We examine how levels of multiple ecosystem services (ESs) change with succession in forests with different tree species composition. More specifically we ask how ecosystem age interacts with environmental conditions to regulate ES delivery. Using the nationwide Swedish forest inventory, comprising boreal and temperate regions, we investigated how levels of six provisioning, regulating, recreational, and/or cultural forest ESs changed with forest age (10-185 years) in stands of different tree species composition. We also tested whether the number of ESs delivered (i.e. multifunctionality) changed substantially with stand age, using different threshold levels for ES delivery. Accounting for environmental conditions and stand properties, we found that levels of single ESs changed with stand age. Tree biomass production usually peaked in young to medium aged stands. In contrast, production of berries and game, and services related to biodiversity, were typically highest in old stands (120-185 years). Consistent with this strong temporal tradeoff, multifunctionality at lower threshold levels increased with stand age in most monocultures and mixtures, with the highest multifunctionality being reached somewhere between 100 and 185 years, depending on tree species composition. This was not evident for the highest threshold ES level (the top-20%), however. Moreover, multifunctionality usually decreased with warmer climatic conditions, with the exception of spruce-pine-birch mixtures. Taken together, our results show that a reduced forest age, e.g. due to forestry targeting early harvest of stands, most likely would limit the delivery of several ESs valued by society and result in less multifunctional forests. To maintain the capacity of forests to deliver high levels of multiple ESs, the role of stand age and tree species composition should be considered in decisions on how to manage future forests.

中文翻译：

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林龄和气候影响森林生态系统服务的提供和多功能性

我们研究了多种生态系统服务 (ES) 的水平如何随着具有不同树种组成的森林的演替而变化。更具体地说，我们询问生态系统年龄如何与环境条件相互作用以调节 ES 的传递。使用包括北方和温带地区在内的瑞典全国森林清单，我们调查了在不同树种组成的林分中，六种供给、调节、娱乐和/或文化森林 ES 的水平如何随林龄（10-185 年）而变化。我们还测试了交付的 ES 数量（即多功能性）是否随林龄发生显着变化，使用不同的 ES 交付阈值水平。考虑到环境条件和林分属性，我们发现单个 ES 的水平随林分年龄而变化。树木生物量生产通常在幼龄到中龄林中达到峰值。相比之下，浆果和野味的产量以及与生物多样性相关的服务通常在老林分（120-185 年）中最高。与这种强烈的时间权衡一致，在大多数单一栽培和混合物中，较低阈值水平的多功能性随着林龄增加而增加，最高多功能性在 100 到 185 年之间达到，具体取决于树种组成。然而，这对于最高阈值 ES 水平（前 20%）并不明显。此外，除云杉-松树-桦木混合物外，多功能性通常会随着气候条件变暖而降低。综上所述，我们的结果表明，森林年龄的降低，例如由于林业针对林分的早期收获，很可能会限制社会重视的几种 ES 的交付，并导致多功能森林的减少。为了保持森林提供高水平多种生态系统的能力，在决定如何管理未来森林时应考虑林龄和树种组成的作用。