scholarly journals Caladium bicolor (heart of Jesus).

Author(s):  
Julissa Rojas-Sandoval

Abstract C. bicolor is a dormant geophyte herb extensively commercialized in the horticultural trade around the world (Deng, 2012; USDA-ARS, 2016). It is often cultivated as an ornamental and potted plant and naturalized populations of C. bicolor can be found in areas within and outside its native distribution range (Madison, 1981; Govaerts, 2016). Currently, C. bicolor is listed as invasive in Trinidad and Tobago, Guam, Micronesia, Palau, Hawaii and the Philippines, where it is considered a species that is altering native plant communities by displacing native species, and changing community structures and ecological functions (Space et al., 2003; Herrera et al., 2010; PIER, 2016; Trinidad Biodiversity, 2016).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval

Abstract Livistona chinensis is a palm tree that has been widely introduced into tropical and warm temperate regions of the world to be used as ornamental. It has escaped from cultivation and become naturalized in disturbed sites, but also in undisturbed natural areas. L. chinensis produces a large amount of fruits and has high germination rates. It grows by forming dense thickets that can crowd out and overshadow native species. Currently, it is listed as invasive in Hawaii, Florida, Bermuda, Mauritius, Reunion and New Caledonia. In Florida, L. chinensis is listed as a category II invasive plant, a category designed for species with the potential to disrupt native plant communities.


Author(s):  
Elizabeth M. Wandrag ◽  
◽  
Jane A. Catford ◽  
◽  
◽  
...  

The introduction of species to new locations leads to novel competitive interactions between resident native and newly-arriving non-native species. The nature of these competitive interactions can influence the suitability of the environment for the survival, reproduction and spread of non-native plant species, and the impact those species have on native plant communities. Indeed, the large literature on competition among plants reflects its importance in shaping the composition of plant communities, including the invasion success of non-native species. While competition and invasion theory have historically developed in parallel, the increasing recognition of the synergism between the two themes has led to new insights into how non-native plant species invade native plant communities, and the impacts they have on those plant communities. This chapter provides an entry point into the aspects of competition theory that can help explain the success, dominance and impacts of invasive species. It focuses on resource competition, which arises wherever the resources necessary for establishment, survival, reproduction and spread are in limited supply. It highlights key hypotheses developed in invasion biology that relate to ideas of competition, outlines biotic and abiotic factors that influence the strength of competition and species' relative competitive abilities, and describes when and how competition between non-native and native plant species can influence invasion outcomes. Understanding the processes that influence the strength of competition between non-native and native plant species is a necessary step towards understanding the causes and consequences of biological invasions.


2010 ◽  
Vol 3 (2) ◽  
pp. 155-168 ◽  
Author(s):  
Travis L. Almquist ◽  
Rodney G. Lym

AbstractAminopyralid efficacy on Canada thistle (Cirsium arvense) and potential to injure native species was evaluated in a restored prairie at the Glacial Ridge Preserve managed by The Nature Conservancy in Polk County, MN. Canada thistle stem density was reduced from 17 to 0.1 stems m−2 10 mo after treatment (MAT) with aminopyralid applied in the fall at 120 g ha−1. Aminopyralid also altered the composition of both Canada thistle–infested and native plant communities. Aminopyralid controlled Canada thistle and removed or reduced several undesirable forb species from the restored prairie communities, such as absinth wormwood (Artemisia absinthium) and perennial sowthistle (Sonchus arvensis). A number of high seral forbs were also reduced or removed by aminopyralid, including maximilian sunflower (Helianthus maximiliani) and purple prairie clover (Dalea purpurea). Foliar cover of high seral forbs in the native plant community was reduced from 12.2 to 7% 22 MAT. The cover of high seral grass species, such as big bluestem (Andropogon gerardii) and Indiangrass (Sorghastrum nutans) increased after aminopyralid application in both the Canada thistle–infested and native plant communities and averaged 41.4% cover compared with only 19.4% before removal of Canada thistle. Species richness, evenness, and diversity were reduced after aminopyralid application in both Canada thistle–infested and native plant communities. However, the benefits of Canada thistle control, removal of undesirable species, and the increase in native grass cover should lead to an overall improvement in the long-term stability and composition of the restored prairie plant community, which likely outweigh the short-term effects of a Canada thistle control program.


