Department of Ecology, University of Szeged, Szeged, 6726, Hungary.
MTA-DE Lendület Functional and Restoration Ecology Research Group, University of Debrecen, Debrecen, 4032, Hungary.
Ecol Appl. 2022 Jan;32(1):e02463. doi: 10.1002/eap.2463. Epub 2021 Nov 21.
Grassland restoration is gaining momentum worldwide to tackle the loss of biodiversity and associated ecosystem services. Restoration methods and their effects on ecological community reassembly have been extensively studied across various grassland types, while the importance of post-restoration management has so far received less attention. Grassland management is an important surrogate for natural disturbances, with which most ancient grasslands have coevolved. Thus, without the reintroduction of management-related disturbance, restoration targets are unlikely to be achieved in restored grasslands. In this study, we aimed to explore how 20 yr of management by mowing once a year or light cattle grazing affects restoration success in Palearctic meadow-steppe grasslands restored by either sowing native grasses (sown sites), applying Medicago sativa as a nurse plant (Medicago sites), or allowing spontaneous succession (spontaneous sites). We found that, following mowing, sown sites maintained long-lasting establishment limitation, while Medicago sites experienced a delay in succession. These limitations resulted in low total and target species richness, low functional redundancy, and distinct species and functional composition compared to reference data from ancient grasslands. Spontaneous sites that were mowed reached a more advanced successional stage, although they did not reach reference levels regarding most vegetation descriptors. Sown and Medicago sites that were grazed had higher total and target species richness than those that were mowed, and showed restoration success similar to that of spontaneous sites, on which grazing had only moderate further positive effects. Grazed sites, irrespective of the restoration method, were uniformly species rich, functionally diverse, and functionally redundant, and thus became important biodiverse habitats with considerable resilience. We conclude that an optimally chosen post-restoration management may have an impact on long-term community reassembly comparable to the choice of restoration method. Restoration planners may, therefore, need to put more emphasis on future management than on the initial restoration method. However, our findings also imply that if local constraints, such as potentially high invasive propagule pressure, necessitate the application of restoration methods that could also hinder the establishment of target species, the long-term recovery of the grassland can still be ensured by wisely chosen post-restoration management.
草原恢复在全球范围内得到了重视，以应对生物多样性的丧失和相关生态系统服务的损失。在各种草原类型中，已经广泛研究了恢复方法及其对生态群落再组装的影响，而恢复后的管理的重要性迄今为止受到的关注较少。草原管理是自然干扰的重要替代物，大多数古老的草原都与这种干扰共同进化。因此，如果不重新引入与管理相关的干扰，恢复目标不太可能在恢复的草原中实现。在这项研究中，我们旨在探讨在 Palearctic 草地草原中，通过每年一次的割草或轻度放牧管理 20 年，如何影响通过播种本地草种（播种点）、应用紫花苜蓿作为保育植物（紫花苜蓿点）或自然演替（自然点）进行恢复的效果。我们发现，在割草后，播种点长期保持建立限制，而紫花苜蓿点经历了演替的延迟。这些限制导致总物种和目标物种丰富度低、功能冗余度低，与古老草原的参考数据相比，物种和功能组成明显不同。经过割草的自然点达到了更先进的演替阶段，尽管它们在大多数植被描述符方面仍未达到参考水平。放牧的播种点和紫花苜蓿点的总物种和目标物种丰富度高于割草点，并且恢复效果与放牧对其自然点的影响相似，只是适度地进一步提高了自然点的恢复效果。无论恢复方法如何，放牧的点均匀地具有丰富的物种、多样的功能和功能冗余，因此成为具有相当弹性的重要生物多样性栖息地。我们得出的结论是，经过优化选择的恢复后管理可能对长期群落再组装产生与恢复方法选择相当的影响。因此，恢复规划者可能需要比初始恢复方法更重视未来的管理。然而，我们的研究结果还表明，如果由于潜在的高入侵繁殖体压力等局部限制需要应用可能会阻碍目标物种建立的恢复方法，那么通过明智地选择恢复后的管理，仍然可以确保草原的长期恢复。
