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Drivers of weed diversity on patch and pattern scale in vineyards of Kosovo
Get PDFThe PhD thesis provides data on the vineyard weed flora and vegetation in Kosovo, especially in the well-known wine-growing regions Rahovec and Suhareka. The data collected and analyzed are important in two ways: On the one hand, they contribute to reducing knowledge gaps on biodiversity and its drivers in Kosovo. Furthermore, the study can help regional agriculture to implement weed management strategies adapted to the species and vegetation that are present.
The investigation methods include (A) field surveys of the weed flora and vegetation and (B) soil chemical analysis in cultivated fields of the study areas, (C) germination experiments in climate chambers, and (D) germination experiments under field conditions. In the germination experiments, four weed species occurring in the two study regions were investigated. The field survey and the field experiments were conducted in Kosovo, the germination experiments in climate chambers at the University of Giessen.
In May to August 2016 and 2017, the weed flora and vegetation was documented on a total number of 70 vineyard patches (35 patches in Rahovec; 35 patches in Suhareka) (A). On each of the 70 patches, four plots were selected randomly for detailed vegetation sampling. Each of the plots was divided into two subplots ‘within’ and ‘between rows of vines’ with a standard size of 1 m x 5 m. To avoid edge effects, the minimum distance of each subplot to the patch border was 5 m. For each subplot vegetation relevés were compiled. For each subplot, additional site data was documented in the field and derived from maps (height above sea level, exposition, aspect, northness, eastness). Based on interviews with the farmers who cultivated the patches, additional information was compiled for each of the 70 patches on herbicide use. This made it possible to distinguish between two management types (with versus without herbicide use) in the data analysis.
On each of the subplots soil sampling (soil depth: 5-15 cm) was carried out (B). In each subplot, the soil of three sub-samples that were taken with a hand auger was mixed. Each of the mixed soil samples was dried at room temperature and sieved (to exclude stones with a size >2 mm from further soil analysis and to quantify the stone content of the soils) before the chemical analysis. Soil pH was measured in both H2Odest. and CaCl2. The total amount of organic matter (OM) was determined by the ignition method. The amount of plant-available P and K was quantified with the help of the Ammonium lactate method.
The vegetation and land management data and the soil data were considered in ordinations and indicator species analysis to relate the diversity of the weed vegetation to the considered management practices and site conditions.
For four selected weed species (Amaranthus retroflexus, Chenopodium album, Echinochloa crus-galli, Solanum nigrum) relations between air temperature and germination were analyzed in climate chambers (C). The seeds were sampled on the patches that were investigated in 2016. The germination experiment was conducted with seeds of the F1-generation of the sampled seeds. The germination succeed was tested for different temperatures ranging from 3 °C to 30 °C. Five replicates with a standard number of 50 seeds per species and temperature level were analyzed. The germination experiment lasted for 12 weeks in winter 2017/18. In addition to the climate chamber experiment, relations between air temperature and germination were studied under field conditions (D). As described before, seeds of the F1-generation of the sampled seeds were also used in the field experiment in 2018. In standardized plots (30 cm x 30 cm) with heat-sterilized soil (to prevent germination of seeds that may occur in the soil) a standardized number of 200 seeds of the selected weed species was investigated by means of weekly recordings within the entire vegetation period. In these recordings the number of germinated seeds was documented. For each of the selected species, three replicates were studied to allow statistical analysis of the data. To relate the germination data to the air temperature during the vegetation period the minimal and maximal air temperature next to the plots was recorded daily.
Overall 84 weed species were recorded during 2016 and 2017 in the two study regions. In both years, the species number was higher in Suhareca region. The species numbers and weed coverage differed considerably between the two regions and management types. Fields without herbicide application in Suhareka region had significantly more species than herbicide-treated ones in Rahovec region. The DCA analysis and the indicator species analysis prove remarkable differences in the weed composition and coverage between the study regions, management types and the small-scale differences within and between the rows of vines in 2016 and 2017. Also the indicator species analysis resulted in differences between the two study regions, management practices and the situation within or between rows of vines.
The mean pH value in H2Odest. and the mean amount of OM were higher in Suhareka compared to Rahovec region, and the mean amount of OM was higher within compared to between rows in both regions. Moreover, the DCA analysis showed a correlation between the vegetation and soil chemical parameters.
The germination experiments in climate chambers and in the field resulted in species specific germination behavior and in differences in the germination rates between the two study regions. There were significant differences between regions at the different temperatures regarding germination of F1 seed of Amaranthus retroflexus and Chenopodium album. Moreover, Echinochloa crus-galli, Chenopodium album and Solanum nigrum achieved higher germination rates from seeds collected in the Suhareka region.
