scholarly journals Diet breadth influences how the impact of invasive plants is propagated through food webs

Ecology ◽  
2010 ◽  
Vol 91 (4) ◽  
pp. 1063-1074 ◽  
Author(s):  
Luisa G. Carvalheiro ◽  
Yvonne M. Buckley ◽  
Jane Memmott
Keyword(s):  
Food Webs ◽  
Invasive Plants ◽  
Diet Breadth ◽  
The Impact

scholarly journals DNA Metabarcoding as a Tool for Disentangling Food Webs in Agroecosystems

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 294
Author(s):  
Ahmadou Sow ◽  
Julien Haran ◽  
Laure Benoit ◽  
Maxime Galan ◽  
Thierry Brévault
Keyword(s):  
Food Webs ◽  
High Throughput Sequencing ◽  
Diet Breadth ◽  
Generalist Predators ◽  
Ecological Processes ◽  
Arthropod Predators ◽  
Trophic Network ◽  
Natural Pest Regulation ◽  
The Impact ◽  
Trophic Linkages

Better knowledge of food webs and related ecological processes is fundamental to understanding the functional role of biodiversity in ecosystems. This is particularly true for pest regulation by natural enemies in agroecosystems. However, it is generally difficult to decipher the impact of predators, as they often leave no direct evidence of their activity. Metabarcoding via high-throughput sequencing (HTS) offers new opportunities for unraveling trophic linkages between generalist predators and their prey, and ultimately identifying key ecological drivers of natural pest regulation. Here, this approach proved effective in deciphering the diet composition of key predatory arthropods (nine species.; 27 prey taxa), insectivorous birds (one species, 13 prey taxa) and bats (one species; 103 prey taxa) sampled in a millet-based agroecosystem in Senegal. Such information makes it possible to identify the diet breadth and preferences of predators (e.g., mainly moths for bats), to design a qualitative trophic network, and to identify patterns of intraguild predation across arthropod predators, insectivorous vertebrates and parasitoids. Appropriateness and limitations of the proposed molecular-based approach for assessing the diet of crop pest predators and trophic linkages are discussed.

Interactions between invasive plants and heavy metal stresses: a review

2021 ◽  
Author(s):  
Jian Li ◽  
Zhanrui Leng ◽  
Yueming Wu ◽  
Yizhou Du ◽  
Zhicong Dai ◽  
...  
Keyword(s):  
Invasive Species ◽  
Invasive Plants ◽  
Native Plants ◽  
Escape Behavior ◽  
Negative Influence ◽  
Plant Litter ◽  
Global Changes ◽  
Native Plant ◽  
Anthropogenic Contamination ◽  
The Impact

Abstract Global changes have altered the distribution pattern of the plant communities, including invasive species. Anthropogenic contamination may reduce native plant resistance to the invasive species. Thus, the focus of the current review is on the contaminant biogeochemical behavior among native plants, invasive species and the soil within the plant-soil ecosystem to improve our understanding of the interactions between invasive plants and environmental stressors. Our studies together with synthesis of the literature showed that a) the impacts of invasive species on environmental stress were heterogeneous, b) the size of the impact was variable, and c) the influence types were multidirectional even within the same impact type. However, invasive plants showed self-protective mechanisms when exposed to heavy metals (HMs) and provided either positive or negative influence on the bioavailability and toxicity of HMs. On the other hand, HMs may favor plant invasion due to the widespread higher tolerance of invasive plants to HMS together with the “escape behavior” of native plants when exposed to toxic HM pollution. However, there has been no consensus on whether elemental compositions of invasive plants are different from the natives in the polluted regions. A quantitative research comparing plant, litter and soil contaminant contents between native plants and the invaders in a global context is an indispensable research focus in the future.

scholarly journals Untangling the roles of parasites in food webs with generative network models

2015 ◽  
Author(s):  
Abigail Z. Jacobs ◽  
Jennifer A. Dunne ◽  
Cristopher Moore ◽  
Aaron Clauset
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Statistical Physics ◽  
Network Models ◽  
Food Web Structure ◽  
Free Living ◽  
Web Structure ◽  
Living Species ◽  
Parasitic Interactions ◽  
The Impact

Food webs represent the set of consumer-resource interactions among a set of species that co-occur in a habitat, but most food web studies have omitted parasites and their interactions. Recent studies have provided conflicting evidence on whether including parasites changes food web structure, with some suggesting that parasitic interactions are structurally distinct from those among free-living species while others claim the opposite. Here, we describe a principled method for understanding food web structure that combines an efficient optimization algorithm from statistical physics called parallel tempering with a probabilistic generalization of the empirically well-supported food web niche model. This generative model approach allows us to rigorously estimate the degree to which interactions that involve parasites are statistically distinguishable from interactions among free-living species, whether parasite niches behave similarly to free-living niches, and the degree to which existing hypotheses about food web structure are naturally recovered. We apply this method to the well-studied Flensburg Fjord food web and show that while predation on parasites, concomitant predation of parasites, and parasitic intraguild trophic interactions are largely indistinguishable from free-living predation interactions, parasite-host interactions are different. These results provide a powerful new tool for evaluating the impact of classes of species and interactions on food web structure to shed new light on the roles of parasites in food webs.

