Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Defoliation (2)
- Herbivory (2)
- Betula (1)
- Betula pubescens (1)
- Biodiversity and ecosystem functioning (1)
-
- Biomass and plant species evenness (1)
- Burning (1)
- CO2 enrichment (1)
- Developmental instability (1)
- Eh (1)
- Elevated CO2 (1)
- Environmental stress (1)
- Fennoscandia (1)
- Fluctuating asymmetry (1)
- Fluctuating asymmetry in leaves (1)
- Global change (1)
- Grassland (1)
- Grasslands (1)
- Grazing (1)
- Hybridization (1)
- Hydrologic alterations (1)
- Levees and water control structures (1)
- Nematodes (1)
- Nitrogen (1)
- Old fields (1)
- Phenolics (1)
- Phleum (1)
- Plant CO2 exchange rates (1)
- Plant community composition; productivity vs. plant diversity (1)
- Poa (1)
Articles 1 - 7 of 7
Full-Text Articles in Entire DC Network
Effects Of Elevated Co2 On The Response Of Phleum Pratense And Poa Pratensis To Aboveground Defoliation And Root-Feeding Nematodes, Brian J. Wilsey
Effects Of Elevated Co2 On The Response Of Phleum Pratense And Poa Pratensis To Aboveground Defoliation And Root-Feeding Nematodes, Brian J. Wilsey
Brian J. Wilsey
Because of the importance of herbivory in many herbaceous plant–dominated ecosystems, it will be important to determine whether interactions exist between herbivory and CO2 enrichment if we are to understand better how ecosystems will respond to global change. In an experiment with the C3 grasses Poa pratensis and Phleum pratense, plants were grown together under ambient (360 ppm) and elevated (650 ppm) CO2, with and without aboveground defoliation, and with or without additions of the root-feeding nematode Pratylenchus penetrans. The objective was to determine whether herbivory would interact with CO2 enrichment in determining biomass responses or whether these factors were …
Yponomeuta Evonymellus Outbreaks In Southern Finland: Spatial Synchrony But Different Local Magnitudes, Brian J. Wilsey, Conchita Alonso, Timo Vuorisalo, Tuija Honkanen
Yponomeuta Evonymellus Outbreaks In Southern Finland: Spatial Synchrony But Different Local Magnitudes, Brian J. Wilsey, Conchita Alonso, Timo Vuorisalo, Tuija Honkanen
Brian J. Wilsey
Defoliations of Prunus padus by Yponomeuta evonymellus were monitored in two areas in southern Finland. During a long-term study (1980–1995) in the area with high peak defoliations, P. padus trees recorded two defoliation peaks, leading to complete defoliation of many trees. The negative relationship between pupal mass and current year tree defoliation during the peak years suggested shortage of food affected reproductive potential of Y. evonymellus. Furthermore, no delayed induced resistance was observed in these populations. Interannual correlations in degrees of defoliation experienced by individual trees were low, i.e. high defoliation in one year did not predict the degree of …
Biodiversity And Ecosystem Functioning: Importance Of Species Evenness In An Old Field, Brian J. Wilsey, Catherine Potvin
Biodiversity And Ecosystem Functioning: Importance Of Species Evenness In An Old Field, Brian J. Wilsey, Catherine Potvin
Brian J. Wilsey
Changes in land use, habitat fragmentation, nutrient enrichment, and environmental stress often lead to reduced plant diversity in ecosystems. However, it remains controversial whether these reductions in diversity will affect energy flow and nutrient cycling. Diversity has two components: species richness, or the number of plant species in a given area, and species evenness, or how well distributed abundance or biomass is among species within a community. We experimentally varied species evenness and the identity of the dominant plant species in an old field of Quebec to test whether plant productivity would increase with increasing levels of evenness, and whether …
Effects Of Resource Availability On Carbon Allocation And Developmental Instability In Cloned Birch Seedlings, Brian J. Wilsey, Janne H. Lappalainen, Jocelyn Martel, Kyösti Lempa, Vladimir Ossipov
