Data from: Past tree influence and prescribed fire mediate biotic interactions and community reassembly in a grassland-restoration experiment

Woody plant encroachment of grasslands is occurring globally, with profound ecological consequences. Attempts to restore herbaceous dominance may fail if the woody state is resilient or if intervention leads to an alternate, undesirable state. Restoration outcomes often hinge on biotic interactions – particularly on priority effects that inhibit or promote community reassembly. Following experimental tree removal from conifer-invaded grasslands, we documented substantial variation in community reassembly associated with the changing abundance of the native clonal sedge Carex inops L.H. Bailey subsp. inops. We explored possible mechanisms for this variation, focusing on the nature and timing of interactions between the meadow community and Carex and on how past tree influence and prescribed fire mediate the outcomes of these interactions. Meadow species increased after tree removal, but less so in burned than in unburned plots. Carex expanded dramatically after fire, particularly where past tree influence had been greater. Meadow species and Carex developed an increasingly negative association over time; pre-emption was reciprocal, but offset in time and space. Meadow species inhibited Carex through vegetative recovery in areas of limited or recent tree influence, irrespective of fire. Carex inhibited meadow reassembly in areas of greater tree influence, but only with burning. Synthesis and applications. Tree removal and fire imposed across a range of altered meadow states yielded varying outcomes, reflecting biotic interactions and species' regenerative traits that inhibited or promoted reassembly. Fire tended to destabilize the remnant meadow community and, in areas more degraded by encroachment, stimulated release of Carex, which inhibited reassembly. Knowledge of the context dependence of biotic interactions can enhance the effectiveness of restoration by establishing the bounds within which treatments produce desirable or undesirable outcomes.

全球范围内，木本植物入侵草原的现象正持续发生，并带来了深远的生态影响。
若木本群落具备恢复力，或是干预措施引发了非预期的替代群落状态，恢复草本优势的尝试可能会失败。
修复成效通常取决于生物间相互作用——尤其是那些抑制或促进群落重建的优先效应（priority effects）。
在对针叶树入侵的草原开展实验性伐除后，我们记录到群落重建过程中存在显著差异，该差异与本土克隆薹草（clonal sedge）*Carex inops* L.H. Bailey subsp. *inops*的丰度变化密切相关。
我们针对该差异的潜在机制展开探究，重点关注草甸群落与该薹草之间相互作用的本质与时序，以及过往树木影响与计划火烧（prescribed fire）如何调节这些相互作用的结果。
伐除树木后，草甸物种的丰度有所提升，但火烧样地的提升幅度低于未火烧样地。
该薹草在火烧后出现显著扩张，尤其在过往树木影响更强的区域。
随着时间推移，草甸物种与该薹草之间的负相关关系逐渐增强；二者存在相互的优先占据效应，但该效应在时间与空间上存在抵消。
在树木影响有限或新近受树木影响的区域，草甸物种通过营养恢复抑制该薹草的生长，且不受火烧处理的影响。
在树木影响更强的区域，该薹草仅在火烧处理下才会抑制草甸群落的重建。
总结与应用。
在一系列经木本入侵改变的草甸状态下开展伐树与火烧处理，得到了各异的修复结果，这反映出抑制或促进群落重建的生物相互作用与物种再生特性的作用。
火烧往往会破坏残存草甸群落的稳定性，而在受木本入侵更为严重的区域，火烧会促进该薹草的种群扩张，进而抑制群落重建。
明晰生物相互作用的情境依赖性，能够通过明确处理措施产生预期或非预期结果的边界条件，提升修复工作的有效性。

搜集汇总

背景与挑战

背景概述

该数据集基于草地恢复实验，研究了过去树木入侵和火管理如何调节生物相互作用和群落重组过程。数据集包含实验子地块的覆盖度、丰富度、火严重度等数据，重点关注入侵树木移除后火对本地物种（如Carex inops）和草地群落恢复的影响。通过分析生物相互作用（如优先效应和竞争），数据集旨在为恢复实践提供基于生态机制的指导。