Knowledge, perceptions and willingness to control designated invasive tree species in urban household gardens in South Africa

Many biological invasions result in negative impacts on the environment and human livelihoods, but simultaneously some also provide benefits that are valued differently by various stakeholders. To inform policy and management of invasive species it is important to assess landowners’ and broader society’s knowledge and perceptions of invasive species, something which is lacking in many contexts, especially in urban settings. In this study we interviewed 153 householders living in a medium-sized South African town who had declared invasive alien trees in their gardens. Less than half of the respondents could identify the invasive tree on their property and only one-third knew that it was an invasive alien species. There was a positive association between income and education levels with exposure to media about invasive alien species and respondents’ ability to identify the species and name any other invasive alien tree species. Knowledge levels were unequal across species. Amongst those who knew the tree was an invasive alien species, reasons why they retained it in their gardens included that it would be costly or too much effort to remove, they liked the tree, that it was not causing any harm and that the property was rented and so its removal was not their responsibility. However, the majority of people (83 %) were willing to have it removed from their garden if done for free by appropriate agencies, which is promising for compliance with new regulations on invasive species implemented at the end of 2014 in South Africa. The results also highlight the need for targeted and appropriate education and awareness programs amongst urban householders on invasive alien species, relevant legislation and their obligations

The social dimensions of biological invasions in South Africa

This chapter examines current knowledge relating to the human and social dimensions of biological invasions in South Africa. We do so by advancing 12 propositions and examining the evidence for or against each using South African literature. The propositions cover four broad issues: how people cause invasions; how they conceptualise them; effects of invasive species on people; and peoples’ responses to them

Consensus and controversy in the discipline of invasion science

Approaches, values and perceptions in invasion science are highly dynamic, and like in other disciplines, views among different people can be somewhat divergent. This has led to debate in the field specifically surrounding the core themes relating to values, management, impacts, and terminology. Considering these debates, we surveyed the views of 698 scientists and practitioners to assess levels of polarization (opposing views) on core and contentious invasion science topics. Our results indicate that although there are generally high levels of consensus in the field, there are still some areas of polarization. Relating to values, there was high polarization regarding claims of invasive species denialism, if invasive species contribute to biodiversity, and, how biodiversity reporting should be conducted. Linking to management there were polarized views on banning the commercial use of beneficial invasive species, the extent to which stakeholders’ perceptions should influence management, if invasive species utilization alone is an appropriate control strategy, and, whether the eradication of invasive plants is possible. For impacts, there was high polarization concerning whether invasive species drive, or are a side effect of degradation, and, if invasive species benefits are understated. For terminology, polarized views related to defining invasive species based only on spread, if labelling species as invasive in their native ranges, and, if language used is too xenophobic. Factor and regression analysis revealed that views were particularly divergent between people working on different invasive taxa (plants and mammals) and in different disciplines (especially between biologists and social scientists), between academics and practitioners, and between world regions (especially between Africa and the Global North). Unlike in other studies, age and gender had a limited influence on response patterns. We highlight that better integration globally and between disciplines, taxa and sectors (e.g., academic vs. practitioners), could help build broader understanding and consensus in the field

Emissions trading, capital flows and the Kyoto Protocol

We use an econometrically estimated multi-region, multi-sector general equilibrium model of the world economy to examine the effects of the tradable emissions permit system proposed in the 1997 Kyoto protocol, under various assumptions about that extent of international permit trading. We focus, in particular, on the effects of the system on international trade and capital flows. Our results suggest that consideration of these flows significantly affects estimates of the domestic effects of the emissions mitigation policy, compared with analyses that ignore international capital flows

Explaining people’s perceptions of invasive alien species:A conceptual framework

Human perceptions of nature and the environment are increasingly being recognised as important for environmental management and conservation. Understanding people's perceptions is crucial for understanding behaviour and developing effective management strategies to maintain, preserve and improve biodiversity, ecosystem services and human well-being. As an interdisciplinary team, we produced a synthesis of the key factors that influence people's perceptions of invasive alien species, and ordered them in a conceptual framework. In a context of considerable complexity and variation across time and space, we identified six broad-scale dimensions: (1) attributes of the individual perceiving the invasive alien species; (2) characteristics of the invasive alien species itself; (3) effects of the invasion (including negative and positive impacts, i.e. benefits and costs); (4) socio-cultural context; (5) landscape context; and (6) institutional and policy context. A number of underlying and facilitating aspects for each of these six overarching dimensions are also identified and discussed. Synthesising and understanding the main factors that influence people's perceptions is useful to guide future research, to facilitate dialogue and negotiation between actors, and to aid management and policy formulation and governance of invasive alien species. This can help to circumvent and mitigate conflicts, support prioritisation plans, improve stakeholder engagement platforms, and implement control measures

