Bark harvesting by human population shapes tree allometry in an economically important species of the Brazilian savanna

Author(s)

Baldauf, Cristina ^{[1, 2]} ; Dias, Arildo S. ^[3] ; Correa, Christiane E. ^[4] ; Santos, Flavio A. M. ^[5]

Affiliation

^[1] Univ Fed Rural Semi Arido, Dept Biociencias, Av Francisco Mota, BR-572 Mossoro, RN - Brazil

^[2] Univ Estadual Campinas UNICAMP, Programa Posgrad Biol Vegetal, Inst Biol, Sao Paulo - Brazil

^[3] Goethe Univ, Inst Phys Geog, Altenhoferallee 1, D-60438 Frankfurt - Germany

^[4] Univ Fed Vale Sao Francisco, Nucleo Ecol & Monitoramento Ambiental, Campus Cieencias Agr, BR 407, BR-56300000 Petrolina, PE - Brazil

^[5] Univ Estadual Campinas UNICAMP, Inst Biol, Dept Biol Vegetal, Sao Paulo - Brazil

• Document type: Journal article
• Source: FOREST ECOLOGY AND MANAGEMENT; v. 496, SEP 15 2021.
• Web of Science Citations: 0

Abstract

Theoretical models of allometric scaling provide an important framework for understanding and predicting how and why the morphology and function of organisms vary with scale. However, the predictions of `universal' scaling models for vascular plants do not consider different environments and disturbance types which can reduce the predictive power of these models. One important source of disturbance in tropical regions is the harvesting of non-timber forest products, such as leaves, flowers, resins and barks. In this context, we examine the influence of bark harvesting and different light environments on scaling of the height and diameter of Himatanthus drasticus (Apocynaceae), an economically important tree species harvested by several local communities living in the Brazilian savanna. By considering this species as a model system and using Bayesian regression, we show that bark harvesting modifies tree allometry and that the empirical scaling exponents diverge from the theoretical predictions. In addition, the results of a mechanistic model of tree growth revealed that bark harvesting affects tree height and that this effect varies independently of the light environment. On the other hand, trees with higher bark harvesting levels presented lower height growth rates when compared to trees without bark harvesting or those with <50% of bark harvesting. Our results highlight the importance of including bark harvesting as a source of disturbance that can cause differences between the observed scaling relationships and those predicted by theoretical models. Finally, from the management perspective, we observed that high levels of bark harvesting could compromise the plant height growth of the debarked trees. Therefore, our recommendation for the management of this species is that the previously defined limits of 50% of bark harvesting should be maintained to avoid the negative effects of harvesting on the tree height over time. (AU)

• FAPESP's process: 08/08737-4 - Evaluation of the harvesting effects on the populations of two species of Cerrado biome: Mauritia flexuosa L.f (Arecaceae) and Himatanthus drasticus (Mart.) Plumel (Apocynaceae)
• Grantee: Flavio Antonio Maës dos Santos
• Support Opportunities: Regular Research Grants