Bare soil cover and arbuscular mycorrhizal community in the first montane forest restoration in Central Argentina

Abstract

Soil erosion affects extensive areas worldwide and must be urgently reduced promoting plant cover and beneficial microorganisms associated with plants, including arbuscular mycorrhizal fungi (AMF). In mountain environments, plant cover is difficult to enhance due to harsh conditions during the dry season and steep slopes. Our objective was to evaluate the percentage of the soil surface covered by plants and the AMF community associated with trees 12.5 years after planting during forest restoration efforts in microsites at different levels of soil degradation. The study was performed in the first montane forest restoration initiative of Central Argentina, where one of the trials consisted of planting Polylepis australis saplings at microsites with different levels of soil degradation: high, intermediate, and low. After 12.5 years, percentage of bare soil cover was significantly reduced by 36 and 37% in the high and intermediate degradation microsites, respectively. Low degradation microsites were initially very low in bare soil and did not significantly change. Mycorrhizal colonization, hyphae, vesicles, arbuscules, AMF diversity, and community structure were similar among microsite types. Percentage of hyphal entry points was higher at microsites with low degradation, number of spores was higher in high and intermediate degradation, and species richness was higher in high degradation. Acaulospora and Glomus were the most abundant genera in all microsites. We conclude that even in the most degraded microsites around 2.8% of the bare soil is covered by vegetation each year and that the arbuscular mycorrhizal community is highly tolerant and adapted to soils with different disturbance types. Implications for Practice• Bare soil cover was reduced by excluding livestock and planting native trees even in the most degraded microsites (outside of erosion gullies). • The arbuscular mycorrhizal fungi community was resilient to degradation and all its species were present even in the most degraded microsites.

Arbuscular mycorrhizal fungi community in coffee agroforestry, consortium and monoculture systems

“…The greater abundance of the Acaulospora and Glomus genera can be attributed to the fact that they produce smaller spores and in greater quantity, being less influenced by seasonal changes when compared to other genera such as Gigaspora, which have larger spores (Sousa et al 2014). These genera are generally found with great frequency in a wide range of forest ecosystems (Davison et al 2015, Soteras et al 2015, Bonfim et al 2016, Araújo et al 2019, Pagano et al 2019, Becerra et al 2019 and also in agricultural ecosystems (Oehl et al 2017, Cristo et al 2018, Vieira et al 2020.…”

Forest restoration under leaf‐cutting ant pressure: distance from ant nests and plastic tree shelters improve sapling survival

“…Renison, personal observation). Reducing disturbances and planting Polylepis australis subsequently favor a range of organisms associated with Polyelpis forests (Becerra et al 2019;Barri et al 2021). Polylepis australis is currently used for important forest restoration efforts (https://www.…”

“…Thus, restoration efforts include fencing to exclude livestock, use of pesticides to kill leaf‐cutting ants, or use of plastic tree shelters to deter ant pruning (Renison et al 2017; D. Renison, personal observation). Reducing disturbances and planting Polylepis australis subsequently favor a range of organisms associated with Polyelpis forests (Becerra et al 2019; Barri et al 2021). Polylepis australis is currently used for important forest restoration efforts (https://www.globalforestgeneration.org/ consulted December 2021).…”