Socio-economic and environmental drivers are causing large scale abandonment of agricultural land worldwide. Simultaneously, there is growing recognition that urgent and widespread revegetation is required in our agricultural landscapes to restore biodiversity, ecosystem services and promote carbon sequestration. The design of effective revegetation strategies, however, can be limited by a lack of knowledge regarding patterns and processes of regeneration. Here, we examine naturally regenerating woody vegetation on 12 old-fields and compare this to paired remnant vegetation across four regions of a semi-arid agricultural area in eastern Australia. We found that naturally regenerating vegetation on old-fields exhibited similarities to remnant vegetation in terms of composition but varied substantially with respect to key structural attributes. Woody vegetation tends to regenerate in these old-fields with relatively high density given sufficient time (~ 30–40 years), but prior to this, very limited structural recovery occurs at all. The composition and richness of tree seedling and shrub assemblages did not differ between remnant and old-field areas. However, tree assemblages in remnant areas differed in composition and had higher species richness. Old-fields had extremely low numbers of exotic trees and shrubs. Simultaneously, most dominant native species present in the remnant vegetation were also observed in regenerating old-fields, contributing to a low degree of compositional difference between old-fields and remnant areas overall. The abundance of paddock trees, time since abandonment and mean annual rainfall are key drivers influencing natural regeneration of these old-fields. We recommend that natural regeneration is a viable form of restoration of old-fields in the northern Murray-Darling Basin given sufficient time.

社会经济和环境驱动因素正在导致全世界范围内大量的农业用地被抛弃。同时，人们越来越认识到，在我们的农业景观中需要紧急和广泛的植被恢复，以恢复生物多样性，生态系统服务并促进碳固存。但是，有效的植被恢复策略的设计可能会因缺乏有关再生模式和过程的知识而受到限制。在这里，我们检查了12个旧土地上自然再生的木本植被，并将其与澳大利亚东部半干旱农业区的四个区域中成对的残留植被进行了比较。我们发现，在旧田地上自然再生的植被在成分上表现出与残余植被的相似之处，但在关键结构属性方面却有很大差异。如果有足够的时间（约30–40年），木质植被往往会在这些老田中以相对较高的密度进行再生，但是在此之前，完全没有进行过结构恢复。剩余和老田间树木幼苗和灌木组合的组成和丰富度没有差异。但是，剩余地区的树木组合组成不同，物种丰富度更高。旧田地的奇异树木和灌木数量极少。同时，在更新的旧田地中还观察到了残留植被中存在的大多数优势本地物种，这导致旧田地和整个残留区之间的成分差异很小。围场树木的丰富，废弃后的时间和年均降雨量是影响这些老田自然更新的关键驱动力。