Prolific production of offspring is generally characteristic of invasive plant species. However, Allee effects and other population-level processes may constrain reproductive success. This study identified variation in seed quality resulting from different genetic diversity levels in parental populations of an invasive grass. Using the outcrossing and wind-pollinated annual grass Lolium multiflorum, experimental populations were created with independently varying size and genetic diversity. Seeds from parental populations with lower diversity germinated and emerged from the soil at significantly lower rates than seeds from populations with the highest diversity. This effect was not detected in later-occurring fitness components such as flower production per planted seed. Reductions in seed germination and seedling numbers can affect future generations by reducing the size and/or genetic diversity of the resulting populations. The reduced offspring quality seen here suggests that fecundity and invasiveness vary not only among invasive species or potential invasive species, but also among populations of the same invasive species and highlights an advantage of genetic diversity within invasions.

Potential allelopathic effects of wax myrtle, Morella cerifera (L.), to Brazilian peppertree, Schinus terebinthifolia Raddi, were investigated in laboratory and field studies. Aqueous leaf extracts of wax myrtle suppressed germination and reduced seedling growth and survival of Brazilian peppertree. Similarly, root washings of wax myrtle negatively affected germination, growth and biomass accumulation of Brazilian peppertree. In field plots planted with equal densities of wax myrtle and Brazilian peppertree saplings, no differences in final densities, growth or vigor between the two species were detected after 14 months, suggesting that neither species was competitively superior to the other. Based on the results of this study, wax myrtle may have value as one tool in an integrated approach to management of Brazilian peppertree, but additional research is required to demonstrate allelopathic effects in the field.

Forests of eastern North American are losing Tsuga candensis (eastern hemlock) ecosystems throughout an expanding portion of its range due to the invasive pest insect Adelges tsugae (hemlock woolly adelgid: HWA). Tsuga canadensis represents a small portion of the landscape, particularly in the central and southern Appalachians where it is largely restricted to cove and riparian areas; however, it is a foundation species that defines a unique forest ecosystem. Consequently, loss of T. canadensis will result in a re-organization of ecosystem structure and function as alternate communities develop. A greater understanding this transition will advance ecological theory, but is also directly applicable to management and restoration planning. While county-level patterns of detection are readily available, less is known about the process of decline and compositional shifts. We identified riparian T. canadensis forests along thirty headwater streams across West Virginia and Virginia, representing an invasion chrononosequence of nine to thirty-two years. Sites encompassed a range in elevation, slope, and aspect, intended to identify patterns of T. canadensis dominance and decline. At each site, we sampled the overstory and sapling vegetation and recorded the crown health of each T. canadensis in transects at 10, 30, and 50 meters from the bank-full stream channel. Although in severe decline, T. canadensis continued to dominate both the overstory and sapling layers across riparian-upland transects across the central Appalachians. Structural equation modeling (SEM) indicated decline was moderated by higher elevations and landscape positions that received less incident radiation due to aspect and slope, but duration of Adelges tsugae invasion was the most influential factor in the decline of crown health for the overstory. SEM also identified decline in the overstory as the most influential factor in the decline of the sapling layer. Future forest function depends on composition, which will likely vary depending on the presence of Rhododendron maximum, an aggressive native shrub. Most importantly, functional processes that respond rapidly to T. canadensis decline are likely to experience continuing fluctuation as the composition shifts more gradually.

Pioneer Mothers' Memorial Forest is a unique largely undisturbed, mixed mesophytic hardwood forest in south-central Indiana, USA. We report on 26 years of change in community composition and structure; plots were previously sampled in 1978 and 1989. In 2004, we re-measured trees ≥ 5 cm in diameter for 153 permanent plots, as well as downed woody debris, and standing dead trees. In 1978, density was 718 stems ha⁻¹ and basal area 26.2 m² ha⁻¹, but by 2004 density had decreased to 493 stems ha⁻¹ with an increase in basal area to 31.4 m² ha⁻¹. Large density decreases were attributed to Acer saccharum, Sassafras albidum, Juniperus virginiana, and Cornus florida mortality, while basal area increased largely because of Liriodendron tulipifera and A. saccharum growth. The stand exhibited a reverse-J diameter distribution, but density in the lower diameter classes, < 15 cm, greatly decreased over time. The overstory (trees ≥ 25 cm) was dominated by A. saccharum, L. tulipifera, Quercus spp., and Fagus grandifolia. The understory was dominated by A. saccharum, which also accounted for > 60% of the ingrowth over the observed period. Diversity exhibited a significant decline between 1978 and 1989 and a negative trend overall. Annual stand mortality averaged 2.2% since 1978, with a U-shaped distribution of high mortality rates in the smallest and largest diameter classes. Most plots (62%) experienced multiple canopy tree deaths, but were not sufficiently large to allow for the ingrowth of Quercus spp. Very few members of shade-intolerant species that dominated the canopy were able to attain canopy status, excepting L. tulipifera stems characterized by good growth rates (mean 7 mm yr⁻¹). Down woody debris and standing dead trees were moderately abundant in varying states of decay across all diameter classes. Without any major disturbance or understory disturbance, shade-intolerant species, notably Quercus and Carya spp., will likely be very limited in the stand, and the forest canopy will eventually be dominated by A. saccharum and F. grandifolia. This study highlights the importance of long-term studies of forest species composition and structure to understand forest ecosystem dynamics.