Open water metabolism and dissolved organic carbon in response to environmental watering in a lowland river–floodplain complex

2016 ◽  
Vol 67 (9) ◽  
pp. 1346 ◽  
Author(s):  
Todd A. Wallace ◽  
Deborah Furst
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Food Webs ◽  
Ecosystem Respiration ◽  
Open Water ◽  
Relative Role ◽  
Eastern Australia ◽  
Return Flows ◽  
Receiving Waters ◽  
The Impact

The relative importance of autochthonous and allochthonous organic material in fuelling ecosystem metabolism is increasingly understood for some river systems. However, in south-eastern Australia, the majority of studies have been conducted during low flows when the supply of allochthonous carbon was limited. Consequently, the importance of episodic inputs of terrestrially derived material in supporting these food webs remains poorly understood. We assessed the influence of return flows from two different scales of environmental watering actions on dissolved organic carbon and open-water productivity in receiving waters adjacent to the watered area. For the wetland-scale event, gross primary productivity and ecosystem respiration increased in the receiving waters during the period of return flows. During the floodplain-scale watering, differences were observed among sites. Within the managed inundation zone, values for net ecosystem productivity switched from near zero during the baseline to strongly negative during the impact period, whereas values at the river sites were either near zero or positive. The results contribute to our understanding of the relative role of allochthonous material in supporting aquatic food webs in lowland rivers, and demonstrate potential for watering actions to have a positive influence on riverine productivity during periods of low water availability.

scholarly journals Tourists increase the contribution of autochthonous carbon to littoral zone food webs in oligotrophic dune lakes

2004 ◽  
Vol 55 (7) ◽  
pp. 701 ◽  
Author(s):  
Wade L. Hadwen ◽  
Stuart E. Bunn
Keyword(s):  
Food Webs ◽  
Littoral Zone ◽  
Algal Biomass ◽  
Carbon Sources ◽  
Nutrient Concentrations ◽  
Relative Importance ◽  
Nutrient Inputs ◽  
Oligotrophic Lakes ◽  
Dune Lakes ◽  
The Impact

Tourists can adversely influence the ecology of oligotrophic lakes by increasing algal production via direct nutrient inputs and/or re-suspension of sediments. To assess the influence of tourists on food web dynamics, we used the natural abundance of stable isotopes of carbon and nitrogen to calculate the relative importance of autochthonous and allochthonous carbon sources to littoral zone food webs across five variously visited perched dune lakes on Fraser Island, Australia. The relative importance of autochthonous (phytoplankton and periphyton) carbon to littoral zone consumers was highly variable across taxa and lakes. Despite the potential influence of algal biomass, ambient nutrient concentrations and tannin concentrations on the contribution of autochthonous carbon to littoral zone food webs, none of these variables correlated to the per cent contribution of autochthonous carbon to consumer diets. Instead, autochthonous sources of carbon contributed more to the diets of aquatic consumers in heavily visited lakes than in less visited lakes, suggesting that tourist activities might drive these systems towards an increased reliance on autochthonous carbon. The assessment of the contribution of autochthonous carbon to littoral zone food webs may represent a more robust indicator of the impact of tourists in oligotrophic lakes than standard measures of nutrient concentrations and/or algal biomass.

scholarly journals Warming shifts top-down and bottom-up control of pond food web structure and function

2012 ◽  
Vol 367 (1605) ◽  
pp. 3008-3017 ◽  
Author(s):  
Jonathan B. Shurin ◽  
Jessica L. Clasen ◽  
Hamish S. Greig ◽  
Pavel Kratina ◽  
Patrick L. Thompson
Keyword(s):  
Food Webs ◽  
Environmental Changes ◽  
Lytic Cycle ◽  
Top Down ◽  
Food Web Structure ◽  
Bottom Up ◽  
Positive Effects ◽  
Freshwater Pond ◽  
Aquatic Food ◽  
The Impact

