A study to investigate the role of population sex ratio in gender switching in an A. Triphyllum population along with the role of different environmental factors and management activities on plant size and population sex ratio in two different populations
The underutilized tropical fruit tree, “cempedak” (Artocarpus integer (Thunb.) Merr. , Moraceae), is a major crop in Malaysia but the distribution of genetic diversity in the crop and its putative wild progenitor, “bangkong” (Artocarpus integer var. silvestris Corner), have not been studied. To investigate the diversity and origins of cempedak,...
Current ecological restoration efforts seek to restore a target community, maximize biodiversity or provide habitat for rare species. In practice, restoration ecology is often initiated and sustained without knowledge or reverence to the belowground ecosystem processes, though these processes often subtend the long-term sustainability of aboveground and belowground ecological communities.
Past efforts to reintroduce the native legume species Desmodium glutinosum and Lespedeza violacea into restored woodlands have not produced self-sustaining populations. Proposed factors preventing reintroduction include herbivory, persistent environmental effects of invasive shrubs, poor performance of commercial Rhizobium inoculants, and competitive displacement associated with elevated nitrogen availability. To address these...
Pollination is a reproductive necessity in the majority of the world’s flowering plants. Pollen limitation threatens plant reproduction, particularly in self-incompatible species. Although assessing pollen limitation usually requires pollen supplementation experiments, alternative methods support the findings of traditional pollen supplementation experiments.
Pollination is a reproductive necessity in the majority of the world’s flowering plants. Pollen limitation threatens plant reproduction, particularly in self-incompatible species. Although assessing pollen limitation usually requires pollen supplementation experiments, alternative methods support the findings of traditional pollen supplementation experiments.
Two experiments were conducted to assess the germination, growth, and survival of Cirsium pitcheri Torr. ex Eaton T & G in the Chicagoland region. The first experiment involved growing seeds from various native populations to determine tolerance for the current Chicagoland climate. The second experiment tested three of the populations...
Habitat fragmentation can alter the conditions of natural plant populations, introducing novel selective pressures. The ability of a population to respond to environmental change can be inferred by assessing the population’s genetic diversity and the heritability of traits thought to be under selection.
Identifying factors that shape the spatial distribution of genetic variation within and among natural populations is crucial to understanding many population> and landscape>level processes. In this study, I characterize the strength and extent of spatial genetic structure in Oenothera harringtonii (Onagraceae), an insect>pollinated, gravity>dispersed herb endemic to the grasslands of...
The tallgrass prairie once dominated much of the mid-western United States. Today, this highly productive system has been severely reduced, contributing to an array of environmental problems. The recent renaissance in natural area restoration and stewardship of the tallgrass prairie in the Chicago Wilderness region (Illinois, USA), especially in the...
Nitrogen (N) deposition can alter belowground microbial communities, especially ectomycorrhizal (ECM) fungi, resulting in a reduced ability of associated trees to access organic nutrients. This study tested whether N addition decreases ECM species richness and shifts ECM species composition across spatial scales in a subtropical slash pine (Pinus elliottii) plantation...
The environmental and plant physiological correlates of plant growth and reproductive effort in the locally threatened orchid, Cypripedium candidum Muhl. ex Willd were examined in the context of a conceptual model of demographic and reproductive trade-offs, focusing on three Illinois populations. This study addresses the current status and long-term trends...
Plant-aphid systems provide a valuable opportunity for studying the ecological consequences of land use change for interacting species. The North American tallgrass prairie has undergone severe reduction and fragmentation due to agricultural development. The prairie perennial Echinacea angustifolia, a model system for studying population-level effects of habitat fragmentation, hosts a...
The introduction of non-native pests in general, and invasive plants in particular, has been receiving increasing interest by scientists, environmental groups, and to a certain extent the general public. Deleterious effects from the release of such alien species include threats to the environment, national economies, and even human health. The...
Underutilized crops have the potential to economically benefit developing countries and to improve global food security. Breadfruit (Artocarpus altilis, Moraceae) is one such crop that can provide essential nutrients and requires relatively low-energy input to maintain compared to major crops. Humans have selected for many cultivars of breadfruit since its...
With increasing urbanization and creation of novel habitat types, green roofs can provide usable habitat for many species. To date, most research on green roofs has focused on minimizing the environmental impacts of buildings but little is known about the ecological services they provide. Previous research has shown that although...
Hybridization is an important evolutionary pathway to genetic diversity, fitness, and ultimately to the emergence of new species. In contrast, hybridization between a native and an introduced species can lead to a loss of locally adapted gene complexes and ultimately to the extinction of the native. In the last decade,...
Once widespread throughout southern Wisconsin, Quercus savannas are now one of the most endangered communities due to fire suppression and increasing landscape fragmentation. These plant communities are also highly susceptible to invasions by nonnative, exotic species. Understanding the mechanisms of exotic species invasion has been the focus of numerous studies....
Fire is an agent of ecosystem change that has played a critical role in shaping the tallgrass prairie ecosystem. Periodic prescribed fire maintains the prairie by removing woody and invasive plant species, and stimulating growth of native herbaceous species. Fire’s beneficial effect on the tallgrass prairie aboveground community, in terms...
Due to concerns about population declines and habitat destruction, secretive marsh birds (SMBs) are of high conservation concern at state, regional, and national levels. Gaps in research on SMB habitat pose barriers to conservation and wetland restoration efforts.
Restoration managers may select seed from a variety sources for their restoration projects. If the purchased seed is not of the local ecotype, land managers run the risk of poor establishment in the short-term and outcrossing between local and non-local ecotypes, genetic swamping, and the loss of local genetic diversity...
Understanding how root traits vary within and among species, and how they respond to heterogeneous environments, can provide important insight into functional plant attributes that influence plant survival in competitive environments. Selecting plant material with root traits that will support its survival in competitive environments may help improve the outcomes...
The prairie grasses Andropogon gerardii and Sorghastrum nutans have seeds with awns that twist in response to changes in humidity. The humidity-sensitive, or hygroscopic, part of the awn twists, moving the bent, passive portion in an arc. This trait has been demonstrated to improve seedling recruitment in other grass species...
Trees in urban areas offer ecosystem services like carbon sequestration, storm water attenuation, reduction of energy used in buildings and wildlife habitat. Cities invest substantial funds and resources to maintain a healthy urban forest, and much research has been done to improve its resiliency and sustainability. Studies have been done...
Because long-chain n-alkanes (n-C21 to n-C37) are found in the epicuticular leaf waxes of all vascular plants and are stable, long-lived molecules, the study of their molecular and isotopic compositions stands to serve as a potentially powerful tool in the fields of modern chemotaxonomy and paleoecology. This study attempts to...
Understanding the factors that drive the maintenance of polymorphisms in plant populations has long been of interest to evolutionary biology. Variation in floral traits has often been attributed to selection by pollinators, but recent evidence suggests that other biotic and abiotic agents may also contribute to floral trait differentiation. In...
Climate change, whether referring to historic ice ages or contemporary shifts in global climate patterns, has been linked to wide-ranging and regionally variable changes in biotic communities.
After large-scale disturbances such as fire, seeding can be necessary to reestablish a plant community and prevent soil erosion. While native plants are ideal for providing ecosystem services and supporting wildlife, currently seeded natives often fail to establish in disturbed landscapes. Further, reseeding with native plants is often hindered by...