New Forests and New Forest People in Central Vietnam: The Acacia Boom

Vietnam is the country with the largest area of plantations of Australasian Acacia species (‘wattles’) in South-East Asia. Between 6 and 9% of the national land area is cultivated with tropical wattles (A. auriculiformis, A. mangium and A. × mangiiformis). From the perspective of its promoters, the wattle plantation industry in Vietnam may be seen as a success beyond expectations. We review the origins of this boom and ask what it has done to and for the coun- try’s landscape and people. The chapter combines findings and insights from an interdisciplinary research project in Thừa Thiên Huế province, north-central Vietnam. Research took place across upland and lowland wattle-growing regions, with ethnic minorities as well as the Kinh majority, and with long-term wattle growers as well as new en- trants. It drew on questionnaires, interviews and observations, as well as information from remote sensing, eco- logical surveys and hydrological assessments. We first describe how substantial areas of ‘new forest’ (short-rotation wattle plantations) were created, initially in degraded bushland, but now sometimes through clearing of highly bi- odiverse natural forest stands. These wattle plantations alter local hydrology, soils and biodiversity, and are exposed to risks including soil erosion and plant pathogens. The plantations provide wood chips and timber, supporting rev- enue, employment and a strong forestry industry. Incomes have risen appreciably for many, although unequally, and a class of successful entrepreneurs has emerged. These plantations alter the livelihoods and identities of upland ‘forest people’, historically shifting cultivators, contributing to what might be called ‘new forest people’. Ethnic mi- nority villagers are building new identities around the wattle economy and around their contracts with state forest agencies, seeing themselves increasingly as forest growers and protectors. We conclude by raising some questions regarding the social changes and issues of environmental sustainability linked to this wattle boom

Distribution of invasive alien Tithonia (Asteraceae) species in eastern and southern Africa and the socio-ecological impacts of T. diversifolia in Zambia

Background: Many alien plant species, such as Tithonia diversifolia, T. rotundifolia and T. tubaeformis, have been introduced to areas outside of their natural distribution range to provide benefits, but have subsequently become invasive, threatening biodiversity and agricultural productivity. Objectives: The aim of this study was to determine the current distribution and dates of introduction of invasive Tithonia species in eastern and southern Africa and to document the effects of T. diversifolia on rural livelihoods in Zambia. Method: Roadside surveys, and other sources of information, were used to determine the distribution of invasive Tithonia species in eastern and southern Africa. Household interviews were conducted to gauge perceptions and understand the impacts of T. diversifolia on local livelihoods in Zambia’s Copperbelt province. Results: Tithonia diversifolia is widespread in Uganda, Kenya, Tanzania, South Africa, Malawi and parts of Zambia but less so in Zimbabwe. Tithonia rotundifolia was comparatively uncommon in eastern Africa but common in some southern African countries, while T. tubaeformis was invasive in Swaziland, South Africa, Zambia and possibly also Zimbabwe. According to the majority of respondents in Zambia, T. diversifolia has negative impacts on native vegetation, mobility or access, water availability, crop yields and animal health. Conclusion: Invasive Tithonia species are widespread and spreading throughout much of Africa. Livelihood and biodiversity costs have not been considered by those actively promoting the use and further dissemination of T. diversifolia. We therefore recommend that detailed cost–benefit studies should be undertaken to support informed decisions on the future management of these species

Navigating power in conservation

Conservation research and practice are increasingly engaging with people and drawing on social sciences to improve environmental governance. In doing so, conservation engages with power in many ways, often implicitly. Conservation scientists and practitioners exercise power when dealing with species, people and the environment, and increasingly they are trying to address power relations to ensure effective conservation outcomes (guiding decision-making, understanding conflict, ensuring just policy and management outcomes). However, engagement with power in conservation is often limited or misguided. To address challenges associated with power in conservation, we introduce the four dominant approaches to analyzing power to conservation scientists and practitioners who are less familiar with social theories of power. These include actor-centered, institutional, structural, and, discursive/governmental power. To complement these more common framings of power, we also discuss further approaches, notably non-human and Indigenous perspectives. We illustrate how power operates at different scales and in different contexts, and provide six guiding principles for better consideration of power in conservation research and practice. These include: (1) considering scales and spaces in decision-making, (2) clarifying underlying values and assumptions of actions, (3) recognizing conflicts as manifestations of power dynamics, (4) analyzing who wins and loses in conservation, (5) accounting for power relations in participatory schemes, and, (6) assessing the right to intervene and the consequences of interventions. We hope that a deeper engagement with social theories of power can make conservation and environmental management more effective and just while also improving transdisciplinary research and practice