Abstract

Globally insects are in decline, with the transformation of natural areas for agriculture one of the most important drivers of this decline. Yet, insects play an important role in regulating ecosystem services such as pollination, soil fertility and pest suppression, so their conservation within agricultural areas is critical. We examined comparative impacts of traditional small-scale low input farming versus large-scale conventional farming systems, and mono-cropped versus inter-cropped systems in Kenyan maize fields on predator, ant and herbivore arthropod species richness and composition. We also considered the value of hedgerows and percentage of surrounding maize cover for arthropod conservation. As expected, traditional farming retained higher herbivore species richness, evenness and abundance, as well as higher predator abundance compared to conventional farming. Percentage maize cover was positively correlated to ant species richness, predator and herbivore abundance, as well as determining species assemblage composition for ants and herbivores. Hedgerow volume and the comparison of mono- vs inter-cropping were important predictors for predator evenness. These results suggest that the low input farming systems retain far higher arthropod numbers, although this does not seem to be due to the use of intercropping on the farms. Rather it seems that hedgerows play an important role in maintaining arthropods. While higher maize coverage surrounding the farm increases the species and abundance of arthropods in the fields, this is most likely due to the high biotope fidelity of arthropods that specialize in open cropping systems such as maize fields.

Implications for insect conservation

The results here are encouraging as the retention of culturally important farming techniques (i.e., the traditional Kenyan farmers) and small improvements, such as the retention of hedgerows, greatly promotes biodiversity in the farmlands.

中文翻译：

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小规模传统玉米种植比传统玉米种植更能促进节肢动物多样性价值

摘要

全球昆虫数量正在减少，农业自然区域的转变是这种减少的最重要驱动因素之一。然而，昆虫在调节授粉、土壤肥力和害虫抑制等生态系统服务方面发挥着重要作用，因此它们在农业区内的保护至关重要。我们研究了肯尼亚玉米田中传统小规模低投入农业与大规模传统农业系统以及单作与间作系统对捕食者、蚂蚁和食草动物节肢动物物种丰富度和组成的比较影响。我们还考虑了树篱的价值和周围玉米覆盖率对节肢动物保护的影响。正如预期的那样，传统农业保留了更高的食草动物物种丰富度、均匀度和丰富度，以及与传统农业相比更高的捕食者丰度。玉米覆盖率与蚂蚁物种丰富度、捕食者和食草动物的丰度以及确定蚂蚁和食草动物的物种组合组成呈正相关。绿篱体积和单作与间作的比较是捕食者均匀度的重要预测指标。这些结果表明，低投入农业系统保留了更高的节肢动物数量，尽管这似乎不是由于在农场使用间作。相反，树篱似乎在维持节肢动物方面发挥着重要作用。虽然农场周围更高的玉米覆盖率增加了田间节肢动物的种类和丰度，

对昆虫保护的影响

这里的结果令人鼓舞，因为保留了具有重要文化意义的耕作技术（即传统的肯尼亚农民）和小的改进，例如保留树篱，极大地促进了农田的生物多样性。