Managing Alien Plants for Biodiversity Outcomes—the Need for Triage

AbstractRecognition that alien plants pose a significant threat to biodiversity has not always translated into effective management strategies, policy reforms, and systems to establish priorities. Thus, many alien plant management decisions for the protection of biodiversity occur with limited knowledge of what needs to be protected (other than biodiversity in a generalized sense) or the urgency of actions. To rectify this, we have developed a triage system that enables alien plant management decisions to be made based on (1) the urgency of control relative to the degree of threat posed to biodiversity, compared with (2) the likelihood of achieving a successful conservation outcome as a result of alien plant control. This triage system is underpinned by a two-step approach, which identifies the biodiversity at risk and assesses sites to determine priorities for control. This triage system was initially developed to manage the threat posed by bitou bush to native species in New South Wales (NSW), Australia. It has subsequently been improved with the national assessment of lantana in Australia, and the adaptation from a single to multiple alien plant species approach on a regional scale. This triage system identifies nine levels of priority for alien plant management aimed at biodiversity conservation, ranging from immediate, targeted action to limited or no action. The development of this approach has enabled long-term management priorities to be set for widespread alien plants that are unlikely to be eradicated. It also enables control to occur in a coordinated manner for biodiversity conservation at a landscape scale, rather than as a series of individual unconnected short-term actions.

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Managing Widespread, Alien Plant Species to Ensure Biodiversity Conservation: A Case Study Using an 11-Step Planning Process

Invasive Plant Science and Management ◽

10.1614/ipsm-d-10-00012.1 ◽

2010 ◽

Vol 3 (4) ◽

pp. 451-461 ◽

Cited By ~ 12

Author(s):

Paul O. Downey

Keyword(s):

Biodiversity Conservation ◽

Plant Species ◽

Planning Process ◽

Management Strategies ◽

Alien Plants ◽

Plant Management ◽

Alien Plant Species ◽

Alien Plant ◽

Management Actions

AbstractOne of the greatest threats to biodiversity is the invasion of ecological communities by alien plants. Management strategies for alien plants, however, rarely focus on specific biodiversity-conservation outcomes, and recovery actions rarely address the threat on a landscape scale. There are many reasons for these failures, including (1) limited knowledge of the native species at risk, (2) a disconnect between policy and management, (3) a disconnect between the fields of weed science and biodiversity conservation, (4) a dearth of data from management actions (for both threat abatement and recovery), and (5) the broadly held assumption that control of alien plants will by itself lead to a positive biodiversity response is often incorrect. Thus, alien plant management strategies with a conservation aim need to include planning processes and assessment measures to ensure that the aim is achieved. Here, I outline an example of the planning steps needed to ensure that the management of widespread alien plant species achieves the greatest possible conservation outcome, using the alien plant program for bitou bush (Chrysanthemoides monilifena) as a case study. In addition, I present an overview of the challenges faced and solutions developed during the transition from planning to management, along with some initial data to demonstrate the success and value of this investment in both planning and implementation during the past decade. Interim results from a series of sites have highlighted the success of the program and led to the program being acknowledged as an important ecological restoration project in Australasia. This success is highly dependent on extensive stakeholder involvement (across land tenures), dedicated coordination, and leadership. The planning process is now being adopted for other alien plants in Australia and can be modified to abate the threat from other alien organisms or other threats to biodiversity because the principles of each step are fundamentally similar.

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Alien woody plants are more versatile than native, but both share similar therapeutic redundancy in South Africa

PLoS ONE ◽

10.1371/journal.pone.0260390 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0260390

Author(s):

Kowiyou Yessoufou ◽

Annie Estelle Ambani ◽

Hosam O. Elansary ◽

Orou G. Gaoue

Keyword(s):

