scholarly journals Developing thresholds of potential concern for invasive alien species: Hypotheses and concepts

Koedoe ◽  
2009 ◽  
Vol 51 (1) ◽  
Author(s):  
Llewellyn C. Foxcroft

The Kruger National Park (KNP) has developed and refined a system of management called ‘strategic adaptive management’ (SAM), which rests on the concept of ‘threshold of potential concern’ (TPC). TPCs represent end-points in a continuum of change. When thresholds are reached – at which point concerns of negative impacts on biodiversity are raised – management options are explicitly considered and implemented. This paper describes the TPCs developed for monitoring and managing invasive alien species (IAS). More importantly, however, it describes the conceptual understanding, principles and hypotheses adopted as the foundations for setting these TPCs. In accordance with adaptive management practices, the TPCs will be revised as the ecological and conceptual understanding of invasions grows and information is gained through research in the KNP and elsewhere.Conservation implication: In accepting that species and systems are variable, and that flux is inevitable and desirable, these TPCs developed for invasive alien species specifi cally, provide end points against which monitoring can be assessed. Once a threshold is reached, the cause of the threshold being exceeded is examined and management interventions recommended.

2020 ◽  
Vol 8 (1) ◽  
pp. 109
Author(s):  
Agus Sayfulloh ◽  
Melya Riniarti ◽  
Trio Santoso

One of the problems encountered by the Bukit Barisan Selatan National Park (TNBBS) is the presence of invasive alien species. Invasive alien species are plants that grow outside their natural distribution and have the ability to cover the area; hence it could suppress the growth of the other plants. The presence of invasive alien species in the national park has been widely reported to cause negative impacts on the ecosystem, local biodiversity, socio-economic, and human health in the vicinity. This study was carried out in the rehabilitation zone of the Sukaraja Atas Resort of TNBBS that had shifted into open land. This study aimed to determine the species and dominance of invasive alien species that exist. The sampling method was used by laying plots consisted of the combination of the line and multiple plot methods with a total plot of 25 plots. Data analysis was performed by selecting invasive alien species observed based related-literature, while the dominance of invasive alien species was calculated by the importance value index (IVI). The results identified 121 species, of which 29 species or 35% of them were classified as invasive alien, which originating from 19 families. Three invasive alien species become the most dominating, namely: Clidemia hirta with an IVI of 22.61, Imperata cylindrica with an IVI of 18.03, and Calliandra calothyrsus with an IVI 17.96. The environmental conditions and species characteristics supported the three invasive alien species domination; hence it inhibited the growth of native species. Keywords:  Bukit Barisan Selatan National Park, invasive alien species, rehabilitation zone


Koedoe ◽  
2011 ◽  
Vol 53 (2) ◽  
Author(s):  
Sharon Pollard ◽  
Derick Du Toit ◽  
Harry Biggs

Protected areas such as the Kruger National Park (KNP) face many management challenges, of which ensuring a healthy flow of rivers into the park is one of the most important. Although previous management policies isolated the KNP from its neighbours, this position has changed as the KNP seeks to negotiate a respected ‘place’ for water and conservation in a competitive environment. A major catalyst for this re-orientation has been the response from the KNP to the growing water crisis where its position needed to be seen within the wider catchment and policy context in South Africa. This paper presents an overview of the transforming management practices of the KNP in a changing political, socio-economic and environmental context, through the lens of water resources. We show that the KNP management model moved beyond inward-looking, isolationist policies to adopt responsivity to major change factors. The new approach was applied first in the sphere of river management in the KNP after which it spread to other domains such as fire and game management. It explicitly incorporates an experimental–reflexive orientation and considers management as a process of learningby- doing. This paper strives to review the transformation since the onset of explicit adaptive management of these rivers. The development of a new stewardship, based on a stakeholdercentred vision and on learning-focused management, has been a main achievement for the KNP. A closer partnership between researchers, managers and field staff, supported with buyin and co-learning, has led to a management framework based on a clear vision informed by stakeholder involvement, an objectives hierarchy, a scoping of management options, a monitoring system and a reflective evaluation process with feedback loops. Although developed through a focus on rivers, the framework can be embraced for the management of ecosystems as a whole.Conservation implications: The explicit adoption of strategic adaptive management for the rivers entering the KNP has had considerable implications not only with regard to management practice within the park, but also for the relationships with neighbours. This has also meant setting and implementing new goals and priorities with managers and staff.


2021 ◽  
Vol 39 (10) ◽  
Author(s):  
Asmida Ahmad ◽  
Nur Fazini Asro Bt. Ramzi Sulaiman ◽  
Nadia Bt. Abu Hasan

River pollution has been a major problem in Malaysia and significantly affects the environment. One of the contributing issues would be the spread of invasive alien fish species that has given negative impacts on the environment and ecological disaster, the human health, harming the native animals and plants, as well the economy. Based on the National Committee on Invasive Alien Species Report in 2018, that 46 invasive alien species from a total of 130 species in the established main invasive alien species lists in Malaysia.  The alien fishes have been known to make their presence in our dams, lakes and rivers but not much attention has been paid to their existence. Based on these facts, it is proven that the issue poses a significant risk hence an urgent attention is required in managing this pollution through proactive legal measures to enforce strictly the existing law so as to prevent the halt of the spread of invasive species. A legal doctrinal and non-doctrinal modes of research are used to examine and review on the existing laws and/or policy governing this issue. This research will help to provide reference and strategic planning via legal approach for better controlling the invasion in our Malaysian waters.  


