Impact of rubber tree dominated land-use on biodiversity and ecosystem services in the Greater Mekong Subregion

Die vorliegende Dissertation analysiert den Einfluss von steigendem Kautschukanbau (Hevea brasiliensis) hinsichtlich Biodiversität und Ökosystemdienstleistungen (ÖSD) in der Greater Mekong Subregion. Kautschukplantagen beeinflussen die Bereitstellung verschiedener Ökosystemdienstleistungen wie Kohlenstoffspeicherung, Wasserverfügbarkeit und qualität und beeinträchtigt die Biodiversität. Um diese Einflüsse zu untersuchen war die erste Aufgabe die Erstellung eines Überblicks über Veröffentlichungen bezüglich ÖSD und Biodiversität in Kautschuk-Anbaugebieten. Die Literaturübersicht zeigte, dass die Mehrzahl der Publikationen nur eine einzige oder sehr wenige ÖSD behandelt. Dies entspricht nicht den Anforderungen von Entscheidungsträgern, die für fundierte Entscheidungen hinsichtlich Landnutzungsplanung oder die Entwicklung von Zahlungen für ÖSD ein holistisches Bild brauchen, das mehrere ÖSD simultan betrachtet. Um einen Beitrag zu einer holistischeren Sichtweise zu leisten, war die zweite Aufgabe die Analyse des Einflusses von Kautschuk auf die ÖSD Kohlenstoffspeicherung, Bodenerosion, Wasserverfügbarkeit und -qualität, sowie Einkommen und Existenzsicherung. Obwohl es bezüglich der Kohlenstoffbindung in verschiedenen Landnutzungsformen noch große Unsicherheiten gibt, verdichten sich die Hinweise darauf, dass in Kautschukplantagen weniger Kohlenstoff gespeichert ist, als in natürlichen Wäldern. Das Risiko von Erodibilität von Böden in Kautschukanlagen ist im Vergleich zu natürlichen Wäldern höher. Der lokale und regionale Wasserkreislauf wird von Kautschukplantagen ebenfalls beeinflusst. Die Wasserqualität für Menschen und wasserlebende Organismen wird ebenfalls beeinträchtigt. Zweifelsfrei hat die Einführung von Kautschuk eine signifikante Steigerung des Farmeinkommens bewirkt. Allerdings legen sich die Bauern mit der Kautschukproduktion auf Jahrzehnte fest und sind somit abhängig von einer einzelnen Kultur. Weitere ökologische Gefahren bestehen durch Pflanzenkrankheiten und schädlinge, ungünstige Witterung oder Klimaveränderung. Die Auswertung der Studien zeigte deutlich, dass der zunehmende Kautschukanbau in der GMS von verschiedenen Problemen und Bedrohungen für die Bauern und die Umwelt begleitet wird. Die Entwicklung von nachhaltigen Landnutzungskonzepten ist daher unabdingbar. Aufgrund der beschriebenen Ergebnisse basieren Vorschläge für eine nachhaltigere Landnutzung auf Diversifizierung der Plantagen und die Wiederaufforstungen von Wäldern, beides erfordert aber ökonomische Anreize für die Bauern. Ein weiterer Teil der Dissertation behandelt die Entwicklung eines Biodiversitäts-Indikators, der in bestehenden Biodiversitätsmodellen verwendet werden kann. Unser Datensatz umfasste Flora, Vertebraten und Invertebraten. Der resultierende Indikator wurde als Eingabe in ein bestehendes Modell zur Bewertung von ÖSD verwendet. Abschließend wurde eine Landnutzungskarte aus dem Jahr 2007 mit zwei Szenarien verglichen. Um ein differenzierteres Bild zu erhalten wurden zusätzlich Untergruppen analysiert. Die erste Untergruppe Arten für den menschlichen Gebrauch beinhaltete nur die Arten, die der Mensch direkt nutzt (Wildbienen für die Honigproduktion und Pflanzen für Traditionelle Chinesische Medizin). Die zweite Unter-gruppe Rote Liste Arten, bestehend aus Pflanzen und Säuger die auf der roten Liste verzeichnet sind, wurde getrennt untersucht, um Naturschutzaspekte mit einzubeziehen. Die Ergebnisse zeigten, dass es bei einer Beschränkung auf die Arten für den menschlichen Gebrauch weniger Unterschiede zwischen den Szenarien gibt, da die Medizinalpflanzen auch in Kautschukplantagen vorkommen, wenn auch mit anderen Arten (Generalisten und Ruderalpflanzen). Dies führt zu einer wichtigen Schlussfolgerung: Allein die Entscheidung Was untersucht wird ist nicht ausreichend (Biodiversität), sondern auch das Wie (Gruppierung von verschiedenen Artgruppen) ist wichtig, da es erhebliche Auswirkungen auf die Ergebnisse hat. In einem letzten Aspekt wurde die Übertragbarkeit der Projektergebnisse auf andere Regionen der Welt untersucht, um die Relevanz des Kautschukanbaus auch für Gebiete außerhalb des eigentlichen Untersuchungsgebietes zu ermitteln. Dafür wurde das System der Land-Archetypen benutzt, das eine große Auswahl von Landnutzungsintensitäten verwendet und gleichzeitig ökologische und sozio-ökonomische Gegebenheiten mit einbezieht. In einem ersten Schritt wurde der Projekt-Archetyp definiert, basierend auf der Zusammenführung von globalen Indikatoren mit deren Hilfe Landnutzung und Landeigenschaften beschrieben werden können. Für das Verbundprojekt Sustainable Rubber Cultivation in the Mekong Region wichen nur wenige der 32 untersuchten globalen Indikatoren von den realen lokalen Werten ab. Das Übertragbarkeitspotenzial für die GMS war relativ hoch und