Plant Species ◽

Native Species ◽

Native Plants ◽

Invasion Biology ◽

Alien Plants ◽

Parasitic Infections ◽

Alien Plant Species ◽

Secondary Chemistry ◽

Alien Plant ◽

Medicinal Flora

Understanding why alien plant species are incorporated into the medicinal flora in several local communities is central to invasion biology and ethnobiology. Theories suggest that alien plants are incorporated in local pharmacopoeias because they are more versatile or contribute unique secondary chemistry which make them less therapeutically redundant, or simply because they are locally more abundant than native species. However, a lack of a comprehensive test of these hypotheses limits our understanding of the dynamics of plants knowledge, use and potential implications for invasion. Here, we tested the predictions of several of these hypotheses using a unique dataset on the woody medicinal flora of southern Africa. We found that the size of a plant family predicts the number of medicinal plants in that family, a support for the non-random hypothesis of medicinal plant selection. However, we found no support for the diversification hypothesis: i) both alien and native plants were used in the treatment of similar diseases; ii) significantly more native species than alien contribute to disease treatments particularly of parasitic infections and obstetric-gynecological diseases, and iii) alien and native species share similar therapeutic redundancy. However, we found support for the versatility hypothesis, i.e., alien plants were more versatile than natives. These findings imply that, although alien plant species are not therapeutically unique, they do provide more uses than native plants (versatility), thus suggesting that they may not have been introduced primarily for therapeutic reasons. We call for similar studies to be carried out on alien herbaceous plants for a broader understanding of the integration of alien plants into the pharmacopoeias of the receiving communities.

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Biological invasions as natural hazards: towards building a strategy to cope with invasive alien plants

10.5194/egusphere-egu21-11167 ◽

2021 ◽

Author(s):

Alexandros Galanidis ◽

Chrysanthi Michelaki ◽

Panagiotis Dimitrakopoulos

Keyword(s):

Risk Assessment ◽

Biological Invasions ◽

Natural Hazards ◽

Management Strategies ◽

Early Warning Systems ◽

Alien Plants ◽

Cultivated Plants ◽

Alien Plant ◽

Non Invasive ◽

Prioritization Scheme

Biological invasions can be compared to natural hazards as besides their environmental effect can also produce rapid and damaging socioeconomic impacts. Additionally, their causes and consequences are generally well understood yet difficult to predict, and their incidence is almost unfeasible to control. For both phenomena, it is their random and uncontrollable nature that demand planning for the worst. Therefore, biological invasions and natural hazards require similar management strategies and commitments.The aim of this study was to support decision makers and stakeholders in Lesvos Island Greece in prioritizing high impact alien plant species. We applied an integrated framework that combined a literature review and a systematic roadside survey of alien plants presence, along with their distribution, abundances, habitat preferences and impacts. Relied on this solid base we structured a prioritization scheme that would identify and rank aliens according to their invasiveness and produce alert lists of the most invasive ones. Two Risk Assessment protocols were implemented: the European and Mediterranean Plant Protection Organization (EPPO) prioritization scheme, and the Australian Weed Risk Assessment (A-WRA). Each screening method delivered assessment lists that classified aliens as invasive, possibly invasive, and non-invasive. With the aim of benchmarking the performances of the two methods we compared their results with a third invasiveness estimation performed by a panel of experts at national level.In total, 151 alien plants from 53 different families were found. The most abundant families were Asteraceae (10%), Amaranthaceae and Poaceae (9%), and Fabaceae (8%). A subset of 87 species, which excluded urban, ornamental, or cultivated plants with rare occurrences and no documented impacts, was assessed. According to the EPPO scheme, 8% of species categorized as invasive, 57% as possibly invasive and 34% as non-invasive. The A-WRA method was stricter, classifying 80% of species as invasive, 14% as possibly invasive and only 6% as non-invasive. Compared to expert&#8217;s opinion, EPPO scheme indicated a 10% match for invasive and a 43% for non-invasive species, whereas A-WRA an 83% and 14% respectively.Main ranking differences between the two methods are due to the diverse input information each one requires, and to differences in the relevant importance of that information to the final ranking. A-WRA is a precautionary method that rejects even minor invaders, whereas EPPO method is a rapid prioritization tool that provides information for a subsequent appropriate Pest Risk Analysis. Our framework delivers critical information and can improve the development of early-warning systems that would promote successful preventative management strategies for biological invasions.Acknowledgements: This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme &#8220;Human Resources Development, Education and Lifelong Learning 2014-2020&#8221; in the context of the project &#8220;An Integrative Framework for the Study of Alien Flora&#8221; (MIS 5049419).

