Changes in arbuscular mycorrhizal fungal communities, mycorrhizal soil infectivity, and phosphorus availability under Chromolaena odorata (Asteraceae) invasions in a West-African forest-savanna ecotone

• Published in: Mycorrhiza Vol. 33; no. 4; pp. 257 - 275
• Main Authors: Touré, Guy-Pacome T., Koné, Armand W., Nandjui, Jacob, Ebou, Anicet E. T., Otinga, Abigael N., Maïga, Assoumane A., Kouadjo, Claude G. Z., Tiho, Seydou, Zézé, Adolphe
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-07-2023; Springer Nature B.V
• Subjects: Abundance; Agricultural land; Agriculture; Arbuscular mycorrhizas; Asteraceae; Availability; Biomedical and Life Sciences; Chromolaena odorata; Colonization; Composition; Cowpeas; Ecology; Farm buildings; Forestry; Forests; Fragments; Habitat fragmentation; Infectivity; Invasions; Life Sciences; Microbiology; Phosphorus; Plant Sciences; Relative abundance; rRNA 18S; Savannahs; Soils; Spores; Vigna unguiculata; 18S rRNA metabarcoding; Siam weed; Mycotrophic invader species; Soil P availability; Lamto reserve; AMF-Soil interactions
• ISSN: 0940-6360; 1432-1890
• DOI: 10.1007/s00572-023-01113-9

Substantial areas of agricultural lands in Sub-Saharan Africa have been invaded by
Chromolaena odorata
(Asteraceae), but the consequences for arbuscular mycorrhiza fungi (AMF) remains poorly understood. This study explores changes in diverse AMF community attributes and soil available phosphorus following
C. odorata
invasion in forest and savanna fragments in Côte d’Ivoire (West Africa). Invaded-forest (COF) and savanna (COS) sites were compared to adjacent natural forest (FOR) and savanna (SAV) fragments, respectively. Physico-chemical variables and AMF spore density parameters were determined for soil samples from 0–20 cm depth. An 18S ribosomal RNA metabarcoding analysis of AMF communities was conducted. In addition, cowpea (
Vigna unguiculata
) was grown on soils collected from these sites under greenhouse conditions for determination of soil mycorrhizal infectivity. Noticeable changes in the composition of AMF communities in
C. odorata
relative to nearby forest and savanna non-invaded sites were observed. AMF-specific richness in COS (47 species) was lower than that in SAV (57 species) while it was higher in COF (68 species) than in FOR (63 species). COF and COS differed in AMF specific composition (Dissimilarity index = 50.6%).
Chromolaena odorata
invasions resulted in increased relative abundances of the genera
Claroideoglomus
and
Glomus
in COF, a decreased relative abundance of
Paraglomus
in COS and decreased relative abundances of
Ambispora
in both COF and COS. Total and healthy spore densities, cowpea root colonization intensity and soil available P were all higher in invaded sites than in natural ecosystems. Remarkably, although these values were different in FOR and SAV, they turned out to be similar in COF and COS (4.6 and 4.2 total spores g
−1
soil, 2.3 and 2.0 healthy spores g
−1
soil, and 52.6 and 51.6% root colonization, respectively) suggesting a
C. odorata
-specific effect. These findings indicate that soil mycorrhizal potential and phosphorus availability have improved following
C. odorata
invasion.