Retention of Matured Trees to Conserve Fungal Diversity and Edible Sporocarps from Short-Rotation Pinus radiata Plantations in Ethiopia

Abstract

This study is conducted in the short-rotation plantations from the Afromontane Region of Ethiopia. Sporocarps were sampled weekly in a set of permanent plots (100 m2) in young, medium-aged, and mature Pinus radiata (Don) plantations. Fungal richness, diversity, and sporocarp yields were estimated. Composite soil samples were also collected from each plot to determine explanatory edaphic variables for taxa composition. We collected 92 fungal taxa, of which 8% were ectomycorrhizal (ECM). Taxa richness, the Shannon diversity index, and ECM species richness were higher in mature stands. Interestingly, 26% of taxa were classified as edible. Sporocarp yield showed increasing trends towards matured stands. OM and C/N ratio significantly affected fungal composition and sporocarp production. The deliberate retention of mature trees in a patch form rather than clear felling of the plantations could be useful to conserve and promote fungal diversity and production, including valuable taxa such as Morchella, Suillus, and Tylopilus in older stands. This approach has important implications for forest floor microhabitats, which are important for macrofungal occurrence and production. Thus, this strategy could improve the economic outputs of these plantations in the Afromontane Region, while the mature trees could serve as a bridge for providing fungal inocula to the new plantations.

Green trees preservation: A sustainable source of valuable mushrooms for Ethiopian local communities

“…This relationship could be attributed to the fact that mycorrhizal fungi tend to expand their mycelial network at the soil interface [ 121 , 122 ], where OM can influence the growth and network formation of mycelia [ 123 ]. Although a single growing season’s worth of data is insufficient to establish a clear relationship between soil OM and macrofungi, our preliminary findings suggest that soil OM content is directly associated with the overall richness and abundance of macrofungal species, a finding that is consistent with previous studies conducted by [ 39 , 124 ].…”

“…[ 3 ]. Most of these species were found in middle-aged and old stands, which agrees with previous studies indicating that older stands harbor valuable species and have higher sporocarp yields than younger stands [ 39 ]. Previous reports have also recognized these edible fungal species as commercial NTFPs [ 86 ], which could potentially enhance the economic performance of forests [ 87 ] and encourage local communities to plant and manage more plantations in their surroundings.…”

“…Furthermore, in some tropical countries, some of these fungal species are exported as forest products to generate income [ 53 ]. Despite the comparatively low total sporocarp yields obtained from the Pinus plantations assessed in this study [ 39 ], the sporocarp biomass obtained provides an insight into the potential production levels of the two plantation types, particularly of the marketable species. Thus, forest managers in Menagesha Suba and Wondo Genet should consider the balance between timber production and fungal conservation for environmental and production purposes.…”

“…Furthermore, stand age is one of the most important factors influencing fungal community variety in plantation forests [ 45 , 84 ]. Studies have shown that fungal diversity tends to increase with stand age, with older forests having a more diverse and complex fungal community compared with younger forests [ 39 , 88 ].…”

“…In plantation forests dominated by a single tree species and characterized by a long rotation, such as temperate or boreal forests, the fungal community is expected to be highly dependent on the type of tree species [38]. In tropical forest systems, where plantations are characterized by a short rotation system and traditional silvicultural practices, such as clear felling and replanting, the impact of tree species and other biotic and abiotic factors on the fungal variety has rarely been studied, particularly in Ethiopian forest systems [39]. However, appropriate management of Ethiopian plantation forests is crucial to provide wood products while maintaining ecosystem integrity to provide a more conducive environment for fungi [39][40][41].…”