Weed Wrangle®, a Functional Model for Teaching the Negative Impacts of Non‐native Invasive Species

2021 ◽  
pp. 303-307
Author(s):  
Elizabeth Lamar ◽  
Cayce McAlister ◽  
Steve Manning
Author(s):  
Lauren M. Smith-Ramesh

Abstract Allelopathy, or the process by which plants influence the growth and performance of their neighbours through the release of chemicals, may play a key role in mediating the impacts of non-native invasive species on their neighbours. The Novel Weapons Hypothesis purports that non-native invasive species are in part successful because they produce harmful allelochemicals to which resident species are particularly susceptible because residents lack a shared evolutionary history with the invader. While allelopathic non-native invaders may reduce the growth and performance of neighbours through direct phytotoxicity, they may more often exert negative impacts through disruption of biotic interactions among resident species. Allelopathy by non-native plants may disrupt mutualisms between resident plants and microbes, plant-herbivore interactions or existing competitive and facilitative interactions among resident plants. For example, several non-native plants are known to disrupt the mutualism between resident plants and mycorrhizal fungi, reducing resident plant fitness to the benefit of the invader. Allelopathic non-natives may also disrupt interactions among resident plants and their herbivores when allelochemicals also influence herbivore behaviour or fitness. Alternatively, biotic interactions can also be protective for resident species, which may be less susceptible to the impacts of non-native species when their mutualisms are intact. As we advance our understanding of allelopathy and its role in mediating the impacts of invasive plant species, we may gain new insights by viewing invasions within a network context rather than focusing on pairwise interactions.


Author(s):  
Lauren M. Smith-Ramesh ◽  

Allelopathy, or the process by which plants influence the growth and performance of their neighbours through the release of chemicals, may play a key role in mediating the impacts of non-native invasive species on their neighbours. The Novel Weapons Hypothesis purports that non-native invasive species are in part successful because they produce harmful allelochemicals to which resident species are particularly susceptible because residents lack a shared evolutionary history with the invader. While allelopathic non-native invaders may reduce the growth and performance of neighbours through direct phytotoxicity, they may more often exert negative impacts through disruption of biotic interactions among resident species. Allelopathy by non-native plants may disrupt mutualisms between resident plants and microbes, plant-herbivore interactions or existing competitive and facilitative interactions among resident plants. For example, several non-native plants are known to disrupt the mutualism between resident plants and mycorrhizal fungi, reducing resident plant fitness to the benefit of the invader. Allelopathic non-natives may also disrupt interactions among resident plants and their herbivores when allelochemicals also influence herbivore behaviour or fitness. Alternatively, biotic interactions can also be protective for resident species, which may be less susceptible to the impacts of non-native species when their mutualisms are intact. As we advance our understanding of allelopathy and its role in mediating the impacts of invasive plant species, we may gain new insights by viewing invasions within a network context rather than focusing on pairwise interactions.


2021 ◽  
Vol 2 (1) ◽  
pp. 69-79
Author(s):  
Hurmat Ejaz ◽  
Esther Somanader ◽  
Uday Dave ◽  
Hermann Ehrlich ◽  
M. Azizur Rahman

Didymosphenia geminata diatoms, or Didymo, was first found to be an invasive species that could have negative impacts on the environment due to the aggressive growth of its polysaccharide-based stalks. The stalks’ adhesive properties have prompted park officials to alert the general public to limit further spread and contamination of this algae to other bodies of water. Although the negative effects of Didymo have been studied in the past, recent studies have demonstrated a potential positive side to this alga. One of the potential benefits includes the structural component of the polysaccharide stalks. The origin of the polysaccharides within stalks remains unknown; however, they can be useful in a waste management and agricultural setting. The primary purpose of this study was to describe both the harmful and beneficial nature of Didymo. Important outcomes include findings related to its application in various fields such as medicine and technology. These polysaccharides can be isolated and studied closely to produce efficient solar power cells and batteries. Though they may be harmful while uncontained in nature, they appear to be very useful in the technological and medical advancement of our society.


Koedoe ◽  
2017 ◽  
Vol 59 (1) ◽  
Author(s):  
Kudakwashe Musengi ◽  
Sally Archibald

Alien invasive species can have negative impacts on the functioning of ecosystems. Plantation species such as pines have become serious invaders in many parts of the world, but eucalypts have not been nearly as successful invaders. This is surprising considering that in their native habitat they dominate almost all vegetation types. Available theory on the qualities that characterise invasive species was used to assess the invasive potential of Eucalyptus grandis – a common plantation species globally. To determine rates of establishment of E. grandis outside plantations, we compared population demographics and reproductive traits at two locations in Mpumalanga, South Africa: one at higher elevation with more frost. Eucalyptus grandis has a short generation time. We found no evidence that establishment of E. grandis was limiting its spread into native grassland vegetation, but it does appear that recruitment is limited by frost and fire over much of its range in Mpumalanga. Populations at both study locations displayed characteristics of good recruitment. Size class distributions showed definite bottlenecks to recruitment which were more severe when exposed to frost at higher elevations. Generally, the rate of spread is low suggesting that the populations are on the establishing populations’ invasion stage. This research gives no indication that there are any factors that would prevent eucalyptus from becoming invasive in the future, and the projected increase in winter temperatures should be a cause for concern as frost is currently probably slowing recruitment of E. grandis across much of its planted range.Conservation implications: Eucalyptus plantations occur within indigenous grasslands that are of high conservation value. Frost and fire can slow recruitment where they occur, but there are no obvious factors that would prevent E. grandis from becoming invasive in the future, and monitoring of its rates of spread is recommended.


