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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation des services écosystémiques par la méthode des matrices de capacité : analyse méthodologique et applications à l'échelle régionale / Ecosystem services assessment based on the capacity matrix : methodological analysis and regional-scale applications

Campagne, Carole Sylvie 05 November 2018 (has links)
Les services écosystémiques (SE) sont définis comme les bénéfices que les humains retirent des écosystèmes. A titre illustratif, un arbre peut produire des fruits, séquestre du carbone et différentes activités récréatives ou valeurs esthétiques lui sont liées. Parmi les différentes approches d’évaluation des SE, la matrice de capacité est une méthode considérée comme flexible et rapide à mettre en œuvre. Constituée d’une table d’allocation d’un score pour chaque SE et chaque écosystème considéré, elle est de plus en plus utilisée en France, ainsi qu’à l’international. Dans le cadre de cette thèse nous avons travaillés sur l’évaluation des scores à dire d’experts dans le but, notamment, de déterminer certains biais et limites méthodologiques, mais également d’explorer des développements innovants pour différentes applications sur le Parc Naturel Région Scarpe-Escaut et la Région Hauts-de-France. Enfin nous avons intégré les disservices (les effets indésirables de la nature sur l’Homme) et l’intégrité écologique (la condition/santé de l’écosystème) dans l’évaluation des SE afin d’avoir une vision plus complète de la relation homme-nature / Ecosystem services (ES) are the benefits that humans derive from ecosystems. For example, a tree produces fruit that we pick, sequesters carbon as it grows, supports various recreational activities and has aesthetic value. Among the different approaches developed to assess ES, the experts-based capacity matrix is flexible and quick to implement. The matrix is a look-up table that assigns each ecosystem type a score defined by experts expressing its ES capacity. It is increasingly used in France, Europe and internationally. Three themes are addressed in the thesis: (i) methodological analysis to define and specify limits and specify methodology to address them, (ii) application of the method to the Scarpe-Escaut Regional Natural Park and to the Hauts-de-France Region, and (iii) integration of the evaluation of disservices (undesired effects of the natural environment on humans) and ecological integrity (condition/health of the ecosystem) into the evaluation of ES to take fuller account of the relation between humans and their natural environment.
2

An Assessment of Ecosystem Services And Disservices in Urban Community Gardens in Berlin (Germany) and Cape Town (South Africa)

Duthie, Tristan 06 December 2018 (has links)
Background: Ecosystem services and disservices research from urban ecological infrastructure currently remain under-explored areas in global literature. Community gardens comprise an even rarer part of this research with few previous studies, as emphasis in research is placed on the ‘big and tangible’ urban green spaces like urban forests and parks, and more recently allotment gardens. Community gardens, however, are an important ecological infrastructure as they provide a range of ecosystem services to urban residents, and act as key spaces for meeting social and environmental objectives in urban development plans and policies. Considering cities are the predominant domain of human habitation, it is important that more research goes into better identifying ecosystem services and disservices from urban green space types, in light of global and local sustainable urban development goals. Methods: Using the cities of Berlin and Cape Town as case studies, this study inventories the range of ecosystem services and disservices provisioned by urban community gardens. A total of 26 gardens across both cities were assessed using in-depth field surveys based on indicators derived from the literature and a ranked-scale questionnaire was answered by 46 participants. Results: Community gardens provide important ecosystem services such as food provisioning, local climate regulation, high species richness of vascular plants, are valued highly by gardeners and local residents for their numerous recreation, tourism and social activities, and foster new principles of socio-environmental thinking and practice in neighbourhoods. Gardens are also found to deliver a few disservices that may influence human health like increasing potentials for allergy problems caused by the spread of pollen from the urban nature in them, and can cause economic impacts if the vegetation damages garden infrastructure. It is important to recognise both