Data from: Ecosystem service multifunctionality of low-productivity forests and implications for conservation and management

Low-productivity forests are often the last remaining pristine forests in
managed forest landscapes and typically overrepresented among protected
forests. However, the provisioning of individual and multiple ecosystem
services (ES-multifunctionality) by these forests remains poorly assessed,
making it difficult to evaluate their importance in forest conservation
and management. Using nationwide data on ecosystem services (ES) from
forest plots, we test whether levels of ES-multifunctionality and
individual ES differ between low-productivity forested mires and rocky
outcrops in relation to the levels of productive forests, and as a
function of forest age, tree species richness and climate. We defined
ES-multifunctionality using different threshold values of the maximum
levels (low, medium and high) and weighted these according to land-use
objectives (equal weight of all services, greater weight to cultural and
supporting ES, or greater weight to production). We show that the
ES-multifunctionality of forested mires is consistently lower than those
of productive forests. However, the ES-multifunctionality increased with
forest age in forested mires but not in productive forests. The
ES-multifunctionality of forested rocky outcrops, on the other hand, was
higher or equivalent to that of productive forests under equal weight and
supporting land-use objectives, respectively. Our findings highlight that
forested rocky outcrops can supply multiple ES, especially older forested
stands with mixtures of coniferous and deciduous trees. Generally, we
found no evidence for strong trade-offs between the ES studied and our
results highlight the importance of forest age for increasing the
ES-multifunctionality of low-productivity forests. Synthesis and
applications. Low-productivity forests should not be exempt of
forestry or protected purely based on low productivity or low land-use
conflict if the goal is to conserve multiple ecosystem services (ES).
Inclusion grounds for protecting low-productivity forests should instead
carefully consider the site type (dry versus wet), forest age, and tree
species richness. In order to maintain higher ES-multifunctionality in
low-productivity forests, older or deciduous trees should also not be
harvested. This will require changes in current conservation or management
policies of low-productivity forests of some countries.

低生产力森林往往是人工管理森林景观中仅存的原始森林，且在受保护森林中占比通常过高。然而，这些森林对单一及多种生态系统服务（生态系统服务多功能性，ES-multifunctionality）的供给能力评估仍显不足，导致其在森林保护与管理中的重要性难以衡量。基于全国森林样地的生态系统服务（ES）数据，我们检验了低生产力沼泽森林与岩石露头森林的生态系统服务多功能性（ES-multifunctionality）及单一生态系统服务水平，是否与高生产力森林存在差异，以及这些差异是否受森林年龄、树种丰富度和气候的影响。我们通过最大水平的不同阈值（低、中、高）定义生态系统服务多功能性（ES-multifunctionality），并根据土地利用目标（所有服务权重相等、文化与支撑性生态系统服务权重更高、或生产功能权重更高）对其进行加权处理。研究发现，沼泽森林的生态系统服务多功能性（ES-multifunctionality）持续低于高生产力森林。但沼泽森林的生态系统服务多功能性随林龄增加而提升，高生产力森林则无此趋势。另一方面，在权重相等及支撑性土地利用目标下，岩石露头森林的生态系统服务多功能性（ES-multifunctionality）分别高于或等同于高生产力森林。研究结果强调，岩石露头森林能够提供多种生态系统服务（ES），尤其是由针叶树与阔叶树混合构成的老龄林分。总体而言，我们未发现所研究的生态系统服务（ES）之间存在显著权衡关系，且结果凸显林龄对提升低生产力森林生态系统服务多功能性（ES-multifunctionality）的重要性。综合与应用：若目标是保护多种生态系统服务（ES），则不应仅基于低生产力或低土地利用冲突，就免除低生产力森林的林业活动或对其进行保护。相反，低生产力森林的保护纳入依据应审慎考虑立地类型（干旱与湿润）、林龄及树种丰富度。为维持低生产力森林较高的生态系统服务多功能性（ES-multifunctionality），老龄树或阔叶树也不应被采伐。这需要部分国家调整现行的低生产力森林保护与管理政策。