Browsing by Subject "Ecosystem services"

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Chinese urbanites and the preservation of rare species in remote parts of the country : the example of Eaglewood
(2014) Pelz, Sonna; Langenberger, Gerhard; Frör, Oliver; Ahlheim, Michael
Based on a Contingent Valuation study in Shanghai we assess peoples willingness to contribute personally to the alleviation of environmental problems occurring in distant parts of the country. One split of our survey assessed Shanghai residents willingness to pay for the preservation of rainforest in Yunnan, while the other split referred to the willingness to pay for the preservation of a single plant species (i.e. eaglewood) growing in this rainforest. The objectives of this study were twofold. Firstly, we wanted to find out if people living in big Chinese cities like Shanghai take an interest in the environmental problems existing in some remote parts of the country and if they are willing to contribute personally to remedy these problems. Secondly, we wanted to learn more about the motivation behind this kind of empathy, if it exists. We were especially interested in the question if this empathy refers to the specific environmental problems we addressed in our surveys or if it is motivated more by a general feeling of obligation towards environmental issues.
Facilitation of weed seed predation by living mulch and cover crops
(2022) Schumacher, Matthias; Gerhards, Roland
Weed seed predation (WSP) is an important agro‐ecosystem service that naturally suppresses weed populations. Disturbances directly interfere with the activity of the seed predators, for example, harvest and soil tillage during a peak in weed seed availability (around cereal harvest). Plant soil cover and reduced soil tillage are factors that might positively affect WSP. We investigated cover crops and living mulch along with soil disturbance (no‐till and conventional seeding) in comparison to a fallow and repeated stubble tillage with a chisel plough in terms of WSP, activity‐density of carabid beetles and soil cover. A field experiment with a randomised complete block design and four replications was conducted at two sites from 2017 until 2019. WSP rates were assessed with seed cards and exclosure cages from July until November during a period of eight consecutive days each month. Living mulch exhibited the highest WSP rates of 72% with a maximum of 95% immediately following cereal harvest in August and September of 2017 and 2019, while the remainder of the treatments ranged from 2% to 5% WSP. In October and November mustard showed on average twice as high WSP rates compared to the other treatments (50% vs. 10%–25%). Seeding and soil tillage did not significantly influence carabid beetle activity‐density and WSP, except for living mulch. Predator groups (invertebrates and vertebrates) were not influenced by the various treatments, rather year and month determined the predator groups dominance. Besides their weed suppressive effects, living mulches and cover crops also facilitate WSP.
Integrated rural and urban agricultural systems for the sustainability transition towards the bioeconomy
(2021) Winkler, Bastian; Lewandowski, Iris
The goal of the bioeconomy is a fundamental transition of both the economy and society towards sustainability. Replacing fossil resources by biomass for the provision of food, feed, fibre and fuel/energy (the 4F’s) will result in a substantial increase in demand for agricultural products. The consequent intensification of agricultural production, however, needs to be achieved while alleviating the societal challenges of the 21st century. The bioeconomy provides a knowledge-based, cross-sectoral and systemic pathway to increase agricultural production that involves all relevant stakeholders in the sustainability transition. This interdisciplinary thesis investigated the contribution that three selected bioeconomic approaches can make to the sustainable intensification of agricultural production, encompassing the growing urban population on the demand side and the numerous smallholder family farmers in countries of the global South on the supply side. The first study develops the ‘Integrated Renewable Energy Potential Assessment’ (IREPA) approach that involves smallholder farmers in planning and selection of renewable energy (RE) technologies for implementation into their agricultural systems. The bottom-up potential assessment, participatory learning and action research and multi-criteria decision analysis supported the smallholders in two case studies in rural South Africa and India in the identification of locally appropriate RE technologies. The second study uses IREPA to explore smallholders’ perception of agricultural RE production. Social, environmental, technical, institutional and economic factors are analysed to identify drivers of and barriers to RE implementation into smallholder agricultural systems. Mainly environmental factors, in particular climate change impacts, motivate smallholders to produce RE, while social factors (social cohesion, gender aspects, well-being, food and water security) determine the actual change. The barrier of high upfront investment costs can be eliminated by falling RET prices, the development of novel rural RE business models and institutional support. In addition, growing smartphone penetration rates in rural areas and open-access online information enables do-it-yourself RET operation and maintenance. Integrated approaches and such insights are crucial for the targeted formulation of agricultural development policies and stakeholder involvement in the sustainability transition towards a bioeconomy. The third study investigates the characteristics of urban gardening in Germany and its potential to encourage sustainable consumer behaviour, based on a review of 657 urban gardening project websites and an online survey involving 380 project participants. The results reveal multiple social, environmental and economic