The Nature Conservancy of Oregon, Burns, Oregon, United States of America.
The Nature Conservancy of Wyoming, Lander, Wyoming, United States of America.
PLoS One. 2023 Mar 30;18(3):e0283678. doi: 10.1371/journal.pone.0283678. eCollection 2023.
The invasion of exotic, annual plant species is a leading contributor to ecological degradation in drylands globally, and the use of pre-emergent herbicide to control these species is common. Pre-emergent herbicides pose challenges for seed-based restoration due to toxicity to the seeds of desired species. Herbicide protection (HP) technologies pose a potential solution by using activated carbon seed treatments to protect desirable seeds from herbicide exposure. In the sagebrush steppe ecosystem of North America, we used an adaptive small plot design over three planting years to test for effects on seeding outcomes (seedling density and size) of large and small multi-seed HP pellets, several single-seed HP coatings, and carbon banding treatments at geographically dispersed sites for several perennial bunchgrasses and the keystone perennial shrub, Wyoming big sagebrush. We also compared different methods of seed delivery and litter pre-seeding management. Seeding success was low overall, especially for sagebrush, and it was clear that other, often less predictable barriers to establishment than herbicide exposure, such as inadequate spring moisture, were strong drivers of seeding outcomes. Despite this, HP treatments were associated with higher seedling density than bare seed in multiple instances, most notably for grasses. The large HP pellet occasionally outperformed the small HP pellet, and several HP coatings performed similarly to the small pellet. Surprisingly, we did not see consistent negative effects of pre-emergent herbicide on unprotected bare seed. We conclude that HP seed treatments show some promise to improve seeding success in the presence of herbicide, but that consistent success will require further improvements to HP treatments as well as integration with other innovations and approaches.
外来一年生植物物种的入侵是导致全球干旱地区生态退化的主要原因之一，因此，使用芽前除草剂来控制这些物种是很常见的。芽前除草剂由于对目标物种的种子具有毒性，因此对基于种子的恢复构成了挑战。通过使用活性炭种子处理来保护所需种子免受除草剂暴露，除草剂保护（HP）技术提供了一种潜在的解决方案。在北美的山艾灌木丛草原生态系统中，我们在三年的种植期内使用适应性小面积设计来测试大、小多粒 HP 丸粒、几种单粒 HP 涂层以及在地理上分散的地点的碳带处理对几种多年生丛生草和关键多年生灌木——怀俄明州大 sagebrush 的播种结果（幼苗密度和大小）的影响。我们还比较了不同的种子传递方法和覆盖前的管理。总体而言，播种成功率很低，尤其是 sagebrush 的播种成功率，显然，除了除草剂暴露之外，其他往往不可预测的建立障碍，如春季水分不足，是播种结果的主要驱动因素。尽管如此，在多种情况下，HP 处理与裸种相比，幼苗密度更高，尤其是对于草类。大 HP 丸偶尔表现优于小 HP 丸，几种 HP 涂层与小丸的表现相似。令人惊讶的是，我们没有看到芽前除草剂对未受保护的裸种的一致负面影响。我们得出的结论是，HP 种子处理在存在除草剂的情况下显示出提高播种成功率的一些希望，但要实现一致的成功，还需要进一步改进 HP 处理，并将其与其他创新和方法相结合。
