Fragmentqualität prägt Waldregeneration eher als Matrixhabitat in einer südafrikanischen Mosaikwaldlandschaft

Land-use change and agricultural intensification are responsible for a global decline of forest cover entailing the fragmentation of forests. Landscapes are increasingly shaped by a mosaic of forest fragments within variable matrix habitat. It is thus essential to understand how these habitat alterations influence function and stability of forest ecosystems. However, the complex relationships between anthropogenic disturbance of forests, concurrent species loss and ecosystem functions are not fully clarified yet. In the present thesis, I investigated the impact of structural forest fragment quality and variable matrix habitat on biodiversity and ecological processes of forest regeneration. For this purpose, I conducted three studies in a fragmented mosaic-forest landscape in KwaZulu-Natal, South Africa. In particular, I assessed (1) seed predation by rodents, (2) establishment of woody seedlings and saplings, and (3) leaf damage on woody seedlings and saplings by insects and pathogens in 24 study plots in scarp forest fragments. These fragments were embedded in four variable matrices: two natural, heterogenous (forest, grassland) and two modified, homogenous matrices (eucalypt plantations, sugarcane fields). In the first field study I assessed rodent diversity and conducted seed predation experiments. As a measure for forest fragment quality important for rodents, I estimated herbal ground vegetation cover. For the second study I identified all trees on 500 m², seedlings on 10 m² and saplings on 50 m² per study plot. I categorized trees, seedlings and saplings as either early- or late-successional species. Moreover, I differentiated between seedlings and saplings of external and local origin depending on the presence of conspecific adult tress within fragments to be able to identify potential seed influx by seed dispersers. Additionally, I measured canopy cover, light intensity and vegetation complexity as parameters of forest fragment quality relevant to seedling establishment. In the third study I used beating samples to collect the arthropod community. Furthermore, I estimated proportions of leaf damage by insect herbivory and leaf pathogens on woody seedlings and saplings. I determined tree diversity, canopy cover and vegetation complexity in terms of forest fragment quality. My investigations showed an increase of rodents and seed predation in small forest fragments, potentially caused by enhanced ground vegetation cover. Especially in fragments with sugarcane matrix rodent abundance and seed predation were significantly higher than in fragments with forest matrix. Further, I found reduced seedling and sapling establishment in forest fragments with modified homogenous surroundings. In particular, these fragments consisted of less late-successional species. This could predominantly be ascribed to reduced canopy cover and increased light intensity. However, seed influx occurred in all forest fragments indicating high matrix permeability for seed dispersers. Moreover, forest fragment quality amplified arthropod predator abundance and reduced arthropod herbivore abundance. Fragment quality effects on herbivory were variable. This mismatch might be related to weak trophic interactions. Matrix habitat had merely marginal effects on the investigated factors. Overall, my results illustrate that forest fragment quality as well as matrix habitat have the potential to alter biodiversity and ecological processes of forest regeneration, but effects on the observed processes differed in strength. Yet, I generally found that forest fragment quality appears to be of high relevance for regeneration, indicating its potential for conservation management of the remaining fragments. Further, the rather weak overall effects of matrix habitat indicate a comparable and generally high permeability for the investigated groups of species. This emphasizes the significant value of forest fragments for the connectivity of remaining forests and the conservation of biodiversity and ecological processes at a landscape scale. Nevertheless, conclusions have to be treated with care. Due to the historical natural fragmentation of scarp forests in KwaZulu-Natal, which might have caused a higher robustness of species towards human-induced fragmentation, my findings might not be transferable to other regions. The scarp forest fragments are characterized by high habitat quality for the different species groups. However, potential shifts in the plant community from late- to early-successional species in fragments enclosed by modified matrices might entail unforeseen cascading effects and negative feedback loops within the ecosystem that still need to be examined. Thus, the value of natural forest as a source of propagules and as habitat for forest