scholarly journals Not All Roads Lead to Rome: A Meta-analysis of Invasive Plant Impact Methodology

2017 ◽  
Vol 10 (4) ◽  
pp. 304-312 ◽  
Author(s):  
Daniel R. Tekiela ◽  
Jacob N. Barney

The negative effects of invasive plant species on native ecosystems, which can be large and long-lasting, are the primary justifications for their research and management. Tremendous effort is focused on quantifying the ecological impacts of invasive plants, though two different methods are primarily used: observational (compare invaded and uninvaded) and removals (compare invaded and invader removal). However, it is unknown whether these methods, which differ in their assumptions and execution, yield similar results, which could affect our ability to draw broad conclusions within and across studies. Therefore, we performed a meta-analysis on 174 studies that described 547 impacts of 72 invasive plants to test the effect of study method, invader cover, and removal period on the direction and magnitude of impact. Overall, by only considering impact magnitude and not direction, both observational and removal methods yielded similar results—invasive plants are changing most aspects of the ecosystem—and the variation among species and study systems was dramatically reduced compared with traditional, directionally focused studies. This is contrary to a similar analysis that did not control for directionality of impacts, which found overall differences in impact depended on methodology. However, even when the effects of study ecosystem, invader life-form, and impact type were accounted for, significant differences occurred between removal and observational studies. Particularly vulnerable systems appear to be those that would be more greatly disturbed by the removal of the target species, such as tree species or invasive plants in riparian areas. Additionally, impact magnitude increased with invader cover and removal time. We confirm that invasive plants impact the systems they invade in a nonuniform manner; however, we suggest some study conditions may be more sensitive to study methodology. Careful consideration should be given as to which methodology is used in the context of the study system.

2017 ◽  
Vol 10 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Daniel R. Tekiela ◽  
Jacob N. Barney

Ecological impacts from invasive plants that have been identified include reductions in biodiversity, changes in resource cycling, and disruptions of ecosystem function. To mitigate these negative ecological impacts, managers work to remove invasive plants. However, removal does not necessarily immediately lead to a return to the uninvaded ecological state. Similarly, the accumulation rate of ecological impacts following invader establishment is almost entirely unknown for most species, hindering identification of optimal management times. The accumulation and loss (so-called legacy effects) of impacts following invader establishment and removal represent an “invasion shadow.” To begin to understand invasion shadows, we measured the changes in biotic and abiotic ecological impacts during establishment and following removal of the forest understory invader Japanese stiltgrass. We found that when the abiotic metrics were considered, seeded areas became more functionally similar to the invaded landscape and removed areas became more similar to the uninvaded landscape. However, while the plant community did not change in a 3-yr period during a new invasion, following invader removal, it became less similar to both the invaded and uninvaded landscape altogether, suggesting legacies. Surprisingly, all changes occurred almost immediately and persisted following invader establishment and removal. Our results show, at least in a 3-yr period, that ecosystems can respond to changes in invader abundance, and in some cases simply removing the invader could result in long-term changes to the resident plant community.


2010 ◽  
Vol 3 (4) ◽  
pp. 470-481 ◽  
Author(s):  
Ramona Robison ◽  
Steve Schoenig ◽  
Douglas W. Johnson ◽  
Elizabeth Brusati ◽  
Joseph M. DiTomaso

AbstractThis project summarizes the opinion of 52 experts on the future research needs in the area of invasive plants in California. Experts included academics at private and public universities, Cooperative Extension educators, land managers, members of nongovernmental organizations (NGOs), employees of restoration companies, and federal, state, and local agency personnel. Surveys were conducted through in-person interviews, written questionnaires, and workshops. The objective was to identify high-priority needs for future research on issues related to invasive plants in California's wildlands. More specifically, the goals were to (1) create a forum for assessing high-priority research needs, (2) guide future research toward these high-priority needs, and (3) facilitate connections and interactions among academic disciplines and between researchers and practitioners by increasing awareness of the range of ongoing research on invasive plants. Priority needs were chosen for 10 broad research topic areas, with specific subtopics addressed within each of these areas. In addition to noting specific research areas, there was a general need expressed for a synthesis of existing scientific information, particularly about the biology and ecology of invasive plants and the ecological impacts, control and management tools, restoration activities, and related social issues surrounding invasive plants. A mutual exchange of information was also considered important among the academic researcher and the field practitioner, as was the development of more effective training programs for land managers.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nardi Torres ◽  
Ileana Herrera ◽  
Laurie Fajardo ◽  
Ramiro O. Bustamante

