How Does Forwarding of Pinus pinea Plantations Affect the Recovery of Plant Assemblages of Stabilised Dunes?

Management of forest plantations towards biodiversity conservation poses a challenge of increasing importance. Felling and subsequent logging have been traditionally used in forest plantations, however, their suitability to restore preexisting habitats has been scarcely studied. This paper reports the effect of felling and forwarding of stone pine (Pinus pinea) plantations on soil disturbance and recovery of native xerophytic community typical of stabilised dunes in the Doñana Protected Area (southern Spain). Soil disturbance was assessed just after forwarding whereas recovery of plant assemblages was evaluated 27 months after the action by comparing species richness and diversity indices and Raunkiaer´s life functional types among four plot types: (i) plots with P. pinea that were not felled or forwarded, (ii) plots with P. pinea that were felled and forwarded, (iii) open areas without P. pinea affected by the forwarder and (iv) well-preserved open areas without P. pinea. Also, plant composition similarities between pairs of plots were evaluated with multivariate tests SIMPER and one-way ANOSIM. The forwarder provoked a shallow disturbance (litter and topsoil mixed) in areas of bare soil ≤ 20% and beside the Dorset heath, but deep disturbance (topsoil removed, subsoil exposed; and ruts) occurred in areas of bare soil>20% and on repeatedly used tracks. Non-forested areas affected by deep disturbance showed a significantly higher recovery of the xerophytic community than areas affected by shallow disturbance but previously occupied by a high cover of P. pinea. Our results provide novel evidence that a high cover of P. pinea slows down the recovery of native plant assemblages to a greater extent than the mere physical disturbance caused by the forwarder in areas without any pines. These results may guide future management actions aimed at enhancing biodiversity in natural areas affected by Pinus plantations and the adoption of responsible forestry practices.