Acidifying arable soils for the restoration of acid grasslands

Abstract

Abstract. Minsmere is a large nature reserve in East Anglia UK, owned and managed by the Royal Society for the Protection of Birds (RSPB). Two blocks of land, which were farmed commercially until 1990, have been bought in an attempt to link existing patches of heathland and acid grassland, thus creating a larger area for conservation. This paper discusses methods for the creation of acid grasslands. Previous studies of the arable soils in these fields identified three constraints ‐a depauperate seed bank, a high pH and vigorous growth of ruderal species after the fields were abandoned. Accordingly, experiments were set up to test the effects of (1) adding seed of species typical of acid grasslands and (2) adding amendments (elemental sulphur, litter of Pteridium aquilinum and pine chippings) to acidify the soil. The results confirmed that ruderal growth was high on unamended plots, but this could be reduced by addition of acidic amendments. Where the cover of ruderals was reduced, the cover of the sown species increased. The sown species colonized adjacent unsown subplots naturally and this was most pronounced where the acidity had been reduced by treatment. The most effective treatment was 21 S/ha, which gave the optimal reduction in soil pH, controlled ruderal growth and provided a reasonable cover of the sown species. The addition of Pteridium litter or pine chippings gave good establishment of sown species, but control of the ruderals was less effective.

Recreation of lowland heathland on ex‐arable land: assessing the limiting processes on two sites with contrasting soil fertility and pH

“…2a,b). In contrast with previous studies (Owen & Marrs 2000b), these changes were associated with a significant increase in the availability of soil P as calcium phosphate complexes were broken down (Fig. 2c,d).…”

“…This experiment demonstrated that applications of S can reduce the pH of agricultural soils, thereby confirming the findings of previous studies (Owen & Marrs 2000b; Lawson et al . 2004): the pH declined to pH < 3·0 on the high S‐addition plots before stabilizing close to the target levels of pH 4·5 and 5·5 (Fig.…”

Do restored calcareous grasslands on former arable fields resemble ancient targets? The effect of time, methods and environment on outcomes

“…Typically, plant attributes found more commonly in ancient calcareous grassland indicate a degree of specialization (animal-dispersed fruits), longevity and stress-tolerance (woody plants and hemicryptophytes). In contrast, ex-arable soil favoured opportunistic, generalist species that thrive on soil where competition for nutrients and space is not yet established (Owen & Marrs 2000), that is, short-lived species of high reproductive rate and few specific habitat requirements. Attributes that epitomize this are wind dispersal of seeds and reliance on a seed bank for reproduction.…”

Past Imperfect

“…Such site-level intensive management as part of restoration is quite prevalent (and more accepted) in European restoration projects (e.g., Owen andMars 2000, Klimkowska et al 2010). However, in much of North America, site/patch restoration without concomitant restoration of the surrounding landscape will inevitably result in the "islands of habitat" phenomena that so many smaller North American protected areas currently face (Gurd andNudds 1999, Parks andHarcourt 2002).…”