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Effects of Alien Plant Invasions on Native Vegetation Remnants on La Réunion (Mascarene Islands, Indian Ocean)

Environmental Conservation ◽

10.1017/s0376892900021305 ◽

1991 ◽

Vol 18 (1) ◽

pp. 51-61 ◽

Cited By ~ 58

Author(s):

Ian A.W. Macdonald ◽

Christophe Thébaud ◽

Wendy A. Strahm ◽

Dominique Strasberg

Keyword(s):

Indian Ocean ◽

Alien Species ◽

Plant Species ◽

Alien Plants ◽

Primary Forest ◽

Plant Management ◽

Native Vegetation ◽

La Réunion ◽

Alien Plant ◽

Forest Remnants

Although most of the lowland endemic forests of the mountainous Indian Ocean island of La Réunion have been converted by Man to other land-uses, relatively intact ecosystems still survive at higher elevations. Given the particular conservational value of these remnants of primary forest, detailed knowledge of the threats faced by these native ecosystems was urgently needed. Accordingly we conducted field surveys through the various plant communities on the island in order to answer particular questions regarding the vulnerability of native vegetation remnants to invasive, introduced plant species.Our results indicated that most invaders colonize human-disturbed sites most successfully. However, such alien plants are also frequent in the Réunion primary forest remnants, with at least 62 species penetrating into areas which have experienced no or little human disturbance. Nevertheless, the forest remnants were still mainly dominated by indigenous or endemic plant species and maintain what is, presumably, their original vegetational structure.The most threatening plant invaders are the trees Psidium cattleianum and Ligustrum robustwn, the bramble Rubus alceifolius, the shrubs Fuchsia magellanica and Lantana camara, and the herbaceous Hedychium gardnerianum, Boehmeria macrophylla, and Boehmeria penduliflora.We found the early stages of primary succession on young volcanic sites to be dominated by aggressively expanding populations of alien species. It appears very unlikely that native species will replace the invaders as the succession proceeds, and furthermore the survival of many indigenous species probably hinges on the active control of alien species.In order for alien plant management efforts to be successful, we propose a priority ranking based on the current and potential future extent of specific infestation, the rate of spread, the difficulty with which a species can be controlled, and its ecological impact on the areas invaded.Finally, the long-term survival of the Réunion ecosystems depends largely upon the drawing up and implementation of an adequate overall conservation policy regarding human-caused invasions by alien plants in the native vegetation.

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Use, perception, and local management of Copernicia prunifera (Miller) H. E. Moore in rural communities in the Brazilian Savanna

10.21203/rs.3.rs-65335/v2 ◽

2021 ◽

Author(s):

José Afonso Santana Almeida ◽

Nágila Alves Feitosa ◽

Leilane Carvalho Sousa ◽

Raimundo Nonato Oliveira Silva ◽

Rodrigo Ferreira Morais ◽

...

Keyword(s):

