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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Sachsens Natur bewahren!: Eine Biodiversitätskonzeption – 2012 bis 2014 erarbeitet von 65 Naturschutzpraktikern in Sachsen

21 February 2019 (has links)
Der Freistaat Sachsen ist nach Artikel 10 der Landesverfassung verpflichtet, den Lebensraum wild lebender Tiere und Pflanzen zu erhalten. Der Handlungsdruck ist groß: Vierzig Prozent der 12 000 Arten Sachsens stehen auf den Roten Liste. Sie sind »gefährdet«, »stark gefährdet« oder »vom Aussterben« bedroht. Zum Schutz der biologischen Vielfalt kann vielfach beigetragen werden, etwa durch die Begrenzung der Flächenneuversieglung, die Vermeidung von Boden- oder Gewässerverunreinigungen durch die konventionelle Landwirtschaft und den Bergbau. Die sächsische Staatsregierung lässt sich öffentlichkeitswirksam als Gönnerin eines nachhaltigen Natur- und Umweltschutzes feiern. Wirksame Maßnahmen für den Naturschutz sind hingegen kaum zu bemerken. Das politische Interesse der aktuellen Regierung am Naturschutz ist ausgesprochen gering. Die Verwaltungsreformen der letzten Jahre haben den Naturschutz geschwächt. Im aktuellen Haushalt ist weder Geld für Flächenankäufe noch für Projekte für das Biotopverbundsystem eingestellt. Um das fortwährende Artensterben aufzuhalten und umzukehren, müssen durch Biotopverbünde und Biotopvernetzungen die Wanderungs- und Ausbreitungswege heimischer Arten wieder hergestellt werden. Bislang gibt es in Sachsen keine Anzeichen dafür, dass bis zum Jahr 2020 auf zehn Prozent der Landesfläche Biotopverbundsysteme eingerichtet werden, wie in der Nachhaltigkeitsstrategie formuliert wird. Doch Biotopverbundsysteme sind nur EIN Instrument. Wenn die industrielle Landwirtschaft weiterhin Gift und Gülle in gigantischen Größenordnungen ausbringt, immer mehr Verkehrswege die Landschaft zerschneiden und der Schwerlastverkehr noch mehr Stickoxide emittiert, wird die Artenvielfalt dennoch weiter schrumpfen. In das Sächsische Naturschutzgesetz müssen verbindliche Festlegungen zum gesetzlichen Regelungen und Instrumente werden der Dringlichkeit nicht gerecht, dem Erhalt der biologischen Vielfalt einen planerischen Rahmen zu geben. Bisher umfassen Naturschutzgebiete weniger als zwei Prozent der Landesfläche im Freistaat.
72

Insektengerechte Landnutzung in Sachsen: Herausforderungen und Handlungsansätze

Schuch, Sebastian, Meyer, Stefan, Wesche, Karsten 17 April 2023 (has links)
Der vorliegende Bericht stellt Ursachen für die Veränderungen der Insektenfauna zusammen. Daraus werden Vorschläge für Maßnahmen in Sachsen abgeleitet und diese inhaltlich sowie räumlich priorisiert. Die Autoren schaffen mit dem Bericht wissenschaftliche Grundlagen und geben Empfehlungen zur weiteren Umsetzung des sächsischen Handlungskonzepts ´Insektenvielfalt. Der Bericht richtet sich an alle Akteure des Naturschutzes und der Landbewirtschaftung. Redaktionsschluss: 20.12.2022
73

Influence of elevations on woody tree species diversity in Nam Kar Natural Reserve of Daklak province, Vietnam