Effects Of Resource Availability On Carbon Allocation And Developmental Instability In Cloned Birch Seedlings, Brian J. Wilsey, Janne H. Lappalainen, Jocelyn Martel, Kyösti Lempa, Vladimir Ossipov
Brian J. Wilsey
Abundant nitrogen improves seedling growth and establishment. Vigorous growth brings about changes in rates and patterns of plant development and changes in the relationship between primary and secondary metabolism, which may make seedlings more susceptible to herbivores and pathogens than are slow-growing seedlings. We studied how nitrogen fertilization and manual defoliation of source leaves affect growth, carbon allocation, and developmental instability in cloned seedlings of white birch (Betula pubescens Ehrh.). Biomass was higher, whereas concentrations of most classes of phenolic compounds were lower in the nitrogen-rich environment. Interestingly, fertilization did not change the concentrations of cell wall–bound proanthocyanidins, which represent …
The Effect Of Water Level Management On The Soils And Vegetation Of Two Coastal Louisiana Marshes, Brian J. Wilsey, K. M. Flynn, I. A. Mendelssohn
The Effect Of Water Level Management On The Soils And Vegetation Of Two Coastal Louisiana Marshes, Brian J. Wilsey, K. M. Flynn, I. A. Mendelssohn
Brian J. Wilsey
Wetland degradation and loss is the result of a combination of natural causes and anthropogenic activities and is a serious problem in coastal Louisiana, where approximately 80% of the total US coastal wetland loss since the 1930’s has occurred. One method currently used to address this wetland loss problem is structural marsh management,which is the use of levees and water control structures to control hydroperiod. The effects of structural marsh management on two managed marshes in Southern Louisiana (Unit 4 of the Rockefeller Wildlife Refuge and the Fina LaTerre Mitigation Bank) were evaluated by comparing the soils and the dominant …
Leaf Fluctuating Assymetry Increases With Hybridization And Elevation In Tree-Line Birches, Brian J. Wilsey, Erkki Haukioja, Julia Koricheva, Matti Sulkinoja
Leaf Fluctuating Assymetry Increases With Hybridization And Elevation In Tree-Line Birches, Brian J. Wilsey, Erkki Haukioja, Julia Koricheva, Matti Sulkinoja
Brian J. Wilsey
Fluctuating asymmetry (FA), or random non-directional deviations from perfect symmetry in bilaterally or radially symmetrical traits, has recently been proposed to be a useful indicator of genetic and environmental stress. However, the factors underlying fluctuating asymmetry, especially in plants, remain poorly understood. We sampled leaf fluctuating asymmetry among and within three species of even-aged birch (Betula pubescens, B. nana, and B. pendula) and their interspecific hybrids growing in common gardens of northern Finland to determine whether hybridization and environmental stress are associated with increased developmental instability. Our predictions were that: (1) interspecific hybrids among B. pubescens, B. nana, and B. …
Effects Of Elevated Co2 And Defoliation On Grasses: A Comparative Ecosystem Approach, Brian J. Wilsey, James S. Coleman, Samuel J. Mcnaughton
Effects Of Elevated Co2 And Defoliation On Grasses: A Comparative Ecosystem Approach, Brian J. Wilsey, James S. Coleman, Samuel J. Mcnaughton
Brian J. Wilsey
Three plant species from each of three grassland ecosystems were grown under elevated (700 mL/m3) and ambient (350 mL/m3) CO2 and were defoliated or left undefoliated to test whether species response to elevated CO2 and grazing is related to evolutionary grazing history or to mode of photosynthesis. The three ecosystems represented a tropical grassland dominated by C4 species (the Serengeti of Africa), a temperate grassland dominated by a mixture of C3 and C4 species (Flooding Pampa of South America), and a northern temperate grassland dominated by C3 species (Yellowstone National Park of North America). Plants were grown in growth chambers …