Hierarchical Consequences of Intraspecific Variation on Community and Ecosystem Re-assembly

人类在恢复受干扰环境的原始结构（如植被组成）和功能方面发挥着重要作用。特别是高草草原的恢复是一个及时的问题，因为这个生态系统的大部分历史范围已经转化为农业。尽管付出了很多努力和兴趣，但对影响恢复成功的许多因素知之甚少。草原草品种的广泛商业化生产源于开发最能控制侵蚀的本土植物的努力。商品生产选择有活力的性状以增加植株成活率。然而，这些特征可能会增加植物相对于原生草原同种植物的竞争能力。在伊利诺斯州南部的一块农田里，将建立试验田，种植主要草原牧草的品种或原生草原品种，并混合种植草原野花。该实验将对植物性状进行为期四年的监测，并评估草的来源（即栽培和原生草原）是否影响其他物种（即野花）的建立，以及恢复过程中发生的其他重要过程的恢复，如植物的整体生长和土壤健康的改善。另外两个位于伊利诺斯州中部和堪萨斯州的试验地也有类似的情况，将对其进行监测，以便将结果推广到整个高草草原地区。虽然在草原恢复中广泛使用栽培品种，但通过引入潜在更具竞争力的植物来恢复栖息地的长期后果（对群落聚集和生态系统恢复）尚不清楚。如果品种是优势竞争者，它们可能会增加恢复对生物多样性至关重要的数量较少的非草类物种的难度。一旦从种子混合物中确定植物组成的几乎不可逆的性质，强调了需要关于用于恢复的物种的生态影响的信息。这与高草草原特别相关，在那里恢复各种物种是很难实现的。

Humans play an important role in restoring disturbed environments to their original structure (e.g., composition of vegetation) and function. Tallgrass prairie restoration, in particular is a timely issue because most of the historic extent of this ecosystem has been converted to agriculture. Despite much effort and interest, little is known about many factors that could influence restoration success. Widespread commercial production of prairie grass cultivars has resulted from efforts to develop native plants best for erosion control. Commercial production selects for vigorous traits to increase plant establishment. These traits, however, may increase the competitive ability of plants relative to plants of the same species from native prairie. Experimental plots will be established with cultivar or native prairie sources of the dominant prairie grasses along with a mix of prairie wildflowers in an agricultural field in southern Illinois. This experiment will monitor plant traits for four years and evaluate whether sources of grasses (i.e., cultivar and native prairie) influence the establishment of other species (i.e., wildflowers) and the recovery of other important processes that occur during restoration such as overall plant growth and improvements in soil health. Two additional sites in central Illinois and Kansas, containing similar experimental plots, will be monitored to generalize results to the tallgrass prairie region as a whole. Although cultivars are widely used in prairie restorations, the long-term consequences (for community assembly and ecosystem recovery) of restoring habitats by introducing potentially more competitive plants are unknown. If cultivars are superior competitors, they may increase the difficulty in restoring the less abundant non-grass species that are critical to biodiversity. The nearly irreversible nature of plant composition once established from seed mixtures underscores the need for information on the ecological effects of species used in restorations. This is particularly relevant to tallgrass prairie, where restoring a variety of species is difficult to achieve.