Edaphic correlates of tree species diversity, composition, and distribution in an eastern arc biodiversity hotspot, Tanzania

Document Type : Research paper


Department of Ecosystems and Conservation, Sokoine University of Agriculture, Morogoro, Tanzania


This study explored the edaphic correlates of tree species diversity, composition and distribution in the Amani Nature Reserve (ANR) and Udzungwa Mountains (UMF). Using canonical correspondence analysis, different ecological gradients explained plant community patterns. In ANR, species richness decreased significantly with pH (r = -0.383, p = 0.03; r = -0.422, p = 0.016) at 0-15 cm and 30-45 cm depth respectively and percentage coarse silt at 30 cm (r = -0.416, p = 0.018). Further, species richness and diversity increased along a gradient of percentage organic carbon (r = 0.35 and r = 0.22) respectively and decreased with bulk density (r = -0.24 and -0.29 at 15 and 30 cm respectively) in UMF. There was pronounced variation in edaphic correlates of tree community patterns between sites. Soil pH was the strongest edaphic correlate of species composition and distribution in ANR while percentage organic carbon was a strong edaphic correlate in UMF. Stronger effects by soil pH indicate the influence of soil chemical properties in the study sites. Variation in the influence of edaphic correlates to tree community patterns between the two sites suggests a need for site-specific assessment of edaphic properties.

Graphical Abstract

Edaphic correlates of tree species diversity, composition, and distribution in an eastern arc biodiversity hotspot, Tanzania


  • There is a direct relationship between soil and vegetation.
  • As a habitat for micro-macro organisms, the soil is of crucial importance.
  • The forest is the sole biodiversity hotspots home for many species.
  • Soil properties affect the performance and shape of soil communities.


Main Subjects

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