Biological Invasions (2021) 23, 537-552

Victor Van der Meersch, Irie Casimir Zo-Bi, Bienvenu H.K. Amani, Justin Kassi N'dja, Anny Estelle N'Guessan and Bruno Herault (2021)
Causes and consequences of Cedrela odorata invasion in West African semi-deciduous tropical forests
Biological Invasions 23 (2), 537-552
Abstract: Most of the West African forests have disappeared or have been deeply fragmented. This deforestation dynamic is still ongoing under a strong demographic pressure, forests being mostly replaced by agricultural lands. On the other hand, some reforestation projects are also undertaken, in particular by planting non-native species like Cedrela odorata. To our knowledge, this study is the first to investigate the causes and consequences of Cedrela odorata spread in West African natural forests. We studied a 400ha area of natural forest where 100ha of permanent plots have been affected by a major fire in 1983. Within these permanent plots, 21,444 trees were mapped, botanically determined and their diameters at breast height were measured in 2018. Using a bayesian hierarchical framework, we modelled the causes of the spread of Cedrela odorata in the studied plots, and its consequences on aboveground biomass and tree community diversity. Regarding the causes, the occurrence of Cedrela odorata is significantly linked to the fire occurence 25 years ago, to the proximity of the forest edge and to the presence of hydromorphic soils. Regarding the consequences, Cedrela odorata invasion doesn't have any significant impact on the above-ground biomass but has a strong negative effect on the tree community diversity, as far as decreasing Simpson diversity in Hill numbers from 27 equivalent species in slightly invaded plots to 2 equivalent species in largely invaded plots. Our results highlight the long-lasting impacts of human disturbance (fire, Cedrela odorata introduction) on forest ecosystems and the need to use local species for ongoing reforestation plans in West African semi-deciduous forests.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
new introduction of pest
environment - cropping system/rotation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cedrela odorata (weed)		Ivory Coast