specialists remains indisputable.Weltweit werden Wälder in alarmierender Geschwindigkeit zerstört und fragmentiert. Landschaften bestehen zunehmend aus Mosaiken mit Waldfragmenten in variablem Matrixhabitat. Es ist daher essentiell zu verstehen, inwiefern diese Habitatveränderungen Funktion und Stabilität von Waldökosystemen beeinflussen. Die komplexen Zusammenhänge zwischen anthropogener Störung von Wäldern, Artenverlust und Ökosystemfunktionen sind jedoch noch nicht hinreichend geklärt. In der vorliegenden Arbeit untersuchte ich den Einfluss von Waldfragmentqualität und Matrixhabitat auf Biodiversität und ökologische Prozesse der Waldregeneration. Ich führte drei Studien in einer fragmentierten Waldlandschaft in KwaZulu-Natal, Südafrika durch. Ich erfasste 1) Samenprädation durch Nager, 2) Etablierung von Baumkeimlingen und -schösslingen sowie 3) Blattschäden an Baumkeimlingen und -schösslingen durch Insekten und Pathogene auf 24 Untersuchungsflächen in Fragmenten so genannter Hangwälder („scarp forests“). Die Waldfragmente waren von vier verschiedenen Matrixhabitaten umgeben: Zwei natürliche, heterogene (Wald, Grassland) und zwei modifizierte, homogene Matrices (Eukalyptus-Plantagen, Zuckerrohrfelder). Für die erste Studie nahm ich die Nagerdiversität auf und führte Samenprädationsexperimente durch. Zudem schätzte ich als Maß für die Fragmentqualität die Bodenbedeckung durch krautige Pflanzen. Für die zweite Studie bestimmte ich die Diversität der Bäume auf 500 m² pro Fläche, die der Keimlinge auf 10 m² und die der Schösslinge auf 50 m². Ich unterteilte Bäume, Keimlinge und Schösslinge in Pionier- und Klimaxarten. Des Weiteren differenzierte ich zwischen Keimlingen und Schösslingen mit externer und lokaler Herkunft, abhängig von der Präsenz artgleicher Bäume im Fragment, um so auf eventuellen Sameneintrag durch Samenausbreiter rückschließen zu können. Außerdem nahm ich Kronenbedeckung, Lichtintensität und Vegetationskomplexität als Parameter der Fragmentqualität auf. Für die dritte Studie ermittelte ich mit einem Klopfschirm die Arthropoden-Gemeinschaft. Zusätzlich schätzte ich den Blattschaden durch Insektenherbivorie und Pathogenbefall an Baumkeimlingen und -schösslingen. Bezüglich der Fragmentqualität nahm ich Baumdiversität, Kronenbedeckung und Vegetationskomplexität auf. Meine Untersuchungen deuteten auf ein erhöhtes Nagervorkommen und verstärkte Samenprädation in kleinen Fragmenten hin, was vermutlich mit der höheren krautigen Bodenbedeckung zusammenhing. Speziell in Fragmenten im Zuckerrohr waren Nagervorkommen und Samenprädation signifikant höher als in Fragmenten mit Waldmatrix. Ferner konnte ich eine reduzierte Keimlings- und Schösslingsetablierung in den Waldfragmenten mit modifizierten Matrices feststellen. Es kam außerdem zu einer Verringerung von Klimaxarten in diesen Fragmenten. Dies wurde hauptsächlich durch abnehmende Kronenbedeckung und erhöhte Lichtintensität bedingt. Jedoch fand Sameneintrag in allen Waldfragmenten statt, was auf die Matrixdurchlässigkeit für Samenausbreiter hindeutete. Des Weiteren kam es zu einem Anstieg an Arhtropoden-Prädatoren und einem Rückgang an Arhtropoden-Herbivoren mit zunehmender Fragmentqualität. Der Einfluss der Fragmentqualität auf Herbivorie war variabel. Diese Abweichungen könnten mit schwachen trophischen Interaktionen zusammenhängen. Das Matrixhabitat hatte nur marginale Effekte auf die untersuchten Faktoren. Insgesamt zeigen meine Ergebnisse, dass Waldfragmentqualität und Matrixhabitat Biodiversität und ökologische Prozesse der Waldregeneration beeinflussen, jedoch waren die Effekte dabei unterschiedlich. Generell schien die Fragmentqualität jedoch eine wichtige Bedeutung für die Regeneration zu haben, was ihr Potential für den Naturschutz hervorhebt. Ferner lassen die schwachen Effekte der variablen Matrices in unserem Untersuchungsgebiet eine vergleichbar hohe Durchlässigkeit für die untersuchten Artengruppen erkennen. Das unterstreicht den Wert der Waldfragmente als Habitatinseln in modifizierten Landschaften und für den Erhalt von Biodiversität und ökologischen Prozessen auf der Landschaftsebene. Nichtsdestotrotz ist bei der Verallgemeinerung der Aussagen Vorsicht angebracht. Aufgrund der historischen, natürlichen Fragmentierung der Hangwälder, die zu einer hohen Robustheit der Artengruppen gegenüber menschlich verursachter Fragmentierung beigetragen haben könnte, sind die Ergebnisse eventuell nur eingeschränkt auf andere Regionen übertragbar. Die Fragmente zeichnen sich zwar durch ihre hohe Habitatqualität für verschiedene Artengruppen aus, jedoch könnten die Verschiebungen in den Pflanzengemeinschaften von Klimax- zu Pionierarten in Fragmenten mit modifizierten Matrices unvorhersehbare Kaskadeneffekte mit sich bringen. Das macht den Erhalt von großen zusammenhängenden Wäldern als Quelle für Klimaxarten und Habitat für spezialisierte Arten unerlässlich

Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this would lead to: (i) improvement of the ecological integrity, (ii) reduction of biodiversity loss, and (iii) faster achievement of objectives of legislative requirements, e.g., the European Water Framework Directive

Untangling the motivations of different stakeholders for urban greenspace conservation in sub-Saharan Africa

Urban expansion is threatening ecosystem service delivery, especially in sub-Saharan Africa where urbanisation rates are among the fastest globally. Greenspaces offer opportunities to prioritise ecosystem services for city residents. However, the success of greenspace conservation is more often driven by their acceptability to a range of stakeholders than by scientific evidence, highlighting the need to acknowledge multiple perspectives when implementing greenspace conservation activities. We used the Q-methodology to describe and compare the viewpoints of three stakeholder categories for the services and disservices provided by greenspaces in two fast-growing Ghanaian cities. Ecosystem services were generally valued, however there was strong heterogeneity in viewpoints among respondents. The main concerns included regulating services, heritage aspects and contributions to economic development. Comparisons between viewpoints revealed both substantial differences between stakeholder categories and consensus around specific ecosystem services. Recognising shared viewpoints and areas of disagreement may increase the acceptability of greenspace implementation measures. Furthermore, addressing the disservices brought about via greenspace degradation is crucial. Our study shows that, in fast-growing cities in Ghana, a forerunner of urban development in Sub-Saharan Africa, specific ecosystem services such as shade provision, play a pivotal role in promoting greenspace conservation

What determines how we see nature? Perceptions of naturalness in designed urban green spaces

1. The multiple benefits of ‘nature’ for human health and well-being have been documented at an increasing rate over the past 30 years. A growing body of research also demonstrates the positive well-being benefits of nature-connectedness. There is, however, a lack of evidence about how people's subjective nature experience relates to deliberately designed and managed urban green infrastructure (GI) with definable ‘objective’ characteristics such as vegetation type, structure and density. Our study addresses this gap.2. Site users (n = 1411) were invited to walk through woodland, shrub and herbaceous planting at three distinctive levels of planting structure at 31 sites throughout England, whilst participating in a self-guided questionnaire survey assessing reactions to aesthetics, perceived plant and invertebrate biodiversity, restorative effect, nature-connectedness and socio-demographic characteristics.3. There was a significant positive relationship between perceived naturalness and planting structure. Perceived naturalness was also positively related to the perceived plant and invertebrate biodiversity value, participants’ aesthetic appreciation and the self-reported restorative effect of the planting. A negative relationship was recorded between perceived naturalness and perceived tidiness and care. Our findings showed that participants perceived ‘naturalness’ as biodiverse, attractive and restorative, but not necessarily tidy. Perceived naturalness was also related to participants’ educational qualifications, gender and nature-connectedness, with women and more nature-connected participants perceiving significantly greater levels of naturalness in the planting.4. These findings are highly significant for policymakers and built environment professionals throughout the world aiming to design, manage and fund urban GI to achieve positive human health and biodiversity outcomes. This applies particularly under austerity approaches to managing urban green spaces where local authorities have experienced cuts in funding and must prioritise and justify GI maintenance practices and regimes

Unpacking Stakeholder Perceptions of the Benefits and Challenges Associated With Urban Greenspaces in Sub-Saharan Africa

