Abstract：
According to the sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC), global climate change is now unequivocal. Tunisia, like many other countries, has been affected by climate changes, including rising temperatures, intense heatwaves, and altered precipitation regimes. Tunisia\'s mean annual temperatures has risen about +1.4 °C in the twentieth century, with the most rapid warming taking place since the 1970s. Drought represents a primary contributing factor to tree decline and dieback. Long-term drought can result in reduced growth and health of trees, thereby increasing their susceptibility to insect pests and pathogens. Reported increases in tree mortality point toward accelerating global forest vulnerability under hotter temperatures and longer, more intense droughts. In order to assess the effect of these climate changes on the current state of forest ecosystems in Tunisia and their evolution, an investigative study was required. Here, we review the current state of knowledge on the effects of climate change on sclerophyllous and semi-deciduous forest ecosystems in Tunisia. Natural disturbance during recent years, as well as the adaptability and resilience of some forest species to climate change, were surveyed. The Standardized Precipitation Evapotranspiration Index (SPEI) is a multi-scalar drought index based on climate data that has been used to analyse drought variability. The SPEI time scale analysis showed a negative trend over the 1955-2021 period in Tunisian forest regions. In 2021, Tunisia lost 280 km2 of tree cover to fires, which is equivalent to 26% of the total lost area between 2008 and 2021. Changing climate conditions have also affected phenological parameters, with an advance in the start of the green season (SOS) of 9.4 days, a delay at the end of the green season (EOS) of 5 days, with a consequent extended duration of the green season (LOS) by an average of 14.2 days. All of these alarming findings invite us to seek adaptation strategies for forest ecosystems. Adapting forests to climate change is therefore a challenge for scientists as well as policymakers and managers.
摘要：
根据政府间气候变化专门委员会（IPCC）的第六次评估报告，全球气候变化现在是明确的。突尼斯,像许多其他国家一样，受到气候变化的影响，包括气温上升,强烈的热浪,和改变的降水制度。突尼斯的年平均气温在20世纪上升了大约+1.4°C，自1970年代以来最迅速的变暖发生。干旱是导致树木退化和枯萎的主要因素。长期干旱会导致树木生长和健康下降，从而增加了它们对害虫和病原体的敏感性。据报道，树木死亡率的增加表明，在高温和更长时间下，全球森林的脆弱性正在加速，更严重的干旱。为了评估这些气候变化对突尼斯森林生态系统现状及其演变的影响，需要进行调查研究。这里,我们回顾了有关气候变化对突尼斯硬叶和半落叶林生态系统影响的现有知识。近年来的自然干扰，以及一些森林物种对气候变化的适应性和复原力，被调查过。标准化降水蒸散指数（SPEI）是基于气候数据的多标量干旱指数，已用于分析干旱变异性。SPEI时间尺度分析显示，在1955-2021年期间，突尼斯森林地区呈负趋势。2021年，突尼斯因火灾损失了280平方公里的树木，相当于2008年至2021年总损失面积的26%。不断变化的气候条件也影响了物候参数,绿色季节（SOS）开始9.4天，在绿色季节（EOS）结束时延迟5天，因此，绿色季节（LOS）的持续时间平均延长了14.2天。所有这些令人震惊的发现都邀请我们寻求森林生态系统的适应战略。因此，使森林适应气候变化是科学家以及政策制定者和管理者面临的挑战。