Nguyen, Thi Thanh Huong, Chau, Thị Nhu Quynh 11 December 2018 (has links)
This paper describes the influence of elevation on woody tree species diversity in Nam Kar Natural Reserve of Daklak, of which remote sensing and GIS techniques were used as the tools in biodiversity inventory and assessment. The whole Reserve area was divided into four elevation classes based on DEM (Digital Elevation Model) using GIS technique. Landsat 8 satellite image was employed to stratify the forest into the four strata. A total of 4 transect lines of 100 m in length and 20 m in width (abbreviated as H1, H2, H3, and H4) established in east-west direction representing for 4 elevation classes was used for surveying biodiversity and stand structure. The different diversity indices were compared among the different elevation classes. The relationships between reflectance value of satellite image, forest strata with biodiversity indices were also analysed. The result shows that the diversity of woody tree species is different among elevation classes. Based on sample plots a total of 135 tree species belonging to 42 genera was found in this area. Although a low inverse correlations were found between number of species composition, basal area, and tree density with DNs, most correlation was statistically insignificant 95%. However, a medium relation between forest strata and number of species composition were found with correlation coefficient r = 0.53 (P<0.00) in the area. / Nghiên cứu này đánh giá đa dạng thực vật thân gỗ tại khu bảo tồn thiên nhiên Nam Kar theo các cấp độ cao khác nhau. Nghiên cứu đã sử dụng ảnh vệ tinh và kỹ thuật GIS để hỗ trong trong việc điều tra và đánh giá đa dạng sinh học. Toàn bộ khu bảo tồn được chia thành 4 cấp độ cao dựa vào mô hình số độ cao (DEM) được thực hiện bằng kỹ thuật GIS. Ảnh Landsat 8 đã được sử dụng để phân chia rừng thành 4 khối trạng thái. Có 4 ô tiêu chuẩn dạng dải có kích thước 100m chiều dài và 20m chiều rộng được đặt ở từng đai cao (viết tắt là H1, H2, H3, và H4) theo hướng cố định Đông – Tây để điều tra đa dạng sinh học và cấu trúc lâm phần của thực vật thân gỗ ở từng đai cao. Các chỉ số đa dạng sinh học đã được so sánh trong từng cấp độ cao. Mối quan hệ giữa giá trị ảnh, hiện trạng rừng với các chỉ số đa dạng cũng được phân tích. Kết quả nghiên cứu cho thấy có sự khác biệt về đa dạng loài thực vật thân gỗ theo từng đai cao. Dựa vào ô mẫu nghiên cứu cũng đã ước tính có 135 loài thuộc 42 chi có trong vùng nghiên cứu. Một số đặc điểm lâm phần như thành phần loài, tiết diệt ngang bình quân và mật độ cây có mối tương quan nghịch với giá trị ảnh vệ tinh tuy nhiên mối quan hệ này không có ý nghĩa thống kê ở độ tin cậy 95%. Tuy vậy nghiên cứu cho thấy có mối tương quan tương quan khá chặt giữa số loài và các khối hiện trạng rừng với hệ số tương quan là 0.53 ở mức P<0.00.
74

Preliminary data on the aquatic invertebrate fauna of the Ma River, Thanh Hoa province: Research article

Ngo, Xuan Nam, Nguyen, Quoc Huy, Nguyen, Nguyen Hang, Pham, Thi Diep, Mai, Trong Hoang, Lai, Ngoc Ca, Dinh, Thi Hai Yen, Nguyen, Van Vinh, Le, Duc Giang, Nguyen, Quang Huy 09 December 2015 (has links)
A field survey for the invertebrate fauna conducted in the Ma River, Thanh Hoa province in 2013. The research applied multivariable analysis performed by the Primer v.6 software, such as CLUSTER, one-way ANOSIM, BEST and DIVERSE. The results showed a list of 138 aquatic invertebrate species. Of these, most were freshwater wide-distributing species coupled with others characterized for brackish and marine waters. The biodiversity status was quite high compared to several other rivers in the North of Vietnam. The list contained many economic-valued species and 2 of these were listed in the Red Data Book of Vietnam. The aquatic invertebrates showed a significant relation to the two different combinations of physiochemical factors for zooplanktons and zoobenthos, respectively. The values of the species number, abundance and Shannon-Weiner index for both of zooplanktons and zoobenthos showed a curved trend from the upper river segments to lower river segments. These figures for zooplanktons peaked in the middle river segments, whereas the numbers for zoobenthos achieved the highest numbers in the estuaries. The species composition of the estuaries differentiated significantly from that of other freshwater habitats. / Năm 2013 đã tiến hành một đợt điều tra khu hệ động vật không xương sống sông Mã, tỉnh Thanh Hóa. Nghiên cứu sử các phân tích đa biến thông qua phần mền Primer v.6, bao gồm: CLUSTER, one-way ANOSIM, BEST và DIVERSE. Kết quả phân tích thu được 138 loài với thành phần loài chủ yếu là những loài nước ngọt thường gặp và phân bố rộng, ngoài ra còn có các loài đặc trưng cho nước lợ và mặn. Trong số các loài thu được, nhiều loài có giá trị kinh tế và 2 loài có tên trong Sách Đỏ Việt Nam. Khu hệ động vật không xương sống sông Mã có quan hệ chặt với hai nhóm chỉ số thủy lý hóa học khác nhau, tương ứng cho động vật nổi và động vật đáy. Giá trị các chỉ số sinh học gồm số lượng loài, mật độ và Shannon-Weiner hồi quy theo đường cong phi tuyến từ thượng lưu tới hạ lưu; đạt giá trị cao nhất tại cửa sông đối với động vật đáy và vùng trung lưu với động vật nổi. Thành phần loài cửa sông khác biệt rõ rệt với thành phần loài các sinh cảnh nước ngọt khác.
75

