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Understanding how reclamation practices influence plant community assembly and succession is an important step in developing realistic indicators and targets for reclamation of oil sands mine sites to upland forest ecosystems. We currently have a poor understanding of factors affecting plant community assembly and succession in reclaimed oil sands sites. Through synthesis of research completed over the last 24 years, we identify four key findings: (i) use of surface soil and forest floor material salvaged from mined areas increases plant species cover, richness, and diversity relative to the use of various other cover soil materials (such as clay subsoil); (ii) stockpiling of salvaged surface soils decreases the abundance of native plant propagules and delays early vegetation community development; (iii) differences in plant community composition between reclaimed and adjacent mature forests remain two decades after placing cover soils; however, differences are smaller with use of forest floor–mineral mix than peat–mineral mix; and (iv) plant community assembly is in progress but communities remain different to those found in natural undisturbed conditions. Our review identified critical knowledge gaps for further research to improve understanding of: (i) long-term (60 to 100 years) plant community composition in reclaimed oil sands sites; (ii) how residual forest patches near disturbed oil sands sites act as seed and propagule sources in newly reclaimed sites; (iii) plant community assembly processes in reclamation sites; (iv) the effect of micro-topographic heterogeneity on plant community development; and (v) how soil nutrient availability in different substrates influences plant community development over the long term. Ongoing support for selected existing studies and establishment of new studies focusing on plant community development through long-term monitoring are highly recommended. [ABSTRACT FROM AUTHOR]

Reintroduction of periodic dormant-season fire and overstory thinning are currently being employed for forest ecosystem management in deciduous forests of eastern North America. These manipulations usually alter the flux of light and the availability of soil nutrients to the perennial herbaceous plants that dominate the understory. We utilized Bayesian statistical methods to examine the effects of prescribed burning (B) and the combination of burning and overstory thinning (T+B) on the morphology, seed production, and early establishment of Desmodium nudiflorum (L.) DC. (Fabaceae) in mixed-oak (Quercus spp.) forests in southern Ohio. During the fourth growing season after the first fire, plants from thinned and burned (T+B) plots were 62% larger than plants from control plots (C). Both burning alone (B) and T+B treatments decreased specific leaf area (SLA). T+B also resulted in significantly decreased root mass ratio (RMR), and increased leaf mass ratio (LMR), and specific root length (SRL). During the first growing season after a second fire, both B and T+B resulted in significantly increased plant biomass, LMR, individual seed mass, and total seed production, as well as decreased SLA and plant height; in contrast, neither B nor T+B had significant impacts on leaf area ratio or seedling establishment. Prescribed fire, especially when combined with thinning, can result in increases in total biomass, seed size, and seed production, and hence enhance the fitness of this perennial herb in these mixed-oak forests. [ABSTRACT FROM AUTHOR]