the benefits and detriments from these urban green spaces so as to better manage them and minimise their impacts and trade-offs to human well-being. Conclusion: Outcomes of this research identify new ecosystem services and disservices inventories and make the net benefit of community gardens explicitly known, which gives credence to their value as a legitimate urban land-use by planners and related decision-makers. Findings show community gardens have a very relevant place in German and South African urban ecosystems research, and this project can significantly impact future work by strengthening the foundation from which we base our understanding – the collection and interpretation of new data. Finally, conclusions show that community gardens can contribute to sustainable urban development in local contexts, and promote Great Transition thinking.:Table of Contents Abstract……………………………………………………………………………………...i Declaration………………………………………………………………………………….ii Acknowledgements………………………………………………………………..……...iii Table of Contents…......…………………………………………………………………..iv List of Tables……………………………………………………………………………….xi List of Figures …………………………….……………………………………………..xiv Chapter One: Introduction……………………………...………………………………...1 1.1. Problem contextualisation …………………………………………..………………1 1.1.1. The changing environment ……………………………………………….....…...1 1.1.2. Ecosystems as the foundation of life ……………………………………………1 1.1.3. Century of the city …………………………………………………………………2 1.1.4. Sustainable Development and the Great Transition ………………………..…4 1.2. Problem statement ……………………………………………….………………….7 1.2.1. Ecosystem services …………………………………………………......………..7 1.2.2. Ecosystem disservices ………………………………………………......……….9 1.2.3. Urban ecosystems and ecological infrastructure .....………………………….11 1.2.4. Aim and objectives ……………………...…...…………………………………..13 1.3. Thesis overview …………………………………………………………..………..14 Chapter Two: State of Research …………………………………………………...….16 2.1. Introduction ……………………………………………………...………………….16 2.2. The role and function of community gardens as urban ecosystems ………....16 2.2.1. Definition of community gardens …………………………………………….....16 2.2.2. Historical context and multi-functional purposes of community gardens …..17 2.2.3. Ecosystem services in community gardens ………………………………......18 2.2.4. Community gardens as the assessment unit for this project ……………......19 2.3. Integrating ecosystem services and disservices concepts into urban planning, environmental management and governance …………………………………….....19 2.3.1. The role of ecosystem services and disservices in urban planning ………..20 2.3.2. The role of ecosystem services and disservices in urban environmental management …………............................................................................................21 2.3.3. The role of ecosystem services and disservices in urban governance …….23 2.4. Research on urban ecosystem services and disservices …………….......…...25 2.4.1. Urban ecosystem services research ……………..………………………........26 2.4.1.1. Categories of ecosystem services in the literature …………………….......26 2.4.1.2. Types of ecological infrastructure in ecosystem services research ……...29 2.4.1.3. Research perspectives in ecosystem services literature ……………….…29 2.4.1.4. Methodology used in ecosystem services research ……………….....…...31 2.4.2. Urban ecosystem disservices research ………………………..……………...33 2.4.2.1. Categories of ecosystem disservices in the literature ………………..……33 2.4.2.2. Types of ecological infrastructure in ecosystem disservices research ......34 2.4.2.3. Research perspectives in ecosystem disservices literature ………………35 2.4.2.4. Methodology used in ecosystem disservices research …………..………..37 2.4.3. Summary of results ………………………………………………………………38 2.5. Research on urban ecosystem services and disservices: Germany and South Africa ……………………...................................................................................…...39 2.5.1. Germany ……………………………………………………..……………………39 2.5.2. South Africa ………………………………………………………………….…...42 2.5.3. Summary of results ………………………………………………………………44 2.6. Research on ecosystem services and disservices from urban gardens with an emphasis on community gardens ……………………………………………………..45 2.6.1. Allotment gardens ………………………………………………………………..45 2.6.2. Home gardens ……………………………………………………………………47 2.6.3. Community gardens ………………………………………………………...…...48 2.6.4. Synthesis ………………………………………………………….………………50 2.7. Conclusions …………………………………………………..…………………….51 Chapter Three: Methods ……..………………………………………………….....…..53 3.1. Introduction ………………………………………………………………………….53 3.2. Case study analysis ………………………………………………………………..55 3.2.1. Case study design ………………………………..……………………………...55 3.2.2. Case study selection …………………………………...