Over-yielding in an intercropping system occurs when the productivity of the intercrop exceeds the overall productivity of the systems managed in segregation. The objective of this systematic review was to calculate the over-yielding of silvopastures compared to open pastures and forests, timber plantations, or orchards managed separately. A literature search was completed for comparisons of the productivity of these practices in temperate regions. Data collected from these studies included mean yields of timber or non-timber forest products, forages, and livestock, as well as the characteristics of the study site. Silvopasture practices improve the productivity of land typically managed separately for pasture or trees by 42–55%, depending on whether the productivity of the pastures is measured by livestock or forage output, respectively. In most cases, over-yielding occurred despite a reduction in individual forage, livestock, or tree productivity in the silvopastures. Calculating confidence intervals around these means was not feasible because standard errors were largely not reported or available. Some assumptions were made about the actual productivity of timber or non-timber forest products. This work illustrates the significant level of over-yielding that may be achieved by integrating trees, forages, and livestock into a single production system.

中文翻译：

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温带林场产量过高：荟萃分析

当间作系统的生产力超过隔离管理系统的总生产力时，就会出现间作系统的超产。本系统评价的目的是计算森林牧场与单独管理的开放牧场和森林、用材种植园或果园相比的高产。完成了文献检索，以比较温带地区这些做法的生产力。从这些研究中收集的数据包括木材或非木材林产品、草料和牲畜的平均产量，以及研究地点的特征。林场的做法将通常单独管理牧场或树木的土地的生产力提高了 42-55%，具体取决于牧场的生产力是分别通过牲畜还是草料产量来衡量的。在大多数情况下，尽管林场中个体草料、牲畜或树木的生产力下降，但仍会出现高产。围绕这些平均值计算置信区间是不可行的，因为标准误差在很大程度上没有报告或可用。对木材或非木材林产品的实际生产力做了一些假设。这项工作说明了通过将树木、草料和牲畜整合到一个单一的生产系统中可以实现的显着超产水平。对木材或非木材林产品的实际生产力做了一些假设。这项工作说明了通过将树木、草料和牲畜整合到一个单一的生产系统中可以实现的显着超产水平。对木材或非木材林产品的实际生产力做了一些假设。这项工作说明了通过将树木、草料和牲畜整合到一个单一的生产系统中可以实现的显着超产水平。