Abstract Background One of the ecological impacts of exotic plant invasions may be alteration of the soil microbial community, which may cause changes to the diversity, richness and function of these communities. In order to explore to what extent invasive plants affect the soil microbial community, we performed a meta-analysis based on 46 scientific articles to document the effect of invasive plants on species richness and diversity of bacteria and fungi. We conducted our study across a range of invaded ecosystems including native communities, and evaluated biomass, richness and diversity. We use a random effects model to determine the increase or decrease in the values of the response variables in the presence of invasive plants. Results The results indicated that the response variable that changed with the invasion of plants was the diversity of bacteria. Bacterial diversity in the soil increases with the presence of invasive plants, specifically herbaceous plants producing allelopathic substances growing in forest ecosystems of temperate zones. Conclusions We provide evidence that invasive plants affect the soil biota differentially; however, it is important to consider more variables such as the N and C cycles, since these processes are mediated by soil biota and litter, and chemical compounds released by plants influence them. Changes in bacterial diversity have consequences for the nutrient cycle, enzymatic activity, mineralization rates and soil carbon and nitrogen content.


2011 ◽  
Vol 4 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Kirk W. Davies ◽  
Dustin D. Johnson

AbstractInvasive plants are negatively affecting the ecological and economic production of rangelands by reducing resource productivity, decreasing biodiversity, displacing native vegetation, and altering ecosystem processes and functions. However, despite these well-known negative effects, once invasive plants are regionally established, limited effort is directed at preventing their continued spread across rangelands. Most efforts are directed at restoration at specific locations while additional rangelands are invaded. Restoring native plant communities invaded by exotic plants is frequently unsuccessful, especially in more arid environments, and is often too costly to apply at the scale required to make meaningful progress in reducing invasive plant populations relative to their expansion. Of the few prevention efforts being implemented, most are a second priority to control and restoration efforts. Integrating strategies to prevent new infestations and restrict the expansion of existing populations in invasive plant management programs is critical to limiting the negative effects of invasive plants in rangelands. However, we are “missing the boat” on this issue by not providing sufficiently developed and validated management actions. Limited information is available for developing management strategies to prevent the spread of invasive plants, although it has been suggested that land managers need to increase biotic resistance of desired plant communities, decrease invasive plant propagule pressure, and eradicate small incipient infestations to prevent the continued expansion of invasive plants. Thus, instead of scientifically validated methods developed to limit the spread of invasive plants, managers are often left with vague suggestions for preventing the continued spread of invasive plants. We suggest that if prevention is going to be successful, researchers are going to need to conduct more applied research to provide land managers with specific prevention strategies and quantify the benefits of various prevention strategies.


2021 ◽  
Vol 288 (1959) ◽  
pp. 20211623
Author(s):  
Malwina Schafft ◽  
Benjamin Wegner ◽  
Nora Meyer ◽  
Christian Wolter ◽  
Robert Arlinghaus

Human presence at water bodies can have a range of ecological impacts, creating trade-offs between recreation as an ecosystem service and conservation. Conservation policies could be improved by relying on robust knowledge about the relative ecological impacts of water-based recreation. We present the first global synthesis on recreation ecology in aquatic ecosystems, differentiating the ecological impacts of shore use, (shoreline) angling, swimming and boating. Impacts were assessed at three levels of biological organization (individuals, populations and communities) for several taxa. We screened over 13 000 articles and identified 94 suitable studies that met the inclusion criteria, providing 701 effect sizes. Impacts of boating and shore use resulted in consistently negative, significant ecological impacts across all levels of biological organization. The results were less consistent for angling and swimming. The strongest negative effects were observed in invertebrates and plants. Recreational impacts on birds were most pronounced at the individual level, but not significant at the community level. Due to publication bias and knowledge gaps, generalizations of the ecological impacts of aquatic recreation are challenging. Impacts depend less on the form of recreation. Thus, selectively constraining specific types of recreation may have little conservation value, as long as other forms of water-based recreation continue.


2020 ◽  
Vol 637 ◽  
pp. 195-208 ◽  
Author(s):  
EM DeRoy ◽  
R Scott ◽  
NE Hussey ◽  
HJ MacIsaac

The ecological impacts of invasive species are highly variable and mediated by many factors, including both habitat and population abundance. Lionfish Pterois volitans are an invasive marine species which have high reported detrimental effects on prey populations, but whose effects relative to native predators are currently unknown for the recently colonized eastern Gulf of Mexico. We used functional response (FR) methodology to assess the ecological impact of lionfish relative to 2 functionally similar native species (red grouper Epinephelus morio and graysby grouper Cephalopholis cruentata) foraging in a heterogeneous environment. We then combined the per capita impact of each species with their field abundance to obtain a Relative Impact Potential (RIP). RIP assesses the broader ecological impact of invasive relative to native predators, the magnitude of which predicts community-level negative effects of invasive species. Lionfish FR and overall consumption rate was intermediate to that of red grouper (higher) and graysby grouper (lower). However, lionfish had the highest capture efficiency of all species, which was invariant of habitat. Much higher field abundance of lionfish resulted in high RIPs relative to both grouper species, demonstrating that the ecological impact of lionfish in this region will be driven mainly by high abundance and high predator efficiency rather than per capita effect. Our comparative study is the first empirical assessment of lionfish per capita impact and RIP in this region and is one of few such studies to quantify the FR of a marine predator.


