Temporal and spatial separation allow coexistence of predatory cladocerans: Leptodora kindtii, Bythotrephes longimanus and Cercopagis pengoi, in southeastern Lake Michigan

The dry matter production and resource allocation patterns of a series of 1- to 5-year-old stands of Rubus idaeus are described. Stand development proceeds along a predictable pattern of development from the building to the self-thinning phases. The building phase is characterized by an active period of vegetative propagation, insuring almost full occupancy of the site at the end of the 2nd to 3rd years. It is suggested that the shift from clonal growth to fruit production in the self-thinning phase represents an adaptive response to a deteriorating environment. Competition for the available assimilates between the 1st-year cane, the primocane, and the 2nd-year cane, the floricane, is minimized by the temporal and spatial separation of their activities.

Download Full-text

Emissions reduction benefits of siting an offshore wind farm: A temporal and spatial analysis of Lake Michigan

Ecological Economics ◽

10.1016/j.ecolecon.2016.07.010 ◽

2016 ◽

Vol 130 ◽

pp. 263-276 ◽

Cited By ~ 2

Author(s):

Amy C. Chiang ◽

Michael R. Moore ◽

Jeremiah X. Johnson ◽

Gregory A. Keoleian

Keyword(s):

Spatial Analysis ◽

Wind Farm ◽

Lake Michigan ◽

Offshore Wind ◽

Emissions Reduction ◽

Offshore Wind Farm ◽

Temporal And Spatial

Download Full-text

Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2013-0514 ◽

2014 ◽

Vol 71 (7) ◽

pp. 1072-1086 ◽

Cited By ~ 20

Author(s):

Mark W. Rogers ◽

David B. Bunnell ◽

Charles P. Madenjian ◽

David M. Warner

Keyword(s):

Food Web ◽

Functional Groups ◽

Lake Michigan ◽

Neogobius Melanostomus ◽

Trophic Levels ◽

Nutrient Concentrations ◽

Ecosystem Structure ◽

Bythotrephes Longimanus ◽

Nutrient Inputs ◽

Food Web Structure

Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

Download Full-text

Distribution patterns of vertebrate and invertebrate planktivores in Newfoundland lakes with evidence of predator–prey and competitive interactions

Canadian Journal of Zoology ◽

10.1139/z90-230 ◽

1990 ◽

Vol 68 (7) ◽

pp. 1559-1567 ◽

Cited By ~ 7

Author(s):

Christine E. Campbell ◽

Roy Knoechel

Keyword(s):

Gasterosteus Aculeatus ◽

Spatial Separation ◽

Distribution Patterns ◽

Competitive Interactions ◽

Cyclopoid Copepod ◽

Predator Prey ◽

Interacting Species ◽

Leptodora Kindtii ◽

Faunal Diversity ◽

Avalon Peninsula

The vertebrate Gasterosteus aculeatus, the threespine stickleback, and the invertebrates Chaoborus punctipennis, Chaoborus trivittatus, and Leptodora kindtii are the major predators of zooplankton in lakes on the Avalon Peninsula, Newfoundland. Predator–prey and competitive interactions among these planktivores are potentially strong. Low faunal diversity in the lakes limits the number of interacting species, which may increase the intensity of the interactions, while the low habitat heterogeneity of the lakes decreases the probability of spatial separation of species to increase rates of species encounters. Analyses of distributional patterns (presence or absence data) of the planktivores in 15 Avalon lakes indicated that the distributions of both Chaoborus spp. were significantly and negatively related to the distribution of sticklebacks. Chaoborus densities were significantly higher in the lakes without sticklebacks. Sticklebacks were observed to eat third and fourth instars of both Chaoborus species in laboratory experiments and hence, through predation, may be able to exclude these species from some lakes. There was no significant relationship between the distributions of Leptodora and sticklebacks or between Leptodora and C. punctipennis, however the distributions of Leptodora and C. trivittatus were significantly and negatively related, indicating a possible competitive interaction. Environmental factors also influence planktivore distribution and abundance: a principal components factor derived from planktivore density data was significantly correlated with cyclopoid copepod biomass, lake SO4 levels, and lake surface area (multiple linear regression, r2 = 0.71).

Download Full-text