benefits of urban gardens for sustainable city development. The diverse gardener communities actively promote sustainable consumer behaviour by (unintentionally) applying several methods known to encourage pro-environmental behaviour. Hence, urban gardens are transformative spaces that involve the growing urban population in the societal transition towards a bioeconomy. In the context of sustainable intensification of biomass production in rural areas, the fourth study investigates the contribution of environmental service assessment and monetization in agricultural systems, using the example of the perennial biomass crop miscanthus for biofuel production. The valorisation makes environmental services - such as soil fertility improvement, carbon sequestration, water and air purification – tangible. This can incentivise payments to farmers for the provision of these public goods. Enhancing and utilising environmental services through nature-based solutions is a promising pathway to sustainable intensification, providing a shift from input-based towards process-based agricultural production. Finally, it can be concluded that integrated approaches which connect different production systems, disciplines and stakeholders are central for the development of the bioeconomy: - The integration of sustainable technologies, such as RE, into agricultural systems requires case-based research and participation of local stakeholders in project planning, decision making and targeted policy formulation. - The integration of the growing urban population in the sustainability transition can be supported by urban gardening because it promotes sustainable consumer behaviour. - The integration of nature-based solutions into agricultural systems enhances environmental service provision and supports the shift from input-based towards process-based agricultural systems. The approaches discussed in this thesis can support the sustainable intensification of agriculture, serve to re-connect the perspectives of rural producers and urban consumers, and enable the involvement of large portions of society in the sustainability transition towards the bioeconomy.
Interactions of farming and plant biodiversity in weed control related ecosystem service provision and weed conservation
(2020) Schumacher, Matthias; Gerhards, Roland
There is evidence that diverse plant communities in terrestrial ecosystems are either more stable or more productive in terms of food web support and ecosystem service provision. In agro-ecosystems, characterized by high disturbance and external inputs, plant diversity and their services can only be provided by weeds. In the first study, vegetation recordings and farmer surveys were conducted in on-farm experiments in two regions of Southwestern Germany. The aim was to examine the effects of agricultural management on weed community composition, weed biodiversity and occurrence of rare arable weed species in cereal fields. Weed biodiversity was influenced mainly by crop species, herbicide use and farming system as well as nitrogen and light availability. Weed communities were quite similar in both study regions and dominated by Alopecurus myosuroides, Galium aparine, Viola arvensis, Polygonum convolvulus and Veronica persica. A redundancy analysis revealed that the weed community was mainly shaped by crop species, tillage, location in the field and timing of herbicide application. The results highlight the erosion of weed communities due to intensive agricultural practices and emphasize the conservation of weed biodiversity per se and rare arable weed species in particular. The next aim was to examine if this biodiversity is able to support weed control related ecosystem services, like the predation of weed seeds. The objectives of this study were to investigate the connection between weed biodiversity, Carabid beetle diversity and weed seed predation as well to evaluate the role of farming intensity in this sequence. For this purpose, on-farm experiments were performed on the Eastern Swabian Alb. A positive correlation between weed biodiversity and Carabid beetle diversity was identified as well as a pattern of medium Carabid beetle diversity providing the highest weed seed predation. There was no consistent influence of farming intensity on weed seed predation. The revealed connection between weed diversity, Carabid beetle diversity and weed seed predation highlights the role of plants in food web support and subsequent ecosystem service provision. The utilization of these services depends on the promotion of biodiversity by designing appropriate management strategies. In the next step, the general principles underlying ecosystem service provision by biodiversity, were conveyed to a cover cropping system. The aim was to test single sown cover crops and species mixtures in terms of weed suppression efficacy and reliability. For this purpose, cover crop species were sown singly and as mixtures in a field experiment. Lower weed dry matter and weed densities were found predominantly in treatments with favorable establishment and above-average biomass production. Mixtures performed much more homogeneous in regard to the measured parameters compared to single sown cover crops. The results suggest that, although particular single sown cover crops are more effective to control weeds than mixtures, mixtures are more reliable under changing conditions. Altering the species composition of cover crop mixtures according to more complementary traits might further improve their weed control efficacy. The results of this dissertation demonstrate the importance of plant biodiversity in the provision and reliability of weed control related ecosystem services, either by weeds themselves or by specifically designed cover crop mixtures. Furthermore, management factors influencing weed biodiversity were determined, which can aid in the creation of more sustainable management strategies for a diverse agroecosystem and the conservation of rare arable weed species.
