Altitudinal Variations in Leaf Functional Traits of some Woody Species in the Savannahs of Ngaoundere (Adamaoua, Cameroon)

Authors: Maigari Pale*, Amadou Zoua Hamadou, Djibrilla Mana, Massai Tchima Jacob, Ranava Dieudonne, Babe Ndara Gregoire, Tchobsala and Ibrahima Adamou

DOI: 10.23880/jenr-16000352

Volume 7, Issue 4

Abstract

In order to contribute to the sustainable management of the Ngaoundere savannahs, experiments in natural environments were carried out to assess interspecific and altitudinal variations in leaf functional traits. To do this, 20 leaves per plant were collected from 7 individuals per species, giving a total of 140 leaves per species for each of the three sites (Dang, Tchabbal and the Cliff) in the Ngaoundere Cameroon savannahs. The leaves were photographed and the images were processed using image j software to estimate leaf area. The data obtained related to certain traits such as dry mass, leaf area, thickness, leaf specific area, specific mass, dry matter content and leaf density. For each of the three sites, dry mass decreased significantly with increasing altitude, from 1.12 g at the Dang site to 0.68 g at the Cliff site. Overall, the water content is higher at the Cliff (47.33%) and lower at Tchabbal (41.93%). Thickness increases with altitude, rising from 0.20 mm at low altitudes (Dang) to 0.30 mm at high altitudes (at the Cliff) and intermediate (0.25 mm) at medium altitudes (Tchabbal). Leaf area decreased significantly with increasing altitude, from 70.45 cm2 at low altitudes (Dang) to 53.05 cm2 at high altitudes (at the Cliff) and intermediate (57.70 cm2) at medium altitudes (Tchabbal). The leaf specific area decreases significantly with altitude, from 115.95 cm2/g at the Dang site to 78.16 cm2/g at the Cliff. Dry matter content increased with altitude, rising from 0.30 g/g at Dang to 0.58 g/g at the Cliff. Specific mass increased with altitude, rising from 0.00 g/cm2 at Dang to 0.02 g/cm2 at the Cliff. Leaf density increased with altitude, from Dang (0.06 g/mm3) to the Cliff (0.10 g/mm3). Finally, the height of the woody plants decreased with altitude, from 5.08 m at Dang to 3.80 m at the Cliff. Overall, leaf traits decreased with altitude, except for thickness and density. These results would thus contribute to an understanding of the functioning of savannah ecosystems in general, and those of Ngaoundere in particular, with a view to their sustainable management.

Keywords: Functional Trait; Altitude; Savannah; Ngaoundere; Adamaoua; Cameroon

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