The Impact of Moss Species and Biomass on the Growth of Pinus sylvestris Tree Seedlings at Different Precipitation Frequencies

Forests

Babs M. Stuiver¹  David A. Wardle²  Michael J. Gundale² 

[1]Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE 901 83 Umeå, Sweden

关键词: boreal forest;    bryophyte;    climate change;    competition;    drought;    facilitation;    forest regeneration;    interactions;    moss depth;    Scots pine;   

DOI  :  10.3390/f5081931

来源: mdpi

【 摘 要 】

Boreal forests are characterized by an extensive moss layer, which may have both competitive and facilitative effects on forest regeneration. We conducted a greenhouse experiment to investigate how variation in moss species and biomass, in combination with precipitation frequency, affect Pinus sylvestris seedling growth. We found that moss species differed in their effects on seedling growth, and moss biomass had negative effects on seedlings, primarily when it reached maximal levels. When moss biomass was maximal, seedling biomass decreased, whereas height and above- relative to below-ground mass increased, due to competition for light. The effect that moss biomass had on seedling performance differed among the moss species. Hylocomium splendens and Polytrichum commune reduced seedling growth the most, likely because of their taller growth form. Seedlings were not adversely affected by Sphagnum girgensohnii and Pleurozium schreberi, possibly because they were not tall enough to compete for light and improved soil resource availability. Reduced precipitation frequency decreased the growth of all moss species, except P. commune, while it impaired the growth of seedlings only when they were grown with P. commune. Our findings suggest that changes in moss species and biomass, which can be altered by disturbance or climate change, can influence forest regeneration.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.