Rural Communities ◽

Native Species ◽

Management Strategies ◽

Wild Plant ◽

Plant Management ◽

Human Populations ◽

Production Chain ◽

Socioeconomic Variables ◽

Number Of Leaves ◽

The Relationship

Abstract Background: Copernicia prunifera is a species native to the northeastern region of Brazil and is economically important as a source of income for many human populations in the region that carry out intense extractive activity on the species. C. prunifera belongs to the Arecaceae family and its production chain includes a set of economic activities based on the use of the stipe, petiole, fiber, fruits, roots and leaves from which carnauba wax is extracted, an economically valuable resource in the region. Our hypothesis was that people would perceive morphological diversity in carnaúba. In addition, we expected to find a correlation between socioeconomic variables and the number of leaves used. This study aimed to evaluate the uses, management, and perception of the species by local extractors.Methods: Two communities were studied, Bem Quer, where 15 extractors were interviewed, and Cana, where 21 extractors considered specialists were interviewed, totaling a sample of 36 interviewees. Interviewees were asked questions about uses, ways of handling, and perception of morphological variation in the carnauba leaves. The number of leaves extracted and the income obtained from the sale of leaves was estimated from interviews and notes that each leader of extractors held during the year of the research and previous years, as well as direct observations made by researchers in the communities. A regression analysis was used to explore the relationships between social variables (age, time in extractive activity, and income obtained from extraction) with the number of leaves exploited. The relationship between time of extraction and time of residence in the community was also analyzed.Results: The leaf was indicated as the most used part, from which an important powder is extracted for the production of wax. In addition, the leaf was also indicated for fertilization and construction. Uses were also indicated for the stem (construction) and fruit (forage). The relationship between the socioeconomic variables, income from extraction, and the number of leaves extracted (in thousands) was significant (R2 =0.73 and p<0.001). However, the other variables analyzed in this study, such as the time spent extracting leaves and the years of residence in the community (R2= 0.03 and p>0.05), the number of leaves extracted and interviewee age (R2= 0.05 and p>0.05), and number of leaves extracted and extraction time (R2 =0.04 and p>0.05) did not indicate a relationship.Conclusion: C. prunifera is economically and culturally important for the studied communities. It is possible that the economic factor is the preponderant force that directs the management strategies of native species. Thus, human selection and traditional plant management may be the main mechanisms that lead wild plant populations to the incipient domestication process. For this species, however, morphological and genetic studies are needed for further clarification.

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A COMPREHENSIVE INVENTORY AND ECOLOGICAL ASSESSMENT OF ALIEN PLANT INVASION IN MIZORAM, INDIA

Indonesian Journal of Forestry Research ◽

10.20886/ijfr.2020.7.2.135-154 ◽

2020 ◽

Vol 7 (2) ◽

pp. 135-154

Author(s):

Rabishankar Sengupta ◽

Sudhansu Sekhar Dash

Keyword(s):

Native Species ◽

Sampling Technique ◽

Alien Plants ◽

Alien Plant ◽

Form Analysis ◽

Native Flora ◽

Traditional Medicines ◽

Extensive Field ◽

Central National Herbarium ◽

Origin Life

Invasion by alien plants has a detrimental effect on the natural forest plant community, leading to the loss of native species. An inventory of alien plants facilitates in determining the potential threats to the natural plant biodiversity. This present paper evaluates the alien plants in Mizoram (an Indo-Burma hotspot region) and provides the first authentic inventory of alien plants of Mizoram along with their diversity, ecological aspects, origin, and status of invasion. Extensive field surveys were done during July 2018 to September 2019 in different protected areas of Mizoram. We adopted Random Sampling Technique using nested quadrats in a plot size of 400 m2 (20 m × 20 m), within which a quadrate size of 5 m × 5 m was laid for shrubs and 1 m × 1 m was laid for herbs. Plant specimens were collected, dried, poisoned with 0.1% Mercuric Chloride (MgCl2); voucher specimens were prepared and deposited in Central National Herbarium, Botanical Survey of India (CAL) after proper identification.The results revealed the occurrence of 163 alien plant species under 135 genera belonging to 51 families in Mizoram. Maximum species were represented by family Asteraceae with 29 species followed by Leguminosae (19 species), Convolvulaceae (9 species), Euphorbiaceae (7 species) and Amaranthaceae (7 species). The 57.66% of the alien species reported from Mizoram were of American origin followed by 11.65 % from African, 7.36% from Mexican and 5.52% from Australian origin. Life form analysis revealed the presence of 58.64 % herbs, 15.43 % trees and 9.87% shrubs. Out of the whole alien plants recorded, 91 species used in traditional medicines, 43 species as ornamental, 15 species were edibles, nine species used as timber and four species used as green manure. The study also recommends the ten most obnoxious species, five neo-invasive plants, which have the greatest potential threats to the native flora. The process and probable causes of invasion in the state were also discussed briefly, which may be utilized in the preparation of conservation or forest management policies.

