Long-term change in calcareous grassland vegetation and drivers over three time periods between 1970 and 2016

Abstract

Analysis of long-term vegetation change is limited. Furthermore most studies evaluating change only examine two snapshots in time, which makes it difficult to define rates of change and accurately assess potential drivers. To assess longterm change in calcareous grassland over multiple time periods, we re-surveyed a transect study undertaken at Parsonage Down National Nature Reserve, Wiltshire, southern England in 1970 and 1990 by T. Wells. We examined differences in soil properties and species traits in each of the survey years to understand potential drivers of vegetation change, including nitrogen deposition and grazing management. There was a clear shift in species composition, combined with significant declines in species richness and diversity between 1970 and 2016, with the greater rate of change occurring between 1990 and 2016. A significant increase in soil total nitrogen was found, which was significantly associated with the decline in species diversity between 1970 and 1990. Significant changes in community-weighted mean traits were identified for plant height (increasing), specific leaf area (decreasing), grazing tolerance (decreasing) and Ellenberg N (decreasing) between 1970 and 2016. By using survey data from multiple time periods, we suggest that N deposition may have contributed Communicated by Zoltan Nagy.Electronic supplementary material The online version of this article (https://doi.().,-volV) ( 01234567 89().,-volV) towards community changes between 1970 and 1990, as indicated by the change in soil properties and the associated decline in species diversity. Vegetation change between 1990 and 2016 is likely to be largely attributable to a decline in grazing pressure, indicated by the increase in taller species and a decrease in grazing tolerance.

Global effects of land-use intensity on local pollinator biodiversity

“…We also found significant reductions in insect abundance and richness in response to increasing fertiliser application rate on croplands, particularly for the hymenopterans and lepidopterans. Sensitivity to land-use for butterflies has previously been attributed to dietary specialism: relative to flies, many butterflies are known to be dietary specialists as larvae 4 , making a reduction in lepidopteran species richness and diversity likely when plant species richness is reduced, which is known to occur at high fertiliser application rates 3 , 41 . Previous research in the temperate zone has indicated beetle flower visitors are sensitive to land-use change 74 .…”

“…Similar indirect effects have also been shown for fertiliser application. For example, nitrogen-based fertilisers reduce plant species diversity 41 , and dispense with the requirement for clover field crop rotation, further reducing floral availability for pollinators 42 .…”

Decrease in species richness and diversity, and shrub encroachment in Cerrado grasslands: A 20 years study

“…The impact of encroaching or "super-dominant" species on richness can be due to competitive exclusion, where taller species outcompete smaller and more slender species; for instance, in the search for light (Ridding et al, 2020). Besides, the emergence of shrubs in wet grasslands led to a greater loss of water through evapotranspiration, consequently decreasing the water available in the soil for other growth forms (Budny & Benscoter, 2016).…”

Microclimate shapes vegetation response to drought in calcareous grasslands

“…At present, area losses as a result of land‐use change are considered the greatest threat to these grasslands and their species (Sala et al, 2000; WallisDeVries et al, 2002; Pompe et al, 2011). In addition, they are negatively affected by habitat degradation due to eutrophication and a lack of management (Bobbink & Willems, 1987; Bennie et al, 2006; Diekmann et al, 2014; Bauer & Albrecht, 2020; Ridding et al, 2020).…”