The Potential Role of Arbuscular Mycorrhizal Fungi in the Restoration of Degraded Lands

Abstract

Experiences worldwide reveal that degraded lands restoration projects achieve little success or fail. Hence, understanding the underlying causes and accordingly, devising appropriate restoration mechanisms is crucial. In doing so, the ever-increasing aspiration and global commitments in degraded lands restoration could be realized. Here we explain that arbuscular mycorrhizal fungi (AMF) biotechnology is a potential mechanism to significantly improve the restoration success of degraded lands. There are abundant scientific evidences to demonstrate that AMF significantly improve soil attributes, increase above and belowground biodiversity, significantly improve tree/shrub seedlings survival, growth and establishment on moisture and nutrient stressed soils. AMF have also been shown to drive plant succession and may prevent invasion by alien species. The very few conditions where infective AMF are low in abundance and diversity is when the soil erodes, is disturbed and is devoid of vegetation cover. These are all common features of degraded lands. Meanwhile, degraded lands harbor low levels of infective AMF abundance and diversity. Therefore, the successful restoration of infective AMF can potentially improve the restoration success of degraded lands. Better AMF inoculation effects result when inocula are composed of native fungi instead of exotics, early seral instead of late seral fungi, and are consortia instead of few or single species. Future research efforts should focus on AMF effect on plant community primary productivity and plant competition. Further investigation focusing on forest ecosystems, and carried out at the field condition is highly recommended. Devising cheap and ethically widely accepted inocula production methods and better ways of AMF in situ management for effective restoration of degraded lands will also remain to be important research areas.

Effect of community-based soil and water conservation practices on arbuscular mycorrhizal fungi types, spore densities, root colonization, and soil nutrients in the northern highlands of Ethiopia

“…Degraded lands harbor low levels of AMF abundance and diversity [19]. Many studies found that disturbance of semi-arid ecosystems decreased mycorrhizal spore density and root colonization [20,21].…”

Exclosures restored the density and root colonization of arbuscular mycorrhizal fungi in Tigray, Northern Ethiopia

“…The function of AMF in exclusion process and knowledge of AMF diversity in a specific area is essencial to utilize AMF in any application (Wang and Zao 2008). The very few conditions where infective AMF are low in density and diversity is when the soil erodes, is disturbed, and is devoid of vegetation cover (Asmelash et al 2016). The presence of enough AMF propagules in a restored site facilitates the establishment of plant communities through increased availability of nutrients and moisture to plant roots (Asmelash et al 2016).…”

“…The very few conditions where infective AMF are low in density and diversity is when the soil erodes, is disturbed, and is devoid of vegetation cover (Asmelash et al 2016). The presence of enough AMF propagules in a restored site facilitates the establishment of plant communities through increased availability of nutrients and moisture to plant roots (Asmelash et al 2016). Though exclosures positively contributed to land rehabilitation, there are limited studies on the role of exclosures to restore arbuscular mycorrhizal fungi.…”

Measuring progress in status of land under forest landscape restoration using abiotic and biotic indicators

“…a narrow focus on plant community composition may not provide accurate projections of future progress (Herrick et al ). Nonetheless, understanding is growing for biotic indicator groups such as lichens (Giordani et al ), mycorrhizal fungi (Ingleby et al ; Vogelsang et al ; Asmelash et al ), bryophytes (Karger et al ), herbs (McLachlan & Bazely ), overall soil quality (Ritz et al ), soil invertebrates (Lavelle et al ) including earthworms (Guéi & Tondoh ), arthropods (Longcore ; Pearce & Venier ; Schmidt et al ) including ants, (Folgarait ; Andersen & Majer ), saproxylic beetles (Lachat et al ; Audino et al ), and single‐species indicators (Siddig et al ). A recent review found 54 empirical studies that used invertebrates as indicators of restoration success, particularly at mine sites.…”