摘要:有机农业有利于增加农田中的植物多样性，而丰富的植物群落可以为其他动物提供诸如蜜源、寄主、栖息地等多种生态系统服务功能。本研究基于一个有机管理的大面积多生境农场及其附近常规管理的农田区，进行植物调查，对比不同管理措施下大棚菜地、果园、稻田田埂、露天田块及其周边的农田边界等5种生境类型农田草本植物α、β和γ多样性的差异。研究发现，虽然有机管理下所有生境的草本植物物种数和药用草本植物物种数（α多样性）的平均数显著高于常规管理农田，但针对某一具体生境比较发现，有机管理仅显著增加了露天田块和水稻田埂的植物物种数，而对其他生境影响不显著。虽然有机管理农场和常规管理农田区的总体物种组成差异（β多样性）不大，但有机管理下水稻田埂和露天田块的草本植物物种组成显著不同于常规管理下的对应生境。总的植物物种数（γ多样性）在有机管理的农场区和常规管理的农田区间没有显著差异。由此可见本研究中有机管理仅有利于水稻田埂和露天田块的草本植物α多样性和β多样性的增加，而对大棚菜地、农田边界和果园影响不明显，并且有机管理并不能显著地增加该地区的草本植物γ多样性。因此有机农业增加植物多样性并不具有普遍性，需要具体考虑不同生境和不同层次多样性指数的差异。
Abstract:Organic agriculture is conducive to increasing plant diversity in farmland, and rich plant communities can provide animals with a range of services, including sources of pollen for honey, host, and habitats. Although there have been many studies of the effect of organic management on plant α diversity in single farmland habitat, little research into β and γ diversity has been conducted. In this study, a large area of organically managed farmland and a nearby conventionally managed farmland with multi-habitats were selected, and the differences in the α, β, and γ diversity of herbaceous plants between two management practices and among different habitat types were studied. In both cases, the farmland habitats included vegetable greenhouse, orchard, open-air field, field boundary, and paddy ridge. The herb plant survey was conducted at the start of summer. Findings from ANOVA revealed that, though the average number of local herb plants and medicinal herb plants (α diversity) was significantly higher in all habitats in organic farmland than the case in conventional farmland, organic management only increased the number of herb plant and medicinal herb plant species in open-air field and the number of medicinal herb plant species in paddy ridge. The impact of organic management on other habitats was not significant. Under conventional management, there were no significant differences in the number of plant species among five habitat types. However, under organic management, the number of herb plant species in open-air field and medicinal herb plant species in paddy ridge were significantly higher than those in vegetable greenhouse. Results of non-metric multi-dimensional analysis based on the Manhattan index indicated that, although there was no difference in the overall species composition (β diversity) of organically managed farmland and conventionally managed farmland, there were significant differences between organic management and conventional management in the herb plant and medicinal herb plant species compositions of open-air field and paddy ridge. β diversity was higher in organic farmland than in conventional farmland, and relatively independent plant communities formed in different habitats. A rarefaction curve of species richness indicated that, although the total number of herb plant species and the number of medicinal herb species (γ diversity) in organically managed farmland were higher than those in conventionally managed farmland, the difference was not significant statistically. Organic management increased the α diversity and β diversity of herbaceous plants in both paddy ridge and open-air field, but there was no obviously beneficial effect of organic management in vegetable greenhouse, field boundary, and orchard. The increase in local α diversity and β diversity did not necessarily result in a significant increase in γ diversity. In summary, it cannot be concluded universally that organic agriculture can increase plant diversity in different habitats and at different spatial scales. It is necessary to specifically consider the differences in different habitats and diversity indices at different spatial scales. Longer implementation of organic management, low-frequency weeding, and artificial increases in the pool of local plant species can help increase herbaceous plant diversity of the entire region and in all habitat types.
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