2020 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Andrew Praciak

Abstract M. zapota, commonly known as sapodilla, is an evergreen tree, 5-20 m tall, with a round, dense crown. Its native range encompasses Central America, Mexico and the West Indies, but it is now widely cultivated for its fruit to a greater or lesser extent in tropical and subtropical lowlands worldwide. It is an important fruit tree all over South-East Asia, grown in home gardens, orchards and plantations. The largest producers of sapodilla fruit are India, Thailand, the Philippines and Malaysia, but it is also grown commercially elsewhere in Asia, South and Central America, and Florida in the USA. Escapes from plantations have caused the species to be classed as a moderately invasive weed in the tropics (Binggeli et al., 1998), although in the USA it is of particular concern in southern and central Florida, where it is classed as a Category I invasive displacing the native flora (Florida Exotic Pest Plant Council, 2001). It is also listed as invasive in Trinidad and Tobago (Trinidad and Tobago Biodiversity, 2017). Trees cast dense shade, making it difficult for other plants to survive in the understorey. Seedlings also grow very densely, inhibiting the establishment of native plant species.


2019 ◽  
Vol 12 (4) ◽  
pp. 203-213 ◽  
Author(s):  
Hannah L. Farrell ◽  
Elise S. Gornish

AbstractBuffelgrass [Pennisetum ciliare (L.) Link] is a drought-tolerant invasive grass that is a threat to native biodiversity in the drylands of the Americas and Australia. Despite efforts from land managers to control P. ciliare, management approaches tend to have mixed success, treatment results can be poorly communicated among entities, and there are few long-term controlled studies. In this literature review, we synthesize data from both peer-reviewed and “gray” literature on the efficacy of management techniques to control P. ciliare and the secondary impacts to native plant communities. Our search resulted in 42 unique sources containing a total of 229 studies that we categorized into 10 treatment types, which included herbicide, seeding, manual removal, fire, grazing, biocontrol, fire + additional treatments, manual removal + additional treatments, herbicide + additional treatments, and herbicide + manual removal. We found that treatments that used multiple techniques in tandem along with follow-up treatments were the most effective at controlling P. ciliare. Fewer than one-third of the studies reported impacts of management on native species, and the most commonly studied treatment (herbicide, N = 130) showed detrimental impacts on native plant communities. However, the average time between treatment and outcome measurement was only 15 mo; we suggest the need for more long-term studies of treatment efficacy and secondary impacts of treatment on the ecosystem. Finally, we conducted a second literature review on P. ciliare biology and traits for mechanisms that allows P. ciliare to alter the invaded environment to facilitate a competitive advantage over native species. We found evidence of self-reinforcing feedbacks of invasion being generated by P. ciliare through its interactions with water availability, nutrient cycling, and disturbance regimes. We developed a conceptual model of P. ciliare based on these feedback loops and offer management considerations based on its invasion dynamics and biology.


Author(s):  
Dorothy Borowy ◽  
Chris Swan

Despite a growing literature-base devoted to documenting biodiversity patterns in cities, little is known about the processes that influence these patterns, and whether they are consistent over time. In particular, numerous studies have identified the capacity of cities to host a rich diversity of plant species. This trend, however, is driven primarily by introduced species, which comprise a large proportion of the urban species pool relative to natives. Using an experimental common garden study, we assessed the relative influence of local assembly processes (i.e., soil environmental filtering and competition from spontaneous urban species) on the taxonomic and functional diversity of native plant communities sampled over four seasons in 2016-2018. Taxonomic and functional diversity exhibited different responses to local processes, supporting the general conclusion that species- and trait-based measures of biodiversity offer distinct insights into community assembly dynamics. Additionally, we found that neither soil nor competition from spontaneous urban species influenced taxonomic or functional composition of native species. Functional composition, however, did shift strongly over time and was driven by community-weighted mean differences in both measured traits (maximum height, Hmax; specific leaf area, SLA; leaf chlorophyll a fluorescence, chl a) and the relative proportions of different functional groups (legumes, annual and biennial-perennial species, C4 grasses, and forbs). In contrast, taxonomic composition only diverged between early and late seasons. Overall, our results indicate that native species are not only capable of establishing and persisting in vacant urban habitats, they can functionally respond to local filtering pressures over time. This suggests that regional dispersal limitation may be a primary factor limiting native species in urban environments. Thus, future regreening and management plans should focus on enhancing the dispersal potential of native plant species in urban environments, in order to achieve set goals for increasing native species diversity and associated ecosystem services in cities.


