After a ground coring was done by Leiden University at Vrouw Vennepolder, pollen research has been conducted by archaeology students. In this bachelor thesis, the pollen diagram which came out as a...Show moreAfter a ground coring was done by Leiden University at Vrouw Vennepolder, pollen research has been conducted by archaeology students. In this bachelor thesis, the pollen diagram which came out as a result of the thesis, has been used to reconstruct the past landscape and to look into ways that the taxa present in the pollen diagram could have been used for multiple purposes. At last, there was something said on the effects this had on the decline of biodiversity in the area. Vrouw Vennepolder is a site located on the northeast outside of Leiden in the municipality of Kaag en Braassem. The region has had peat extractions from the 11th century onwards. The polder itself was created in the 17th century as a result of merging four pieces of land together. The plants indicate that they were on slightly saline grounds before peat extraction started in the 11th century AD. After that, the plants representing the layers are mostly fresh or brackish water plants. Both during the peat extraction and the polder formation, there were taxa present that could have been used by the local population. These plants include a variety of trees, shrubs and herbaceous species that are known for their specific uses both in the past and now. For the dating of the site, peat accumulation rates and a pollen diagram from Kijkduin have been used. These two factors together gave a good comparison of the time development in the pollen diagram of Vrouw Vennepolder. The development starts at 170 centimetres and ends at 50 centimetres. There is no clear timespan given to the layers below 170 centimetres. One can see a transition of the plant populations present at the site on the pollen diagram. As the human influence got bigger at the site, the biodiversity declined too. The distribution of trees and shrubs also changed over time, as herbaceous plant species slowly got more represented. Nadat door de Universiteit Leiden een grondboring was gedaan op de Vrouw Vennepolder, is er pollenonderzoek gedaan door archeologie studenten. In deze bachelorscriptie is het pollendiagram dat naar aanleiding van het proefschrift naar voren is gekomen, gebruikt om het landschap uit het verleden te reconstrueren en om te onderzoeken hoe de taxa in het pollendiagram voor meerdere doeleinden konden worden gebruikt. Uiteindelijk is er ook iets gezegd over de effecten dat dit had op de achteruitgang van de biodiversiteit in het gebied. Vrouw Vennepolder ligt in het noordoosten buiten Leiden in de gemeente Kaag en Braassem. Vanaf de 11e eeuw wordt turf gewonnen in de regio. De polder zelf is in de 17e eeuw ontstaan door het samenvoegen van vier stukken land. De planten in het pollendiagram geven aan dat ze op licht zoute gronden stonden voordat de turfwinningen in de 11e eeuw begonnen. Daarna zijn de planten die de lagen vertegenwoordigen meestal zoet- of brakwaterplanten geweest. Zowel tijdens de turfwinning als de polder formatie waren er taxa aanwezig die door de lokale bevolking gebruikt hadden kunnen worden. Deze planten omvatten een verscheidenheid aan bomen, struiken en kruidachtige soorten die zowel in het verleden als heden bekend staan om verschillende gebruiken. Voor de datering van de vindplaats is gebruik gemaakt van veen accumulatie snelheden en een pollendiagram uit Kijkduin. Deze twee factoren samen gaven een goede vergelijking van het tijdsverloop in het pollendiagram van Vrouw Vennepolder. De ontwikkeling begint bij 170 centimeter en eindigt bij 50 centimeter. Er is geen duidelijke tijdsaanduiding gegeven aan de lagen onder de 170 centimeter. Op het pollendiagram is een overgang te zien van de aanwezige planten populaties op de locatie. Naarmate de menselijke invloeden op de plaats groter werden, nam ook de biodiversiteit af. Ook de verspreiding van bomen en struiken veranderde in de loop van de tijd, omdat kruidachtige plantensoorten langzaamaan meer vertegenwoordigd werden.Show less
In this academic thesis the impact and extent of effect of invasive alien plant species, specifically their pollen byproduct, on human health is examined. As research on the presence and subsequent...Show moreIn this academic thesis the impact and extent of effect of invasive alien plant species, specifically their pollen byproduct, on human health is examined. As research on the presence and subsequent influence of such plants’ pollen on a native ecosystem and the humans therein is widely understudied, this study aims to substantiate the repercussions of the ever-growing pollen count of these plants on human health. The goal is to null or verify the assertions that these species spread with little difficulty, exponentially increase the overall pollen count, and contribute pollen variants of harsher impact on human health. The research conducted does a case study of the Netherlands, and specifically The Hague, using two plant species (common ragweed and mugwort) - widely considered invasive in other ecosystems - that remain scientifically overlooked though recorded. Making use of related and comparative data pooled in desk research, a pollen index was constructed to narrowly approximate the pollen count and allergenicity of common ragweed and mugwort. Medical studies test-prove that these invasive plant species have highly allergenic pollen which in turn cause hay fever symptoms. Additionally, the yearly pollen index spanning from 2012 to 2020 showcases an intensification of the allergenicity of the air due to these species, and the weekly pollen index spanning from 2012 to 2015 illustrates clear prolongation of the flowering (i.e. allergy) season through the years. This research paper has quantified the overlooked looming urban, scientific, environmental and medical risk of such invasive plant species’ pollen. Observations of similarly burdened ecosystems has shown elaborated solutions, the like of introducing insects that eradicate these species’ pollen and its spread. The efficacy of these solutions has yet to be weighed including potentially pending consequences (disservices) linked to introducing the alien animal species in the ecosystem.Show less
Human activities have impacted the natural landscape and vegetation from the emergence of agriculture onwards. Subsequent traces of anthropogenic activities are documented and preserved in...Show moreHuman activities have impacted the natural landscape and vegetation from the emergence of agriculture onwards. Subsequent traces of anthropogenic activities are documented and preserved in paleoenvironmental archives, such as peat or lake sequences. The current study utilizes a high-resolution pollen dataset retrieved from a peat sequence in combination with archaeological data from the area to reconstruct the paleoenvironment and cultural landscape of the area of Haraldstadmyr bog in Southeastern Norway. An in-depth analysis of agricultural activities was performed focusing on the period of the Early Iron Age to the Medieval Period. Utilizing radiocarbon dating, a chronology of farming activities was provided. Archaeological burial dates from a local burial site located were used in comparison with the pollen data to interpret habitational patterns of the local area. As a result, periods of intensive farming as well as periods of abandonment were identified. In addition, periods of pastoral farming were distinguished from periods of mixed farming. The forcing factors of the changes seen in farming strategies and agricultural intensity are likely related to climate changes as well as societal changes in the area. In this study, a new finding is proposed, indicating an abandonment of the area around 950 CE. An abandonment of the agricultural area in Southeastern Norway in the mid 10th century has not been previously discovered nor studied. Further in-depth studies are needed in order to confirm this finding, as well as to identify the forcing factors of the abandonment.Show less