unterstützt damit die Wichtigkeit der Projektergebnisse für diese große Region.The present dissertation analyzes the impact of rubber tree (Hevea brasiliensis) dominated land-use on biodiversity and ecosystem services (ESS) in the Greater Mekong Subregion (GMS). Although originating from South-America natural rubber is mainly cultivated in South-East Asia. This expansion of rubber plantations affects different ESS such as carbon storage, availability and quality of water and threatens biodiversity in this highly biodiverse region. In order to analyze these impacts the first task was to give a comprehensive overview about publications concerning ESS and biodiversity in rubber cultivation systems. A thorough literature review showed that the majority of publications concentrated on single or few ESS, which does not match the demands of decision-makers. In order to make sound decisions for land-use planning or developing Payments for Ecosystem Services Schemes a holistic view including multiple services. In order to fill this knowledge gap, the second task was to analyze the impacts of rubber on the ESS carbon storage, soil erosion, water availability and water quality and economically and socially related ESS, such as income and livelihood security. Although there are still great uncertainties about carbon storage in different land-use systems there are hints that the carbon storage in rubber plantations is lower than in natural forests. Concerning erodibility, rubber plantations increase the soil erosion risk compared to natural forests. Rubber cultivation also affects the local and regional water balance. Since rubber production in monocultures requires the use of huge amounts of pesticides and chemical fertilizers which enter the aquatic system by rainfall-induced run-off, water quality for humans and aquatic organisms is as well threatened. Undoubtedly, from an economic point of view the introduction of rubber resulted in significant increases in household income and is hence a possibility to move households and communities out of poverty. However, by deciding to grow rubber, farmers are committing themselves for decades to come and are thus dependent on a single product, which exposes them to further risks. In addition, there are ecological hazards due to crop diseases, pests, unfavorable weather conditions or changes in climate. The review of studies clearly indicates that increasing rubber cultivation in the GMS is accompanied by various problems and threats to farmers and the environment. Therefore, the development of more sustainable land-use concepts is required. Concordantly, suggestions for land-use change are based on system diversification and forest restoration, which both require economic incentives for farmers. The next part of this dissertation deals with the development of a biodiversity indicator (based on selected flora and fauna species) that can be included in existing biodiversity models to show the impact that different rubber cultivation scenarios will have on various species groups. A combination of multi-species data supplemented with literature data was used and included flora, vertebrates and invertebrates. The resulting indicator was used as input into an established ESS assessment framework. Finally, a current land-use map from 2007 was compared with two scenarios. In order to get a more detailed picture, sub-groups of biodiversity were analyzed as well. First, a sub-group of human use species category was assessed which included only species which are directly used by humans. Second, the sub-group red list species, consisting of red list plants and mammals was analyzed separately to include the conservational aspect. The results showed that when considering the indices from the category human use species there is less of an impact between the scenarios, because medicinal plants for example are still commonly distributed within rubber plantations, albeit with different species (generalists, ruderal flora). This leads to an important conclusion: not only the decision on what is analyzed (biodiversity), but also how it is analyzed (groups of different species) considerably influences the results. To complete this dissertation the transferability of this place-based research to other regions of the world was tested to assess the relevance beyond the study area. To do this the system of land archetypes was used, which utilizes a wide range of land-use intensity metrics and incorporates simultaneously environmental and socio-economic conditions. In a first step, the project archetype was defined, based on a synthesis of global land system indicators. For the project Sustainable Rubber Cultivation in the Mekong Region, only few of the 32 global indicators did not closely match the local reality. The transferability potential for the GMS was quite high and therefore emphasizes the importance of the project results for this huge region

