Summary1. The search for appropriate management strategies to control invasive plants is an important theme in environmental management. However, the recovery of the resident community species complement does not necessarily respond predictably to restoration efforts. Increasing restoration success requires an understanding of the resistance and resilience of the invaded community and the response of the newly developing community to management. Here, we used Pteridium-invaded heath and grass communities as a test system and investigated the effects of recommended Pteridium aquilinum control treatments on vegetation composition and diversity. 2. We evaluated seven field experiments in four regions of Great Britain designed to test five Pteridium control treatments, including 'one-off' (applied only at the start) and 'repeated' (applied regularly) treatments, against an untreated experimental control. The sites had context-dependent restoration targets, either a Calluna heathland or acid grassland. Species cover and diversity responses (higher plants, mosses plus lichens) to these treatments were monitored annually for 10 years. 3. Pteridium control treatments induced significant change in species composition compared to experimental controls in both vegetation types. On Calluna target sites, 'repeated' treatments overcame the resistance of the invaded community producing a gradual divergence in species composition and species diversity. In contrast, the 'one-off' treatments were ineffective. 4. At the acid grassland target sites, all treatments overcame the resistance of the Pteridiumdominated state producing changes in species composition in comparison with experimental controls. 5. Synthesis and applications. There are two important results for land managers: (i) where Calluna heathland is the target, 'repeated' treatments (cutting once or twice per year) were effective in overcoming the resistance of invaded community and moving species composition towards the target state, effectively creating an alternative state; (ii) where acid grassland is the target both 'one-off' and 'repeated' treatments overcame the invaded community resistance ('one-off' also overcame resilience) producing changes in species composition in the desired direction. The effectiveness of 'one-off' treatments was site dependent and produced alternative stable states within 10 years. In contrast, 'repeated' treatments were site independent but took longer to work and were more expensive.

It is concluded that successful development of national weed control programs requires multi-site experimental approaches. Here, meta-analyses demonstrate that variation in effectiveness between sites could be explained in part by pre-specified variables. Reliance on data from a single site for policy formulation is therefore clearly dangerous.

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Questions: The objectives of this study were to assess the effect of Pteridium aquilinum (bracken) control treatments, at the national scale, and the impact of restoration practices, at the local scale, on P. aquilinum performance. Hypotheses: 1. Geographical location (locally between and within sites) affects the control of P. aquilinum through time. 2. Are the P. aquilinum control treatments successful at all sites, and if so which ones? 3. The treatments applied at the individual site level to restore vegetation influences the performance of P. aquilinum through time. Location: Four geographically distinct acid grassland and heathland sites infested with P. aquilinum across Great Britain. Methods: Six main‐plot, bracken control treatments were applied to all sites with site‐specific vegetation restoration treatments. Response variables (P. aquilinum cover, frond length and density) were monitored twice yearly, in June and August between 1993 and 2003. Results: Between‐ and within‐site spatial variation was found, although impact is perhaps less than suggested from shorter‐term data. Despite local variation all sites responded similarly to bracken control treatments; asulam treatment resulted in a rapid reduction in frond performance followed by a continued recovery taking approximately ten years to return to untreated values. Cutting treatments tended to have a slower impact at the start but an increasing one over time, especially cutting twice per year. Restoration treatments had a limited impact; the only significant effect in August was grass seeding on frond length at Sourhope. In June only, the plots where sheep were fenced out showed a significant reduction in P. aquilinum cover at Peak. Conclusions: Long‐term control of Pteridium aquilinum at all sites and on all measures was best achieved using a continuous cutting treatment, preferably twice per year.