………………………..55 3.2.3. Case study methods ……………………………………..………………………56 3.3. Quantification of community garden share ………………………………….…..57 3.3.1. GIS methods ……………………………....……………………………………..57 3.4. Ecosystem services and disservices assessments …………………………….58 3.4.1. Indicator analysis ………………………………………………………………...58 3.4.2. Field protocol ……………………………………….....………………………….65 3.4.2.1. Site walkover procedure and field protocol checklist …………….………...66 3.4.3. Questionnaire …………………………………………………………………….67 3.5. Data-synthesis, -results and -conclusions …………....…………………………70 3.5.1. Quantitative data …………………………………………....……………………70 3.5.2. Qualitative data …………………………………………………………………..70 3.5.3. Burkhard-type matrices ………………………………………………………….71 3.6. Data reliability ………………………………...…………………………………….72 3.7. Data validity …………………………………………………………………………73 3.8. Ethical considerations ………………………………………….………………….73 3.9. Conclusions ……………………………………......……………………………….74 Chapter Four: Case Study Cities ………………………………….……….......……...75 4.1. Introduction …………………………...…………………………………………….75 4.2. Case study: Berlin ………………………..………………………………………...75 4.2.1. Geographical location and demographic set-up ……………………..……….75 4.2.2. Landscape and climate …………………….....………………………………...76 4.2.3. Administrative structure and governance …………………………...………...77 4.2.4. Socio-economic contextualisation …………………………………..………….78 4.2.5. Urban green …………………………………....………………………………...79 4.2.6. Urban gardening regulations ……………………………………….…………..80 4.3. Case study: Cape Town …………………………………………………………...81 4.3.1. Geographical location and demographic set-up …………………………..….81 4.3.2. Landscape and climate ……………………………..…………………………...82 4.3.3. Administrative structure and governance …………………………...………...84 4.3.4. Socio-economic contextualisation ……………………………………..……….85 4.3.5. Urban green ……………………………………....……………………………...85 4.3.6. Urban gardening regulations ……………………………….…………………..86 4.4. Conclusions ………………………..……………………………………………….87 Chapter Five: Results ………………………………………………………….………..88 5.1. Introduction ………………………………………………………………………….88 5.2. Community garden share ………………………………………………………….88 5.3. Ecosystem services assessments ……………………………………....……….92 5.3.1. Provisioning services …………………………………………………………….92 5.3.1.1. Food …………………………………………………………………....……….92 5.3.1.1.1. Crops ……………………………………………………….....……………...92 5.3.1.1.2. Livestock …………………………………………………….....…………….96 5.3.1.2. Raw materials ………………………………………………………......……...98 5.3.1.3. Fresh water supply ………………………………………………….…………99 5.3.1.4. Medicinal resources …………………………………………….....…………102 5.3.2. Regulating services ………………………...…………………………………..104 5.3.2.1. Local climate regulation ………………………………………………….….104 5.3.2.2. Local air quality regulation ……………………………………………….….109 5.3.2.3. Moderation of extreme events: rain and wind storms, flood prevention........................................................................................................…..112 5.3.2.4. Water flow regulation and runoff mitigation ……………....………………..114 5.3.2.5. Erosion prevention and maintenance of soil fertility ……………………...116 5.3.3. Habitat/Supporting services …………………………………..……………….118 5.3.3.1. Maintenance of genetic diversity ……………………………………………118 5.3.4. Cultural services ………………………………………………………………..128 5.3.4.1. Recreation and mental and physical health …………………....………….128 5.3.4.2. Tourism………………………………....……………………………………...131 5.3.4.3. Aesthetic appreciation and inspiration for culture, art, design …......……133 5.3.4.4. Spiritual experience and sense of place ……………………………...…...135 5.3.5. Discussion of major ecosystem services findings …………………..………138 5.4. Ecosystem disservices assessments ……………………...…………………...142 5.4.1. Ecological impacting disservices ……………………………….....………….142 5.4.1.1. Displacement of native by invasive species that cause harm …………...142 5.4.2. Economic impacting disservices …………………………………….………..145 5.4.2.1. Damage to infrastructure by nature ………………………….....………….145 5.4.2.2. Costs associated with repairs and maintenance of urban vegetation/nature ………...................................................................................................................146 5.4.3. Health impacting disservices ……………………………..…………………...148 5.4.3.1. Allergies/respiratory problems caused by the spread of pollen …….…...148 5.4.3.2. Wild or semi-wild animals in urban green spaces that cause anxiety over fear of attack, safety or inconvenience ……………………………………………...151 5.4.4. Psychological impacting disservices …………………………………………153 5.4.4.1. Certain smells, sounds or behaviours from people, plants and animals may be considered a nuisance or cause annoyance ………………………………........153 5.4.4.2. Aesthetic and hygiene impacts due to animal excrement …………….