Valverde Juan C, Rubilar Rafael A, Medina Alex, Pincheira Matías, Emhart Verónica, Espinoza Yosselin, Bozo Daniel, Campoe Otávio C
Cooperativa de Productividad Forestal, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Victoria 500, Concepción 4030555, Chile.
Forest Engineering School, Tecnológico de Costa Rica, Cartago 302101, Costa Rica.
Plants (Basel). 2025 Jul 19;14(14):2232. doi: 10.3390/plants14142232.
Water scarcity is a key constraint for commercial plantations, particularly given the increasing frequency of droughts driven by climate change. This study assessed annual transpiration (Tr) and water use efficiency (WUE) across eight genotypes subjected to contrasting irrigation regimes (WR). A split-plot design was implemented, comprising two irrigation levels: high (maintained above 75% of field capacity) and low (approximately 25% above the permanent wilting point). The genotypes included (EgH, EgL), (EngH, EngL), (En), (Ecg), (Eb), and (Es). Between stand ages of 7 and 9 years (2020-2023), we measured current annual increment (CAI), leaf area index (LAI), Tr, and WUE. Under high WR, CAI ranged from 8 to 36 m ha yr, Tr from 520 to 910 mm yr, and WUE from 0.7 to 2.9 kg m. Low irrigation reduced CAI by 5-25% and Tr by 10-35%, while WUE responses varied across genotypes, ranging from a 12% decrease to a 48% increase. Based on their functional responses, genotypes were grouped as follows: (i) stable performers (Es, Ecg, Eb) exhibited high WUE and consistent Tr under both WR; (ii) partially plastic genotypes (EgH, EngH) combined moderate reductions in Tr with improved WUE; and (iii) water-sensitive genotypes (EgL, EngL, En) showed substantial declines in Tr alongside variable WUE gains. These findings underscore the importance of selecting genotypes with adaptive water-use traits to improve the resilience and long-term sustainability of plantations in Mediterranean environments.
水资源短缺是商业种植园面临的关键制约因素，尤其是考虑到气候变化导致干旱频率不断增加的情况。本研究评估了八种基因型在不同灌溉制度（WR）下的年蒸腾量（Tr）和水分利用效率（WUE）。采用了裂区设计，包括两个灌溉水平：高灌溉水平（保持在田间持水量的75%以上）和低灌溉水平（比永久萎蔫点高约25%）。这些基因型包括（EgH、EgL）、（EngH、EngL）、（En）、（Ecg）、（Eb）和（Es）。在7至9年树龄（2020 - 2023年）期间，我们测量了年生长量（CAI）、叶面积指数（LAI）、Tr和WUE。在高WR条件下，CAI范围为8至36 m·ha⁻¹·yr⁻¹，Tr范围为520至910 mm·yr⁻¹，WUE范围为0.7至2.9 kg·m⁻²。低灌溉使CAI降低了5 - 25%，Tr降低了10 - 35%，而WUE的响应因基因型而异，从降低12%到增加48%不等。根据它们的功能响应，基因型被分为以下几类：（i）稳定表现型（Es、Ecg、Eb）在两种WR条件下均表现出高WUE和一致的Tr；（ii）部分可塑性基因型（EgH、EngH）在Tr适度降低的同时WUE有所提高；（iii）水分敏感型基因型（EgL、EngL、En）表现出Tr大幅下降以及WUE的变化。这些发现强调了选择具有适应性水分利用特性的基因型对于提高地中海环境中种植园的恢复力和长期可持续性的重要性。
