Calcareous grasslands are of high conservation importance and have been maintained by livestock grazing over many centuries. Following the reduction in traditional livestock grazing (cattle and sheep) of semi-natural grassland during the twentieth century, conservation-based grazing management was introduced in order to conserve remaining grasslands. In UK semi-natural grasslands, grazing pressure has fluctuated over time due to changes in conservation funding and stock availability, whilst the time of year at which stock graze has also shifted. There is little quantitative data available to demonstrate the details of changed grazing patterns, or their long-term effects on the vegetation, thus the full impacts of these changes are not well understood. This study examines the response of a diverse calcareous grassland community to changes in grazing management between 1979 and 2010 at Martin Down National Nature Reserve, southern England, using historical vegetation surveys and grazing records collected and recorded by reserve staff. Historical data showed a shift in grazing regime, whereby grazing occurred across all seasons in the early period, but switched to predominately the autumn and winter in the present century. Despite this significant shift in management over time, the vegetation community did not change dramatically over this period, although small increases in species richness and diversity were detected. The richness of calcareous grassland indicator species remained largely consistent, suggesting the conservation value of the grassland persisted, and the community types also stayed fairly constant over the 31 years. Furthermore, weak evidence was found for impacts of grazing in particular seasons on vegetation community measures; species richness, species diversity, indicator richness, indicator abundance, grass abundance and forb abundance. This study suggests that these vegetation communities are robust to changes in grazing seasonality providing that sufficient grazing pressure is provided within the year. The compartmentalised grazing employed at Martin Down may be a useful method for ensuring this outcome. However more research is required, preferably using controlled field experiments before more reliable recommendations can be prescribed.

石灰质草原具有高度的保护重要性，几个世纪以来一直由牲畜放牧维持。随着 20 世纪半天然草原的传统牲畜放牧（牛和羊）的减少，引入了基于保护的放牧管理以保护剩余的草原。在英国半天然草原，由于保护资金和牲畜供应的变化，放牧压力随着时间的推移而波动，而牲畜放牧的时间也发生了变化。很少有定量数据可以证明放牧模式变化的细节或其对植被的长期影响，因此这些变化的全部影响尚不清楚。本研究使用历史植被调查和保护区工作人员收集和记录的放牧记录，检查了 1979 年至 2010 年间英格兰南部马丁唐国家自然保护区的不同钙质草原社区对放牧管理变化的反应。历史资料表明，放牧制度发生了转变，早期为全季放牧，本世纪转为以秋冬季为主。尽管随着时间的推移管理发生了重大转变，但植被群落在此期间并未发生显着变化，尽管检测到物种丰富度和多样性略有增加。钙质草地指示物种丰富度基本保持一致，表明草地保护价值持续存在，并且社区类型在 31 年中也保持相当稳定。此外，发现特定季节放牧对植被群落措施影响的证据不足；物种丰富度、物种多样性、指标丰富度、指标丰度、草丰度和杂草丰度。这项研究表明，如果一年内提供足够的放牧压力，这些植被群落对放牧季节性的变化是稳健的。Martin Down 采用的分区放牧可能是确保这一结果的有用方法。然而，在制定更可靠的建议之前，还需要更多的研究，最好使用受控的现场实验。发现特定季节放牧对植被群落措施影响的证据不足；物种丰富度、物种多样性、指标丰富度、指标丰度、草丰度和杂草丰度。这项研究表明，如果一年内提供足够的放牧压力，这些植被群落对放牧季节性的变化是稳健的。Martin Down 采用的分区放牧可能是确保这一结果的有用方法。然而，在制定更可靠的建议之前，还需要更多的研究，最好使用受控的现场实验。发现特定季节放牧对植被群落措施影响的证据不足；物种丰富度、物种多样性、指标丰富度、指标丰度、草丰度和杂草丰度。这项研究表明，如果一年内提供足够的放牧压力，这些植被群落对放牧季节性的变化是稳健的。Martin Down 采用的分区放牧可能是确保这一结果的有用方法。然而，在制定更可靠的建议之前，还需要更多的研究，最好使用受控的现场实验。这项研究表明，如果一年内提供足够的放牧压力，这些植被群落对放牧季节性的变化是稳健的。Martin Down 采用的分区放牧可能是确保这一结果的有用方法。然而，在制定更可靠的建议之前，还需要更多的研究，最好使用受控的现场实验。这项研究表明，如果一年内提供足够的放牧压力，这些植被群落对放牧季节性的变化是稳健的。Martin Down 采用的分区放牧可能是确保这一结果的有用方法。然而，在制定更可靠的建议之前，还需要更多的研究，最好使用受控的现场实验。