Many countries have adopted large-scale tree planting programmes as a climate mitigation strategy and to support local livelihoods. We evaluate a series of large-scale tree planting programmes using data collected from historical Landsat imagery in the state of Himachal Pradesh in Northern India. Using this panel dataset, we use an event study design to estimate the socioeconomic and biophysical impacts over decades of these programmes. We find that tree plantings have not, on average, increased the proportion of forest canopy cover and have modestly shifted forest composition away from the broadleaf varieties valued by local people. Further cross-sectional analysis, from a household livelihood survey, shows that tree planting supports little direct use by local people. We conclude that decades of expensive tree planting programmes in this region have not proved effective. This result suggests that large-scale tree planting may sometimes fail to achieve its climate mitigation and livelihood goals.

许多国家已采用大规模植树计划作为减缓气候变化的战略并支持当地生计。我们使用从印度北部喜马偕尔邦历史 Landsat 图像收集的数据评估一系列大规模植树计划。使用该面板数据集，我们使用事件研究设计来估计这些计划数十年的社会经济和生物物理影响。我们发现，平均而言，植树并没有增加森林冠层覆盖的比例，并且适度地将森林构成从当地人重视的阔叶品种上转移开。来自家庭生计调查的进一步横断面分析表明，植树几乎不支持当地人直接使用。我们得出的结论是，该地区数十年来昂贵的植树计划并未被证明是有效的。这一结果表明，大规模植树有时可能无法实现其减缓气候变化和生计目标。