…155 5.4.4.3. Aesthetic unpleasantness due to dense/overgrown vegetation …………156 5.4.4.4. Psychological feelings of insecurity/fear associated with overgrown or dark urban green spaces ………….………………………………………………………..157 5.4.4.5. Vegetation blocking views ………………………………….....…………….159 5.4.5. General impacting disservices on human well-being ……………….……...161 5.4.5.1. Presence of protected species can restrict the uses of an area, hindering benefit of those seeking to enjoy nature ………………………….…………………161 5.4.6. Discussion of major ecosystem disservices findings ……………….………162 5.5. Final assessment of results using Burkhard-type matrices …………….…….165 5.5.1. Ecosystem services …………………………......……………………………..166 5.5.2. Ecosystem disservices ……………………………..………………………….168 5.5.3. Synthesis ………………………………………………………………………..169 5.6. Conclusions ………………………..……………………………………………...170 Chapter Six: Discussion…………….………………………………………………….172 6.1. Introduction ……………...………………………………………………………...172 6.2. Meeting objectives ……………………………………..…………………………172 6.2.1. Calculate the quantitative share of urban community gardens in Berlin and Cape Town ………................................................................................................173 6.2.2. Identify suitable sampling community gardens in Berlin and Cape Town from which to assess existing ecosystems services and disservices ………………….174 6.2.3. Identify and assess which ecosystems services and disservices are provided by the chosen sampling community gardens in Berlin and Cape Town …….…...175 6.2.4. Demonstrate the relevance and contribution of community gardens to sustainable urban development and the Great Transition ……..………………….176 6.3. Limitations of the study …………….....………………………………………….178 6.3.1 Methods …………………………………..………………………………………178 6.3.2. Field work ……………………………………………..…………………………179 6.4. Outlook …………………………………………………………………………….180 6.4.1. Implications for research ………………………………………..……………..180 6.4.2. Implications for policy and practice ………………………………………..….182 6.5. Conclusions …………………………………………..…………………………...184 Chapter Seven: Conclusions …………………………………………………..……..186 7.1. Summary of thesis …………………………………………………….………….186 7.2. General conclusions …………………………………………………….………..187 7.3 Final insights …………………………………………………...…………………..189 References ………………………………...…………………………………………...190 Appendices ……………………………………………………………………………..223 Appendix A – Comprehensive lists of ecosystem services and disservices indicators derived from the literature ……………….………………………………..223 Appendix B – Field Protocol: site walkover procedure (A) and field protocol checklist (B) ……………...............................................................................…….231 Appendix C – Questionnaire disseminated in this study .………………………….238 Appendix D – Additional information for results of ecosystem services and disservices assessments …….........................................................................…..251 Appendix E – Full calculations of final assessment scores used in Burkhard-type matrices ……………….....................................................................................….320
3

Ecosystem Services and Disservices in an Agriculture–Forest Mosaic : A Study of Forest and Tree Management and Landscape Transformation in Southwestern Ethiopia

Ango, Tola Gemechu January 2016 (has links)
The intertwined challenges of food insecurity, deforestation, and biodiversity loss remain perennial challenges in Ethiopia, despite increasing policy interventions. This thesis investigates smallholding farmers’ tree- and forest-based livelihoods and management practices, in the context of national development and conservation policies, and examines how these local management practices and policies transform the agriculture–forest mosaic landscapes of southwestern Ethiopia. The thesis is guided by a political ecology perspective, and focuses on an analytical framework of ecosystem services (ESs) and disservices (EDs). It uses a mixed research design with data from participatory field mapping, a tree ‘inventory’, interviews, focus group discussions, population censuses, and analysis of satellite images and aerial photos. The thesis presents four papers. Paper I investigates how smallholding farmers in an agriculture–forest mosaic landscape manage trees and forests in relation to a few selected ESs and EDs that they consider particularly beneficial or problematic. The farmers’ management practices were geared towards mitigating tree- and forest-related EDs such as wild mammal crop raiders, while at the same time augmenting ESs such as shaded coffee production, resulting in a restructuring of the agriculture–forest mosaic. Paper II builds further on the EDs introduced in paper I, to assess the effects of crop raids by forest-dwelling