Direct and indirect effects of termites on savanna tree-seedling growth

作者：Muller Kayleigh; Ward David^*

来源：Plant Ecology, 2013, 214(6): 811-819.

DOI：10.1007/s11258-013-0209-7

• Acacia sieberiana
• Celtis africana
• Resource heterogeneity
• Soil compaction
• Ziziphus mucronata

Termites are considered to be ecosystem engineers because they modify their biophysical environments. We tested the effects of soil-nutrient alteration in termite-enriched soils compared with termite-free open savannas. We also tested whether non-nutrient alterations (soil disturbance) induced by termites led to changes in tree-seedling growth. Soil samples taken from termite-enriched soils and adjacent open savanna sites in KwaZulu-Natal, South Africa were analyzed for nitrogen, pH, organic carbon and water-holding capacity. Seeds from three dominant tree species, Acacia sieberiana, Celtis africana and Ziziphus mucronata, were grown in soils taken from termite-enriched soils and adjacent savannas. Overall, organic carbon and nitrogen content were higher in termite-enriched soils than in adjacent savannas. We found that these differences in nutrients did not directly affect seedling growth rates or final height. However, C. africana had increased growth rates in compacted termite-enriched soils, while A. sieberiana seedlings were taller in non-compacted soils. We conclude that the indirect effects of disturbance by termites may be as important as the direct effects of increased nutrients for growth of savanna trees.

• 出版日期2013-6