scholarly journals Invertebrate Community Composition Across Inundation Regimes and Its Potential to Reduce Plant Stress

2000 ◽  
Author(s):  
Inez Lawson
Keyword(s):  
Community Composition ◽  
Plant Stress ◽  
Invertebrate Community

Limited effects of stocked trout on littoral invertebrates in boreal foothills lakes

2012 ◽  
Vol 69 (1) ◽  
pp. 178-190 ◽  
Author(s):  
Leslie E. Nasmith ◽  
William M. Tonn ◽  
Cynthia A. Paszkowski ◽  
Garry J. Scrimgeour
Keyword(s):  
Community Composition ◽  
Size Structure ◽  
Invertebrate Community ◽  
Negative Effects ◽  
High Productivity ◽  
Recreational Angling ◽  
Key Characteristics ◽  
Littoral Zones ◽  
Littoral Invertebrates ◽  
The Impact

Stocking lakes with trout for the purposes of recreational angling is a management strategy that introduces a new predator into these systems and thus deserves careful scrutiny. To assess the impact of non-native trout on littoral invertebrates in naturally fish-bearing lakes in the boreal foothills of Alberta, Canada, we compared their community composition, abundance, and size structure in stocked (n = 5) and unstocked (n = 6) lakes over a 2-year period. We detected no clear negative effects of introduced trout on invertebrate community composition and only few taxa-specific examples of decreased or increased invertebrate abundance. Furthermore, predation by trout had inconsistent direct effects on the size structure of invertebrate populations. Indirect effects were suggested by increased abundances and sizes of some invertebrate taxa in stocked lakes and might also contribute to the limited overall differences that we observed. We propose that net effects of stocked trout on littoral invertebrates are influenced by key characteristics of receiving ecosystems. In our boreal foothills lakes, dense macrophyte cover in warm littoral zones, high productivity, abundant forage fish, and limited densities of trout all likely combine to allow littoral invertebrate communities to withstand the impact of introduced trout with minimal effects.

scholarly journals Factors Promoting Coexistence between Endemic Ants and Invasive Wasps

2021 ◽  
Author(s):  
◽  
Catherine Duthie
Keyword(s):  
Invasive Species ◽  
Community Composition ◽  
Isotope Ratios ◽  
Trophic Levels ◽  
Niche Shift ◽  
Niche Separation ◽  
Invertebrate Community ◽  
Nothofagus Forests ◽  
Foraging Pattern ◽  
The Impact

<p>Invasive animals can alter the community composition of native ecosystems by means of competition and predation. In this study I investigated the factors that may facilitate coexistence between endemic ants and invasive wasps. Previous research has shown that entire communities can be impacted by invasions. Endemic species subject to pressure from invasive species may undergo a niche shift to enable coexistence and minimise the impact of this pressure. The invertebrate community composition of Nothofagus forests in the South Island of New Zealand has been altered by predation from Invasive Vespula wasps. Ants and wasps in this ecosystem coexist on the same trophic level; they simultaneously fill multiple trophic roles as primary predators, secondary predators, and primary consumers. The outcome of competition between species such as ants and wasps is not easy to predict, and may vary in different communities and with different densities of competitors. In this dissertation I aimed to determine the extent to which competition occurs between native ants and invasive Vespula wasps, and to investigate the impacts of invasion on the native invertebrate community. I quantified the invertebrate community composition of Nothofagus forests and then experimentally reduced wasp numbers to investigate any changes as a result of a reduction in predation or competition. The observed changes in community composition were as a result of differing abundances of taxonomic groups within my study sites. In order to more robustly determine the community effects of wasp removal it may be necessary to reduce wasp numbers by up to 90% for many years. Even under these conditions, species that are particularly vulnerable to wasp predation or competition may have already been permanently excluded from this system. I then investigated temporal niche shifts by native ants when faced with reduced competition for food resources from invasive wasps. There was an increase in the numbers of ants foraging on honeydew when I experimentally reduced wasp numbers. This increase may be due to increases in both the quantity and quality of the available honeydew. When densities of wasps were substantially reduced there was a difference in the foraging abundances of ants and wasps; however, there was no change in the overall temporal foraging pattern of ants. Isotope ratios and consequently trophic levels of native competitors may change in response to the removal of an invasive species. To test this I examined changes in isotope ratios as a result of removal of wasps. The observed changes in the trophic levels of both ants and wasps appear to be a result of natural seasonal variation in consumption related to the nutritional requirements of the colony. Finally, I examined behavioral interactions between native ants and invasive wasps during foraging. This study has indicated that wasps may find and access resources more readily when ants are present. Native ants may facilitate foraging by wasps, as demonstrated by the increase in wasp numbers when foraging in the presence of ants. Additionally, the impact of competition between wasps and ants is likely to be density dependant. Co-occurrence between endemic and invasive competitors is possible through two important mechanisms, niche separation and behavioural adaptations. Native ants in this system are able to forage in different temporal niches than invasive wasps, and their dominant behaviour serves to diminish competitive interactions. These findings have implications for the ecology of these forests in understanding the considerable impact that invasive species may have on native ecosystems and particularly those species which have similar resource requirements.</p>

