The restoration of degraded mountain woodlands: effects of seed provenance and microsite characteristics on Polylepis australis seedling survival and growth in Central Argentina

RENISON, D.; CINGOLANI, A.; SUAREZ, R.; MENOYO, E.; COURTSIERS, C.; SOBRAL, A.; HENSEN, I.

RESTORATION ECOLOGY

Blackwell Publishing

Año: 2005 vol. 13 p. 1 - 9

1061-2971

South American high mountain ecosystems are greatly influenced by human disturbance. In the mountains of Córdoba /Argentina, Polylepis australis (Tabaquillo or Queñoa) woodlands are currently highly fragmented and subject to extensive burning and livestock grazing, resulting in severe changes of habitat characteristics which hamper natural regeneration. In order to find out how to achieve successful reforestation, we compared Polylepis australis seedling survival, growth and the development of a shrubby habit from two seed provenances. Survival of planted seedlings after 5 years was 70 %, with most deaths (19%) in the first year and declining mortality with ongoing establishment. Survival did not show any relationship with seed provenance or microsite characteristics. Height growth averaged 34.6 ± 1.2 cm in five years. Seedlings produced from seeds collected in a well preserved woodland grew taller and showed a higher tendency for a development of shrubby habit than those collected in a degraded woodland. Seedlings planted in more degraded microsites with exposed soil or rock due to past grazing pressure grew less tall and developed a more shrubby habit than those planted in better preserved microsites. Our results show that restoration of degraded areas with Polylepis australis is possible and that there is potential to improve restoration success with a careful selection of seed provenance and planting microsites.