학술논문

Controlling the invader Urochloa decumbens: Subsidies for ecological restoration in subtropical Campos grassland.
Document Type
Article
Source
Applied Vegetation Science. Jan2019, Vol. 22 Issue 1, p96-104. 9p.
Subject
*SAVANNAS
*HAY handling
*HERBICIDE application
*RESTORATION ecology
*SOWING
Language
ISSN
1402-2001
Abstract
Questions: Restoration of grassy biomes is currently of large importance, and controlling invasive grasses is often key to restoring these ecosystems in the tropics and subtropics. We combined different ecological restoration techniques to evaluate potential to control the invasive grass Urochloa decumbens and restore plant species composition. Specific questions were: (a) are herbicide application and topsoil removal efficient to control U. decumbens cover and allow native species establishment; and (b) are hay transfer and sowing native grass species efficient to reintroduce native species and increase their cover? Location: Campos grasslands, southern Brazil. Methods: We combined the follow restoration techniques: (a) herbicide application or topsoil removal to control the invasive species, and (b) hay transfer or sowing of native grasses to reintroduce native species. We assessed and compared native plant species richness, vegetation cover, native species cover, U. decumbens cover and other exotic species cover in 2016 and 2017. Results: Herbicide application reduced invasive species cover more than topsoil removal, even though both were effective. The decrease of U. decumbens cover led to an increase in native species cover and native species richness. Hay transfer and sowing native grasses did not produce satisfactory results for native species reintroduction. Native species richness and U. decumbens cover increased from 2016 to 2017. Conclusion: Herbicide application was a better option to control U. decumbens and to allow recovery of native species. However, use of herbicides in restoration is controversial, and more detailed studies on impacts are necessary. Environmental filters appear to be a major cause for failure of hay transfer and seeding species. Recovery of the native plant community is a great challenge in invaded subtropical grasslands, and additional management actions and time are necessary to increase the establishment of native species. Our study, being one of first restoration ecology study at Campos grasslands ever published, highlight the first acquired knowledges to restore this important ecosystem, and our results may be useful here and in other subtropical and tropical grasslands ecosystems invaded. [ABSTRACT FROM AUTHOR]