wild mammals on farmers’ livelihoods. The EDs of wild mammals and human–wildlife conflict are shown to constitute a problem that goes well beyond a narrow focus on yield loss. The paper illustrates the broader impacts of crop-raiding wild mammals on local agricultural and livelihood development (e.g. the effects on food security and children’s schooling), and how state forest and wildlife control and related conservation policy undermined farmers’ coping strategies. Paper III examines local forest-based livelihood sources and how smallholders’ access to forests is reduced by state transfer of forestland to private companies for coffee investment. This paper highlights how relatively small land areas appropriated for investment in relatively densely inhabited areas can harm the livelihoods of many farmers, and also negatively affect forest conservation. Paper IV investigates the patterns and drivers of forest cover change from 1958 to 2010. Between 1973 and 2010, 25% of the total forest was lost, and forest cover changes varied both spatially and temporally. State development and conservation policies spanning various political economies (feudal, socialist, and ‘free market-oriented’) directly or indirectly affected local ecosystem use, ecosystem management practices, and migration processes. These factors (policies, local practices, and migration) have thus together shaped the spatial patterns of forest cover change in the last 50 years. The thesis concludes that national development and conservation policies and the associated power relations and inequality have often undermined local livelihood security and forest conservation efforts. It also highlights how a conceptualization of a local ecosystem as a provider of both ESs and EDs can generate an understanding of local practices and decisions that shape development and conservation trajectories in mosaic landscapes. The thesis draws attention to the need to make development and conservation policies relevant and adaptable to local conditions as a means to promote local livelihood and food security, forest and biodiversity conservation, and ESs generated by agricultural mosaic landscapes. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 3: Submitted. Paper 4: Manuscript.</p>
4

Tolerance towards wildlife in the Atlantic forest: an empirical test across ecological contexts and mammal specie / Tolerância à fauna silvestre na Mata Atlântica: um teste empí­rico em diferentes contextos ecológicos e espécies de mamíferos

Teixeira, Lucas Manuel Cabral 03 July 2018 (has links)
Human-wildlife conflicts (HWC) emerge as complex conservation challenges impairing human livelihood and wildlife populations. Research on HWC, however, has traditionally approached these components apart and focused on single/ similar species, hampering a broader understanding of the connections between ecological drivers and human dimensions of conflicts. We here develop and test a model integrating ecological and human components of HWC, focusing on three species - opossum, crab-eating fox and puma. We investigated the pathways through which the ecological context (forest cover) affects experiences with wildlife (contact and damage), and how such experiences influence tolerance via beliefs, emotions and attitude. We interviewed 114 landowners across 13 landscapes varying in forest cover in a region of the Brazilian Atlantic forest and tested our model using Piecewise Structural Equation Modeling. We found that: i. forest cover negatively affected tolerance, but just towards the largest species; ii. relevance and effects of distinct experiences with wildlife on beliefs and emotions varied across species; iii. beliefs and emotions influenced tolerance, but negative emotions were relevant only for the largest species. Conflicts with larger species can then be understood as disservices provided by forests, indicating the relevance of framing HWC within a broader perspective that consider the trade-offs with ecosystems services. For some species, positive experiences with wildlife may counteract the negative effects of damages to livestock in shaping human behavior. Models such as ours - that structure relationships between ecological and human components - can help identifying deeper, more effective leverage points to improve interventions to mitigate HWC / Conflitos entre seres humanos e fauna silvestre emergem como desafios complexos, ameaçando o sustento de populações humanas e a conservação de populações de animais silvestres. Contudo, pesquisas sobre conflitos tradicionalmente abordam esses componentes separadamente e focam em espécies individuais ou similares, dificultando o entendimento mais amplo das conexões entre determinantes ecológicos