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New Forests

, Volume 33, Issue 2, pp 171–181 | Cite as

Variation of seed mass and its effects on germination in Polylepis australis: implications for seed collection

  • Peggy Seltmann
  • Ilona Leyer
  • Daniel Renison
  • Isabell Hensen
Original Paper

Abstract

South American Polylepis mountain forests are recognised as being one of the most endangered forest ecosystems in the world. Reforestation measures have been strongly recommended but may be hampered due to the very low seed germination reported for several Polylepis species. In order to facilitate reforestation we analysed the influence of seed mass on germination probability for Polylepis australis seeds in the Córdoba mountains (central Argentina). We collected seeds from 43 trees distributed throughout five woodland fragments located within two regions differing in size, topographical position, and altitude (1,900 m a.s.l. and 2,200 m a.s.l.). Seeds of Polylepis australis exhibited a great variation in terms of mass and percent seed germination among individual trees and among geographical regions. The results of logistic regression showed that germination probability was highly correlated with seed mass. However, the explained deviance significantly increased by including the region, the woodland fragment and especially the individual tree in addition to seed mass in the regression models. We conclude that selecting seeds on the basis of mass is an appropriate way to enhance germination prospects for reforestation projects. However, no absolute mass values are applicable in this context as the highest germination probabilities were reached at varying seed mass values depending on geographical region, woodland fragment or individual tree. We suggest collecting the relatively heaviest available seeds, even though the absolute seed mass may be low.

Keywords

Argentina Logistic regression Mountain woodlands Polylepis australis Reforestation Seed germination Seed mass 

Notes

Acknowledgements

We thank the Volkswagen foundation for supporting this project, the Club Andino Córdoba and Villa Carlos Paz for providing lodging in the field, and the National Parks Administration (Argentina) for providing working permits.

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Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Peggy Seltmann
    • 1
  • Ilona Leyer
    • 2
  • Daniel Renison
    • 3
  • Isabell Hensen
    • 1
  1. 1.Institute of Geobotany and Botanical GardenMartin-Luther-University Halle-WittenbergHalle/SaaleGermany
  2. 2.Department of Biology, Conservation BiologyPhilipps-University MarburgMarburgGermany
  3. 3.Cátedra de Ecología GeneralNational University of CórdobaCórdobaArgentina

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