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USGS · 70155823

Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A.

Abstract

In the Mississippi River Alluvial Valley (MAV), complete alteration of river-floodplain hydrology allowed for widespread conversion of forested bottomlands to intensive agriculture, resulting in nearly 80% forest loss. Governmental programs have attempted to restore forest habitat and functions within this altered landscape by the methods of tree planting (afforestation) and local hydrologic enhancement on reclaimed croplands. Early assessments identified factors that influenced whether planting plus tree colonization could establish an overstory community similar to natural bottomland forests. The extent to which afforested sites develop typical understory vegetation has not been evaluated, yet understory composition may be indicative of restored site conditions. As part of a broad study quantifying the ecosystem services gained from restoration efforts, understory vegetation was compared between 37 afforested sites and 26 mature forest sites. Differences in vegetation attributes for species growth forms, wetland indicator classes, and native status were tested with univariate analyses; floristic composition data were analyzed by multivariate techniques. Understory vegetation of restoration sites was generally hydrophytic, but species composition differed from that of mature bottomland forest because of young successional age and differing responses of plant growth forms. Attribute and floristic variation among restoration sites was related to variation in canopy development and local wetness conditions, which in turn reflected both intrinsic site features and outcomes of restoration practices. Thus, understory vegetation is a useful indicator of functional progress in floodplain forest restoration.

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90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 31.109388560814963° to 35.90684930677121° latitude; -92.48291015625° to -89.1650390625° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeXRIS

Diane De Steven, Stephen Faulkner, Bobby D. Keeland, M.J. Baldwin, John W. McCoy, Steven C. Hughes. 2015-04-09. Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A.. https://doi.org/10.1111/rec.12210

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Biocrust restoration in novel climates: Assisted migration, habitat amelioration, and varied community composition as climate-smart techniques

Introduction Successful restoration of terrestrial drylands depends on stable, fertile soils that retain water. These functions are provided by biological soil crusts (biocrust), suggesting their reestablishment is a critical step in dryland restoration. Restoration may be hindered by the increasingly documented negative effects of climate change, while new climate-smart biocrust restoration methods may improve short- and long-term restoration outcomes. Objectives In this study, we evaluated three approaches to climate-smart biocrust restoration: assisted migration, habitat amelioration via shading, and varied community composition. Methods We collected biocrusts from across wide geographic gradients spanning multiple climate regimes, including wide ranges of mean annual temperature, mean annual precipitation, and precipitation seasonality. We used biocrust from these different environments as inoculum in two common garden restoration trials, in a research greenhouse testing shading and drying, and at a rangeland field site evaluating shading and warming. Results Community composition was related to climate across the natal (inoculum source) sites, and differences in the initial proportion of moss, lichen, and cyanobacteria resulted in different responses to experimental restoration treatments. We found mixed support for the efficacy of assisted migration and likely not enough success to outweigh the potential risks at present. Shading facilitated moss establishment even under warmer and drier conditions but inhibited lichen establishment and had little effect on cyanobacteria, which colonized quickly between mosses and lichens. Conclusion Overall, our results suggest several potential paths forward for biocrust restoration in warming drylands.

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Assessing working lands as habitat for disturbance-dependent birds using autonomous recording units

Introduction Working lands can provide habitat for declining disturbance-dependent birds, such as Bachman's Sparrow ( Peucaea aestivalis ) and Northern Bobwhite ( Colinus virginianus ), but it remains unclear whether restoration following intensive land use (e.g. surface mining) yields habitat comparable to less intensive land uses (e.g. timber production). Objectives We evaluated effects of land use both in working lands (recently replanted surface mine reclamation site and recently replanted timber production site) and reference sites explicitly managed for wildlife (recently restored young pine savanna and mature pine savanna) and understory vegetation characteristics on relative abundance of disturbance-dependent birds within upland pine ( Pinus spp.) communities in southeastern Georgia, United States. We hypothesized that the mine reclamation site would support similar bird species but in lower relative abundances than other land uses. Methods We conducted daily acoustic surveys using autonomous recording units (ARUs) and measured vegetation surveys once per point from May to June 2024. We used Royle-Nichols models, an adapted occupancy model, to estimate relative abundance for eight bird species. Results Land use influenced relative abundance for all species and explained more variation in relative abundance than measured understory vegetation characteristics. The mining reclamation site supported most disturbance-dependent species and, in some cases, equal or higher relative abundances, particularly for Northern Bobwhite and Common Nighthawk ( Chordeiles minor ). Responses across timber production and savanna sites varied by species. Vegetation effects were generally weaker and species-specific, suggesting that land use history and associated habitat legacies play an important role in structuring these bird communities. Conclusion Working lands, including reclaimed mines, can provide habitat for disturbance-dependent birds, and ARUs are effective for evaluating these patterns across land uses.

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