Oak seedling performance and soil development across a forest restoration chronosequence following agriculture in the American Midwest—a greenhouse experiment

• Published in: Restoration ecology Vol. 30; no. 5
• Main Authors: Woods, Michaela J., Frankenberg, Sarah J., Juodvalkis, Joseph R., Lloyd, Mary C., Cobb, Meredith, McEwan, Ryan W.
• Format: Journal Article
• Language: English
• Published: Malden, USA Wiley Periodicals, Inc 01.07.2022; Blackwell Publishing Ltd
• Subjects: abandoned agriculture; Agricultural land; Biomass; bur oak; Carbon; Deciduous trees; Ectomycorrhizas; Environmental restoration; Enzymatic activity; Enzyme activity; Forests; Fungi; Moisture effects; Nitrogen; Nutrient content; old field; Organic matter; Organic soils; Parameters; Physicochemical processes; Plant species; Planting; Population decline; Quercus; Quercus macrocarpa; Reforestation; Restoration; Seedlings; Soil; Soil conditions; soil enzyme; Soil microorganisms; Soil moisture; Soil nutrients; Soil water
• ISSN: 1061-2971; 1526-100X
• DOI: 10.1111/rec.13587

Overcoming establishment limitation is an integral task during forest restoration on degraded lands for tree species whose prominence is declining, such as those in the Quercus genus. Fallow agricultural lands are suitable for forest restoration efforts by planting seedlings; however, tree seedling success may be limited due to soil conditions that are distinct from relict forests. Here, we assessed soil nutrient content, physicochemical parameters, and microorganism function via soil enzyme activity from five restorations that were implemented 0, 7, 10, 50, or 100 years ago. We planted Q. macrocarpa (bur oak) seedlings in soils collected from each site for 5 months before collecting dry biomass, used as a proxy for size. We found that Q. macrocarpa seedlings had the largest total biomass when they were planted in soils from older restorations. There was a significant positive correlation of the amount of soil carbon, nitrogen, organic matter, and soil moisture with tree size, and these soil parameters increased with forest age. We assessed seedling roots for mutualistic ectomycorrhizal fungi, but we did not find associations between their presence and tree size. Forest restoration is a complex process, which can take many decades, but we suggest that reforestation may be accelerated by implementing active soil restoration to increase soil carbon, nitrogen, and water holding capacity prior to planting tree seedlings in target sites. Active soil restoration may aide in overcoming a significant portion of establishment limitation of ecologically important tree species that typically do not fare well in early‐stage restorations.