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Assessing the association between pathways of alien plant invaders and their impacts in protected areas

NeoBiota ◽

10.3897/neobiota.43.29644 ◽

2019 ◽

Vol 43 ◽

pp. 1-25 ◽

Cited By ~ 8

Author(s):

Llewellyn C. Foxcroft ◽

Dian Spear ◽

Nicola J. van Wilgen ◽

Melodie A. McGeoch

Keyword(s):

Protected Areas ◽

National Parks ◽

Native Species ◽

Management Strategies ◽

Ornamental Plants ◽

Physical Structure ◽

Ecological Impacts ◽

Alien Plant ◽

Plant Invaders ◽

Chi Squared

Protected areas face mounting pressures, including invasion by alien plant species. Scientifically sound information is required to advise invasive species management strategies, where early detection and rapid response is particularly important. One approach to this is to determine: (i) the relative importance of pathways of invasion by which a species is introduced, (ii) the range of likely impacts associated with each species, and (iii) the relationship between pathways and impacts, to assess the relative threats posed by different pathways of alien species introductions. This assessment was performed on 139 alien plants that are invasive across the South African National Parks (19 national parks, covering ~39,000 km2), and based on available literature and expert opinion, known to have negative ecological impacts. For each species the likelihood of being introduced by each of eight pathways, and of having negative impacts in each of 13 identified impact categories, was assessed. The similarity of impact and pathway types between species was assessed using the Jaccard index and cladograms. Differences in the prevalence of impacts and pathways and relationships between these were assessed using a Chi-squared contingency and Generalised Linear Model. Nearly 80% of the species are ornamental plants and about 60% are also dispersed by rivers, highlighting the importance of managing ornamental species and surveillance along rivers in preventing future invasions. As to the impacts, ~95% of the species compete directly with native species and 70% change the physical structure of the environment. The majority of species exert multiple impacts, with 70% of species assessed having five or more impacts. There was a significant positive relationship between the number of pathways via which a species can be introduced into an area and the number of potential impacts they can have. This suggests that species using multiple pathways reach a wider range of suitable habitats, increasing the potential for different kinds of impacts over a wider area.

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Use of a rapid roadside survey to detect potentially invasive plant species along the Garden Route, South Africa

Koedoe ◽

10.4102/koedoe.v61i1.1515 ◽

2019 ◽

Vol 61 (1) ◽

Cited By ~ 4

Author(s):

Johan A. Baard ◽

Tineke Kraaij

Keyword(s):

South Africa ◽

South African ◽

National Park ◽

Invasive Plant ◽

Alien Plants ◽

Plant Distribution ◽

Plant Management ◽

Alien Plant ◽

Invasive Alien Plant ◽

Roadside Survey

Early detection of emerging or sleeper weeds and monitoring of alien plant invasions forms the foundation of effective invasive alien plant management. Using a rapid roadside survey technique, we aimed to (1) establish a baseline of alien plant distribution and abundance along roads in the Garden Route, South Africa, and (2) identify priority species (particularly sleeper weeds) and priority areas to inform appropriate management action. We surveyed along 530 km of roads and recorded 109 alien and/or extralimital species across 1942 point locations. Of these, 35 species were considered to be sleeper weeds on account of displaying estimated dispersal distances distinctive of invasive plants and not being listed by the South African Plant Invaders Atlas (SAPIA) or regulated by South African legislation. Roads along natural forest and fynbos vegetation (often within the Garden Route National Park) displayed lower incidences of alien plants than those associated with degraded or transformed land, with roads along farmland associated with the highest incidences of alien plants. Roads in the Southern Cape region had more species and higher densities of alien plants than roads in the Tsitsikamma region, and a few species were exclusive to either.Conservation implications: Our inventory contributed significant new records and range extensions to SAPIA, while the identified sleeper weeds offered suggestions for species that may be considered for regulation under the National Environmental Management: Biodiversity Act of South Africa. We furthermore provided information to facilitate (1) timely management of emerging invasive alien plants, (2) prioritisation of species and areas for management action, and (3) future monitoring of alien plants in the Garden Route National Park and surrounds.

