Effects of Forest Composition and Disturbance on Arbuscular Mycorrhizae Spore Density, Arbuscular Mycorrhizae Root Colonization and Soil Carbon Stocks in a Dry Afromontane Forest in Northern Ethiopia

Emiru Birhane,Lindsey Norgrove,Meley Mekonen Rannestad,Gebeyehu Taye,Ermias Aynekulu,Kbrom Fissiha Gebretsadik

doi:10.3390/d12040133

Abstract

We investigated arbuscular mycorrhizal fungi (AMF) spore density and root colonization in three distinct dry Afromontane forest plant communities, representing differing levels of disturbance and soil properties. Soil and root samples were collected from sixty-five 50 × 50-m plots from four plant communities. We collected data for AMF spore density, AMF root colonization and soil organic carbon stocks in 0–25 and 25–50 cm soil depth ranges. AMF spore density, and root colonization differed significantly among plant communities. The least disturbed Juniperus procera–Maytenus senegalensis (Jupr-Mase) plant community, which contained high tree and shrub density, had the highest AMF spore density, root colonization and soil carbon stocks. The most disturbed Cadia purpurea–Opuntia ficus-indica (Capu-Opfi) community which contained the lowest tree and shrub density supported the lowest AMF spore density, root colonization and soil carbon stocks. There was no significant difference in spore density between the two soil depths, but AMF root colonization was significantly higher in the upper soil than in the subsoil (p < 0.001). The difference in soil properties was not uniform between plant communities. Conserving remnant dry Afromontane forests and restoring the degraded forests are critical to improve and maintain forest ecosystem functioning and sustain ecosystem services.

Highlights

Tropical dry forests have some potential to help mitigate climate change, reduce desertification and land degradation, and provide livelihood products and services for millions of people living in dryland regions
The arbuscular mycorrhizal fungi (AMF) spore density and root colonization were significantly different between communities, probably due to both the plant host specificity of AMF and the different levels of disturbance between the plant communities
Root colonization was significantly different between different soil depths, whereas spore density did not vary with depth

Summary

Introduction

Tropical dry forests have some potential to help mitigate climate change, reduce desertification and land degradation, and provide livelihood products and services for millions of people living in dryland regions. Diversity 2020, 12, 133 causes species loss [3,4,5,6] Such changes may have cascading effects on soil microorganisms, including arbuscular mycorrhizal fungi (AMF). AMF possess fungal structures in the form of arbuscules, vesicle and hyphae, which are found in roots, and external hyphae and spores in the soil [8]. The relationship between these fungal symbionts and their hosts is generally mutualistic, with the host plant benefitting primarily through the enhanced acquisition of soil nutrients, phosphorus [7]. They are occasionally parasitic, depending on the host-plant species and the species of AMF [14]

Methods

Results

Discussion

Conclusion