e dimensões humanas dos conflitos. Neste estudo, desenvolvemos e testamos um modelo conceitual integrando componentes ecológicos e humanos dos conflitos, focando em três espécies - gambá, cachorro-do-mato e onça-parda. Investigamos os caminhos através dos quais o contexto ecológico (cobertura florestal) afeta experiências (contato e dano), e como tais experiências influenciam a tolerância à fauna por meio de crenças, emoções e atitude. Entrevistamos 114 proprietários rurais em 13 paisagens com diferentes proporções de cobertura florestal em uma região da Mata Atlântica e testamos nosso modelo usando equações estruturais do tipo Piecewise. Encontramos que: i. a cobertura florestal afetou negativamente a tolerância, mas apenas para a maior espécie; ii. a importância e os efeitos de diferentes experiências com a fauna sobre crenças e emoções variaram entre as espécies; iii. crenças e emoções influenciaram a tolerância, mas emoções negativas foram relevantes apenas para a maior espécie. Conflitos com espécies maiores podem então ser entendidos como desserviços providos por florestas, indicando a relevância de inserir os conflitos humano-fauna em perspectiva mais ampla, que considere as relações com serviços ecossistêmicos. Para algumas espécies, experiências positivas podem compensar os efeitos negativos dos danos a criações na formação do comportamento humano. Modelos como o nosso - que estruturem as relações entre os componentes ecológicos e humanos - podem ajudar a identificar pontos de alavancagem mais profundos e efetivos para melhorar intervenções visando a mitigação dos conflitos com a fauna
5

Tolerance towards wildlife in the Atlantic forest: an empirical test across ecological contexts and mammal specie / Tolerância à fauna silvestre na Mata Atlântica: um teste empí­rico em diferentes contextos ecológicos e espécies de mamíferos

Lucas Manuel Cabral Teixeira 03 July 2018 (has links)
Human-wildlife conflicts (HWC) emerge as complex conservation challenges impairing human livelihood and wildlife populations. Research on HWC, however, has traditionally approached these components apart and focused on single/ similar species, hampering a broader understanding of the connections between ecological drivers and human dimensions of conflicts. We here develop and test a model integrating ecological and human components of HWC, focusing on three species - opossum, crab-eating fox and puma. We investigated the pathways through which the ecological context (forest cover) affects experiences with wildlife (contact and damage), and how such experiences influence tolerance via beliefs, emotions and attitude. We interviewed 114 landowners across 13 landscapes varying in forest cover in a region of the Brazilian Atlantic forest and tested our model using Piecewise Structural Equation Modeling. We found that: i. forest cover negatively affected tolerance, but just towards the largest species; ii. relevance and effects of distinct experiences with wildlife on beliefs and emotions varied across species; iii. beliefs and emotions influenced tolerance, but negative emotions were relevant only for the largest species. Conflicts with larger species can then be understood as disservices provided by forests, indicating the relevance of framing HWC within a broader perspective that consider the trade-offs with ecosystems services. For some species, positive experiences with wildlife may counteract the negative effects of damages to livestock in shaping human behavior. Models such as ours - that structure relationships between ecological and human components - can help identifying deeper, more effective leverage points to improve interventions to mitigate HWC / Conflitos entre seres humanos e fauna silvestre emergem como desafios complexos, ameaçando o sustento de populações humanas e a conservação de populações de animais silvestres. Contudo, pesquisas sobre conflitos tradicionalmente abordam esses componentes separadamente e focam em espécies individuais ou similares, dificultando o entendimento mais amplo das conexões entre determinantes ecológicos e dimensões humanas dos conflitos. Neste estudo, desenvolvemos e testamos um modelo conceitual integrando componentes ecológicos e humanos dos conflitos, focando em três espécies - gambá, cachorro-do-mato e onça-parda. Investigamos os caminhos através dos quais o contexto ecológico (cobertura florestal) afeta experiências (contato e dano), e como tais experiências influenciam a tolerância à fauna por meio de crenças, emoções e atitude. Entrevistamos 114 proprietários rurais em 13 paisagens com diferentes proporções de cobertura florestal em uma região da Mata Atlântica e testamos nosso modelo usando equações estruturais do tipo Piecewise. Encontramos