和最高气温成正相关）和月份（与相对湿度成负相关）之间变化，并且平坦的地区要高于坡地。凋落物的产量也随着年龄的增长而增加，直到被抛弃后达到18-25年，达到与成熟森林相似的值。它与落叶树种的地上生物量呈正相关，而与常绿树种的基础面积呈负相关。