Author: engeladmin

Plant Response to Herbivory and Belowground Nitrogen Cycling

Student Database

Author: Holland, Elizabeth A.; Detling, James K. Description: Plant responses to herbivory and links to belowground nitrogen cycling were investigated at Wind Cave National Park, South Dakota. Laboratory estimates of net nitrogen mineralization were highest in soils from the more altered areas of prairie dog colonies (Cynomys ludovicianus) and lowest in the adjacent, lightly grazed, uncolonized grassland. The ratio of CO2: net nitrogen mineralized, as index of immobilization, was highest in the uncolonized grassland and lowest in the altered core areas. Soil moisture was an important modifier of in situ…

See more and a link to full text

Succession and Fire Season in Experimental Prairie Plantings

Student Database

Author: Howe, Henry F. Description: Fire season influenced the cover of species and flowering guilds of plants in replicated grass and forb plantings of tallgrass prairie species in Wisconsin. Over two burn cycles at 3-yr intervals, cover increased in the rhizomatous perennials Andropogon gerardii, Aster simplex and Solidago altissima in plots burned in spring, or summer, or left unburned, but cover showed dramatic positive or negative responses to spring or summer burns in Agropyron repens, Erigeron annuus, Panicum virgatum, Phalaris arundinacea, and Rudbeckia hirta. Aggregate response of flowering guilds was…

See more and a link to full text

Managing Species Diversity in Tallgrass Prairie: Assumptions and Implications

Student Database

Author: Howe, Henry F. Description: Conservation and restoration ecology efforts may conserve or restore a particular image of a community, a variety of plausible images, or maximum biological diversity. The choice is a policy decision that should reflect relevant history and sound science. Here I argue that common methods of conserving and restoring tallgrass prairie have a weak scientific rationale, are not consistent with plausible history, and threaten prairie biodiversity. Dormant-season burns and grazer exclusion are human interventions that may promote artificially consistent dominance of large grasses utilizing the C4…

See more and a link to full text

Fire and Litter Effects in Undisturbed Bluestem Prairie in Kansas

Student Database

Author: Hulbert, Lloyd C. Description: Two-by-two-meter plots of undisturbed, nearly pure Andropogon gerardi prairie were subjected to four treatments: burning, clipping and removal of the litter, burning the clipped litter and returning the ash, and the control (natural litter). Treatments were started in early April before growth began. Differences in results among the denuded plots were small and nonsignificant, but highly significant differences were found between denuded and control plots. Tiller number was increased 1.5 to 2.7 times by removal of litter. Growth began earlier in denuded than control plots….

See more and a link to full text

The effects of forest disturbance on diversity of tropical soil nematodes

Student Database

Author: Bloemers, G. F.; Hodda, M.; Lambshead, P. J. D.; Lawton, J. H.; Wanless, F. R. Description: We provide the first account of the effects of forest disturbance on species richness of nematodes in tropical forest soils, from 24 sites along gradients of disturbance and regeneration in the Mbalmayo Forest Reserve, Cameroon. Species richness was very high. Samples of 200 nematodes from individual soil cores contained a maximum of 89 and an average of 61 species; in total we recorded 431 species and approximately 194 genera. The model of Siemann…

See more and a link to full text

Influences of Trees on Savanna Productivity: Tests of Shade, Nutrients, and Tree-Grass Competition

Student Database

Author: Belsky, A. Joy Description: To determine why herbaceous productivity in tropical and subtropical savannas is often significantly higher under crowns of isolated trees than in adjacent grasslands, experimental plots were established in three concentric zones, crown, tree-root, and grassland, surrounding isolated trees of Acacia tortilis in low-rainfall and high-rainfall savannas in Tsavo National Park, Kenya. Plots were fertilized (to determine the importance of nutrient enrichment by trees), shaded (to determine the importance of crown shade), fertilized and shaded (to identify fertilizer x shade interactions), or trenched (tree roots entering…

See more and a link to full text

Effect of fire on hard-coated Cistaceae seed banks and its influence on techniques for quantifying seed banks

Student Database

Author: Ferrandis, Pablo; Herranz, Jose M.; Martinez-Sanchez, Juan J. Description: The impact of fire on hard-coated Cistaceae (Halimium ocymoides, Cistus ladanifer, and C. salvifolius) soil seed banks in a Mediterranean ‘maquis’ shrubland, and its effect on seed germinability were studied. The study also contrasts the effectiveness of two widely used techniques for quantifying seed banks, the seedling emergence and the physical separation methods, in relation to fire. The null hypothesis that a massive enhancement of physically-dormant Cistaceae seed germination by fire would make use of the time-consuming physical separation technique…

See more and a link to full text

Evolutionary Ecology across Three Trophic Levels: Goldenrods, Gallmakers, and Natural Enemies

Student Database

Author: Abrahamson, Warren G.; Weis, Arthur E. Description: In a work that will interest researchers in ecology, genetics, botany, entomology, and parasitology, Warren Abrahamson and Arthur Weis present the results of more than twenty-five years of studying plant-insect interactions. Their study centers on the ecology and evolution of interactions among a host plant, the parasitic insect that attacks it, and the suite of insects and birds that are the natural enemies of the parasite. Because this system provides a model that can be subjected to experimental manipulations, it has allowed…

See more and a link to full text

Numbers and Biomass of Selected Insect Groups on Burned and Unburned Sand Prairie

Student Database

Author: Anderson, Roger C.; Leahy, Theresa; Dhillion, Shivcharn S. Description: Abundance and biomass of selected insect groups were sampled on adjacent burned and unburned sand prairie for 3 years following a single spring burn. The abundance of all insects combined was significantly lower on the burned site than on the unburned site in the 1st yr postburn but not in subsequent years of the study. Of the selected insect groups, ants were significantly (P < 0.05) more abundant on the burned site than the unburned site for the 1st yr…

See more and a link to full text

Perceived Trustworthiness of Natural Language Generators

Featured Database

Author: Cabrero-Daniel, Beatriz; Cabrero, Andrea Sanagustin Description: Natural Language Generation tools, such as chatbots that can generate human-like conversational text, are becoming more common both for personal and professional use. However, there are concerns about their trustworthiness and ethical implications. The paper addresses the problem of understanding how different users (e.g., linguists, engineers) perceive and adopt these tools and their perception of machine-generated text quality. It also discusses the perceived advantages and limitations of Natural Language Generation tools, as well as users’ beliefs on governance strategies. The main findings of…

See more and a link to full text
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.