Vascular plants and plant habitats of Brush Creek Island, Lewis County, Kentucky, U.S.A.

A descriptive survey of the vascular flora and plant habitats of Brush Creek Island, a 6.7-ha Ohio River island in Lewis County, Kentucky, was conducted during 1995–1996 and 2012. Brush Creek Island (BC), one of three Ohio River islands politically a part of Kentucky, is currently under private ownership and projected as a future part of the Ohio River Islands National Wildlife Refuge. Two major habitats in 2012 were Vegetated Unconsolidated Shoreline and Bottomland Hardwood Forest, a final sere of Late Old Field and Immature Bottomland Hardwood Forest. Two additional 1996 habitats, a seasonal Riverine Emergent Wetland and Late Old Field, were altered through fluvial action and secondary succession processes by 2012. An annotated list consists of 330 species in 220 genera from 82 families. Taxa are composed of one Monilophyte, four Magnoliids, 76 Monocots, and 249 Eudicots. Ninety-three taxa (28.2%) are non-native adventive or naturalized spe-cies. Forty-eight taxa (54%) are classified as Kentucky invasive plants. A total of 189 species (57.3%) are hydrophytes. Ninety-five native or non-native taxa (28.8%) are Lewis County distribution records.

Remote Assessment of Swamp and Bottomland Hardwood Habitat Condition in the Maurepas Diversion Project Area

This study used high spatial resolution satellite imagery to identify and map Bottomland Hardwood (BLH) BLH and swamp within the Maurepas Diversion Project area and use Light Detection and Ranging (Lidar) elevation data, vegetation indices, and established stand-level thresholds to evaluate the condition of forested habitat. The Forest Condition methods and data developed as part of this study provide a remote sensing-based supplement to the field-based methods used in previous studies. Furthermore, several advantages are realized over traditional methods including higher resolution products, repeatability, improved coverage, and reduced effort and cost. This study advances previous methods and provides products useful for informing ecosystem decision making related to environmental assessments.

Remotely sensed habitat assessment of bottomland hardwood and swamp habitat : West Shore Lake Pontchartrain Hurricane Storm Damage Risk Reduction System potential impact area

This study used remote sensing techniques to identify and assess the current condition of bottomland hardwood (BLH) and swamp habitats within the West Shore Lake Pontchartrain (WSLP) hurricane storm-damage risk reduction system (HSDRRS) project area. This effort provides baseline knowledge of the location and quality of these habitats prior to the construction of the WSLP HSDRRS project. The resultant products will assist the USACE—New Orleans District (MVN) by informing ecosystem decision-making related to environmental assessments.

Tree-level Growth of Four Oak Species in a Bottomland Hardwood Plantation: Implications for Silvicultural Treatments

A 41-year-old bottomland hardwood plantation experiment located in southeastern Arkansas was revisited in 2017 to evaluate basal area increment (BAI) of four oak species [cherrybark oak (Quercus pagoda Raf.), swamp chestnut oak (Q. michauxii Nutt.), Nuttall oak (Q. texana Buckl.), and water oak (Q. nigra L.)] planted in monoculture in relation with species, spacing, thinning, and neighborhood competition. Species had a significant effect on BAI (P = 0.04), with cherrybark oak and Nuttall oak demonstrating the greatest (21.5 ± 2.5 cm2 year−1) and lowest (12.7 ± 2.9 cm2 year−1) growth rates, respectively, whereas BAI declined significantly with increasing competition (P = 0.03). However, rates of growth decline with competition did not differ between species (P > 0.05 for competition × species term), and thinning and spacing treatments had no effect on BAI (P > 0.05). We recommend that repetitive thinning, rather than a single thinning, would be appropriate to maintain a positive impact on oak growth. Managing stand density would not only provide opportunities for improving timber production, but also would enhance ecological benefits (e.g., wildlife habitat) through diversification of structure within monoculture plantations. Study Implications: This research supports the general concept that stand density management may effectively alleviate tree-level stresses on bottomland oak species related to intra-specific competition while improving their growth. In particular, repeated thinning could help reduce growth stagnation and maintain tree-level vigor. Repeated tending entries would also create multiple opportunities to simultaneously improve timber production and enhance ecological benefits in bottomland oak monocultures. Finally, the findings of this study confirm the importance of correctly matching species to site when artificially regenerating bottomland oaks.

Bottomland hardwood forest growth and stress response to hydroclimatic variation: evidence from dendrochronology and tree ring Δ¹³C values

Wetland forests around the world have been reduced to a small proportion of their original expanse due to changing climatic conditions and intensification of human land use activities. As a case in point, the Columbia bottomland hardwood forests along the Brazos–Colorado coastal basin on the Gulf coast of Texas are currently threatened by an increasingly erratic hydroclimate in the form of both extreme floods and droughts and by urban expansion. In this study, we use dendrochronology and tree ring carbon isotopes to understand the effect of changing hydroclimatic conditions on the functional attributes of these forests. We examined the tree rings of Quercus nigra at four sites within the Columbia bottomlands, of which one site experiences frequent and prolonged flooding, while the other three are less flood prone. The objectives of this study were to (i) understand the impact of hydroclimatic variation on radial growth, using tree ring width analysis, (ii) assess the magnitude of physiological stress inflicted by extreme hydroclimatic conditions, using tree ring Δ13C measurements as a proxy, and (iii) evaluate the relationship between tree ring width and Δ13C values. Radial growth across the landscape was influenced most strongly by the midgrowing season climate, while the early growing season climate had the strongest effect on Δ13C. Growth inhibition was minimal, and tree ring Δ13C values were not affected in trees at the wetter site under extreme hydrological conditions such as droughts or floods. In addition, trees at the wet site were less sensitive to precipitation and showed no response to higher temperatures. In contrast, trees at the three drier sites experienced growth inhibition and had lower tree ring Δ13C values during dry periods. Our results indicate more favorable growing conditions and lower stress in trees growing under wetter hydrological conditions. Management and conservation strategies dependent on site-specific conditions are critical for the health of these wetland forests under a rapidly changing hydroclimate. This study provides the first dendrochronological baseline for this region and a better understanding of favorable conditions for the growth and health of these forests, which can assist in management decisions such as streamflow regulation and conservation plans.