We explored the structure of plant assemblages that settles around the anthills of a guild of Hymenoptera Formicidae (Messor wasmanni Krausse 1910, Tapinoma nigerrimum Nylander 1856 and Aphaenogaster spinosa Emery 1878), observable in urban grasslands dominated by Dasypyrum villosum (Rome, Central Italy). Since it is known that ants act as a disturbing factor on plant assemblages of grasslands, our hypothesis was that vegetation structures suffer from some stressors that affect, in this plant association, the dominant plant structure. We compared the plant assemblages observed in the plots of the anthills with the control grassland assemblages using a diversity/dominance diagram. We recorded 63 plant taxa. The average number of plant species was found to be significantly lower in anthill plots than in control grassland plots. In anthill plots, dominant plant species (Polygonum romanum, Poa trivialis Vulpia myuros, Aira elegantissima and Vulpia ligustica) have been found to be different from control grassland plots (Convolvolus arvensis, Dasypyrum villosum, Poa trivialis and Sheradia arvensis). Anthill plant assemblages were found to be significantly different (One-way PERMANOVA) and poorer in terms of species richness, less diversified, and with a reduced species turnover than control grassland plots. Whittaker plot analysis seems to show that the plant assemblages of the control, with greater evenness, emphasize a stressed condition in anthill plant assemblages. Non-metric multidimensional scaling shows a set of species strictly linked to anthills. Our data seem to confirm the role of ants as a stressor in the plant assemblage structures of Mediterranean urban grasslands. However, our results also show that the peculiar ant nest conditions may favor plant species less represented in the Dasypyretum grasslands (i.e. Polygonum romanum) or even absent in this plant assemblage (i.e. Aira elegantissima, Cynodon dactylon and Poa annua), thus increasing the overall local plant diversity.

我们探索了在膜翅目蚁科 ( Messor wasmanni Krausse 1910、Tapinoma nigerrimum Nylander 1856 和Aphaenogaster spinosa Emery 1878) 的蚁丘周围定居的植物组合的结构，这些植物组合可以在以绒毛菊为主的城市草原中观察到（罗马，意大利中部）。由于众所周知蚂蚁是草原植物组合的干扰因素，我们的假设是植被结构受到一些压力源的影响，在这种植物组合中，主要植物结构受到影响。我们使用多样性/优势图比较了在蚁丘地块中观察到的植物组合与对照草地组合。我们记录了 63 个植物分类群。发现蚁丘地块的植物物种平均数量显着低于对照草地地块。在蚁丘地块中，优势植物物种（Poa trivialis Vulpia myuros、Aira Elegantissima和Vulpia ligustica）被发现与对照草地地块不同（Convolus arvensis、Dasypyrum villosum、Poa trivialis和Sheradia arvensis）。与对照草地相比，蚁丘植物组合被发现存在显着差异（单向 PERMANOVA），并且在物种丰富度、多样性较低和物种周转率方面较差。Whittaker 图分析似乎表明，对照的植物组合具有更大的均匀度，强调蚁丘植物组合中的压力条件。非度量多维缩放显示了一组与蚁丘严格相关的物种。我们的数据似乎证实了蚂蚁在地中海城市草原植物组合结构中作为压力源的作用。然而，我们的研究结果还表明，特殊的蚁巢条件可能有利于在蚁巢中较少出现的植物物种。Dasypyretum草原（即Polygonum romanum ）或什至不存在于该植物组合中（即Aira Elegantissima、Cynodon dactylon和Poa annua），从而增加了当地植物的整体多样性。