Peat bog restoration: Effect of phosphorus on plant re-establishment

Vegetation responses to phosphorus (P) fertilization were assessed on post-vacuum extracted peatlands under ecological restoration. The study aimed to evaluate the importance of P fertilization in promoting plant re-establishment and to delineate fertilization practices. A total of 11 P treatments were tested across three different peatlands under restoration. After three growing seasons, it was found that bryophytes (excluding sphagna) were the main strata benefiting from P fertilization. Mosses like Polytrichum strictum showed positive responses to P addition, provided that the rewetting was optimal and that these bryophytes were present in the donor site. The optimal dose of phosphate rock (PR) to encourage plant re-establishment appears to be in the range of 15–25 g PR m−2. Fertilization timing should be investigated further as applications would probably have more impact during periods of high nutrient uptake by target plants in establishment phase than before or after other restoration steps. Furthermore, splitting the fertilization in two applications slightly improves the re-establishment of P. strictum. Fertilization in peatland restoration remains a site-specific decision, considering intrinsic site properties and the effectiveness of restoration measures.