Urban greenspaces underpin ecosystem service provision in cities and are therefore indispensable for human well-being. Nevertheless, they are increasingly disappearing from cities in Sub-Saharan Africa. Understanding how the stakeholders influencing urban greenspace management perceive the benefits provided by urban greenspaces and the challenges to its conservation and management is critical for reversing this trend. Using Malawi’s capital city, Lilongwe, as a case study, we conducted 44 semi-structured interviews to explore the profiles and perceptions of stakeholders who currently hold influence over greenspace planning, conservation and management. Stakeholders with influence over urban greenspace management described the main focus of their organisation as relating to urban planning, natural resources protection and management, development work, or the hospitality business sector. Critically, only a third of all stakeholders focused on natural resources protection and management. Stakeholders had nuanced and varied appreciations of the benefits that greenspaces provide. Regulation and maintenance ecosystem services, as well as cultural services were frequently mentioned. However, provisioning services were mostly mentioned by those in development work. Stakeholders also identified an additional suite of societal benefits that do not directly map onto ecosystem service frameworks, such as the generation of financial income and the provision of employment opportunities. Challenges identified as hampering the planning, conservation and management of greenspaces included inappropriate urbanisation, lack of coordination and participation, and population growth. Lack of coordination was however not widely acknowledged among those focusing on natural resources protection, who conversely identified population growth more often than any other groups. Highlighting how stakeholders with varying priorities perceive ecosystem services a first step towards improving greenspaces management both for their better acceptation and for improving their potential for biodiversity conservation. Specifically, we bring attention to need for stakeholders working with natural resources protection to recognise more the need for collaborations and engagement. Additional research is also necessary to understand how those different perspectives might be integrated into ongoing processes and procedures to manage greenspaces in Sub-Saharan Africa

Review of the Mental Health and Well-being Benefits of Biodiversity

Little is known about the contribution that biodiversity has on mental health and well-being. To date, only one systematic review has investigated the health and well-being benefits from contact with biodiversity (Lovell et al. J Toxicol Environ Health B Crit Rev 17(1):1–20, 2014). The number of research studies investigating the health and well-being effects of biodiversity has increased since this publication. Here, we provide an update, focusing on the impact of biodiversity on mental health and well-being. Our objectives are to: (i) identify and describe the literature published after 2012; and (ii) synthesise all results from Lovell et al. (J Toxicol Environ Health B Crit Rev 17(1):1–20, 2014) and the more recently published literature to assess whether biodiversity influences mental health and well-being. Sixteen recently published studies met the inclusion criteria. The literature is varied with different study designs, measures of biodiversity, mental health and well-being. The synthesis of results was drawn from 24 studies: nine from Lovell et al. (J Toxicol Environ Health B Crit Rev 17(1):1–20, 2014) and 15 identified by this chapter. There is some evidence to suggest that biodiversity promotes better mental health and well-being. However, more studies reported non-significant results. The evidence is not yet of the extent necessary to characterise the role of biodiversity in relation to mental health or well-being. Future interdisciplinary research directions are discussed

Biodiversity and health in the urban environment

Biodiversity underpins urban ecosystem functions that are essential for human health and well-being. Understanding how biodiversity relates to human health is a developing frontier for science, policy and practice. This article describes the beneficial, as well as harmful, aspects of biodiversity to human health in urban environments. Recent research shows that contact with biodiversity of natural environments within towns and cities can be both positive and negative to human physical, mental and social health and well-being. For example, while viruses or pollen can be seriously harmful to human health, biodiverse ecosystems can promote positive health and well-being. On balance, these influences are positive. As biodiversity is declining at an unprecedented rate, research suggests that its loss could threaten the quality of life of all humans. A key research gap is to understand-and evidence-the specific causal pathways through which biodiversity affects human health. A mechanistic understanding of pathways linking biodiversity to human health can facilitate the application of nature-based solutions in public health and influence policy. Research integration as well as cross-sector urban policy and planning development should harness opportunities to better identify linkages between biodiversity, climate and human health. Given its importance for human health, urban biodiversity conservation should be considered as public health investment

What is urban nature and how do we perceive it?

This chapter discusses the complexities and apparent contradictions in defining ‘nature’ and ‘urban nature’ in the context of human-nature interactions. It explains why urban nature is so important to human health and well-being at this point in the twenty first century, focusing particularly on why considering nature perception is crucial if we are to plan, design and manage urban nature to prioritise people’s aesthetic appreciation, health and well-being. Nature-perceptions are then framed in relation to diversity in nature: the role of varying biodiversity, perceived biodiversity and different aesthetics of nature (specifically flowering and colour , structure and care). The significance of varying socio-cultural and geographical contextual factors in nature perception is then highlighted. The chapter closes by addressing implications for policy and practice and future research directions in relation to urban nature perception . The author draws extensively from her own and related research

"Beratung" als eine zusätzliche Kompetenz für Erwachsenenbildner-/innen? Evaluation einer Fortbildung