Aerobiologia ◽  
2020 ◽  
Vol 36 (4) ◽  
pp. 669-682 ◽  
Author(s):  
Antonella Cristofori ◽  
Edith Bucher ◽  
Michele Rossi ◽  
Fabiana Cristofolini ◽  
Veronika Kofler ◽  
...  

AbstractArtemisia pollen is an important aeroallergen in late summer, especially in central and eastern Europe where distinct anemophilous Artemisia spp. produce high amounts of pollen grains. The study aims at: (i) analyzing the temporal pattern of and changes in the Artemisia spp. pollen season; (ii) identifying the Artemisia species responsible for the local airborne pollen load.Daily pollen concentration of Artemisia spp. was analyzed at two sites (BZ and SM) in Trentino-Alto Adige, North Italy, from 1995 to 2019.The analysis of airborne Artemisia pollen concentrations evidences the presence of a bimodal curve, with two peaks, in August and September, respectively. The magnitude of peak concentrations varies across the studied time span for both sites: the maximum concentration at the September peak increases significantly for both the BZ (p < 0.05) and SM (p < 0.001) site. The first peak in the pollen calendar is attributable to native Artemisia species, with A. vulgaris as the most abundant; the second peak is mostly represented by the invasive species A. annua and A. verlotiorum (in constant proportion along the years), which are causing a considerable increase in pollen concentration in the late pollen season in recent years.. The spread of these species can affect human health, increasing the length and severity of allergenic pollen exposure in autumn, as well as plant biodiversity in both natural and cultivated areas, with negative impacts on, e.g., Natura 2000 protected sites and crops.


Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 842 ◽  
Author(s):  
Gentili ◽  
Ferrè ◽  
Cardarelli ◽  
Montagnani ◽  
Bogliani ◽  
...  

The introduction of invasive alien plant species (IAPS) can modify plant-soil feedback, resulting in an alteration of the abiotic and biotic characteristics of ecosystems. Prunus serotina, Quercus rubra and Robinia pseudoacacia are IAPS of European temperate forests, where they can become dominant and suppress the native biodiversity. Assuming that the establishment of these invasive species may alter native forest ecosystems, this study comparatively assessed their impact on ecosystems. This study further investigated plant communities in 12 forest stands, dominated by the three IAPS and native trees, Quercus robur and Carpinus betulus (three plots per forest type), in Northern Italy, and collected soil samples. The relationships between the invasion of the three IAPS and modifications of humus forms, soil chemical properties, soil biological quality, bacterial activity and plant community structure and diversity (α-, β-, and γ-diversity) were assessed using one-way ANOVA and redundancy analyses (RDA). Our comparative study demonstrated that invaded forests often had unique plant and/or soil properties, relative to native forests, and the degree of dissimilarity depended on the invasive species. Particularly, Q. rubra is related to major negative impacts on soil organic horizons and low/modified levels of microarthropod and plant biodiversity. R. pseudoacacia is associated with an altered base content of soil and, in turn, with positive feedback to the soil biological quality (QBS-ar) and plant diversity, but with a high cover compared with other alien plant species. P. serotina is associated with intermediate impacts and exhibits a plant species assemblage that is more similar to those of native forest stands. Our work suggests impact-based management decisions for the three investigated IAPS, since their effects on the diversity and composition of resident ecosystems are very different.


Ecography ◽  
2017 ◽  
Vol 41 (8) ◽  
pp. 1283-1294 ◽  
Author(s):  
M. Kołodziej-Sobocińska ◽  
M. Brzeziński ◽  
A. Niemczynowicz ◽  
A. Zalewski

Author(s):  
Jeanine Velez-Gavilán

Abstract Pteris multifida is a herbaceous fern native to temperate and tropical eastern Asia and naturalized on many continents as a result of being widely cultivated. Although it is an urban weed, it is not considered by most countries as an invasive or noxious weed. There is no information available on the species affecting native species or natural habitats. Although one source lists P. multifida as an invasive species in many countries outside of Africa due to it being easily dispersed by spores, there are no references or further information to support this statement. It is reported as an alien invasive species in Germany, but only as occurring in sheltered sites, growing on light-vents in cellars and walls. A species assessment for Florida, USA indicates, P. multifida is neither a weed of natural habitats nor of agriculture. The species has not been listed as an invasive plant in any state or natural areas of the USA. However, P. multifida has been assigned a Tier II Invasive Species status (defined as having moderate negative impacts on wildlife or natural communities in Louisiana), but of limited concern and/or extent in Louisiana. Pteris multifida is recorded in Cuba as potentially invasive being categorized as a species with a tendency to proliferate in some areas and capable of producing vast amounts of diaspores with high dispersal potential. No further details are given about potential invasiveness.


Fire ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 7
Author(s):  
Leonel J. R. Nunes ◽  
Catarina I. R. Meireles ◽  
Carlos J. Pinto Gomes ◽  
Nuno M. C. Almeida Ribeiro

Invasive species are an environmental problem affecting worldwide ecosystems. In the case of Acacia dealbata Link., the negative impacts affect the productivity of the forests due to the competition established with native species while contributing to a significant increment in the available fuel load, increasing the risk of fire. In Portugal, chemical and mechanical methods are mostly used in the control of these species. However, the costs are often unsustainable in the medium term, being abandoned before completing the tasks, allowing the recovery of the invasive species. The establishment of value chains for the biomass resulting from these actions was pointed out by several authors as a solution for the sustainability of the control process, as it contributes to reducing costs. However, the problems in quantifying the biomass availability make it challenging to organize and optimize these actions. This work, which started from a dendrometrical analysis carried out in stands of A. dealbata, created a model to assess woody biomass availability. The model proved to be statistically significant for stands with trees younger than 20 years old. However, the amount of data collected and the configuration of the settlements analyzed do not allow extrapolation of the model presented to older settlements.


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