Schmitt S, Trueba S, Coste S, Ducouret É, Tysklind N, Heuertz M, Bonal D, Burban B, Hérault B, Derroire G
CNRS, UMR EcoFoG (Agroparistech, Cirad, INRAE, Université des Antilles, Université de la Guyane), Campus Agronomique, Kourou, French Guiana.
Université de Bordeaux, INRAE, BIOGECO, Pessac, France.
Plant Biol (Stuttg). 2022 Apr;24(3):458-463. doi: 10.1111/plb.13395. Epub 2022 Feb 4.
The dry and wet seasons in the Neotropics have strong effects on soil water and nutrient availability, as well as on forest dynamics. Despite these major effects on forest ecology, little is known on how leaf traits vary throughout the seasons in tropical rainforest trees. Here, we investigated the influence of seasonal variations in climate and soil characteristics on leaf trait variation in two tropical tree species. We measured two leaf traits, thickness and water mass per area, in 401 individuals of two species of Symphonia (Clusiaceae) in the Paracou research station in French Guiana tropical lowland rainforest. We found a significant effect of seasonal variation on these two leaf traits. Soil relative extractable water was a strong environmental predictor of leaf trait variation in response to seasonal variation. Reduced soil water availability during the dry season was associated with increased leaf thickness and water mass per area, possibly as a result of stomatal closure. Our findings advocate the need to account for environmental seasonality when studying leaf traits in seasonal ecosystems such as tropical forests.
新热带地区的干湿季节对土壤水分和养分有效性以及森林动态有着强烈影响。尽管对森林生态有这些重大影响，但对于热带雨林树木的叶片性状如何随季节变化却知之甚少。在此，我们研究了气候和土壤特征的季节性变化对两种热带树种叶片性状变异的影响。我们在法属圭亚那热带低地雨林的帕拉库研究站，对两种共生树种（藤黄科）的401个个体测量了两个叶片性状，即厚度和单位面积水质量。我们发现季节变化对这两个叶片性状有显著影响。土壤相对可提取水分是叶片性状变异响应季节变化的一个强有力的环境预测指标。旱季土壤水分有效性降低与叶片厚度增加和单位面积水质量增加有关，这可能是气孔关闭的结果。我们的研究结果表明，在研究热带森林等季节性生态系统中的叶片性状时，需要考虑环境季节性。