2020 ◽  
Vol 30 (1) ◽  
pp. 21-31 ◽  
Author(s):  
R. Chaudhary ◽  
B. B. Shrestha ◽  
H. Thapa ◽  
M. Siwakoti

Extent of plant invasions has been expected to be low in protected areas such as national parks due to low anthropogenic activities and high wilderness. However, recent researches across the world have revealed that plant invasions can be severe in the national parks with negative impacts on the protected species and ecosystems. Unfortunately, the status of plant invasions in the national parks of Nepal is mostly unknown. In this study, we sampled at seven locations inside the Parsa National Park (PNP) to document diversity and abundance of invasive alien plant species (IAPS) and their impacts on tree regeneration. Altogether, 130 quadrats of 10 m × 10 m were sampled. We recorded 14 IAPS in the PNP. Three of the IAPS (Chromolana odorata, Lantana camara and Mikania micrantha) were among the 100 of the world’s worst invasive alien species. C. odorata was found to be the most frequent IAPS with the highest cover. The frequency and cover of the IAPS were higher at the sites close to the settlements than at the sites away from the settlements. The species richness of the IAPS was also higher at the sites closer to the settlements than away. The sapling density of the tree species was found to have declined with the increasing cover of the IAPS suggesting that the IAPS had negatively affected tree regeneration. Our data revealed that the PNP has already witnessed massive plant invasions with widespread occurrence of three of the world’s worst invasive species. Therefore, it is high time to integrate management of invasive alien species in the management plan of the park.


2004 ◽  
Vol 31 (4) ◽  
pp. 274-282 ◽  
Author(s):  
SCOTT E. REID ◽  
JEFFREY L. MARION

The expansion and proliferation of backcountry campsites is a persistent problem in many parks and protected areas. Shenandoah National Park (SNP) has one of the highest backcountry overnight use densities in the USA national parks system. SNP managers implemented a multi-option backcountry camping policy in 2000 that included camping containment with established campsites. These actions were intended to reduce the number of campsites and the area of camping disturbance at each site. This paper describes a longitudinal adaptive management assessment of the new campsite policies, applying quantitative measures of campsite conditions to evaluate the efficacy of management interventions. Physical campsite measurements combined with qualitative visitor interviews indicated SNP had successfully reduced the number of campsites and aggregate measures of camping-related disturbance in the Park, while minimizing the use of regulations, site facilities and staff resources. Implications for managers of other protected areas are that an established site camping policy can minimize camping disturbance, including the number and size of campsites, provided managers can sustain rehabilitation efforts to close and restore unneeded campsites. Experiential attributes, such as the potential for solitude, can also be manipulated through control over the selection of established campsites. Integrating resource and social science methods also provided a more holistic perspective on management policy assessments. Adaptive management research provided a timely evaluation of management success while facilitating effective modifications in response to unforeseen challenges. Conclusions regarding the effectiveness of a visitor impact containment strategy involving an established site camping option are offered.


NeoBiota ◽  
2021 ◽  
Vol 67 ◽  
pp. 459-483 ◽  
Author(s):  
Axel Eduardo Rico-Sánchez ◽  
Phillip J. Haubrock ◽  
Ross N. Cuthbert ◽  
Elena Angulo ◽  
Liliana Ballesteros-Mejia ◽  
...  

Invasive alien species (IAS) are a leading driver of biodiversity loss worldwide, and have negative impacts on human societies. In most countries, available data on monetary costs of IAS are scarce, while being crucial for developing efficient management. In this study, we use available data collected from the first global assessment of economic costs of IAS (InvaCost) to quantify and describe the economic cost of invasions in Mexico. This description was made across a range of taxonomic, sectoral and temporal variables, and allowed us to identify knowledge gaps within these areas. Overall, costs of invasions in Mexico were estimated at US$ 5.33 billion (i.e., 109) ($MXN 100.84 billion) during the period from 1992 to 2019. Biological invasion costs were split relatively evenly between aquatic (US$ 1.16 billion; $MXN 21.95 billion) and terrestrial (US$ 1.17 billion; $MXN 22.14 billion) invaders, but semi-aquatic taxa dominated (US$ 2.99 billion; $MXN 56.57 billion), with costs from damages to resources four times higher than those from management of IAS (US$ 4.29 billion vs. US$ 1.04 billion; $MXN 81.17 billion vs $MXN 19.68 billion). The agriculture sector incurred the highest costs (US$ 1.01 billion; $MXN 19.1 billion), followed by fisheries (US$ 517.24 million; $MXN 9.79 billion), whilst most other costs simultaneously impacted mixed or unspecified sectors. When defined, costs to Mexican natural protected areas were mostly associated with management actions in terrestrial environments, and were incurred through official authorities via monitoring, control or eradication. On natural protected islands, mainly mammals were managed (i.e. rodents, cats and goats), to a total of US$ 3.99 million, while feral cows, fishes and plants were mostly managed in protected mainland areas, amounting to US$ 1.11 million in total. Pterygoplichthys sp. and Eichhornia crassipes caused the greatest reported costs in unprotected aquatic ecosystems in Mexico, and Bemisia tabaci to terrestrial systems. Although reported damages from invasions appeared to be fluctuating through time in Mexico, management spending has been increasing. These estimates, albeit conservative, underline the monetary pressure that invasions put on the Mexican economy, calling for urgent actions alongside comprehensive cost reporting in national states such as Mexico.


