1. Hydromorphological rehabilitation through installing large woody material (LWM) is increasingly being used to reverse degradation of stream ecosystems. There have been many criticisms of stream rehabilitation projects, because many have not met their goals and many others have not been monitored well enough to assess whether their goals were met.
2. In a before–after–control design (with samples collected 1 year before and two successive years after LWM installation), instream biotopes and their macroinvertebrate assemblages were used as structural and functional units to assess the effectiveness of LWM installed at the Rolleston Brook, a headwater tributary of the River Welland in Leicestershire, UK.
3. The project was successful in enhancing the coefficient of variation of channel water depth and width, wetted surface area, number of instream biotopes, and the biotope diversity in the rehabilitated reach.
4. LWM installation led to significant increases in macroinvertebrate total density, total biomass, and taxon richness. Macroinvertebrate community composition was also enhanced, so that it became more similar to that of the control reach.
5. Small increases in the number of instream biotopes (appearance of gravel and leaf litter) and changes in biotope proportions (decreasing percentage of silt) were significantly related to changes in the macroinvertebrate community metrics in the rehabilitated reach.
6. The results show that using macroinvertebrate community composition is more effective than only using taxon richness and/or diversity metrics for understanding the relationship between LWM installation and macroinvertebrate community responses. To be effective, samples must also be collected in a predefined sampling protocol stratified at the instream biotope level. This approach would be of great benefit in evaluating biodiversity conservation value, and could be incorporated into the advice provided by Natural England concerning restoration and protection of English rivers that are designated as Sites of Special Scientific Interest under UK legislation or Special Areas of Conservation under European legislation.

中文翻译：

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在上游水源中添加大量木本材料对大型无脊椎动物群落结构和功能具有直接好处。

1. 通过安装大型木质材料（LWM）进行的水形态恢复正越来越多地用于逆转河流生态系统的退化。对溪流修复项目提出了许多批评，因为许多项目没有达到其目标，而其他许多项目还没有得到足够的监控以评估其目标是否实现。
2. 在前后对照设计中（在LWM安装前1年和连续2年后收集的样品）中，将上游生物群落及其大型无脊椎动物组合用作结构和功能单元，以评估在Rolleston Brook，LWM上安装的LWM的有效性。韦兰河的源头支流在英国莱斯特郡。
3. 该项目成功地提高了河道水深和宽度，湿润的表面积，河床生物群落的数量以及修复后河段生物群落多样性的变异系数。
4. LWM的安装导致了大型无脊椎动物总密度，总生物量和分类单元丰富度的显着增加。无脊椎动物的群落组成也得到了增强，使其与对照范围更加相似。
5. 上游生物群落数量的小幅增加（砾石和叶子凋落物的出现）和生物群落比例的变化（淤泥百分比的降低）与恢复后的大型无脊椎动物群落指标的变化显着相关。
6. 结果表明，使用大型无脊椎动物群落组成比仅使用分类单元丰富度和/或多样性度量标准来了解LWM安装与大型无脊椎动物群落反应之间的关系更有效。为了有效，还必须按照在上游生物群落水平分层的预定义采样方案收集样品。这种方法在评估生物多样性保护价值方面将大有裨益，并且可以纳入英国自然保护协会提供的有关恢复和保护英国河流的建议中，该建议被英国立法指定为具有特殊科学意义的地点，而在欧洲则被指定为特殊保护区立法。