scholarly journals Drivers of tropical soil invertebrate community composition and richness across tropical secondary forests using DNA metasystematics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katie M. McGee ◽  
Teresita M. Porter ◽  
Michael Wright ◽  
Mehrdad Hajibabaei
Keyword(s):  
Land Use ◽  
Community Composition ◽  
Tropical Forests ◽  
Secondary Forest ◽  
Soil Invertebrates ◽  
Primary Forest ◽  
Soil Invertebrate ◽  
Secondary Forests ◽  
Invertebrate Community ◽  
Invertebrate Communities

Abstract Tropical forests are fundamental ecosystems, essential for providing terrestrial primary productivity, global nutrient cycling, and biodiversity. Despite their importance, tropical forests are currently threatened by deforestation and associated activities. Moreover, tropical regions are now mostly represented by secondary forest regrowth, with half of the remaining tropical forests as secondary forest. Soil invertebrates are an important component to the functioning and biodiversity of these soil ecosystems. However, it remains unclear how these past land-use activities and subsequent secondary forest developments have altered the soil invertebrate communities and any potential ecological consequences associated with this. DNA metabarcoding offers an effective approach to rapidly monitor soil invertebrate communities under different land-use practices and within secondary forests. In this study, we used DNA metabarcoding to detect community-based patterns of soil invertebrate composition across a primary forest, a 23-year-old secondary forest, and a 33-year-old secondary forest and the associated soil environmental drivers of the soil invertebrate community structure in the Maquenque National Wildlife Refuge of Costa Rica (MNWR). We also used a species contribution analysis (SIMPER) to determine which soil invertebrate groups may be an indication of these soils reaching a pre-disturbed state such as a primary forest. We found that the soil invertebrate community composition at class, order, family, and ESV level were mostly significantly different across that habitats. We also found that the primary forest had a greater richness of soil invertebrates compared to the 23-year-old and 33-year-old secondary forest. Moreover, a redundancy analysis indicated that soil moisture influenced soil invertebrate community structure and explained up to 22% of the total variation observed in the community composition across the habitats; whereas soil invertebrate richness was structured by soil microbial biomass carbon (C) (Cmic) and explained up to 52% of the invertebrate richness across the primary and secondary forests. Lastly, the SIMPER analysis revealed that Naididae, Entomobryidae, and Elateridae could be important indicators of soil and forest recuperation in the MNWR. This study adds to the increasing evidence that soil invertebrates are intimately linked with the soil microbial biomass carbon (Cmic) and that even after 33 years of natural regrowth of a forest, these land use activities can still have persisting effects on the overall composition and richness of the soil invertebrate communities.

Are nesting seabirds important determinants of invertebrate community composition on subantarctic Adams Island?

Polar Biology ◽  
2014 ◽  
Vol 37 (4) ◽  
pp. 531-540 ◽  
Author(s):  
I. E. Bassett ◽  
G. P. Elliott ◽  
K. J. Walker ◽  
S. Thorpe ◽  
J. R. Beggs
Keyword(s):  
Community Composition ◽  
Invertebrate Community

scholarly journals The effects of run-of-river hydroelectric power schemes on invertebrate community composition in temperate streams and rivers

PLoS ONE ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. e0171634 ◽  
Author(s):  
Gary S. Bilotta ◽  
Niall G. Burnside ◽  
Matthew D. Turley ◽  
Jeremy C. Gray ◽  
Harriet G. Orr
Keyword(s):  
Community Composition ◽  
Hydroelectric Power ◽  
Invertebrate Community ◽  
Streams And Rivers ◽  
Temperate Streams ◽  
Run Of River

Invertebrate community composition differs between invasive herb alligator weed and native sedges

2012 ◽  
Vol 41 ◽  
pp. 65-73 ◽  
Author(s):  
Imogen E. Bassett ◽  
Quentin Paynter ◽  
Jacqueline R. Beggs
Keyword(s):  
Community Composition ◽  
Invertebrate Community ◽  
Alligator Weed
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