scholarly journals Top predator introduction changes the effects of spatial isolation on freshwater community structure

Ecology ◽  
2021 ◽  
Author(s):  
Rodolfo Mei Pelinson ◽  
Mathew A. Leibold ◽  
Luis Schiesari
Keyword(s):  
Community Structure ◽  
Top Predator ◽  
Spatial Isolation ◽  
Freshwater Community Structure ◽  
Freshwater Community

Nutrients and sediment modify the impacts of a neonicotinoid insecticide on freshwater community structure and ecosystem functioning

2019 ◽  
Vol 692 ◽  
pp. 1291-1303 ◽  
Author(s):  
Ana M. Chará-Serna ◽  
Luis B. Epele ◽  
Christy A. Morrissey ◽  
John S. Richardson
Keyword(s):  
Community Structure ◽  
Ecosystem Functioning ◽  
Neonicotinoid Insecticide ◽  
Freshwater Community Structure ◽  
Freshwater Community

scholarly journals Disentangling the influence of abiotic variables and a non-native predator on freshwater community structure

Ecosphere ◽  
2015 ◽  
Vol 6 (12) ◽  
pp. art285 ◽  
Author(s):  
Katie S. Pagnucco ◽  
Anthony Ricciardi
Keyword(s):  
Community Structure ◽  
Abiotic Variables ◽  
Freshwater Community Structure ◽  
Native Predator ◽  
Freshwater Community

scholarly journals Strong effects of a mutualism on freshwater community structure

Ecology ◽  
2020 ◽  
Author(s):  
Robert P. Creed ◽  
James Skelton ◽  
Kaitlin J. Farrell ◽  
Bryan L. Brown
Keyword(s):  
Community Structure ◽  
Freshwater Community Structure ◽  
Freshwater Community

scholarly journals Regulation of Freshwater Community Structure at Multiple Intensities of Dragonfly Predation

Ecology ◽  
1984 ◽  
Vol 65 (5) ◽  
pp. 1546-1555 ◽  
Author(s):  
James H. Thorp ◽  
Marian L. Cothran
Keyword(s):  
Community Structure ◽  
Freshwater Community Structure ◽  
Freshwater Community

scholarly journals Spatial and Resource Factors Influencing High Microbial Diversity in Soil

2002 ◽  
Vol 68 (1) ◽  
pp. 326-334 ◽  
Author(s):  
Jizhong Zhou ◽  
Beicheng Xia ◽  
David S. Treves ◽  
L.-Y. Wu ◽  
Terry L. Marsh ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Communities ◽  
Uniform Distribution ◽  
Diversity Index ◽  
Carbon Surface ◽  
Low Carbon ◽  
Small Subunit Rrna ◽  
Surface Soils ◽  
Diversity Patterns ◽  
Spatial Isolation

ABSTRACT To begin defining the key determinants that drive microbial community structure in soil, we examined 29 soil samples from four geographically distinct locations taken from the surface, vadose zone, and saturated subsurface using a small-subunit rRNA-based cloning approach. While microbial communities in low-carbon, saturated, subsurface soils showed dominance, microbial communities in low-carbon surface soils showed remarkably uniform distributions, and all species were equally abundant. Two diversity indices, the reciprocal of Simpson’s index (1/D) and the log series index, effectively distinguished between the dominant and uniform diversity patterns. For example, the uniform profiles characteristic of the surface communities had diversity index values that were 2 to 3 orders of magnitude greater than those for the high-dominance, saturated, subsurface communities. In a site richer in organic carbon, microbial communities consistently exhibited the uniform distribution pattern regardless of soil water content and depth. The uniform distribution implies that competition does not shape the structure of these microbial communities. Theoretical studies based on mathematical modeling suggested that spatial isolation could limit competition in surface soils, thereby supporting the high diversity and a uniform community structure. Carbon resource heterogeneity may explain the uniform diversity patterns observed in the high-carbon samples even in the saturated zone. Very high levels of chromium contamination (e.g., >20%) in the high-organic-matter soils did not greatly reduce the diversity. Understanding mechanisms that may control community structure, such as spatial isolation, has important implications for preservation of biodiversity, management of microbial communities for bioremediation, biocontrol of root diseases, and improved soil fertility.

scholarly journals Top predator introduction changes the effects of spatial isolation on freshwater community structure

2019 ◽  
Author(s):  
Rodolfo Mei Pelinson ◽  
Mathew A. Leibold ◽  
Luis Schiesari
Keyword(s):  
Community Structure ◽  
Dispersal Limitation ◽  
Interspecific Variation ◽  
Trophic Levels ◽  
Predatory Fish ◽  
Macroinvertebrate Communities ◽  
Local Conditions ◽  
Freshwater Habitats ◽  
Spatial Isolation ◽  
Predatory Insects

