In recent decades, there has been a decline in growth in a rear-edge broadleaf forest of Fagus sylvatica , Quercus petraea , and Q uercus pyrenaica . Although temperatures have been rising due to climate change, the observed decline in growth was mainly attributed to increased density and competition between trees since the cessation of traditional uses such as logging in the 1960s. In recent decades, two major factors have influenced tree growth in many forests: climate warming, which is associated with aridification and negative growth trends in many Mediterranean forests, and abandonment of forest management, resulting from forest policy in conjunction with rural depopulation in Europe, often leading to an increase in competition and a decrease in growth. Here, we study the growth trends in a mixed forest of Fagus sylvatica, Quercus petraea, and Quercus pyrenaica, where the abandonment of traditional uses in the 1960s has been followed by an increase in tree density. In this forest, both F. sylvatica and Q. petraea reach their south-westernmost limits of distribution. Using dendrochronological methods and growth modeling, we assess the importance of climate warming on the shifts in competitive growth advantage of these three coexisting tree species and the relative importance of climate and competition on growth trends. Q. petraea and especially F. sylvatica showed a favorable evolution of their competitive capacity, despite the increase in temperatures that has occurred in the area in recent decades. F. sylvatica presented the lowest sensitivity to climate. Under the current climate and forest structure conditions, competition is the most limiting factor on tree growth for the two oak species.

中文翻译：

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竞争压倒气候，成为混合壳斗科地中海后缘森林生长下降的触发因素

近几十年来，山毛榉、栎属栎和比南栎的后缘阔叶林的生长量有所下降。尽管气候变化导致气温上升，但观察到的增长下降主要归因于自 1960 年代停止伐木等传统用途以来树木的密度增加和竞争。近几十年来，有两个主要因素影响了许多森林的树木生长：气候变暖，这与许多地中海森林的干旱化和负增长趋势有关，以及森林政策与欧洲农村人口减少导致森林管理的放弃，通常会导致竞争加剧和增长下降。在这里，我们研究了 Fagus sylvatica、Quercus petraea、和 Quercus pyrenaica，在 1960 年代放弃传统用途之后，树木密度增加了。在这片森林中，F. sylvatica 和 Q. petraea 都达到了它们最西南的分布范围。使用树木年代学方法和生长模型，我们评估了气候变暖对这三种共存树种竞争生长优势变化的重要性，以及气候和竞争对生长趋势的相对重要性。Q. petraea，尤其是 F. sylvatica，尽管近几十年来该地区的气温有所上升，但它们的竞争能力表现出有利的发展。F. sylvatica 对气候的敏感性最低。在目前的气候和森林结构条件下，