The effects of global and local environmental changes are transmitted through networks of interacting organisms to shape the structure of communities and the dynamics of ecosystems. We tested the impact of elevated temperature on the top-down and bottom-up forces structuring experimental freshwater pond food webs in western Canada over 16 months. Experimental warming was crossed with treatments manipulating the presence of planktivorous fish and eutrophication through enhanced nutrient supply. We found that higher temperatures produced top-heavy food webs with lower biomass of benthic and pelagic producers, equivalent biomass of zooplankton, zoobenthos and pelagic bacteria, and more pelagic viruses. Eutrophication increased the biomass of all organisms studied, while fish had cascading positive effects on periphyton, phytoplankton and bacteria, and reduced biomass of invertebrates. Surprisingly, virus biomass was reduced in the presence of fish, suggesting the possibility for complex mechanisms of top-down control of the lytic cycle. Warming reduced the effects of eutrophication on periphyton, and magnified the already strong effects of fish on phytoplankton and bacteria. Warming, fish and nutrients all increased whole-system rates of net production despite their distinct impacts on the distribution of biomass between producers and consumers, plankton and benthos, and microbes and macrobes. Our results indicate that warming exerts a host of indirect effects on aquatic food webs mediated through shifts in the magnitudes of top-down and bottom-up forcing.

scholarly journals The Impact of Invasive Aliens Species of Plant in Dryland Crop Production

2020 ◽  
Vol 9 (3S) ◽  
pp. 64-67
Keyword(s):  
Invasive Plants ◽  
Agricultural Production ◽  
Crop Production ◽  
Invasive Alien Species ◽  
Alternanthera Sessilis ◽  
The Third ◽  
Global Issue ◽  
Agriculture Sustainability ◽  
The Stability ◽  
The Impact

The existence of invasive alien species (IAS) in an ecosystem has become a global issue that continues to be discussed. Invasive plants led to the dominance of the crop in the fulfillment of competition for nutrients, water, light, and pollinated by pollinators. In Indonesia there are 27 IAS that is very dangerous and threatens the stability of the ecosystem. The introduction of IAS in Indonesia generally lowers production reached 20%, 1 individual IAS in the area of 0.1 m2 can reduce 57% of agricultural production. This aims to determine the introduction of IAS and its impact on agricultural. The method used is the analysis of vegetation, a literature review of national and international journals and complemented by interviews was conducted in June-October 2018 in Pacitan, East Java. Based on the research known biodiversity in the study site was (2.99) and Evenness medium (e '= 0.41) with the third-highest family Compositae (IVIs = 53.1), Poaceae (IVIs = 41.16), and Amaranthaceae (IVIs = 23.97). Cyperaceae and Compositae is the most dominant and is found throughout the agricultural types in the sites. Compositae is dominating (IVIs = 53.1). Alternanthera sessilis (IVIs = 23.97), Cyanthillium cinereum (IVIs = 1.45), and Ecinochloa colona (IVIs = 12.33). Based on the concept of IAS disturbance caused interference in terms of the type, intensity, spatial reach, frequency, and other factors are interspecific. According to the concept of disturbance the solution is control the growth and spread of IAS to save the ecosystem and agriculture sustainability.

scholarly journals Do Cultivars of Native Plants Support Insect Herbivores?

2018 ◽  
Vol 28 (5) ◽  
pp. 596-606 ◽  
Author(s):  
Emily C. Baisden ◽  
Douglas W. Tallamy ◽  
Desiree L. Narango ◽  
Eileen Boyle
Keyword(s):  
Disease Resistance ◽  
Food Webs ◽  
Native Plants ◽  
Fruit Size ◽  
Common Garden ◽  
Insect Herbivores ◽  
Native Plant ◽  
Genetic Changes ◽  
Native Plant Species ◽  
The Impact

Native plants are becoming widely used in built landscapes to help mitigate the loss of biodiversity caused by urbanization. The primary advantage of native plant species over introduced ornamentals is their ability to support the development of the insects that fuel vertebrate food webs as well as specialist pollinators. The horticultural industry has introduced many cultivars of native plants to improve their aesthetic value and disease resistance, but there has been little work that measures the impact of these genetic changes on insect herbivores and pollinators. Here we measure how six desirable traits in native woody plant cultivars (leaf color, variegation, fall color, habit, disease resistance, and fruit size) compare with their wild types in terms of their ability to support insect herbivore development, abundance, and species richness. Using a common garden experiment, we quantified the abundance and diversity of insect herbivores using each species and its cultivars for growth and development over a 2-year period, as well as cumulative feed damage over the entire season. We also conducted feeding tests with evergreen bagworm (Thyridopteryx ephemeraeformis) to measure the preference of hatchling caterpillars for cultivars vs. straight species. We found that cultivars that had leaves altered from green to red, blue, or purple deterred insect feeding in all three experiments, a preference for variegated cultivars in one of our three experiments, but no consistent pattern of use among the species and cultivars chosen for other traits. These results suggest that the usefulness of native cultivars in restoring insect-driven food webs depends on the cultivar trait that has been selected.

Impact of invasive plants on food webs and pathways

2013 ◽  
Vol 21 (3) ◽  
pp. 249-259
Author(s):  
Wang Sikai ◽  
Sheng Qiang ◽  
Chu Tianjiang ◽  
Li Bo ◽  
Chen Jiakuan ◽  
...  
Keyword(s):  
Food Webs ◽  
Invasive Plants
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