AbstractThe importance of local selective pressures on community structure is predicted to increase with spatial isolation when species favored by local conditions also have higher dispersal rates. In freshwater habitats, the introduction of predatory fish can produce trophic cascades because fish tend to prey upon intermediate predatory taxa, such as predatory insects, which indirectly benefits herbivores and detritivores. Similarly, spatial isolation is known to limit predatory insect's colonization rates more strongly than of herbivores and detritivores, thus generating similar effects. Here we tested the hypothesis that the effect of introduced predatory fish on macroinvertebrate community structure increases across a gradient of spatial isolation by conducting a field experiment where artificial ponds with and without fish (the Redbreast Tilapia) were constructed at three different distances from a source wetland. Overall results show that fish do reduce the abundance of predatory insects but have no effect on the abundance of herbivores and detritivores. Spatial isolation, however, does strengthen the trophic cascade caused by dispersal limitation of predatory insects, but only in the absence of fish. More importantly, macroinvertebrate communities with and without fish tend to diverge more strongly at higher spatial isolation, however, this pattern was not due to an increase in the magnitude of the effect of fish, as initially hypothesized, but to a change in the effect of isolation in the presence of fish. We argue that as spatial isolation increases, suitable prey, such as predatory insects become scarce and fish increases predation pressure upon herbivores and detritivores, dampening the positive effect of spatial isolation on them. Our results highlight the importance of considering interspecific variation in dispersal and multiple trophic levels to better understand the processes generating metacommunity structures.

Effect of lake size, isolation and top predator presence on nested fish community structure

2016 ◽  
Vol 43 (7) ◽  
pp. 1425-1435 ◽  
Author(s):  
Georgina V. Braoudakis ◽  
Donald A. Jackson
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Fish Community Structure ◽  
Top Predator ◽  
Lake Size

scholarly journals Impacts of agrochemical intensification on the assembly and reassembly of a mainland-island model metacommunity

2021 ◽  
Author(s):  
Rodolfo Mei Pelinson ◽  
Bianca Rodrigues Strecht ◽  
Erika Mayumi Shimabukuro ◽  
Luis Cesar Schiesari
Keyword(s):  
Community Structure ◽  
Rainy Season ◽  
Isolation By Distance ◽  
Single Pulse ◽  
Temporary Pond ◽  
Species Dispersal ◽  
Crop Fields ◽  
Predatory Insect ◽  
Spatial Isolation ◽  
Predatory Insects

ABSTRACTMany lentic aquatic environments are found embedded in agricultural fields, forming complex metacommunity structures. These habitats are vulnerable to contamination by agrochemicals, which can differentially affect local communities depending on the intensity and variability of species dispersal rates. We conducted a field experiment to assess how agrochemical intensification simulating the conversion of savannas into managed pastures and sugarcane fields affects freshwater community structure at different levels of spatial isolation. We constructed forty-five 1,200-L artificial ponds in a savanna landscape at three distances from a source wetland (30 m, 120 m, and 480 m). Ponds were spontaneously colonized by aquatic insects and amphibians and treated with no agrochemicals (‘savanna’ treatment), fertilizers (‘pasture’ treatment), or fertilizers and a single pulse of the insecticide fipronil and the herbicide 2,4-D (‘sugar cane’ treatment) following realistic dosages and application schedules. The experiment encompassed the entire rainy season. ‘Pasture’ communities were only slightly different from controls largely because two predatory insect taxa were more abundant in ‘pasture’ ponds. ‘Sugarcane’ communities strongly diverged from other treatments after the insecticide application, when a decrease in insect abundance indirectly benefitted amphibian populations. However, this effect had nearly disappeared by the end of the rainy season. The herbicide pulse had no effect on community structure. Spatial isolation changed community structure by increasing the abundance of non-predatory insects. However, it did not affect all predatory insects nor, surprisingly, amphibians. Therefore, spatial isolation did not change the effects of agrochemicals on community structure. Because agrochemical application frequently overlaps with the rainy season in many monocultures, it can strongly affect temporary pond communities. Ponds embedded in pastures might suffer mild consequences of fertilization by favoring the abundance of few predators through bottom-up effects. Ponds in sugarcane fields, however, might experience a decline in the insect population, followed by an increase in the abundance of amphibians tolerant to environmental degradation. Furthermore, we found no evidence that isolation by distance can change the general effects of chemical intensification, but future experiments should consider using real crop fields as the terrestrial matrix since they can represent different dispersal barriers.

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