Simulating the impact of land use change and climate change on the supply of ecosystem services in a rubber-dominated watershed in Southwestern China
(2020) Thellmann, Kevin; Asch, Folkard
This cumulative PhD thesis investigates the expansion of rubber (Hevea brasiliensis Müll. Arg.) plantations and the ensuing multiple impacts on biodiversity and the supply of ecosystem services (ESS) in a mountainous watershed in Xishuangbanna Prefecture, Southwestern China. In recent decades, the study area, the Nabanhe Reserve, saw the expansion of rubber plantations and the loss of extensive forest areas, which led to a substantial decline in ESS. Workshops with regional stakeholders resulted in the development of three future land use scenarios for Nabanhe Reserve (2015 – 2040), varying in their degree of rubber expansions, management options and reforestations efforts. In the first study, the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) modeling framework was used to analyze the impact of these rubber expansion scenarios on selected ESS: sediment retention, water yield, habitat quality, and carbon sequestration. In addition, a model for assessing potential rubber yields was developed and implemented in ArcGIS. The analysis also included different statistical weighting methods to include rankings for the preference of ESS from three contrasting stakeholder groups (prefecture administration, tourists, off-site citizens). The study concludes that the integrated ESS indices would be overestimated without the inclusion of the stakeholder groups. The second study introduced a new method to identify potential tipping points in the supply of ESS. Here, time-series data derived from InVEST have been combined with a sequential, data-driven algorithm (R-method) to identify potential tipping points in the supply of ESS within two contrasting scenarios of rubber expansion in Nabanhe Reserve. The tipping point analysis included hydrological, agronomical, and climate-regulation ESS, as well as multiple facets of biodiversity. The model results showed regime shifts indicating potential tipping points, which were linked to abrupt changes in rubber yields, in both scenarios and at varying spatial scales. The study concludes that sophisticated land use planning may provide benefits in the supply of ESS at watershed scale, but that potential trade-offs at sub-watershed scales should not be neglected. The third study focused on modeling hydrological ESS (water yield and sediment export) in Nabanhe Reserve under multiple scenarios of land use and climate change in order to assess how both drivers influence the supply of these ESS. Three rubber expansion scenarios were analyzed in combination with multiple climate change scenarios using the InVEST modeling framework. Simulation results showed that the effect of land use and land management decisions on water yield in Nabanhe Reserve are relatively minor (4% difference in water yield between land use scenarios), when compared to the effects that future climate change will exert on water yield (up to 15% increase or 13% decrease in water yield compared to the baseline climate). Changes in sediment export were more sensitive to land use change (15% increase or 64% decrease) in comparison to the effects of climate change (up to 10% increase). The study concludes that in the future, particularly dry years may have a more pronounced effect on the water balance in Nabanhe Reserve as the higher potential evapotranspiration increases the probability for periods of water scarcity, especially in the dry season. In conclusion, the studies showed detrimental consequences induced by rubber expansions for all assessed ESS, with the exception of rubber yields. Further continuing the trend of rubber expansions in the study area is not the best option in terms of integrated ESS supply on a landscape scale. Land use planning alternatives, such as rubber expansions restricted to suitable areas only, in combination with reforestation efforts at less suitable locations, may be used to keep crucial environmental functions intact. Policy regulations at the local level, 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. The implementation of these regulations might still pose a considerable challenge. The methods introduced in this Dissertation can easily be transferred to regions facing comparable land use situations, as InVEST and a large amount of the utilized spatial datasets are freely available.