Author(s):  
Elizabeth M. Wandrag ◽  
Jane A. Catford

Abstract The introduction of species to new locations leads to novel competitive interactions between resident native and newly-arriving non-native species. The nature of these competitive interactions can influence the suitability of the environment for the survival, reproduction and spread of non-native plant species, and the impact those species have on native plant communities. Indeed, the large literature on competition among plants reflects its importance in shaping the composition of plant communities, including the invasion success of non-native species. While competition and invasion theory have historically developed in parallel, the increasing recognition of the synergism between the two themes has led to new insights into how non-native plant species invade native plant communities, and the impacts they have on those plant communities. This chapter provides an entry point into the aspects of competition theory that can help explain the success, dominance and impacts of invasive species. It focuses on resource competition, which arises wherever the resources necessary for establishment, survival, reproduction and spread are in limited supply. It highlights key hypotheses developed in invasion biology that relate to ideas of competition, outlines biotic and abiotic factors that influence the strength of competition and species' relative competitive abilities, and describes when and how competition between non-native and native plant species can influence invasion outcomes. Understanding the processes that influence the strength of competition between non-native and native plant species is a necessary step towards understanding the causes and consequences of biological invasions.


2016 ◽  
pp. 28-36 ◽  
Author(s):  
Ya. M. Golovanov ◽  
L. M. Abramova

Increase of anthropogenic pressure on nature ecosystems leads to synanthropization of flora and vegetation. A replacement of native species in communities with synanthropic ones, including alien species, takes place as well as a change of native plant communities by synanthropic ones, decrease of biodiversity, simplification of structure, decrease in efficiency and stability of plant communities (Gorchakovskij, 1999). Synanthropization as an indicator of anthropogenic transformation of vegetation is a traditional object of studies (Sudnik-Wojcikowska, 1988; Abramova, 2010; Abramova, Mirkin, 2000; Abramova, Mikhailova, 2003; etc.). The ratio of synanthropic and native flora species for an assessment of synanthropization level is usually used. The assessment of synanthropization level is the most important element of monitoring as it helps to estimate a degree of ecosystems disturbance and to develop a system of their rational use and protection. Processes of synanthropization are most expressed in the towns. The towns are the heterotrophic ecosystems including uniform group of anthropogenically transformed communities formed on the residential, industrial, transport, agrarian, recreational territories where the florogenesis and the phytocoenogenesis are highly specific (Burda, 1991; Ilminskikh, 1993). The urban environment can have the leveling impact on climatic factors therefore the floras of towns in different nature zones quite often have the common features (Ilminskikh, 1993). An increase of a syntaxonomic variety due to destruction of native vegetation is compensated by increase of synanthropic syntaxa number from the synanthropic classes of vegetation, and also communities of aggressive alien species which are combined with species of local flora. The regularities of synanthropization of urban flora and vegetation are less studied (Kowarik, 1990; Burda, 1991; etc.). Due to a growth of urbanization process around the world the studying of anthropogenic transformation of ve­getation cover is required. The article is devoted to the analysis of regularities of synanthropization of plant cover in towns of the southern Cis-Urals belonging to the Southern industrial zone of Bashkortostan Republic. 3 towns — Sterlitamak, Salavat and Ishimbay representing different categories by their population size were chosen for an assessment of synanthropization level.


2021 ◽  
Author(s):  
Quadri Agbolade Anibaba ◽  
Rahila M Yilangai ◽  
Zingfa W Wala ◽  
Sonali Saha

Abstract Invasive alien species (IAS) and land-use represent major threats to native plant communities around the globe. However, studies on IAS and potential ecological impacts in the context of land-use are limited in sub-Saharan Africa. Using a set of 45 plots in Jos metropolis in central Nigeria, we assessed the abundance of invasive Tithonia diversifolia (Hemls.) A. Gray, and its relationship with abundance and diversity of native plant species among land-use types. Abundance of T. diversifolia was the highest in farmland when compared to riparian and roadside land-use types. Also, the abundance and diversity of native species were lowest in farmland when compared to the roadside and riparian plant communities with increased T. diversifolia abundance. We showed that while T. diversifolia has low impact on native species, land-use type is an important predictor of native abundance and diversity. Although T. diversifolia has benefitted from the disturbances across land-use types, we found a very weak negative estimate of T. diversifolia effects on native species. These results consolidate existing evidence that land-use transformation in sub-Saharan Africa provides opportunities for alien plant invasion and native species decline. More important is the preservation of land-use types, which will result in a synergy of conservation effort - both reducing T. diversifolia abundance and preserving native plant abundance and diversity in central Nigeria.


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