The summarized results can be interpreted in several ways: The current diversity of the vegetation in the studied vineyards is generally low due to implemented weed control measures. However, At the patch scale, the land-use intensity (with versus without herbicide application; lower intensity ‘within rows’ than ‘between rows’) is a driver of vegetation diversity, while at the pattern scale, differences in land-use intensity between the two study regions and also differences in soil chemical characteristics affect vegetation diversity.
The region-dependent differences in temperature-dependent germination rates found in the germination experiments with the F1 generation of selected weed species indicate genetic differences between the populations studied. Since both regions are not far from each other within Kosovo, these differences could be a consequence of different intensities of cultivation in both regions and resulting genetic differences of the populations.
The results are discussed with recommendations for a more sustainable use of the wine growing areas of Kosovo in the future. Options for organic management and future soil management with plant cover are presented in regard to their importance for ecosystem services and biodiversity protection
Landscape structure and land use in the Greater and Lesser Caucasus of Georgia: Impacts of societal change and potentials for sustainable development
Get PDFIn two Georgian high-mountain landscapes, Kazbegi in the Greater and Bakuriani in the Lesser Caucasus, the land use and the structural diversity of the cultural landscape have been investigated in three studies. Along steep altitudinal gradients a variety of mountain biotopes and habitats of open lands and forests are located in these landscapes. Land use and landscape structure is substantially influenced by local small-scaled subsistence farming with low number of cattle and small parcels of cultivated land for vegetable cultivation and haymaking. In both regions, agriculture is practiced on low-yielding marginal locations due to climate conditions in the high mountains. The large number of heated glasshouses for vegetable cultivation in the Kazbgei region is an example to tackle the difficult high-mountain farming conditions in an energy-intensive way. Both study regions are also subject to consequences of the countrywide political and economic restructuring since Georgian independence in 1991. On the one hand, urban regions are suffering by outmigration of the population, especially by the youth, with adverse consequences for the agriculturally used land and therefore for the landscape structure and biodiversity. On the other hand, since the 2010ies the tourism begins to flourish in both regions, with increasing employment possibilities for the population in the tourism sector.
In the field of tension between the two opposing developments, the synthesis´ investigations focus on three different focal points. However, the land-use pattern and the structural diversity of high mountain cultural landscapes are always the heart and the linkage of research and evaluation. First, for the Bakuriani region in the Lesser Caucasus the land-use pattern and forest structure have been investigated. In this Lesser Caucasus study area forest is the dominating land cover. Considering this, the naturalness of the diverse mountain forest types were analyzed along altitudinal belts. These forests were characterized by a high degree of naturalness and a traditional silvo-cultural land-use system of forest pastures and forest meadows. Second, for the Kazbegi region in the Greater Caucasus the land-use change from 1987 to 2015 have been analyzed and quantified in consideration of societal and structural development. In this study, changes in land use and land cover have been quantified spatially explicit in relation to the distinctive high mountain topography at settlement level. Third, interdisciplinary and sustainable land-use concepts have been developed for the Kazbegi region to promote the profitability of agricultural production while respecting the ecology of the mountain landscape. With ecological and socio-economic parameters and indicators three normative land-use scenarios have been developed to meet sustainable development goals of the UN. These scenarios can help optimizing farm management and the use of inputs in the local agriculture.
According to the described studies and in comparison to various scientific concepts like the multifunctionality of landscapes, ecosystem services, the concept of hemeroby, and ‘One Health’, the landscape structure and the pattern of land use in both regions were studied and evaluated. Landscape structure today is still characterized by traditional agricultural land use adapted to high mountain conditions. However, in both study regions the retreat of agriculture is evident, indicated by increasing shrubification and reforestation. Non-intensive high-mountain farming that is adapted to the diverse topography with a small-scaled pattern of various climatic conditions shall be decisive, i.e. beneficial and preserving, for an exceptional high mountain biodiversity. The agricultural cultivation of the mountain landscape is a formative factor for biodiversity and species protection in both regions. Additionally, it also shapes the landscape in the sense that it is currently gaining in national and international tourist appeal. The importance of the two core issues mentioned above, high mountain biodiversity and tourism, has been recognised by politicians in the recent past and various protection measures and support actions have been formulated and established.Sonstige Drittmittelgeber/-inne
Analyzing the inclusion of nature in an oil palm plantation: a landscape ecological case study in Mapiripán, Meta, Colombia
Get PDFOil palm plantations are known for their adverse effects on biodiversity and human well-being. Such industrial agricultural landscapes are homogeneous and oversimplify biodiversity and convey little or no human well-being. Yet, an oil palm plantation design implementing land sharing and land sparing simultaneously can provide a place for biodiversity conservation, generate social landscape values and provide human well-being. Also, local biodiversity controls agricultural pests.