Social-ecologically more sustainable agricultural production
(2023) von Cossel, Moritz; Castro-Montoya, Joaquín; Iqbal, Yasir
Theoretical analysis and preference modelling for the valuation of ecosystem services from native pollinators in selected Thai rural communities
(2018) Narjes, Manuel; Lippert, Christian
Until now, the existing microeconomic models concerned with pollination markets have not accommodated the global diversity of beekeeper-farmer interactions. The most prominent of such theoretical models is dedicated to describing the determinants of colony stocking densities and of equilibrium wages that farmers have paid to commercial beekeepers for decades in the highly bee-pollination reliant almond monocultures of California. This cumulative dissertation generalizes this basic model by taking into account the marginal productivity of a given agro-ecosystem’s wild bees and the opportunity costs that farmers incur when assigning labor time to beekeeping. In that regard, we assessed the economic potential of on-farm beekeeping, which can involve several bee species, by juxtaposing this activity’s net benefits against those from hiring commercial pollination services. In addition to serving as a classification tool for a plurality of farmer-beekeeper-nature interactions and related optimization problems, the resulting analytical framework helps identifying the institutional settings that are most likely to lead to a specific bioeconomic equilibrium supply of pollination. What is more, it illustrates the interplay of the pertinent economic and agro-ecological factors, thus assisting the postulation of empirically testable hypotheses. We also conducted two separate discrete choice experiments (DCEs) with orchardists from the Thai provinces of Chiang Mai (N = 198 respondents) and Chanthaburi (N = 127), in order to elicit their preferences for changes in the population of local wild bees that would hypothetically result from a conservation policy consisting (along with a per-household implementation fee) of at least one of the following three measures: (i) offering farmers bee-friendly alternatives to conventional agro-chemicals, (ii) enabling the protection and/or rehabilitation of natural bee habitats near cropland, and (iii) fostering the husbandry of native bee species by transferring technical knowledge on the practice of on-farm beekeeping. In this context, we fitted random parameter logit models on the Chiang Mai dataset. They yielded a significant willingness to pay (WTP) for the presented conservation measures and suggested that the disutility the respondents perceived for a 50% decline in the local population of native bees was greater than the utility they would derive from experiencing a bee population increase of the same magnitude. Moreover, comparing our aggregated WTP estimates to the expected production losses, showed that orchard farmers underestimated the true use value of pollination. On the other hand, the average WTP for all conservation measures combined by far exceeded the costs that, according to our calculations, each household would incur for such a project to be implemented. Our models also indicated a significant preference heterogeneity in the sampled population, which we could partly explain with idiosyncratic variables such as the respondents’ attitudes towards native bees and beekeeping. Finally, we examined further sources of randomness in the observed choice behavior, by modelling the unknown choice decision-relevant influences that could not be captured during the DCEs. To that end, we fitted generalized mixed logit (GMXL) models on the pooled datasets, which allowed comparing, on a common utility scale, the part-worth (value) estimates from Chiang Mai and Chanthaburi, where different experimental designs were applied. Our results reveal that farmers in Chanthaburi, who reported having experienced crop declines that they attributed to insufficient pollination, introduced less subjective factors into their choices than their Chiang Mai counterparts, who may have been less familiar with the importance of conserving bees. Moreover, the GMXL results also suggest that Chanthaburi farmers placed a significantly higher value on the above-mentioned measures (i) and (ii), while caring comparatively less about a 50% decline in local wild bee colonies. One can thus hypothesize that an actual local pollinator decline may have made Chanthaburi farmers more aware of the importance of conserving native bees, while paradoxically making them more independent from the provision of wild pollination services, as they started managing crop pollination with stingless bees.
Wood-ash fertiliser and distance from drainage ditch affect the succession and biodiversity of vascular plant species in tree plantings on marginal organic soil
(2022) Zuševica, Austra; Celma, Santa; Neimane, Santa; von Cossel, Moritz; Lazdina, Dagnija
Cutaway peatland is a marginal land, which without further management is an unfavourable environment for plant growth due to low bearing capacity, high acidity and unbalanced nutrient composition of the soil. After wood-ash application, the soil becomes enriched with P and K, creating better conditions for tree growth. In addition to being economically viable, tree plantations ensure long-term carbon storage and promote habitat restoration. In a three-year term, we studied how distance from a drainage ditch and three different doses of wood-ash—5, 10, and 15 tons per hectare—affect the diversity of vascular plants in a tree plantation on a cutaway peatland. Plant species richness, vegetation cover and composition were positively affected by the distance from the drainage ditch and application with fertiliser, but in most cases, fertiliser dose had no significant effect. Both cover and species diversity were not affected by the planted tree species. In a tree plantation, herbaceous plants provide soil fertility by decay and recycling, and reduce mineral leaching in the long term. Since vascular plants play an important role in both the development of habitats and tree growth, it is important to know how multiple factors influence the development of vegetation in tree plantations.