que: i. a cobertura florestal afetou negativamente a tolerância, mas apenas para a maior espécie; ii. a importância e os efeitos de diferentes experiências com a fauna sobre crenças e emoções variaram entre as espécies; iii. crenças e emoções influenciaram a tolerância, mas emoções negativas foram relevantes apenas para a maior espécie. Conflitos com espécies maiores podem então ser entendidos como desserviços providos por florestas, indicando a relevância de inserir os conflitos humano-fauna em perspectiva mais ampla, que considere as relações com serviços ecossistêmicos. Para algumas espécies, experiências positivas podem compensar os efeitos negativos dos danos a criações na formação do comportamento humano. Modelos como o nosso - que estruturem as relações entre os componentes ecológicos e humanos - podem ajudar a identificar pontos de alavancagem mais profundos e efetivos para melhorar intervenções visando a mitigação dos conflitos com a fauna
6

How vertebrate communities affect quality and yield of macadamia farms in Levubu, South Africa

Linden, Valerie M. G. 15 May 2019 (has links)
PhD (Zoology) / Department of Zoology / Ecosystem services and disservices are important features in agro-ecosystems and both can have relevant economic impacts on farmers. While there has been much research on the value of ecosystem services, especially that of pest control by bats and birds, ecosystem disservices are often overlooked or estimated separately. Both, services and disservices, however, change with landscape and may be supported by natural vegetation. It is hence inevitable to assess them together to uncover their relative value and importance. Habitat loss and fragmentation are major threats to biodiversity and ecosystem services. Agricultural intensification can cause habitat loss and can negatively affect natural ecosystems and their services. However, the removal of natural vegetation can also reduce ecosystem disservices that origin from natural areas. This study focused on the economic trade-off between biocontrol by bats and birds and crop raiding by vervet monkeys in South African macadamia orchards, using vertebrate exclusion experiments. Crop quality and yield were assessed and extrapolated to income values. The study furthermore focused in more detail on the impact of orchard edge habitat and farm management on bats as ecosystem service providers as well as the arthropod community, which can provide both services (pollination, biocontrol) as well as disservices (crop damage). The macadamia industry is highly profitable and plantings are expanding worldwide. South Africa is currently the largest macadamia producer in the world and the study area, Levubu, holds some of the oldest macadamia plantings in the country. The subtropical climate and high annual rainfall make this area an intensively farmed landscape. Levubu lies at the foothills of the Soutpansberg, a centre of biodiversity and patches of natural vegetation wind through orchards of macadamia, avocado, banana and timber. Insect pest pressure is high in the macadamia industry, with several stink bug species (Hemiptera) and two moth species (Lepidoptera) accounting for most of the damage to the crop. Chapter One provides a detailed overlook over the South African macadamia industry, describes the major pest insect species and their impact on the crop and highlights the role of ecosystem services and disservices and the potential importance of remaining natural areas. Over three consecutive seasons, between September 2015 and May 2018, bats, birds and monkeys were excluded, using cages with nets, from a total of 96 macadamia trees. Four treatments were applied (Full, Day, Night, Control) to distinguish between effects of the different functional groups. Exclusions took place at orchard edges with natural or human-modified edge habitat to assess the impact of vicinity to natural vegetation on pest control and crop raiding. Results presented in Chapter Two showed that biocontrol by bats and birds was stronger near natural vegetation and significantly impacted crop quality as well as yield. Effects of bats and birds were still significant at human-modified edges, whereas crop raiding by monkeys is limited to the natural orchard edges. The economic impact analysis shows that the benefits of biocontrol through bats and birds outweighed the income losses due to crop-raiding monkeys. The value of bats and birds was as high as USD 5000 per hectare per year through prevented insect damage and a 60% crop increase. Crop-raiding affected the yield, which dropped by about 26% and resulted in losses of about USD 1500 per hectare. These results highlight the importance of integrating natural areas into agricultural