Einfluss dreijährig variierter Stoppelbearbeitung auf den Bodensamenvorrat unter den Produktionsbedingungen des Ökologischen Landbaus

Mit der Stoppelbearbeitung sollen ausgefallene Kultur- und Unkrautpflanzensamen zur Keimung angeregt und in den nachfolgenden Bearbeitungsgängen vernichtet werden, um so die Anzahl der neu zur Population hinzukommenden Individuen so gering wie möglich zu halten. In Feldversuchen zur Wirkung der Stoppelbearbeitung wurde keine populationsmindernde Wirkung der Stoppelbearbeitung auf annuelle Unkräuter festgestellt (z.B. KOCH & RADEMACHER, 1966; BOSTRÖM et al., 2000; PEKRUN & CLAUPEIN, 2001). Mit der oberirdischen Population der Unkräuter wird jeweils nur ein Teil der Population erfasst. In diesen Erhebungen wurde der Versuch unternommen, durch zusätzliche Erhebung des Bodensamenvorrats die Wirkung der Stoppelbearbeitung auf die Gesamtpopulation zu beschreiben

Investigating potential transferability of place-based research in land system science

Much of our knowledge about land use and ecosystem services in interrelated social-ecological systems is derived from place-based research. While local and regional case studies provide valuable insights, it is often unclear how relevant this research is beyond the study areas. Drawing generalized conclusions about practical solutions to land management from local observations and formulating hypotheses applicable to other places in the world requires that we identify patterns of land systems that are similar to those represented by the case study. Here, we utilize the previously developed concept of land system archetypes to investigate potential transferability of research from twelve regional projects implemented in a large joint research framework that focus on issues of sustainable land management across four continents. For each project, we characterize its project archetype, i.e. the unique land system based on a synthesis of more than 30 datasets of land-use intensity, environmental conditions and socioeconomic indicators. We estimate the transferability potential of project research by calculating the statistical similarity of locations across the world to the project archetype, assuming higher transferability potentials in locations with similar land system characteristics. Results show that areas with high transferability potentials are typically clustered around project sites but for some case studies can be found in regions that are geographically distant, especially when values of considered variables are close to the global mean or where the project archetype is driven by large-scale environmental or socioeconomic conditions. Using specific examples from the local case studies, we highlight the merit of our approach and discuss the differences between local realities and information captured in global datasets. The proposed method provides a blueprint for large research programs to assess potential transferability of place-based studies to other geographical areas and to indicate possible gaps in research efforts

Assessing Ecosystem Services in Rubber Dominated Landscapes in South-East Asia—A Challenge for Biophysical Modeling and Transdisciplinary Valuation

