School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada.
Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA.
Nat Ecol Evol. 2021 Sep;5(9):1283-1290. doi: 10.1038/s41559-021-01510-3. Epub 2021 Jul 22.
Restoration of degraded drylands is urgently needed to mitigate climate change, reverse desertification and secure livelihoods for the two billion people who live in these areas. Bold global targets have been set for dryland restoration to restore millions of hectares of degraded land. These targets have been questioned as overly ambitious, but without a global evaluation of successes and failures it is impossible to gauge feasibility. Here we examine restoration seeding outcomes across 174 sites on six continents, encompassing 594,065 observations of 671 plant species. Our findings suggest reasons for optimism. Seeding had a positive impact on species presence: in almost a third of all treatments, 100% of species seeded were growing at first monitoring. However, dryland restoration is risky: 17% of projects failed, with no establishment of any seeded species, and consistent declines were found in seeded species as projects matured. Across projects, higher seeding rates and larger seed sizes resulted in a greater probability of recruitment, with further influences on species success including site aridity, taxonomic identity and species life form. Our findings suggest that investigations examining these predictive factors will yield more effective and informed restoration decision-making.
需要紧急恢复退化的旱地，以缓解气候变化、扭转荒漠化，保障生活在这些地区的 20 亿人民的生计。已经为旱地恢复设定了大胆的全球目标，要恢复数百万公顷退化的土地。这些目标被质疑过于雄心勃勃，但如果没有对成功和失败的全球评估，就不可能评估其可行性。在这里，我们研究了六大洲 174 个地点的恢复播种结果，涵盖了 671 个植物物种的 594065 次观测。我们的研究结果表明有理由保持乐观。播种对物种的存在有积极影响：在几乎三分之一的处理中，100%播种的物种在第一次监测时都在生长。然而，旱地恢复是有风险的：17%的项目失败，没有任何播种的物种建立，随着项目的成熟，播种的物种数量持续减少。在各个项目中，较高的播种率和较大的种子大小会增加物种的繁殖机会，而对物种成功的进一步影响包括地点的干旱程度、分类学身份和物种生活形态。我们的研究结果表明，对这些预测因素的研究将产生更有效和明智的恢复决策。
