Urban domestic gardens (III): Composition and diversity of lawn floras

Abstract: Question: How do lawn floras compare with those of semi‐natural grasslands? Are the compositions of lawn floras determined by local, within‐garden factors (e.g. lawn management and size) or by regional factors (e.g. climate and location)? Are lawn floras nested (like semi‐natural grasslands) or not (like cultivated parts of gardens)? Are there gradients of species composition within lawns? Location: Sheffield, UK. Methods: We examined the composition of the floras of entire lawns and of two 1‐m 2 lawn quadrats in 52 gardens. Results: A total of 159 species of vascular plants was recorded, 60 of them only once. Most lawn species were forbs, but most lawn cover consisted of grasses. Lawn species were predominantly natives. Bigger lawns had more species, but richness was not closely linked to other environmental or management variables. Composition of lawn floras varied with altitude, with woodland and wetland plants more common in the higher west of the city, and weeds of waste ground in the east. The species‐area curve derived from 1‐m 2 lawn quadrats was very similar to that of semi‐natural grasslands. Lawn quadrats were significantly nested, with rarer species mostly confined to more species‐rich quadrats. Trampling‐tolerant Poa annua was more abundant in the part of the lawn nearer the house. Conclusions: In most respects, lawns behaved much more like semi‐natural grasslands than like cultivated flower beds and borders. Species composition of lawns is strongly influenced by local climate. Most lawns show an internal gradient of composition, linked to a gradient of intensity of use.