Ecological significance of wood anatomy of Alseis pickelii Pilg. & Schmale (Rubiaceae) in a Tropical Dry Forest

This work describes, analyzes and compares the wood anatomy of Alseis pickelii from two distinct sites in Tropical Dry Forest. One site is an exploited forest that was disturbed by deforestation whereas the other site is preserved and has not been logged since selective logging in the 1960's. For the evaluation of wood anatomy, plant material was processed following standard techniques for light microscopy and histochemical tests. The results indicated that A. pickelii did not vary qualitatively between the two sites. The histochemical tests indicated the presence of prismatic crystals and starch in radial parenchyma of samples from both sites. Some quantitative parameters differed significantly between the two sites including: vessel frequency; vessel length and lumina area; intervessel pits; diameter, lumina, length and wall thickness of fibres; and radial parenchyma width. In general, these quantitative parameters had higher values in the samples from the exploited site, suggesting an adjustment to the more severe drought conditions there. Quantitative anatomical differences in the samples from the two sites show the influence that environmental conditions can have on wood anatomy. The observed anatomical characteristics may also be useful for taxonomic and ecological studies of this species and genus.