Repeated Selective Cutting Controls Neotropical Bracken (Pteridium arachnoideum) and Restores Abandoned Pastures

Abstract

Neotropical bracken fern invades disturbed forests and burned and abandoned pastures in Latin America, inhibiting the growth of associated vegetation and altering community structure. Cutting of all aboveground vegetation every 6 to 12 mo has proven to be inefficient as a control method. We studied the impact of selective cutting of bracken every 2 mo, shading, and a combination of cutting + shading during 14 mo in a bracken-dominated, abandoned pasture in Veracruz, Mexico. At the end of the experiment, cutting with or without shading drastically reduced bracken cover from >90% to less than 1%, decreased leaf number from 18 to fewer than two leaves per m2, and depleted bracken leaf biomass. The significant reduction of bracken was correlated with a significant 3.9- to 5.7-fold increase in richness of other plant species. Cutting without shading was the only treatment that significantly reduced rhizome biomass to less than 62% of control plots, whereas cutting + shading was the only treatment to promote a significant increase in both cover and shoot biomass of successional plant species. Selective cutting of P. arachnoideum repeated every 2 mo was more successful than nonselective cuttings repeated at longer intervals, because it removed newly emerging leaves before their complete expansion and supported the recovery and reestablishment of other plant species, which may help to control bracken. Although costs for the first year of selective cutting were twice as much as for nonselective cutting, it may prove less expensive and more efficient than nonselective cutting in the long term.

Comparing the success of active and passive restoration in a tropical cloud forest landscape: A multi-taxa fauna approach

“…P . arachnoideum creates a dense layer of vegetation on the ground and prevents the establishment of cloud forest tree species [ 59 ]. This slows down succession, and consequently the recovery of forest-specialist animals.…”

“…In addition, in the forest with passive restoration, there are canopy gaps with 12 times more cover of the invasive fern Pteridium arachnoideum, compared to the forest with active restoration [13]. P. arachnoideum creates a dense layer of vegetation on the ground and prevents the establishment of cloud forest tree species [59]. This slows down succession, and consequently the recovery of forest-specialist animals.…”

Who will win where and why? An ecophysiological dissection of the competition between a tropical pasture grass and the invasive weed Bracken over an elevation range of 1000 m in the tropical Andes

“…Our study explains why using Setaria and presumably other C4-photosynthesis-type grasses as forage plants in tropical pastures above 1800 m a.s.l. elevation will not allow sustainable pasture farming without further measures of Bracken control [ 22 , 23 ].…”