2021 ◽  
Author(s):  
Walid Fathy Mohamed ◽  

Alien animals cause drastic and negative impacts on biota and ecosystems. The feral donkey Equus asinus is an invasive alien species in Saudi Arabia. Damage of farms and plant consumed by feral donkeys were studied in the area between Al-Ula and Al-Wajh governorates in order to spot their harmful effects in this region and to propose possible solutions to the problems they caused. Surveys and direct interviews and conversations with farmers and villagers were the selected methods used to collect information. Prevention, and management actions were suggested to decrease numbers of feral donkeys. A useful investment potential was proposed to get some benefits from them.


Our Nature ◽  
1970 ◽  
Vol 5 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Sasinath Jha

This paper deals in general with diversity of vascular plants, status of invasive alien species (IAS) and nationally threatened plant species, human use potentials of phytodiversity, and some phytodiversity-based measures to restore and improve the Ramsar characteristics of Beeshazar Lake and surrounding landscape system, which isa part of the Barandabhar forest corridor (BFC) - an extension of buffer zone of the Chitwan National Park, Nepal. Keywords: Phytodiversity, Beeshazar Lakedoi:10.3126/on.v5i1.797Our Nature (2007)5:41-51


2021 ◽  
Vol 24 (1) ◽  
pp. 41-65
Author(s):  
Kenny Ng

Marine invasive alien species are sea-based organisms that are non-native to a marine ecosystem, and which can or have spread to a degree that has an adverse impact on biodiversity and human livelihoods. In a globalized and inter-connected world, the threats posed by marine invasive alien species are here to stay. Accordingly, it often has been lamented that the threats from marine alien species are too difficult to combat effectively. In Australia, these threats are exacerbated by the country's unique characteristics such as its sheer size, as well as its geographical and historical isolation from the rest of the world. More importantly for the purposes of this article, Australia's unique constitutional framework that entrenches its national system of federalism has led to complex power-sharing arrangements between the Commonwealth, and the State and Territory governments in the management of invasive alien species, which are arguably inadequate to combat marine invasive alien species effectively. In Australia, laws have been made to manage only one vector of marine invasive species, ballast water from vessels, but not for other vectors. This article analyses how marine invasive alien species are currently managed within the Australian legal framework, and discusses what can be done to improve the status quo in order effectively to control the spread of such foreign organisms. It argues with optimism that marine invasive alien species can be effectively managed under a strong legal framework that seeks to prevent their occurrence and minimize the negative impacts of their occurrence. Such a legal framework consists of sound domestic laws and institutions, the effects of which can be enhanced by greater international cooperation.


Koedoe ◽  
2011 ◽  
Vol 53 (2) ◽  
Author(s):  
Craig A. McLoughlin ◽  
Andrew Deacon ◽  
Hendrik Sithole ◽  
Thomas Gyedu-Ababio

The Kruger National Park’s (KNP) adopted system of management, called Strategic Adaptive Management (SAM), originated during the Kruger National Park Rivers Research Programme (KNPRRP) of the 1990s. An important concept in SAM is the thresholds of potential concern (TPCs), representing end-points in a continuum of change. TPCs within the KNP SAM system guide management if or when reached, ‘red-flagging’ possible negative biodiversity impacts and catalysing consideration of management options. TPC-related monitoring generates the strategic information for ongoing evaluation, learning and adaptation within SAM. Post- KNPRRP, although river flow and water quality TPCs have been implemented partly, those designed to detect undesirable changes in biodiversity have not been implemented, until recently. This paper describes the history, rationale, application and ongoing developments associated with the KNP river TPCs over the last decade, providing some key lessons for organisations utilising SAM. The paper concludes with an overview of new thinking and future directions envisaged for the KNP river TPCs, as part of the KNP SAM system. Conservation implications: This paper documents important concepts of strategic adaptive management associated with the KNP river systems. Understanding, related to the rationale and justification for use and development or refinement of the thresholds of potential concern, lays an important foundation for ongoing work in managing these rivers adaptively.


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