Fire recurrence and time since last fire interact to determine the supply of multiple ecosystem services by Mediterranean forests

Wildfires shape the composition and functioning of Mediterranean
ecosystems, but we do not know how these ecosystems respond to both the
higher fire recurrence and shorter recovery times expected for future
climatic scenarios.  We sampled 29 plots with different fire
recurrences (from 0 to  4 fires over the past decades) and time
since the last fire (up to 35 years; hereafter TSLF) in Southeast Spain,
to assess the effect of fire recurrence and TSLF on 25 ecosystem
attributes, five related ecosystem services (biodiversity conservation,
carbon sequestration, disturbance regulation, food production, 
and supporting services), plus the synergies and trade-offs between them.
High fire recurrence (number of fires) and TSLF interacted to determine
ecosystem services but did not affect the synergies and trade-offs between
them. Fire recurrence reduced many ecosystem functions and ecosystem
multifunctionality. However, this effect dampened, and even became
positive, for biodiversity conservation and food production services
provided enough (> 20 years) time to recover. The combined effects
of fire recurrence and TSLF, however, reduced carbon sequestration and had
no overall effects on supporting services. Disturbance regulation, in
turn, diminished drastically with the first fire, with no effect of
further fires or their interaction with TSLF. Our results show which
ecosystem services will suffer more from an increase in fire recurrence,
and where restoration and management efforts should focus to maximize the
provision of those services more demanded by stakeholders.

野火塑造了地中海生态系统的组成与功能，但对于未来气候情景下预期的更高火灾复发率和更短恢复时间，我们尚不清楚这些生态系统将如何响应。我们在西班牙东南部选取了29个样地，这些样地具有不同的火灾复发率（过去几十年间0至4次火灾）和末次火灾后时间（最长35年，以下简称末次火灾后时间（TSLF）），旨在评估火灾复发率与TSLF对25项生态系统属性、5项相关生态系统服务（生物多样性保护、碳固存、干扰调节、粮食生产及支撑服务）以及它们之间协同作用与权衡关系的影响。高火灾复发率（火灾次数）与TSLF存在交互作用，共同决定生态系统服务，但未对它们之间的协同作用与权衡关系产生影响。火灾复发率降低了多项生态系统功能及生态系统多功能性。然而，若生物多样性保护与粮食生产服务拥有足够（>20年）的恢复时间，这种负面影响会减弱，甚至转为正面效应。不过，火灾复发率与TSLF的联合效应降低了碳固存，且对支撑服务无整体影响。另一方面，首次火灾会导致干扰调节能力急剧下降，后续火灾及其与TSLF的交互作用对此无显著影响。我们的研究结果揭示了哪些生态系统服务会因火灾复发率上升而受损更严重，以及应将恢复与管理工作的重点放在何处，以最大限度地提供利益相关者更需求的服务。