landscapes, even if they incur the risk of being disadvantageous. Farmers need to be made aware of the enormous economic benefits. Effective crop raiding mitigation strategies still need to be researched to avoid negative association with natural areas. These can, however, possibly also limit access for biocntrol agents, like bats and birds and thereby reduce their economic impact. Especially the removal of natural areas or establishment of buffer zones of unpalatable crops between agricultural land and forests is not advisable. Integrative research in agro-ecosystems on trade-offs between a variety of ecosystem services and disservices is necessary in future, rather than assessing them separately. The bat community on macadamia farms was monitored monthly and compared between orchard edges. Stationary bat detectors were placed at each set of exclosures for two consecutive nights a month, automatically recording from sunset to sunrise. Recorded bat calls were identified manually to species level and activity converted to Miller’s activity index, which counts the number of active minutes per species per night. We analysed the activity per feeding guild over season and landscape setting, estimated species richness and diversity (Hill’s numbers) and species turnover between farms, season and landscape setting, using diversity partitioning. The bat community was mostly influenced by seasonality with season turn-over accounting for 21% of total bat diversity (21.25 species). Edge habitat on the other hand only accounted for 5%. We found higher species richness and activity in the high season compared to the low. While there was no difference in diversity in the high season between the two orchard edge types, species diversity at the human-modified edge was lower than in the natural during the low season. Natural habitat might therefore be more important in the low season, while its effect is overwritten by high food availability during the high season. Clutter-edge species furthermore were more active at the natural orchard edges than open-air feeders, which were in turn more active at human-modified edges. Both activities dropped significantly during the low season. Chapter Three concludes that the macadamia landscape is able to support a high bat species diversity, which is affected by seasonal differences, probably due to food availability. Natural areas are important to be maintained to support sensitive species, relying on clutter habitat and natural roosts. Habitat features as well as farm management can also influence arthropod communities. Visual observations took place each month for 20 minutes per tree. Observations were counted and identified to at least order level. Chapter Four concentrates on the impact of orchard edge habitat and insecticide treatment on honey bees (83% of Hymenoptera observations) abundance. Honey bees were the only taxon significantly responding to both variables, with higher abundance close to natural areas and increasing abundance with increasing time since pesticide application. Honey bees furthermore seemed to recover slightly quicker from population crashes after insecticide treatments at natural edges than they did at human-modified edges. Hymenoptera can be highly beneficial to macadamia farmers, as farmers are heavily relying on pollination by honey bees and parasitoids are known to feed on major macadamia pest insect species. These ecosystem service providers were mostly affected by habitat and management practices, which may compromise their ecosystem service provision. Although commercial bee hives are exposed throughout macadamia orchards, they do not appear to fully replace the pollination and biocontrol services provided by feral species, which can be enhanced through resource supplementation by patches of nearby natural vegetation. Chapter Five concludes with emphasizing the general importance of natural vegetation in landscape planning of agricultural areas. This study proved confidently that benefits through ecosystem services largely outweigh negative impacts of ecosystem disservices, both stemming from these natural areas. Through the inclusion, maintenance and restoration of such patches of natural vegetation, farmers can potentially increase the value and effectiveness of biocontrol by bats and birds or other services. Seasonality largely determined bat species diversity, and a general high species diversity was observed in the macadamia landscape, possibly due to a certain degree of landscape heterogeneity and high food availability. Activity patterns of clutter-edge and open-air feeding bats varied with edge habitat, while clutter-dependent bat species / NRF

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