Author(s):  
Henn Ojaveer ◽  
Jonne Kotta ◽  
Okko Outinen ◽  
Heli Einberg ◽  
Anastasija Zaiko ◽  
...  

Author(s):  
Ryan D McMullan ◽  
Rachel Urwin ◽  
Peter Gates ◽  
Neroli Sunderland ◽  
Johanna I Westbrook

Abstract Background The operating room (OR) is a complex environment in which distractions, interruptions, and disruptions (DIDs) are frequent. Our aim was to synthesise research on the relationships between DIDs and (a) operative duration, (b) team performance, (c) individual performance, and (d) patient safety outcomes; in order to better understand how interventions can be designed to mitigate the negative effects of DIDs. Methods Electronic databases (MEDLINE, Embase, CINAHL, PsycINFO) and reference lists were systematically searched. Included studies were required to report quantitative outcomes of the association between DIDs and team performance, individual performance, and patient safety. Two reviewers independently screened articles for inclusion, assessed study quality, and extracted data. A random effects meta-analysis was performed on a subset of studies reporting total operative time and DIDs. Results Twenty-seven studies were identified. The majority were prospective observational studies (n=15), of moderate quality (n=15). DIDs were often defined, measured, and interpreted differently in studies. DIDs were significantly associated with: extended operative duration (n=8), impaired team performance (n=6), self-reported errors by colleagues (n=1), surgical errors (n=1), increased risk and incidence of surgical site infection (n=4), and fewer patient safety checks (n=1). A random effects meta-analysis showed that the proportion of total operative time due to DIDs was 22.0% (95% CI 15.7-29.9). Conclusion DIDs in surgery are associated with a range of negative outcomes. However, significant knowledge gaps exist about the mechanisms that underlie these relationships, as well as the potential clinical and non-clinical benefits that DIDs may deliver. Available evidence indicates that interventions to reduce the negative effects of DIDs are warranted, but current evidence is not sufficient to make recommendations about potentially useful interventions.


Agronomy ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 32 ◽  
Author(s):  
Malin Broberg ◽  
Petra Högy ◽  
Håkan Pleijel

Elevated carbon dioxide (eCO2) stimulates wheat grain yield, but simultaneously reduces protein/nitrogen (N) concentration. Also, other essential nutrients are subject to change. This study is a synthesis of wheat experiments with eCO2, estimating the effects on N, minerals (B, Ca, Cd, Fe, K, Mg, Mn, Na, P, S, Zn), and starch. The analysis was performed by (i) deriving response functions to assess the gradual change in element concentration with increasing CO2 concentration, (ii) meta-analysis to test the average magnitude and significance of observed effects, and (iii) relating CO2 effects on minerals to effects on N and grain yield. Responses ranged from zero to strong negative effects of eCO2 on mineral concentration, with the largest reductions for the nutritionally important elements of N, Fe, S, Zn, and Mg. Together with the positive but small and non-significant effect on starch concentration, the large variation in effects suggests that CO2-induced responses cannot be explained only by a simple dilution model. To explain the observed pattern, uptake and transport mechanisms may have to be considered, along with the link of different elements to N uptake. Our study shows that eCO2 has a significant effect on wheat grain stoichiometry, with implications for human nutrition in a world of rising CO2.


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
A. G. Bezerra ◽  
G. N. Pires ◽  
M. L. Andersen ◽  
S. Tufik ◽  
H. Hachul

Sleep disorders are commonly observed among postmenopausal women, with negative effects on their quality of life. The search for complementary therapies for sleep disorders during postmenopausal period is of high importance, and acupuncture stands out as an appropriate possibility. The present review intended to systematically evaluate the available literature, compiling studies that have employed acupuncture as treatment to sleep disorders in postmenopausal women. A bibliographic search was performed in PubMed/Medline and Scopus. Articles which had acupuncture as intervention, sleep related measurements as outcomes, and postmenopausal women as target population were included and evaluated according to the Cochrane risk of bias tool and to the STRICTA guidelines. Out of 89 search results, 12 articles composed our final sample. A high heterogeneity was observed among these articles, which prevented us from performing a meta-analysis. Selected articles did not present high risk of bias and had a satisfactory compliance rate with STRICTA guidelines. In general, these studies presented improvements in sleep-related variables. Despite the overall positive effects, acupuncture still cannot be stated as a reliable treatment for sleep-related complaints, not due to inefficacy, but rather limited evidence. Nevertheless, results are promising and new comprehensive and controlled studies in the field are encouraged.


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