An Integration of nature in an oil palm plantation can foresee benefits and risks to the oil palm and workers. First, a heterogeneous agricultural landscape can provide habitat to local species, which can act as a biological control in agricultural systems. Second, it can provide social landscape values and change and shape humans’ perception of the plantation. Third, workers are positively or negatively affected by interacting with nature inside the plantation.
Intensive large-scale agricultural landscapes such as plantations are often considered and designed as sole production areas. They can also exhibit a complex spatial pattern of vegetation types, implementing land sparing and land sharing approaches. The company, Poligrow Colombia SAS, has implemented these approaches in the Macondo plantation for a decade. The company followed the principles and criteria of the RSPO and the Rainforest Alliance plus the national laws to design the oil palm plantation. As
a result, the plantation has different vegetation types besides oil palms, namely compositional and configuration heterogeneity. The Macondo plantation has gained a nature-enhanced agricultural landscape that can create different habitats for local flora and fauna and provide ecological and social values. For instance, biological control service for oil palms pests of Opsiphanes cassina and Rhynchophorus palmarum. Also, workers can perceive social landscape values such as shade and water provision. A nature-enhanced plantation design is possible to implement and maintain, though it generates costs. Yet, implementing both approaches provides a framework to make large-scale farming systems more sustainable. It is possible to argue that nature-enhanced plantation design is more sustainable as compared to monocultures. Other oil palm plantations and other large-agricultural systems can see the Macondo plantation design as viable. Production areas and conservation areas, with native flora and fauna, are intertwined. However, it is still unknown whether implementing both approaches simultaneously in an oil palm plantation can bring any benefits to the agricultural landscape structure, provision of social landscape values and human wellbeing.
This interdisciplinary study explores the role of nature in oil palm plantations. Specifically, to analyze the landscape characteristics of the Macondo plantation for two purposes: a) ecologically, the landscape composition and configuration of the plantation enhance landscape connectivity and pest control service, 2) socially, owing to the landscape characteristics, plantation workers perceive social landscape values,
well-being and better working conditions in the plantation. Chapter 1 is the general introduction describing the oil palm plantations worldwide. Chapter 1 summarizes the ecological and social effects of rapid oil palm expansion in tropical regions. Chapter 2 is a description of the study area. The chapter begins with a description of the Meta department and the municipality of Mapiripán to understand the general context of
the eastern region. Following is a description of the company Poligrow Colombia SAS and the Macondo plantation where the case study was performed. Chapter 3 is the theoretical framework of the project. Chapter 4 is the research design and research questions.
In Chapter 5, the landscape analysis of the Macondo plantation is related to pest occurrence. To show relationships among the landscape structural types, land cover, and pest occurrence, a landscape analysis by multivariate cluster analysis and an NMDS ordination were performed. The results show that a heterogeneous plantation improves landscape connectivity and control pest populations.
In Chapter 6, the specific nature-enhanced plantation design can provide social landscape values, SLV, to workers is examined. The results on the structural landscape analysis of the plantation, in Chapter 5, were analyzed jointly with the results from the participatory mapping with plantation workers. The correspondence between landscape analysis and the location of the perceived values is analyzed, revealing socio-ecological hotspots (e.g., epiphytarium). It highlights the relationship between the landscape characteristics of the plantation and the social landscape values perceived by workers. Workers perceive most social landscape values in the prevalence of landscape connectivity and heterogeneity.
Chapter 7 addresses whether plantation workers relate to and perceive nature (e.g., gallery and riparian forests) and non-natural areas (e.g., crops such as oil palm) in the plantation. Using qualitative content analysis from focus group discussion and in-depth interviews with workers, I infer they derive a great variety of values and also experience ambivalent relationships towards nature in the plantation. Through the
perceived benefits to humans and other species, a possible naturalization process might happen on such a nature-enhanced plantation.
Finally, Chapter 8 is the general discussion and conclusions.Sonstige Drittmittelgeber/-inne
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Flächenstillegungen und Extensivierungsmaßnahmen im Ackerbau Flora, Vegetation und Stickstoff-Haushalt
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