Data from: Consequences of aboveground invasion by non-native plants into restored vernal pools do not prompt changes in belowground processes

Given the frequent overlap between biological plant invasion and
ecological restoration efforts it is important to investigate their
interactions to sustain desirable plant communities and modify long-term
legacies both above and belowground. To address this relationship, we used
natural reference, invaded, and constructed vernal pools in the Central
Valley of California to examine potential changes in direct and indirect
plant effects on soils associated with biological invasion and active
restoration ecosystem disturbances. Our results showed that through a
shift in vegetation composition and changes in the plant community tissue
chemistry, invasion by non-native plant species has the potential to
transform plant inputs to soils in vernal pool systems. In particular, we
found that while non-native litter decomposition was driven by seasonal
and interannual variability, associated with changes in precipitation, the
overall decomposition for non-native litter was drastically lower than
native species. This shift has important implications for long-term
alterations in plant-based inputs to soils in a negative feedback to
nutrient cycling. Moreover, these results were independent of historic
active restoration efforts. Despite the consistent shift in plant litter
decomposition rates and community composition, we did not detect
associated shifts in belowground function associated with invasion by
non-native plants. Instead, soil C:N ratios and microbial biomass did not
differ between invaded and reference naturally occurring pools but were
reduced in the manipulated restored pools independent of invasion levels.
Our results suggest that while there is an observed invasive positive
feedback aboveground, this trajectory is not necessarily represented
belowground and restoration legacies were still dominant ten years after
practices were applied. Restoration practices that limit invasive plant
feedbacks and account for soil legacy recovery, therefore offer the best
solution for disturbed ephemeral ecosystems.

鉴于植物生物入侵（biological plant invasion）与生态恢复工作之间的频繁重叠，探究二者的相互作用对于维持理想植物群落、改变地上与地下的长期遗留效应至关重要。为厘清这一关系，我们利用加州中央谷地的自然参照、已入侵及人工构建的春池（vernal pool），探究生物入侵与主动恢复这两种生态系统扰动下，植物对土壤的直接与间接影响可能发生的变化。研究结果表明，非本地植物物种的入侵可通过改变植被组成与植物群落的组织化学特性，潜在地转变春池系统中植物向土壤的输入。具体而言，我们发现尽管非本地凋落物的分解受季节与年际变异（与降水变化相关）的驱动，但其整体分解速率显著低于本地物种。这种转变对于植物向土壤输入的长期改变具有重要意义，并对养分循环形成负反馈。此外，这些结果与历史上的主动恢复工作无关。尽管植物凋落物分解速率与群落组成发生了持续变化，但我们并未检测到与非本地植物入侵相关的地下功能变化。相反，已入侵池与自然参照池之间的土壤碳氮比（C:N ratios）和微生物生物量并无差异，但在人工修复池中，无论入侵程度如何，这两项指标均有所降低。研究结果表明，尽管观察到地上部分存在入侵正反馈，但这一趋势未必在地下部分体现；且恢复措施实施十年后，恢复遗留效应仍占主导地位。因此，限制入侵植物反馈并考虑土壤遗留效应恢复的修复措施，是受扰动短暂生态系统的最佳解决方案。