Farm structure and environmental context drive farmers’ decisions on the spatial distribution of ecological focus areas in Germany

Alarcón‑Segura, V., Roilo, S., Paulus, A., Beckmann, M., Klein, N., Cord, A. F. 14 August 2024 (has links)
Context: Ecological Focus Areas (EFAs) were designed as part of the greening strategy of the common agricultural policy to conserve biodiversity in European farmland, prevent soil erosion and improve soil quality. Farmers receive economic support if they dedicate at least 5% of their arable farmland to any type of EFA, which can be selected from a list of options drawn up at the European Union level. However, EFAs have been criticized for failing to achieve their environmental goals and being ineffective in conserving farmland biodiversity, mainly because they are not spatially targeted and because they promote economic rather than ecological considerations in farm management decisions. Objectives: We used a spatially explicit approach to assess the influence of farm and field context as well as field terrain and soil conditions on the likelihood of whether or not a particular EFA type was implemented in a field. Methods: We used a multinomial model approach using field-level land use and management data from 879 farms that complied with the EFA policy in 2019 in the Mulde River Basin in Saxony, Germany. Geospatial environmental information was used to assess which predictor variables (related to farm context, field context or field terrain and soil conditions) increased the probability of a field being assigned to a particular EFA. We tested the hypothesis that productive EFAs are more often implemented on fields that are more suitable for agricultural production and that EFA options that are considered more valuable for biodiversity (e.g. non-productive EFAs) are allocated on fields that are less suitable for agricultural production. Results: We found that farms embedded in landscapes with a low proportion of small woody features or nature conservation areas mainly fulfilled the EFA policy with productive EFAs (e.g. nitrogen fixing crops). Conversely, farms with a higher proportion of small woody features or nature conservation areas were more likely to adopt non-productive EFAs. As predicted, large and compact fields with higher soil fertility and lower erosion risk were assigned to productive EFAs. Non-productive EFAs were placed on small fields in naturally disadvantaged areas. EFA options considered particularly beneficial for biodiversity, such as fallow land, were allocated far away from other semi-natural or nature protection areas. - Conclusions Our results highlight that the lack of spatial targeting of EFAs may result in EFA options being assigned to areas where their relative contribution to conservation goals is lower (e.g. farms with higher shares of protected areas) and absent in areas where they are most needed (e.g. high intensity farms). To ensure that greening policies actually promote biodiversity in European agriculture, incentives are needed to encourage greater uptake of ecologically effective measures on intensively used farms. These should be coupled with additional measures to conserve threatened species with specific habitat requirements.
76

Digital Environmental Humanities

Langer, Lars, Burghardt, Manuel, Borgards, Roland, Köhring, Esther, Wirth, Christian 26 June 2024 (has links)
No description available.
77

Peeking Inside the DH Toolbox - Detection and Classification of Software Tools in DH Publications

Ruth, Nicolas, Niekler, Andreas, Burghardt, Manuel 26 June 2024 (has links)
Digital tools have played an important role in Digital Humanities (DH) since its beginnings. Accordingly, a lot of research has been dedicated to the documentation of tools as well as to the analysis of their impact from an epistemological perspective. In this paper we propose a binary and a multi-class classification approach to detect and classify tools. The approach builds on state-of-the-art neural language models. We test our model on two different corpora and report the results for different parameter configurations in two consecutive experiments. In the end, we demonstrate how the models can be used for actual tool detection and tool classification tasks in a large corpus of DH journals.
78

Diversity and tree neighborhood effects on the growth dynamics of European beech and the stand seed bank in temperate broad-leaved forests of variable tree diversity / Diversitäts- und Nachbarschaftseffekte auf die Zuwachsdynamiken von Rotbuche und die Bestandessamenbank in temperaten Laubwäldern unterschiedlicher Baumartendiversität

Mölder, Inga 13 March 2009 (has links)
No description available.
79

Community structure and interaction webs of flower-visiting and cavity-nesting insects along an experimental plant diversity gradient / Diversität und Struktur von Bestäuber- und Nisthilfenlebensgemeinschaften entlang eines Pflanzendiversitätsgradienten

Ebeling, Anne 03 July 2008 (has links)
No description available.
80

Landscape context of bee, wasp and parasitoid diversity: grass-strip corridors, fallows and food webs / Bienen- Wespen- und Parasitoidendiversität im Landschaftskontext: Randstreifen-Korridore, Brachen und Nahrungsnetze

Krewenka, Kristin Marie 21 July 2011 (has links)
No description available.

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