The encroachment of woody plants into grasslands, woodland, and savanna has increased markedly over the past century, prompting the use of different physical methods to remove woody plants and restore grasses. Roller‐chopping is used extensively in the Americas, but little is known about its long‐term effectiveness for restoration, and whether its effectiveness varies with the intensity of encroachment. We compared the effects of roller‐chopping, under three treatment intensities (control, single treatment, double treatment), on woody plant density, ground cover, and groundstorey plants at sites of low, moderate, and high woody plant density in a semi‐arid eastern Australian woodland over 10 years. Both single and double treatment significantly altered the size distribution of Dodonaea viscosa, which comprised more than 85% of woody plants at all sites. Thus, roller‐chopping changed the size distribution of the community from an even‐size distribution to one dominated by shorter plants, irrespective of initial encroachment level. The effectiveness of roller‐chopping was strongly site‐specific, with significant reductions in density at low‐ and high‐density sites, but no clear trend in relation to the intensity of treatment (i.e. single cf. double treatment). The effectiveness of roller‐chopping was unsustained over the long term, with the suppressive effect on woody density diminishing over time. Grass cover increased with increasing intensity of woody removal, but only at the low‐density site and with some ill‐defined, variable, and short‐term effects on plant composition. Managers should consider that the short‐term effects may not adequately reflect the long‐term results of woody plant removal using the roller‐chopper.

中文翻译：

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滚木砍伐对控制木本虫害的长期有效性有限

在过去的一个世纪中，木本植物对草原，林地和热带稀树草原的侵害显着增加，促使人们使用各种物理方法清除木本植物并恢复草木。滚刀斩波在美洲已广泛使用，但对其恢复的长期效果以及其有效性是否随侵害强度而变化知之甚少。我们比较了三种处理强度（对照，单处理，双重处理）下半切式种植对低，中和高木本植物密度，木本植物密度，地被植物和地上植物的轮作的影响。超过十年的澳大利亚东部干旱林地。单次处理和双重处理均显着改变了粘皮十二指肠的大小分布，其中所有地点的木本植物均占85％以上。因此，不管最初的侵占水平如何，砍伐都会使群落的大小分布从均匀的分布变为较短的植物为主的分布。滚刀切碎的效果强烈地针对特定地点，在低密度和高密度地点的密度显着降低，但与治疗强度（即单处理与双重处理）没有明显的关系。从长远来看，切碎辊的有效性无法维持，随着时间的流逝，对木本密度的抑制作用逐渐减弱。草木覆盖率随木本植物清除强度的增加而增加，但仅在低密度地区，并且对植物组成有不确定的，可变的和短期的影响。