The concept of ecosystem services (ESS) has been increasingly recognized for its potential in decision making processes concerning environmental policy. Multidisciplinary projects on rubber (Hevea brasiliensis) cultivation, integrating research on a variety of ESS, have been few and far between. More than three years of iterative workshops with regional stakeholders resulted in the development of future land use scenarios for our study area in Xishuangbanna, PR China. We used the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) modeling framework to analyze their impact on sediment retention, water yield, habitat quality, and carbon sequestration and developed a model for assessing rubber yields. We investigated the percentage deviations of integrated ESS indices in each scenario, as compared to the initial state of 2015 and as a novelty used different statistical weighting methods to include rankings for the preference of ESS from three contrasting stakeholder groups. The business-as-usual scenario (BAU, continuous rubber expansions) revealed an increase in rubber yields trading off against all other ESS analyzed. Compared to BAU, the measures introduced in the balanced-trade-offs scenario (reforestation, reduced herbicide application, riverine buffer zones, etc.) reduced the total amount of rubber yield but enhanced habitat quality and regulating ESS. The results show that the integrated indices for the provisioning of ESS would be overestimated without the inclusion of the stakeholder groups. We conclude that policy regulations, if properly assessed with spatial models and integrated stakeholder feedback, have the potential to buffer the typical trade-off between agricultural intensification and environmental protection.Peer Reviewe

Biodiversity and ecosystem services−A case study for the assessment of multiple species and functional diversity levels in a cultural landscape

This research article published by Elsevier B.V., 2017The expansion of large-scale plantations has a major impact on landscapes in the Tropics and Subtropics. Crops like soy bean, oil palm and rubber have led to drastic changes in land cover over the past decades, thereby altering ecosystem functions and services (ESS). Associated shifts in ESS such as climate regulation, erosion and water cycles, biodiversity as well as soil fertility or the provisioning of raw materials have been assessed through several models and software solutions (InVEST, ARIES, MIMES). However, suitable methods for the integration of a range of biodiversity assessments in agricultural landscapes are scarce. With this study, we introduce a methodology for incorporating multiple levels of species diversity into models to allow an integrated evaluation of ESS. We collected data sets from both published and unpublished sources on the distribution of vascular plants, selected pollinator groups, ground beetles, ungulates as well as amphibians, mammals, reptiles and birds in rubber-dominated landscapes, with a focus on our study sites in Southwest China and Thailand. Based on this information, we developed a common classification scheme that enables the integration of different facets of biodiversity (species diversity and functional diversity) to complement an interdisciplinary ESS assessment. Species diversity data were normalized against the most divers habitats reported (using habitat scores) to assess the impact of rubber cultivation on multiple levels of biodiversity. This resulted in a comparable matrix of different land use types and their suitability as habitat for the respective species groups allowing the aggregation of very diverse indicators. The findings were applied to two alternative land use scenarios in southern China to highlight the potential effects of land use and management decisions on species and functional diversity. Our results highlighted that the conservation oriented scenario did score higher for habitat suitability in both total species (+5%) as well as IUCN Red List species (+6%) assessments compared to the current state or business as usual scenarios (-2% and −3% compared to current state). The process presented here allows for an application within established ESS software programs, in our case InVEST, using aggregated indices while additionally providing enhanced opportunities for comparable, spatially explicit assessments of the expected impact of the analyzed scenarios on specific species groups

Artificial Intelligence in Public Discourse

This book contains 26 studies conducted by students in the Cognitive Science seminar "Artificial Intelligence in Public Discourse". In their studies, they explore the use of the term Artificial Intelligence (AI) and related subfields in various parts of public discourse such as Twitter, user comments on news sites, expert interviews, government documents, television shows, newspapers, etc. It is investigated which strengths, weaknesses, opportunities, and threats are ascribed to AI technology and how this relates to the technical and academic state of the art and discussion. Most studies employ qualitative methods, but quantitative and mixed-methods approaches are also used