Beratung ist erneut in das Zentrum theoretischer Diskurse der Erwachsenenbildung gerückt, seitdem unter dem Stichwort "Selbstorganisiertes Lernen" darüber nachgedacht wird, wie subjektive Lernzugänge und -prozesse begleitet werden können. Der gesellschaftliche Strukturwandel, bedingt durch die technologische Entwicklung und die fortschreitende Globalisierung, stellt Ausbildung und Weiterbildung vor neue Aufgaben: sie müssen verstärkt auf die sich ausdifferenzierenden Lebensläufe und Berufsbiographien eingehen. Weiterbildungs- und Lernberatung werden damit zur unabdingbaren professionellen Begleitung, wenn es um die berufliche und/oder persönliche Weiterentwicklung bzw. Umorientierung geht. Dieser Beitrag stellt zentrale Ergebnisse der Evaluation einer Zertifikatsfortbildung "Beratung in Arbeits-, Lehr- und Lernsituationen" des Deutschen Instituts für Erwachsenenbildung (DIE) dar. (DIPF/Orig.

Fragment quality rather than matrix habitat shapes forest regeneration in a South African mosaic-forest landscape

Land-use change and agricultural intensification are responsible for a global decline of forest cover entailing the fragmentation of forests. Landscapes are increasingly shaped by a mosaic of forest fragments within variable matrix habitat. It is thus essential to understand how these habitat alterations influence function and stability of forest ecosystems. However, the complex relationships between anthropogenic disturbance of forests, concurrent species loss and ecosystem functions are not fully clarified yet. In the present thesis, I investigated the impact of structural forest fragment quality and variable matrix habitat on biodiversity and ecological processes of forest regeneration. For this purpose, I conducted three studies in a fragmented mosaic-forest landscape in KwaZulu-Natal, South Africa. In particular, I assessed (1) seed predation by rodents, (2) establishment of woody seedlings and saplings, and (3) leaf damage on woody seedlings and saplings by insects and pathogens in 24 study plots in scarp forest fragments. These fragments were embedded in four variable matrices: two natural, heterogenous (forest, grassland) and two modified, homogenous matrices (eucalypt plantations, sugarcane fields). In the first field study I assessed rodent diversity and conducted seed predation experiments. As a measure for forest fragment quality important for rodents, I estimated herbal ground vegetation cover. For the second study I identified all trees on 500 m², seedlings on 10 m² and saplings on 50 m² per study plot. I categorized trees, seedlings and saplings as either early- or late-successional species. Moreover, I differentiated between seedlings and saplings of external and local origin depending on the presence of conspecific adult tress within fragments to be able to identify potential seed influx by seed dispersers. Additionally, I measured canopy cover, light intensity and vegetation complexity as parameters of forest fragment quality relevant to seedling establishment. In the third study I used beating samples to collect the arthropod community. Furthermore, I estimated proportions of leaf damage by insect herbivory and leaf pathogens on woody seedlings and saplings. I determined tree diversity, canopy cover and vegetation complexity in terms of forest fragment quality. My investigations showed an increase of rodents and seed predation in small forest fragments, potentially caused by enhanced ground vegetation cover. Especially in fragments with sugarcane matrix rodent abundance and seed predation were significantly higher than in fragments with forest matrix. Further, I found reduced seedling and sapling establishment in forest fragments with modified homogenous surroundings. In particular, these fragments consisted of less late-successional species. This could predominantly be ascribed to reduced canopy cover and increased light intensity. However, seed influx occurred in all forest fragments indicating high matrix permeability for seed dispersers. Moreover, forest fragment quality amplified arthropod predator abundance and reduced arthropod herbivore abundance. Fragment quality effects on herbivory were variable. This mismatch might be related to weak trophic interactions. Matrix habitat had merely marginal effects on the investigated factors. Overall, my results illustrate that forest fragment quality as well as matrix habitat have the potential to alter biodiversity and ecological processes of forest regeneration, but effects on the observed processes differed in strength. Yet, I generally found that forest fragment quality appears to be of high relevance for regeneration, indicating its potential for conservation management of the remaining fragments. Further, the rather weak overall effects of matrix habitat indicate a comparable and generally high permeability for the investigated groups of species. This emphasizes the significant value of forest fragments for the connectivity of remaining forests and the conservation of biodiversity and ecological processes at a landscape scale. Nevertheless, conclusions have to be treated with care. Due to the historical natural fragmentation of scarp forests in KwaZulu-Natal, which might have caused a higher robustness of species towards human-induced fragmentation, my findings might not be transferable to other regions. The scarp forest fragments are characterized by high habitat quality for the different species groups. However, potential shifts in the plant community from late- to early-successional species in fragments enclosed by modified matrices might entail unforeseen cascading effects and negative feedback loops within the ecosystem that still need to be examined. Thus, the value of natural forest as a source of propagules and as habitat for forest specialists remains indisputable