Currently, the quantitative assessment of revegetation is often limited to within a few years of vegetation construction. Thus, it is imperative to gather information regarding vegetation transition such as plant species composition and identify new indicators that can be applied to evaluate long-term vegetation restoration on revegetated slopes. To achieve this, the vegetation on the oldest expressway slopes in Japan and its transitions were studied 53 years after construction using the Braun–Blanquet method, cluster analysis, and indicator species analysis (INSPAN), and two vegetation successional patterns were identified. The first pattern, a vegetation transition dominated by deciduous broad-leaved trees, was observed on orthosere slopes. Despite a previous study predicting the establishment of a Pinus densiflora-dominant community by about 50 years after construction, no adult P. densiflora trees were identified in this study, and pine wilt disease was implicated. The second pattern, a transition to a plagiosere with Pueraria lobata as an indicator species, was observed on slopes where a P. densiflora-dominant community had been established 33 years after the construction. A plagiosere with a bamboo-dominant community was newly identified in addition to the previously reported P. lobata-dominated one. All the plagiosere slopes displayed single-peak community structures, in which the highest coverage was recorded for the lower tree layer, community height was less than 10 m, and P. lobata as an indicator species. It is suggested that these common features are indicative of the vegetation shift to a plagiosere and are useful as long-term revegetation evaluation criteria.

中文翻译：

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中部地区建设后53年的人造斜坡上的长期植被过渡

目前，对植被的定量评估通常仅限于植被建设的几年之内。因此，必须收集有关植被过渡的信息，例如植物物种组成，并确定可用于评估植被坡上的长期植被恢复的新指标。为了实现这一目标，在日本最古老的高速公路斜坡及其过渡期之后的植被，在建设53年后使用Braun-Blanquet方法，聚类分析和指示物种分析（INSPAN）进行了研究，并确定了两种植被演替模式。在正石坡上观察到第一种模式，即以落叶阔叶树为主的植被过渡。尽管先前的一项研究预言了松树的建立建造后约50年为主要群落，在该研究中未鉴定到成年的体育花树，也暗示有松树枯萎病。第二种模式是在建设33年后建立了以P. densiflora为主的群落的斜坡上，观察到以葛根为指示物种向斜gi过渡。用竹为主的社区一plagiosere除了此前公布的是新标识葛根-dominated之一。所有斜方斜坡均表现出单峰群落结构，其中较低的树层记录了最高的覆盖率，群落高度小于10 m，以及P. lobata作为指示物种。建议这些共同特征指示植被向to生过渡，并可用作长期植被评估标准。