Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials

Vegetation mats for horticulture and landscaping usually consist of coconut fibre and straw. They have hardly any available nutrients and serve only as a carrier material for plant growth. Water capacity is low. By incorporating raw sheep‘s wool, nutrients, such as nitrogen, potassium, and sulphur can positively influence the nutrient content of the carrier material. Water storage and water holding capacity are increased by the wool. In this study, three different thick-layered vegetation mats with different proportions of sheep’s wool and coir fibres were developed for the pre-cultivation of perennials. The focus is on the evaluation of sheep’s wool as a carrier material compared to pure coconut fibre as well as the plant growth of the eight perennial species used (Achillea clypeolata ‘Moonshine’, Achnatherum calamagrostis ‘Algäu’, Anaphalis triplinervis, Aster dumosus ‘Prof. Anton Kippenberg’, Aster dumosus ‘Silberball’, Centranthus ruber ‘Coccineus’, Coreopsis verticillata, Salvia nemorosa ‘Rosakönigin’). The vegetation mats with sheep’s wool contained 230, 241, and 308 g nitrogen (N)/m2 and the coir mats contained 75 g N/m2. The water content ranged from 16.0 to 22.1 vol% for the sheep’s wool mats and 12.6 vol% for the coir mat at pF1 (is equal to matrix potential at −10 hPa). The air content ranged from 71.9 to 77.0 vol% for the sheep’s wool mat and 79.4 vol% for the coir mat at pF1. On all vegetation mats containing sheep’s wool, the overall impression of the perennials was better than in the control. Especially good were Asters. At the end of the trial, the assessment scores of Asters on the sheep’s wool mats were two scores higher than on the coir mat. Aster dumosus ‘Prof. Anton Kippenberg’ achieved an average plant height between 35.8, 35.8, and 36.5 cm on the sheep’s wool mats and 14.4 cm on the coir mat. Aster dumosus ‘Silberball’ yielded 41.3, 42.3, and 44 cm on the sheep’s wool mats and 26.7 cm on the coir mat. No significant differences regarding plant height between the different variants of sheep’s wool mats emerged. Therefore, these mats can be used as alternative planting concepts for landscaping.German Federal Ministry of Economics and Technology (BMWi)Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)Open Access Publication Fund of Humboldt-UniversitätPeer Reviewe

Co-variation of crenarchaeol and branched GDGTs in globally-distributed marine and freshwater sedimentary archives

Two major types of glycerol dialkyl glycerol tetraethers (GDGTs) are commonly used in paleoecological and paleoclimatological reconstructions: isoprenoidal and branched GDGTs. In aquatic environments, it was originally assumed that isoprenoidal GDGTs, especially crenarchaeol, derive mainly from aquatic Thaumarchaeota, whilst branched GDGTs are an allochthonous input derived from soil Bacteria. Recently, direct co-variation of crenarchaeol and branched GDGTs has been described in two marine sedimentary records, and this observation suggests in situ production of branched GDGTs is possible at least in some aquatic environments. After investigating 30 published and unpublished data sets from downcore and surface sediments as well as sediment traps from 19 distinct regions around the world, we found a widespread significant correlation between concentrations of branched GDGTs and crenarchaeol (p<0.01; r²=0.57-0.99), even when normalized against TOC, where available. These data sets include freshwater and marine environments with varying distances from the shore, varying redox conditions and different terrestrial matter input pathways. Our findings from this large-scale data set suggest that a common or mixed source for both GDGT types is actually commonplace in lacustrine and marine settings.Keywords: Branched GDGTs, Oceans, Crenarchaeol, Archaea, Isoprenoid GDGTs, Lakes, In situ production

Defining Planktonic Protist Functional Groups on Mechanisms for Energy and Nutrient Acquisition: Incorporation of Diverse Mixotrophic Strategies

Arranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic “phytoplankton” and phagotrophic “microzoo-plankton”. However, there is a growing recognition of the importance of mixotrophy in euphotic aquatic systems, where many protists often combine photoautotrophic and phagotrophic modes of nutrition. Such organisms do not align with the traditional dichotomy of phytoplankton and microzooplankton. To reflect this understanding,we propose a new functional grouping of planktonic protists in an eco- physiological context: (i) phagoheterotrophs lacking phototrophic capacity, (ii) photoautotrophs lacking phagotrophic capacity,(iii) constitutive mixotrophs (CMs) as phagotrophs with an inherent capacity for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope for significant changes in trophic dynamics depending on the protist functional type description. Accord- ingly, to better reflect the role of mixotrophy, we recommend that as important tools for explanatory and predictive research, aquatic food-web and biogeochemical models need to redefine the protist groups within their frameworks