Knowledge, both of the historical range of spruce-dominated forests and associated site conditions, is needed by land managers to help define restoration goals and potential sites for restoration. We used an existing digital database of witness trees listed in deeds from 1752 to 1899 to compare characteristics of red spruce (Picea rubens Sarg.) sites to non-red spruce sites to gain an understanding of historical spruce-dominated forests in West Virginia. The analysis revealed that red spruce witness trees were found at significantly higher elevations than non-spruce witness trees across the study area. However, spruce witness trees in the Western Allegheny Mountains subsection were found at significantly lower elevations than non-spruce witness trees. Indicator species analysis determined red spruce to be associated with toe slopes, benches, and valleys, although most locations were on side slopes. Across the entire study area, red spruce witness trees were more likely to be found on northeastern aspects and on acidic and frigid soils of the Mandy series. Historically, red spruce was associated with American beech (Fagus grandifolia Ehrh.), birch (Betula L.), and hemlock (Tsuga canadensis (L.) Carrière). This information should be used to guide red spruce restoration efforts and shows that a range of ecological settings should be considered when setting goals and implementing active management.

Ice storms are one of the main causes of disturbance and mortality in oak forests and can occur more frequently than wind storms, fire, diseases, and insect outbreaks. The effects of the 2009 ice storm on the tree species were studied in an upland oak-hickory forest at Bernheim Forest, Kentucky. Approximately 14% of the trees showed some damage from the ice storm with Ostrya virginiana, Acer rubrum, and Quercus rubra being the most susceptible to damage. Quercus velutina, Quercus alba, and Sassafras albidium were least susceptible. Pole size trees were more vulnerable to damage than sapling and sawtimber. Trees found in the midstory, and on the eastern slope had more damage from the ice storm than the other trees. Immediately following the ice storm, seedlings showed a high mortality, and it took until 2011 before most species returned to pre ice storm levels. Seedling numbers did not return to pre ice storm levels on the ridgetop and western upper slopes, which are more vulnerable to drought. By damaging the A. rubrum more than the Quercus and Carya species, and opening the understory, the ice storm is reducing midstory canopy and may be changing the composition of upland oak forests.

Floristic Quality Assessment (FQA) is a recognized bioassessment technique for evaluating habitat nativity or resource condition (status) using conservatism of the plant community. The Mid-Atlantic Floristic Quality Assessment Project (MAR-FQA) was undertaken in 2009 to advance floristic quality assessment in the Mid-Atlantic region. The primary objectives of the project were to assign coefficients of conservatism to the regional flora; describe the Mid-Atlantic region in terms of its floristic composition, conservatism, and nativity; and examine the potential subjectivity of coefficient values. We identified 4208 unique plant species of which 2822 were ranked. The flora was dominated by perennial forbs and graminoids. Two-thirds was native to either all or part of the region, while one-third was considered non-native to the region or to North America. Most coefficient ranks fell within the mid to upper range of the scale with distribution noticeably skewed toward higher conservatism due to a greater number of taxa with coefficients of 8, 9, and 10. Our investigation of bias in the approach indicated that subjectively assigned conservatism values were remarkably accurate. Over 75% of highly conservative taxa were found exclusively at high-quality wetland sites while less than 5% of generalist taxa were restricted to a single condition category. While FQA has been successfully used to assess habitat on both the state and sub-regional scales, it is now possible to deploy it in the Mid-Atlantic region. As a bioassessment tool, it offers a relatively rapid, reliable, and repeatable approach to assessing the somewhat arbitrary concept of quality. As such, it is an important addition to any botanist's tool kit.

A recent survey in areas of the Amazonia and the Atlantic Forest in Brazil, and revision of the exsiccates deposited in herbaria INPA, SP and URM resulted in new records of Hymenochaetaceae: eight for the State of Rondônia, one for Acre, Amapá and Amazonas, three for Pará and two for Roraima. Coltricia barbata, C. duportii, Hymenochaete porioides and H. unicolor are new records to the Brazilian Amazonia, while C. velutina is recorded for the first time after its description. A key to the Hymenochaete species known from Brazil is provided and the new combination Hymenochaete iodina is proposed.

In this work fresh material and herbarium specimens of Lentinus and Panus from the semi-arid region of Brazil were analyzed. A new species, Panus parvus, is described as one of the smallest species among the lentinoid species. Lentinus bertieri, L. swartzii, Panus tephroleucus, and P. velutinus are recorded for the first time for the Brazilian semi-arid region. Additional, comments and a key to the species of Lentinus and Panus from this region are provided. Panus caespiticola, Panus hirtiformis, and Panus neostrigosus are new combinations proposed here for a clear understanding in the discussion of Panus parvus.

Lecythis ibiriba (Lecythidaceae), a new combination, is described, illustrated, and discussed. This species occurs as a shrub or small- to medium-sized tree that grows in the Atlantic Forest of northeastern Brazil. Lecythis ibiriba differs from most species of Lecythis by having seeds with poorly developed basal arils and stalked vestigial stamens that are curved but not swept inward. Morphologically, it is similar to L. lurida; however, differences in the bark, leaves, flowers, and fruits justify its recognition as a separate species.