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Alien plant invasions in Mediterranean habitats: an assessment for Sicily

Biological Invasions ◽

10.1007/s10530-021-02561-0 ◽

2021 ◽

Author(s):

Riccardo Guarino ◽

Milan Chytrý ◽

Fabio Attorre ◽

Flavia Landucci ◽

Corrado Marcenò

Keyword(s):

Alien Species ◽

Native Species ◽

Vascular Plant ◽

Regional Scale ◽

Plant Invasions ◽

Life Forms ◽

Habitat Specificity ◽

Alien Plant ◽

Alien Flora ◽

The Impact

AbstractLevels of plant invasions in different habitat types were assessed in several regional studies, but few of them were from the Mediterranean. Here we compare the levels of vascular plant invasion across habitats and plant communities of Sicily. We used a large dataset of plant species presences/absences in vegetation plots to analyze the invasion patterns across habitats considering biogeography, life form and phenology of alien plants. Vegetation plots were classified based on the EUNIS classification of European habitats. The invasiveness of each species was expressed in terms of its absolute and percentage frequency. Representation of different life forms and phenological patterns was compared between alien and native species. The fidelity of alien species to individual habitats was calculated using the phi coefficient. Our analysis shows that annual and woody species are the most represented life forms in the alien flora of Sicily and that alien species tend to have a longer flowering period than the native species. The investigated habitats differed strongly in their level of invasion by alien species, ranging from 0 to 15.6% of aliens of all species recorded. Most of the habitats were colonized by very few alien species or completely lacked them, except for sandy coasts, naturally-disturbed riverbeds, and synanthropic habitats. It must be noted, however, that the number of alien species occurring in a given habitat does not relate to the severity of the impact of invasion in that habitat. Some habitats are invaded by few (or single) species, which attain a high cover, transforming the whole ecosystem. The habitat-based approach proved to be suitable for evaluating the habitat specificity and frequency of alien species at a regional scale, improving the capacity for risk assessment in different ecological contexts.

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Does the invasion of Northern Red Oak Quercus rubra in parkland influence the diversity of birds?

Biologia ◽

10.1515/biolog-2017-0022 ◽

2017 ◽

Vol 72 (2) ◽

Cited By ~ 1

Author(s):

Emilia Grzędzicka ◽

Katarzyna Kowalik ◽

Barbara Bacler-Żbikowska

Keyword(s):

Plant Species ◽

Bird Species ◽

Coal Industry ◽

Alien Plants ◽

Forest Birds ◽

Bird Diversity ◽

Red Oak ◽

Northern Red Oak ◽

Alien Plant Species ◽

Alien Plant

AbstractInvasive plants are non-native, but in most cases naturalised, species that have successfully spread outside of their native range. Aliens invaded all habitats, are competing with native plants, thus, after the direct destruction of habitats, invasions are recognised as the second largest danger for biodiversity. Northern Red Oak is one of the most common invasive tree species dispersed primarily by birds, but new studies have shown that it is also spread continuously in a forest stand. The main aim of our research was to check how strong is the invasion of Northern Red Oak in Silesia Park, where it was introduced together with other alien plant species, and how this invasion interacts with bird diversity. Silesia Park was created 65 years ago on the surface largely ravaged by coal industry. Because many studies indicate birds as vectors of alien plants invasion, we examined the bird fauna in a described area, looking for species that can contribute to spreading oaks. Research showed the diversity of 50 bird species. Surface with a presence of Northern Red Oak was characterised by greater participation of alien plant species than the patch of natural forest, which existed there long before the park creation. The greatest bird diversity was found in the most natural part of Silesia Park, and the lowest in the area of invasion, especially in the case of species classified as “forest birds”. The presence of alien plants increased number of “non-forest” birds, mostly synanthropic species. We also found that Northern Red Oak spreads by spontaneous seed dispersal.

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