scholarly journals Acacia dealbata Link. Aboveground Biomass Assessment: Sustainability of Control and Eradication Actions to Reduce Rural Fires Risk

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.

Environments ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 57 ◽  
Author(s):  
Leonel J. R. Nunes ◽  
Mauro A. M. Raposo ◽  
Catarina I. R. Meireles ◽  
Carlos J. Pinto Gomes ◽  
Nuno M. C. Almeida Ribeiro

Climate change has enhanced the occurrence of rural fires, since changes in the hydrological cycle have led to the occurrence of increasingly long and frequent periods of drought. This recurrence of rural fires in Portugal, in turn, has led to the successive elimination of vast areas traditionally occupied by native species or species of economic interest, which are being successively replaced by new species with invasive behavior. Among these, Acacia dealbata stands out for its dispersion capacity and for the area it has already occupied. In the present work, which reviews the evolution of forest cover over the last 18,000 years in the Serra da Estrela Natural Park, we intend to demonstrate that fire acts as a species selection agent and that it enhances the development of heliophile and pyrophyte species. For this purpose, an area of the municipality of Seia was selected, more specifically Casal do Rei, where the development of Acacia dealbata forests is monitored. In the end, it was concluded that, in fact, by analyzing the ages of the specimens present in these populations, fire acts as a selection agent by freeing up the space previously occupied by other species, opening the way for the growth of heliophiles and pyrophytes invasive species while enhancing their germination.


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.


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.


2016 ◽  
Vol 22 (4) ◽  
pp. 377 ◽  
Author(s):  
Inti Keith ◽  
Terence P. Dawson ◽  
Ken J. Collins ◽  
Marnie L. Campbell

Worldwide, marine biological invasions of non-native species have increased significantly in recent years due to a rapid rise in global trade, transport and tourism. Invasions occur when non-native species are transported from one region to another and establish, often resulting in competition displacing native species and changing ecosystems. Historic literature searches were conducted along with dive surveys of the main ports and in sites around the archipelago in order to produce a baseline of which non-native species are present in the Galapagos Marine Reserve at this time. Confounding processes of anthropogenic and natural activities are increasing the potential spread of marine invasive species in the Eastern Tropical Pacific and the Galapagos Marine Reserve. We discuss the potential vectors facilitating marine invasions with the suggestion that marine traffic could be the most influential vector in the transport of marine non-natives to the Galapagos Marine Reserve. The challenge for marine park authorities is to identify those species that are likely to cause negative impacts on native biodiversity and ecosystems before they establish in the Galapagos, and to develop pre-emptive strategies that would likely include prevention as well as risk-based management strategies to remove them or to mitigate their harmful effects.


Behaviour ◽  
2018 ◽  
Vol 155 (1) ◽  
pp. 55-67 ◽  
Author(s):  
Pedro Filipe Pereira ◽  
Rui Lourenço ◽  
Paulo Gama Mota

Abstract Behavioural dominance and aggressiveness may be crucial traits facilitating the establishment of invasive species. Few studies considered agonistic interactions between exotic and native bird species in feeding contexts, particularly when the exotic has social habits. We aimed to know if individuals of a social invasive species, the red-billed leiothrix Leiothrix lutea, are: more aggressive; the initiators of the first interaction; and dominant (i.e., won most interactions) over native opponents in a feeding context. We performed an experiment in a closed environment forcing dyadic interactions between an individual of a native species facing a leiothrix individual. We found that the leiothrix was the initiator in most experiments, being apparently dominant over natives. However, the invader was not more aggressive than natives. This can increase the risk of injury for natives because the leiothrix has a relatively larger body size. We discuss possible negative impacts of the leiothrix on native species.


Check List ◽  
2021 ◽  
Vol 17 (6) ◽  
pp. 1615-1622
Author(s):  
Felipe Polivanov Ottoni ◽  
Erick Cristofore Guimarães ◽  
Jadson Pinheiro Santos ◽  
Pâmella Silva de Brito ◽  
Josie South ◽  
...  

During a field expedition in 2020, we recorded specimens of an invasive platy fish, Xiphophorus maculatus, in the state of Maranhão, Brazil. This new occurrence, in the Municipality of São Luis, is only the second time that this non-native species has been found in northeastern Brazil. We provide an updated list of all invasive species recorded from the island of São Luís, highlighting the negative impacts they may confer for the native biodiversity.


ISRN Botany ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Joëlle Gérard ◽  
Ludwig Triest

Introduction of invasive macrophytes often leads to competition with native species or with already established invasive species. Competition between invasive species in multiple-invaded systems is expected to be particularly high, especially when they share growth form and position in the water column. We performed indoor experiments between invasive free-floating Lemna minuta and Landoltia punctata in monocultures and mixtures under a phosphorus gradient concurring with hypereutrophic, eutrophic, mesotrophic, and oligotrophic conditions. Our results showed that a phosphorus reduction from hypereutrophic to eutrophic had important negative impacts on the relative growth rate (RGR) of both species. A further reduction to mesotrophic condition did not alter either species RGR. However, species strategies and nutrient uptake differed. Both intra- and interspecific interference occurred; however, the intensity differed between phosphorus concentrations. Difference in RGR (RGRD) showed L. minuta to gain at high phosphorus levels, while a reduction favoured L. punctata. In oligotrophic condition, either species hardly produced new daughter fronds. Our results are useful to (1) understand the effects of phosphorus and setting target values in the process of eutrophication reduction and (2) diminish the impacts of invasive lemnids since a water column phosphorus reduction would prevent large impacts.


Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 21
Author(s):  
Leonel J. R. Nunes ◽  
Abel M. Rodrigues ◽  
Liliana M. E. F. Loureiro ◽  
Letícia C. R. Sá ◽  
João C. O. Matias

The use of biomass as an energy source presents itself as a viable alternative, especially at a time when the mitigation of climate change requires that all possibilities of replacing fossil fuels be used and implemented. The use of residual biomass also appears as a way to include in the renewable energy production system products that came out of it, while allowing the resolution of environmental problems, such as large volumes available, which are not used, but also by the elimination of fuel load that only contributes to the increased risk of rural fires occurrence. Invasive species contribute to a significant part of this fuel load, and its control and eradication require strong investments, so the valorization of these materials can allow the sustainability of the control and eradication processes. However, the chemical composition of some of these species, namely Acacia dealbata, Acacia melanoxylon, Eucalyptus globulus, Robinia pseudoacacia and Hakea sericea, presents some problems, mainly due to the nitrogen, chlorine and ash contents found, which preclude exclusive use for the production of certified wood pellets. In the case of Eucalyptus globulus, the values obtained in the characterization allow the use in mixtures with Pinus pinaster, but for the other species, this mixture is not possible. From a perspective of local valorization, the use of materials for domestic applications remains a possibility, creating a circular economy process that guarantees the sustainability of operations to control and eradicate invasive species.


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